/* ============================================================
   DESIGN SYSTEM — 何宏祥个人网站
   风格：建筑极简 × 几何科技
   ============================================================ */

:root {
  --color-bg:            #F4F4F2;
  --color-bg-rgb:        244, 244, 242;
  --color-surface:       #FFFFFF;
  --color-bg-subtle:     #ECEAE7;

  --color-text-primary:  #111111;
  --color-text-rgb:      17, 17, 17;
  --color-text-secondary:#4A4A4A;
  --color-text-muted:    #8B8B8B;

  --color-accent:        #1E4D8C;
  --color-accent-rgb:    30, 77, 140;
  --color-accent-light:  #4A7FC1;
  --color-accent-pale:   #E8EFF8;

  --color-line:          #D4D4D0;
  --color-line-strong:   #ABABAB;

  --font-sans:  'Noto Sans SC', 'Inter', -apple-system, sans-serif;
  --font-en:    'Inter', -apple-system, sans-serif;
  --font-mono:  'JetBrains Mono', 'Courier New', monospace;

  --text-hero:  clamp(3rem, 8vw, 7rem);
  --text-h1:    clamp(2rem, 4vw, 3.5rem);
  --text-h2:    clamp(1.25rem, 2vw, 1.75rem);
  --text-h3:    1.125rem;
  --text-body:  1rem;
  --text-small: 0.875rem;
  --text-micro: 0.75rem;

  --weight-thin:    100;
  --weight-light:   200;
  --weight-regular: 300;
  --weight-medium:  400;

  --space-2:  1rem;
  --space-3:  1.5rem;
  --space-4:  2rem;
  --space-6:  3rem;
  --space-8:  4rem;
  --space-12: 6rem;
  --space-16: 8rem;

  --container-max: 1200px;
  --gutter: clamp(1.5rem, 4vw, 4rem);

  --shadow-md:     0 4px 12px rgba(0,0,0,0.08);
  --shadow-accent: 0 8px 24px rgba(30, 77, 140, 0.12);
}

/* ============================================================
   Progress Bar
   ============================================================ */
.progress-bar {
  position: fixed;
  top: 0; left: 0;
  height: 2px;
  width: 0%;
  background: var(--color-accent);
  z-index: 200;
  transition: width 0.1s linear;
}

/* ============================================================
   Lightbox
   ============================================================ */
.lightbox {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.88);
  z-index: 300;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-4);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  animation: lightboxIn 0.25s cubic-bezier(0.16,1,0.3,1);
}
.lightbox[hidden] { display: none; }
@keyframes lightboxIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}
.lightbox-img {
  max-width: min(90vw, 860px);
  max-height: 88vh;
  object-fit: contain;
  box-shadow: 0 24px 80px rgba(0,0,0,0.5);
  animation: lightboxImgIn 0.3s cubic-bezier(0.16,1,0.3,1);
}
@keyframes lightboxImgIn {
  from { transform: scale(0.92); opacity: 0; }
  to   { transform: scale(1);    opacity: 1; }
}
.lightbox-close {
  position: absolute;
  top: 1.5rem; right: 1.5rem;
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.2);
  color: rgba(255,255,255,0.8);
  font-size: 1rem;
  width: 2.5rem; height: 2.5rem;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}
.lightbox-close:hover { background: var(--color-accent); color: #fff; border-color: var(--color-accent); }

/* ============================================================
   Reset & Base
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--color-bg);
  color: var(--color-text-primary);
  font-family: var(--font-sans);
  font-weight: var(--weight-regular);
  font-size: var(--text-body);
  line-height: 1.8;
  letter-spacing: 0.02em;
  overflow-x: hidden;
}
img { display: block; max-width: 100%; }
a { color: inherit; }

/* ============================================================
   Layout
   ============================================================ */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--gutter);
}
.section { padding: var(--space-16) 0; }

/* ============================================================
   Reveal Animations
   ============================================================ */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s cubic-bezier(0.16,1,0.3,1),
              transform 0.7s cubic-bezier(0.16,1,0.3,1);
}
.reveal.visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  .hero-name-en { animation: none; clip-path: none; }
  .marquee-track { animation: none; }
  .hero-scroll-line::after { animation: none; }
}

/* ============================================================
   Navigation
   ============================================================ */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem var(--gutter);
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background 0.4s, border-color 0.4s;
}
.nav.scrolled {
  background: rgba(var(--color-bg-rgb), 0.93);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom-color: var(--color-line);
}
.nav-brand {
  font-family: var(--font-en);
  font-weight: var(--weight-thin);
  font-size: 1.1rem;
  letter-spacing: 0.2em;
  color: var(--color-text-primary);
  text-decoration: none;
}
.nav-links { display: flex; gap: 2.5rem; }
.nav-link {
  font-family: var(--font-en);
  font-size: var(--text-micro);
  font-weight: var(--weight-medium);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color 0.2s;
}
.nav-link:hover  { color: var(--color-accent); }
.nav-link.active { color: var(--color-accent); }
.nav-link:focus { outline: 2px solid var(--color-accent); outline-offset: 4px; }

/* ============================================================
   Hero
   ============================================================ */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  --mx: 50%;
  --my: 50%;
}
/* 鼠标聚光灯 */
.hero::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(700px circle at var(--mx) var(--my), rgba(var(--color-accent-rgb), 0.07), transparent 65%);
  pointer-events: none;
  z-index: 0;
  transition: background 0.1s;
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.hero-bg-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 40%;
  opacity: 0.07;
  filter: grayscale(20%);
}
.hero-geo {
  position: absolute;
  right: -5%;
  top: 50%;
  transform: translateY(-50%);
  width: 55%;
  height: auto;
  pointer-events: none;
}
.hero-content {
  position: relative;
  z-index: 1;
  padding-top: 7rem;
  padding-bottom: 6rem;
}
.hero-label {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-3);
}
.hero-name {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: var(--space-4);
  line-height: 1;
}
.hero-name-en {
  font-family: var(--font-en);
  font-size: var(--text-hero);
  font-weight: var(--weight-thin);
  letter-spacing: -0.02em;
  color: var(--color-text-primary);
  clip-path: inset(0 100% 0 0);
  animation: maskReveal 1.2s cubic-bezier(0.16,1,0.3,1) 0.15s forwards;
}
.hero-name-zh {
  font-family: var(--font-sans);
  font-size: clamp(1.25rem, 2.5vw, 2rem);
  font-weight: var(--weight-light);
  color: var(--color-text-muted);
  letter-spacing: 0.15em;
}
@keyframes maskReveal {
  from { clip-path: inset(0 100% 0 0); }
  to   { clip-path: inset(0 0% 0 0); }
}
.hero-tagline {
  font-size: clamp(1rem, 1.8vw, 1.25rem);
  font-weight: var(--weight-light);
  color: var(--color-text-secondary);
  margin-bottom: 0.5rem;
  letter-spacing: 0.03em;
}
.hero-sub {
  font-family: var(--font-mono);
  font-size: var(--text-small);
  color: var(--color-text-muted);
  margin-bottom: var(--space-6);
  letter-spacing: 0.05em;
}
.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; }
.hero-scroll {
  position: absolute;
  bottom: 2.5rem;
  left: var(--gutter);
  display: flex;
  align-items: center;
  gap: 1rem;
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  letter-spacing: 0.18em;
  color: var(--color-text-muted);
  z-index: 1;
}
.hero-scroll-line {
  width: 60px;
  height: 1px;
  background: var(--color-line);
  position: relative;
  overflow: hidden;
}
.hero-scroll-line::after {
  content: '';
  position: absolute;
  top: 0; left: -100%;
  width: 100%; height: 100%;
  background: var(--color-accent);
  animation: scanLine 2.2s ease-in-out infinite;
}
@keyframes scanLine {
  0%   { left: -100%; }
  50%  { left: 0; }
  100% { left: 100%; }
}

/* ============================================================
   Buttons
   ============================================================ */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 2rem;
  background: var(--color-text-primary);
  color: var(--color-bg);
  font-family: var(--font-en);
  font-size: var(--text-small);
  font-weight: var(--weight-medium);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-decoration: none;
  border: 1px solid var(--color-text-primary);
  cursor: pointer;
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  transition: background 0.25s, border-color 0.25s, transform 0.2s;
}
.btn-primary:hover { background: var(--color-accent); border-color: var(--color-accent); transform: translateY(-2px); }
.btn-primary:active { transform: translateY(0); }
.btn-primary:focus { outline: 2px solid var(--color-accent); outline-offset: 4px; }

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 2rem;
  background: transparent;
  color: var(--color-text-primary);
  font-family: var(--font-en);
  font-size: var(--text-small);
  font-weight: var(--weight-medium);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-decoration: none;
  border: 1px solid var(--color-line-strong);
  cursor: pointer;
  transition: border-color 0.25s, color 0.25s, transform 0.2s;
}
.btn-outline:hover { border-color: var(--color-accent); color: var(--color-accent); transform: translateY(-2px); }
.btn-outline:focus { outline: 2px solid var(--color-accent); outline-offset: 4px; }

/* ============================================================
   Section Labels & Titles
   ============================================================ */
.section-label {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-2);
}
.section-title {
  font-family: var(--font-sans);
  font-size: var(--text-h1);
  font-weight: var(--weight-thin);
  letter-spacing: -0.01em;
  line-height: 1.15;
  margin-bottom: var(--space-8);
}

/* ============================================================
   Stats
   ============================================================ */
.stats {
  background: var(--color-text-primary);
  padding: var(--space-12) 0;
  border-top: 1px solid rgba(255,255,255,0.06);
}
.stats-grid {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
}
.stat-item {
  flex: 1;
  text-align: center;
  padding: var(--space-4) var(--space-6);
}
.stat-number {
  font-family: var(--font-en);
  font-size: clamp(3rem, 7vw, 5.5rem);
  font-weight: var(--weight-thin);
  color: var(--color-bg);
  letter-spacing: -0.02em;
  line-height: 1;
  margin-bottom: 0.5rem;
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum";
  white-space: nowrap;
  display: inline-block;
}
/* 第4项：数字 + 单位并排 */
.stat-number-wrap {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: 0.06em;
  margin-bottom: 0.5rem;
}
.stat-number-wrap .stat-number { margin-bottom: 0; }
.stat-num-unit {
  font-family: var(--font-en);
  font-size: clamp(1.3rem, 2.8vw, 2.2rem);
  font-weight: var(--weight-thin);
  color: rgba(244,244,242,0.7);
  line-height: 1;
  padding-bottom: 0.18em;
  letter-spacing: 0.02em;
}
.stat-label {
  font-family: var(--font-sans);
  font-size: var(--text-small);
  font-weight: var(--weight-medium);
  color: rgba(244,244,242,0.75);
  margin-bottom: 0.25rem;
  letter-spacing: 0.04em;
}
.stat-desc {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: rgba(244,244,242,0.3);
  letter-spacing: 0.1em;
}
.stat-divider {
  width: 1px;
  height: 5rem;
  background: rgba(255,255,255,0.08);
  flex-shrink: 0;
}
@media (max-width: 600px) {
  .stats-grid    { flex-direction: column; gap: var(--space-4); }
  .stat-divider  { width: 3rem; height: 1px; }
}

/* ============================================================
   About
   ============================================================ */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-12);
  align-items: start;
}
.about-left .section-title { margin-bottom: var(--space-4); }
.about-text {
  color: var(--color-text-secondary);
  line-height: 1.95;
  margin-bottom: var(--space-3);
  font-weight: var(--weight-regular);
}
.info-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border: 1px solid var(--color-line);
}
.info-card {
  padding: var(--space-4) var(--space-3);
  border-right: 1px solid var(--color-line);
  border-bottom: 1px solid var(--color-line);
  border-top: 2px solid transparent;
  transition: border-top-color 0.3s, background 0.3s;
}
.info-card:nth-child(2n) { border-right: none; }
.info-card:nth-child(3), .info-card:nth-child(4) { border-bottom: none; }
.info-card:hover { border-top-color: var(--color-accent); background: var(--color-surface); }
.info-label {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: 0.4rem;
}
.info-value {
  font-size: var(--text-body);
  font-weight: var(--weight-medium);
  color: var(--color-text-primary);
  line-height: 1.5;
}

/* ============================================================
   Skills Marquee
   ============================================================ */
.skills {
  padding: var(--space-12) 0;
  background: var(--color-bg-subtle);
  overflow: hidden;
}
.skills-header { margin-bottom: var(--space-6); }
.skills-header .section-title { margin-bottom: 0; }
.marquee-wrapper { overflow: hidden; }
.marquee-row { overflow: hidden; padding: 0.6rem 0; }
.marquee-track {
  display: flex;
  gap: 2rem;
  width: max-content;
  align-items: center;
  font-family: var(--font-en);
  font-size: clamp(0.875rem, 1.4vw, 1.1rem);
  font-weight: var(--weight-light);
  letter-spacing: 0.05em;
  color: var(--color-text-secondary);
  white-space: nowrap;
}
.marquee-track span { flex-shrink: 0; }
.marquee-track .dot { color: var(--color-accent); font-weight: var(--weight-medium); font-size: 1.1em; }
.marquee-left  { animation: marqueeLeft  28s linear infinite; }
.marquee-right { animation: marqueeRight 28s linear infinite; }
.marquee-wrapper:hover .marquee-track { animation-play-state: paused; }
@keyframes marqueeLeft  { from { transform: translateX(0); }   to { transform: translateX(-50%); } }
@keyframes marqueeRight { from { transform: translateX(-50%); } to { transform: translateX(0); }   }

/* ============================================================
   Experience
   ============================================================ */
.exp-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
}
.exp-card {
  background: var(--color-surface);
  border: 1px solid var(--color-line);
  padding: var(--space-6);
  position: relative;
  overflow: hidden;
  transition: border-color 0.3s, box-shadow 0.3s, transform 0.3s;
}
.exp-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 0; height: 2px;
  background: var(--color-accent);
  transition: width 0.45s cubic-bezier(0.16,1,0.3,1);
}
.exp-card:hover { border-color: rgba(var(--color-accent-rgb), 0.25); transform: translateY(-4px); box-shadow: var(--shadow-accent); }
.exp-card:hover::before { width: 100%; }
.exp-number {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: var(--color-accent);
  letter-spacing: 0.1em;
  margin-bottom: var(--space-3);
}
.exp-title {
  font-size: var(--text-h3);
  font-weight: var(--weight-medium);
  color: var(--color-text-primary);
  margin-bottom: var(--space-3);
  line-height: 1.5;
}
.exp-desc {
  color: var(--color-text-secondary);
  font-size: var(--text-small);
  line-height: 1.85;
  margin-bottom: var(--space-4);
}
.exp-desc strong { color: var(--color-accent); font-weight: var(--weight-medium); }
.exp-tags { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.tag {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  background: var(--color-accent-pale);
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  letter-spacing: 0.04em;
  border: 1px solid rgba(var(--color-accent-rgb), 0.18);
  transition: background 0.2s, color 0.2s;
}
.tag:hover { background: var(--color-accent); color: #fff; }

/* ============================================================
   AI Capability
   ============================================================ */
.ai-power { background: var(--color-surface); }

/* —— Plan A：SVG 金字塔 —— */
.ai-pyramid-wrap { margin-bottom: var(--space-16); }
.ai-pyramid-svg {
  width: 100%;
  max-width: 900px;
  display: block;
  margin: 0 auto var(--space-4);
}

/* 层填充 */
.pyr-fill-4 { fill: rgba(var(--color-accent-rgb), 0.88); }
.pyr-fill-3 { fill: rgba(var(--color-accent-rgb), 0.10); }
.pyr-fill-2 { fill: rgba(var(--color-accent-rgb), 0.055); }
.pyr-fill-1 { fill: rgba(var(--color-accent-rgb), 0.025); }

/* 轮廓与分隔线 */
.pyr-outline {
  stroke: var(--color-accent);
  stroke-width: 1;
  opacity: 0.35;
}
.pyr-divider {
  stroke: var(--color-accent);
  stroke-width: 0.8;
  opacity: 0.28;
}
.pyr-divider--faint { opacity: 0.18; }

/* 层级标签（mono小字） */
.pyr-lv {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  fill: rgba(var(--color-accent-rgb), 0.55);
  letter-spacing: 3px;
}
.pyr-lv--light { fill: rgba(255,255,255,0.55); }
.pyr-lv--muted { fill: rgba(139,139,139,0.6); }

/* 层级名称 */
.pyr-name {
  font-family: 'Inter', sans-serif;
  font-size: 15px;
  font-weight: 300;
  fill: var(--color-text-primary);
  letter-spacing: 1px;
}
.pyr-name--light { fill: rgba(255,255,255,0.95); }
.pyr-name--muted { fill: #8B8B8B; }

/* 描述文字 */
.pyr-desc {
  font-family: 'Inter', sans-serif;
  font-size: 10px;
  fill: var(--color-text-secondary);
  letter-spacing: 0.5px;
}
.pyr-desc--light { fill: rgba(255,255,255,0.65); }
.pyr-desc--muted { fill: #ABABAB; }

/* 「我在这里」指示器 */
.pyr-pointer-line {
  stroke: var(--color-accent);
  stroke-width: 1;
  opacity: 0.7;
}
.pyr-pointer-dot {
  fill: var(--color-accent);
  opacity: 0.85;
}
.pyr-pointer-text {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  fill: var(--color-accent);
  letter-spacing: 2px;
}

.ai-stack-quote {
  font-size: var(--text-small);
  color: var(--color-text-muted);
  font-style: italic;
  letter-spacing: 0.03em;
  padding-left: var(--space-6);
  border-left: 2px solid var(--color-line);
  max-width: 540px;
  margin: 0 auto;
}

/* —— Plan B：工作流 —— */
.ai-workflow-title {
  font-family: var(--font-mono);
  font-size: var(--text-small);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}
.ai-workflow {
  display: flex;
  align-items: center;
  gap: 0;
  overflow-x: auto;
  padding-bottom: var(--space-2);
}
.ai-wf-step {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
  background: var(--color-bg);
  border: 1px solid var(--color-line);
  padding: var(--space-3) var(--space-4);
  min-width: 90px;
  text-align: center;
  flex-shrink: 0;
  transition: border-color 0.3s, transform 0.3s;
  position: relative;
}
.ai-wf-step::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.35s cubic-bezier(0.16,1,0.3,1);
}
.ai-wf-step:hover { border-color: rgba(var(--color-accent-rgb),0.3); transform: translateY(-3px); }
.ai-wf-step:hover::before { transform: scaleX(1); }

.ai-wf-num {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: var(--color-text-muted);
  letter-spacing: 0.1em;
}
.ai-wf-name {
  font-size: var(--text-small);
  font-weight: var(--weight-medium);
  color: var(--color-text-primary);
  white-space: nowrap;
}
.ai-wf-tag {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  letter-spacing: 0.08em;
  padding: 0.15rem 0.5rem;
  border: 1px solid;
}
.ai-wf-tag--ai   { color: var(--color-accent); background: var(--color-accent-pale); border-color: rgba(var(--color-accent-rgb),0.2); }
.ai-wf-tag--tool { color: var(--color-text-secondary); background: var(--color-bg-subtle); border-color: var(--color-line); }

.ai-wf-arrow {
  font-size: 1rem;
  color: var(--color-line-strong);
  padding: 0 0.5rem;
  flex-shrink: 0;
  margin-top: -0.5rem;
}

@media (max-width: 960px) {
  .ai-tier { flex-wrap: wrap; gap: var(--space-2); }
  .ai-tier-left { min-width: 100px; }
}
@media (max-width: 600px) {
  .ai-tier { padding: var(--space-3) var(--space-3); }
  .ai-wf-step { min-width: 76px; padding: var(--space-2) var(--space-2); }
}

/* ============================================================
   Credentials
   ============================================================ */
.certs { background: var(--color-bg-subtle); }

.cert-featured {
  display: flex;
  gap: var(--space-8);
  align-items: center;
  background: var(--color-surface);
  border: 1px solid var(--color-line);
  padding: var(--space-6);
  margin-bottom: var(--space-6);
  text-decoration: none;
  color: inherit;
  transition: border-color 0.3s, box-shadow 0.3s, transform 0.3s;
  position: relative;
  overflow: hidden;
}
.cert-featured::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.45s cubic-bezier(0.16,1,0.3,1);
}
.cert-featured:hover { border-color: rgba(var(--color-accent-rgb),0.3); box-shadow: var(--shadow-accent); transform: translateY(-3px); }
.cert-featured:hover::before { transform: scaleX(1); }

.cert-featured-img {
  width: 340px;
  flex-shrink: 0;
  border: 1px solid var(--color-line);
}
.cert-level {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  letter-spacing: 0.2em;
  color: var(--color-surface);
  background: var(--color-accent);
  padding: 0.2rem 0.7rem;
  display: inline-block;
  margin-bottom: var(--space-3);
}
.cert-featured-title {
  font-size: var(--text-h2);
  font-weight: var(--weight-light);
  color: var(--color-text-primary);
  margin-bottom: 0.5rem;
  line-height: 1.3;
}
.cert-featured-org {
  font-family: var(--font-mono);
  font-size: var(--text-small);
  color: var(--color-accent);
  letter-spacing: 0.04em;
  margin-bottom: 0.4rem;
}
.cert-featured-date {
  font-size: var(--text-small);
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
}
.cert-featured-hint {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: var(--color-text-muted);
  letter-spacing: 0.1em;
}

.cert-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
}
.cert-thumb {
  background: var(--color-surface);
  border: 1px solid var(--color-line);
  text-decoration: none;
  color: inherit;
  overflow: hidden;
  transition: border-color 0.3s, box-shadow 0.3s, transform 0.3s;
  display: block;
}
.cert-thumb:hover { border-color: rgba(var(--color-accent-rgb),0.3); box-shadow: var(--shadow-md); transform: translateY(-3px); }
.cert-thumb img { width: 100%; display: block; }
.cert-thumb-label {
  font-size: var(--text-small);
  font-weight: var(--weight-medium);
  color: var(--color-text-primary);
  padding: var(--space-2) var(--space-3) 0.2rem;
}
.cert-thumb-org {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: var(--color-text-muted);
  letter-spacing: 0.08em;
  padding: 0 var(--space-3) var(--space-2);
}

@media (max-width: 960px) {
  .cert-featured { flex-direction: column; }
  .cert-featured-img { width: 100%; }
}
@media (max-width: 600px) {
  .cert-grid { grid-template-columns: 1fr; }
}

/* ============================================================
   Methodology
   ============================================================ */
.method { background: var(--color-surface); }
.method-intro {
  color: var(--color-text-secondary);
  margin-top: calc(-1 * var(--space-6));
  margin-bottom: var(--space-8);
}
.method-steps {
  display: flex;
  align-items: stretch;
  margin-bottom: var(--space-8);
}
.method-step {
  flex: 1;
  background: var(--color-bg);
  border: 1px solid var(--color-line);
  padding: var(--space-6);
  position: relative;
  overflow: hidden;
  transition: border-color 0.3s, box-shadow 0.3s, transform 0.3s;
}
.method-step::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.45s cubic-bezier(0.16,1,0.3,1);
}
.method-step:hover::before { transform: scaleX(1); }
.method-step:hover {
  border-color: rgba(var(--color-accent-rgb), 0.25);
  box-shadow: var(--shadow-accent);
  transform: translateY(-4px);
}
.method-step-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: var(--space-3);
}
.method-step-num {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: var(--color-text-muted);
  letter-spacing: 0.1em;
}
.method-badge {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  letter-spacing: 0.12em;
  font-weight: var(--weight-medium);
  padding: 0.2rem 0.6rem;
  border: 1px solid;
}
.method-badge--hook  { color: var(--color-accent); background: var(--color-accent-pale); border-color: rgba(var(--color-accent-rgb), 0.2); }
.method-badge--value { color: var(--color-accent-light); background: rgba(74,127,193,0.08); border-color: rgba(74,127,193,0.2); }
.method-badge--cta   { color: var(--color-surface); background: var(--color-accent); border-color: var(--color-accent); }
.method-step-title {
  font-size: var(--text-h3);
  font-weight: var(--weight-medium);
  color: var(--color-text-primary);
  margin-bottom: var(--space-3);
  line-height: 1.4;
}
.method-step-desc {
  color: var(--color-text-secondary);
  font-size: var(--text-small);
  line-height: 1.85;
  margin-bottom: var(--space-3);
}
.method-step-desc strong { color: var(--color-accent); font-weight: var(--weight-medium); }
.method-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.method-list li {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: var(--color-text-muted);
  letter-spacing: 0.04em;
  padding-left: 1.1rem;
  position: relative;
}
.method-list li::before {
  content: '—';
  position: absolute;
  left: 0;
  color: var(--color-accent);
}
.method-connector {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-line-strong);
  padding: 0 var(--space-2);
  flex-shrink: 0;
}
.method-callout {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-6);
  border-left: 2px solid var(--color-accent);
  background: var(--color-accent-pale);
  max-width: 720px;
}
.method-callout-icon {
  font-size: 1.5rem;
  font-weight: var(--weight-thin);
  color: var(--color-accent);
  flex-shrink: 0;
  line-height: 1.5;
}
.method-callout p {
  color: var(--color-text-secondary);
  font-size: var(--text-small);
  line-height: 1.85;
}

/* ============================================================
   Knowledge System
   ============================================================ */
.knowledge { background: var(--color-bg-subtle); }
.knowledge-intro {
  color: var(--color-text-secondary);
  margin-top: calc(-1 * var(--space-6));
  margin-bottom: var(--space-8);
  max-width: 600px;
}

/* —— Pipeline —— */
.kn-pipeline {
  display: flex;
  align-items: stretch;
  margin-bottom: var(--space-12);
  gap: 0;
}
.kn-pipe-step {
  flex: 1;
  background: var(--color-surface);
  border: 1px solid var(--color-line);
  padding: var(--space-4) var(--space-4);
  text-align: center;
  position: relative;
  transition: border-color 0.3s, transform 0.3s;
}
.kn-pipe-step::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s cubic-bezier(0.16,1,0.3,1);
}
.kn-pipe-step:hover { border-color: rgba(var(--color-accent-rgb),.25); transform: translateY(-3px); }
.kn-pipe-step:hover::before { transform: scaleX(1); }
.kn-pipe-step--accent {
  background: rgba(var(--color-accent-rgb), 0.06);
  border-color: rgba(var(--color-accent-rgb), 0.2);
}
.kn-pipe-step--accent .kn-pipe-num { color: var(--color-accent); }
.kn-pipe-step--accent .kn-pipe-title { color: var(--color-accent); }
.kn-pipe-num {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: var(--color-text-muted);
  letter-spacing: 0.12em;
  margin-bottom: 0.5rem;
}
.kn-pipe-title {
  font-size: var(--text-small);
  font-weight: var(--weight-medium);
  color: var(--color-text-primary);
  margin-bottom: 0.6rem;
  line-height: 1.3;
}
.kn-pipe-desc {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--color-text-muted);
  line-height: 1.8;
  letter-spacing: 0.03em;
}
.kn-pipe-arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-line-strong);
  padding: 0 0.5rem;
  font-size: 1rem;
  flex-shrink: 0;
  margin-top: -0.5rem;
}

/* —— 信息源卡片 —— */
.kn-sources-header {
  margin-bottom: var(--space-4);
}
.kn-sources-label {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  letter-spacing: 0.2em;
  color: var(--color-accent);
  display: block;
  margin-bottom: 0.3rem;
}
.kn-sources-header p {
  font-size: var(--text-small);
  color: var(--color-text-muted);
}
.kn-sources-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-3);
  margin-bottom: var(--space-12);
}
.kn-source-card {
  background: var(--color-surface);
  border: 1px solid var(--color-line);
  padding: var(--space-4) var(--space-4) var(--space-3);
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  position: relative;
  overflow: hidden;
  transition: border-color 0.3s, box-shadow 0.3s, transform 0.3s;
}
.kn-source-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s cubic-bezier(0.16,1,0.3,1);
}
.kn-source-card:hover {
  border-color: rgba(var(--color-accent-rgb),.3);
  box-shadow: var(--shadow-accent);
  transform: translateY(-3px);
}
.kn-source-card:hover::before { transform: scaleX(1); }
.kn-source-name {
  font-size: var(--text-body);
  font-weight: var(--weight-medium);
  color: var(--color-text-primary);
  line-height: 1.3;
}
.kn-source-desc {
  font-size: var(--text-small);
  color: var(--color-text-secondary);
  line-height: 1.6;
  flex: 1;
}
.kn-source-platform {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: var(--color-accent);
  letter-spacing: 0.1em;
  background: var(--color-accent-pale);
  border: 1px solid rgba(var(--color-accent-rgb),.18);
  padding: 0.15rem 0.5rem;
  display: inline-block;
  align-self: flex-start;
}
.kn-source-arrow {
  position: absolute;
  top: var(--space-3);
  right: var(--space-3);
  font-size: 1rem;
  color: var(--color-text-muted);
  transition: color 0.2s, transform 0.2s;
}
.kn-source-card:hover .kn-source-arrow {
  color: var(--color-accent);
  transform: translate(2px, -2px);
}
.kn-source-avatar {
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 50%;
  background: rgba(var(--color-accent-rgb), 0.10);
  border: 1px solid rgba(var(--color-accent-rgb), 0.22);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: var(--weight-medium);
  color: var(--color-accent);
  flex-shrink: 0;
  margin-bottom: 0.25rem;
  transition: background 0.3s, border-color 0.3s;
}
.kn-source-card:hover .kn-source-avatar {
  background: rgba(var(--color-accent-rgb), 0.2);
  border-color: rgba(var(--color-accent-rgb), 0.45);
}

/* —— 知识图谱 SVG —— */
.kn-graph-wrap {
  background: var(--color-surface);
  border: 1px solid var(--color-line);
  padding: var(--space-6);
}
.kn-graph-label {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  letter-spacing: 0.2em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}
.kn-graph-svg { width: 100%; display: block; }
.kg-line {
  stroke: var(--color-accent);
  stroke-width: 0.8;
  opacity: 0.2;
}
.kg-line--faint { opacity: 0.1; }
.kg-node {
  fill: var(--color-accent);
  opacity: 0.5;
}
.kg-node--sm { opacity: 0.35; }
.kg-node-center {
  fill: none;
  stroke: var(--color-accent);
  stroke-width: 1;
  opacity: 0.4;
}
.kg-node-center-inner { fill: var(--color-accent); opacity: 0.7; }
.kg-label {
  font-family: 'Inter', sans-serif;
  font-size: 11px;
  fill: var(--color-text-secondary);
  letter-spacing: 0.5px;
}
.kg-label--sm { font-size: 10px; fill: var(--color-text-muted); }
.kg-label--center {
  font-size: 11px;
  font-weight: 500;
  fill: var(--color-accent);
  letter-spacing: 1px;
}
.kn-graph-caption {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: var(--color-text-muted);
  letter-spacing: 0.1em;
  margin-top: var(--space-3);
  text-align: center;
}

@media (max-width: 960px) {
  .kn-sources-grid { grid-template-columns: repeat(2, 1fr); }
  .kn-pipeline { flex-direction: column; }
  .kn-pipe-arrow { transform: rotate(90deg); align-self: center; }
}
@media (max-width: 600px) {
  .kn-sources-grid { grid-template-columns: 1fr 1fr; }
}

/* ============================================================
   Why Me
   ============================================================ */
.why-me { background: var(--color-bg-subtle); }
.why-list { display: flex; flex-direction: column; gap: var(--space-3); max-width: 800px; }
.why-item {
  display: flex;
  gap: var(--space-4);
  align-items: flex-start;
  padding: var(--space-4) var(--space-4);
  border-left: 2px solid var(--color-line);
  transition: border-left-color 0.3s, background 0.3s;
}
.why-item:hover { border-left-color: var(--color-accent); background: rgba(var(--color-bg-rgb), 0.6); }
.why-num {
  font-family: var(--font-en);
  font-size: 1.75rem;
  font-weight: var(--weight-thin);
  color: var(--color-accent);
  flex-shrink: 0;
  line-height: 1;
  padding-top: 0.05rem;
}
.why-text { font-size: var(--text-body); color: var(--color-text-secondary); line-height: 1.85; }
.why-text strong { color: var(--color-text-primary); font-weight: var(--weight-medium); }

/* ============================================================
   Contact (dark)
   ============================================================ */
.contact {
  background: var(--color-text-primary);
  color: var(--color-bg);
  text-align: center;
}
.contact .section-label { color: rgba(var(--color-accent-rgb), 0.7); }
.contact-title {
  font-family: var(--font-en);
  font-size: var(--text-h1);
  font-weight: var(--weight-thin);
  letter-spacing: 0.06em;
  color: var(--color-bg);
  margin-bottom: var(--space-2);
}
.contact-sub {
  color: rgba(244,244,242,0.45);
  font-size: var(--text-body);
  margin-bottom: var(--space-8);
}
.contact-info {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--space-6);
  margin-bottom: var(--space-8);
  flex-wrap: wrap;
}
.contact-divider { width: 1px; height: 3.5rem; background: rgba(244,244,242,0.12); }
.contact-item { text-align: left; }
.contact-label {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(244,244,242,0.35);
  margin-bottom: 0.3rem;
}
.contact-value {
  font-size: var(--text-h3);
  font-weight: var(--weight-light);
  color: var(--color-bg);
  letter-spacing: 0.02em;
}
.wechat-copy {
  cursor: pointer;
  position: relative;
  transition: color 0.2s;
}
.wechat-copy:hover { color: var(--color-accent-light); }
.wechat-copy::after {
  content: attr(data-tip);
  position: absolute;
  left: 50%; top: -2rem;
  transform: translateX(-50%);
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  letter-spacing: 0.1em;
  background: var(--color-accent);
  color: #fff;
  padding: 0.2rem 0.6rem;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s;
}
.wechat-copy.copied::after { opacity: 1; }
.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 1rem 2.5rem;
  background: transparent;
  color: var(--color-bg);
  font-family: var(--font-en);
  font-size: var(--text-small);
  font-weight: var(--weight-medium);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  text-decoration: none;
  border: 1px solid rgba(244,244,242,0.25);
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  transition: background 0.25s, border-color 0.25s, transform 0.2s;
}
.btn-download:hover { background: var(--color-accent); border-color: var(--color-accent); transform: translateY(-2px); }
.btn-download:focus { outline: 2px solid var(--color-accent); outline-offset: 4px; }

/* ============================================================
   Footer
   ============================================================ */
.footer {
  background: var(--color-text-primary);
  border-top: 1px solid rgba(255,255,255,0.06);
  padding: var(--space-4) 0;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.footer-name {
  font-family: var(--font-sans);
  font-size: var(--text-small);
  font-weight: var(--weight-light);
  letter-spacing: 0.12em;
  color: rgba(244,244,242,0.35);
}
.footer-year {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: rgba(244,244,242,0.25);
  letter-spacing: 0.1em;
}

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 960px) {
  .about-grid    { grid-template-columns: 1fr; gap: var(--space-6); }
  .exp-grid      { grid-template-columns: 1fr 1fr; }
  .method-steps  { flex-direction: column; }
  .method-connector { transform: rotate(90deg); align-self: center; padding: var(--space-2) 0; }
  :root          { --space-16: 5rem; }
}
@media (max-width: 600px) {
  .nav-links     { display: none; }
  .hero-actions  { flex-direction: column; }
  .hero-actions a { text-align: center; justify-content: center; }
  .info-grid     { grid-template-columns: 1fr; }
  .info-card     { border-right: none !important; }
  .info-card:nth-child(1), .info-card:nth-child(2), .info-card:nth-child(3) { border-bottom: 1px solid var(--color-line); }
  .exp-grid      { grid-template-columns: 1fr; }
  .contact-info  { flex-direction: column; gap: var(--space-3); }
  .contact-divider { width: 3rem; height: 1px; }
  :root          { --space-16: 4rem; }
}

/* ============================================================
   动漫角色 · Hero 区右侧
   ============================================================ */


.hero-char-wrap {
  position: absolute;
  right: 6%;
  bottom: 0;
  width: 320px;
  height: 90%;
  z-index: 1;
  pointer-events: none;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  /* 入场动画 */
  animation: charSlideIn 1s cubic-bezier(0.16,1,0.3,1) 0.6s both;
}
@keyframes charSlideIn {
  from { opacity: 0; transform: translateY(40px); }
  to   { opacity: 1; transform: translateY(0); }
}
.hero-char-img {
  height: 100%;
  width: auto;
  max-width: none;
  object-fit: contain;
  object-position: bottom center;
  /* 浮动动画 */
  animation: charFloat 4s ease-in-out infinite;
  /* 3D 视差由 JS 控制 */
  transform-style: preserve-3d;
  will-change: transform;
  /* 底部渐隐 */
  -webkit-mask-image: linear-gradient(to top, transparent 0%, black 18%);
  mask-image: linear-gradient(to top, transparent 0%, black 18%);
  filter: drop-shadow(0 20px 40px rgba(30,77,140,0.18));
}
@keyframes charFloat {
  0%, 100% { transform: translateY(0px); }
  50%       { transform: translateY(-12px); }
}
@media (max-width: 1100px) {
  .hero-char-wrap { right: 1%; width: 240px; opacity: 0.75; }
}
@media (max-width: 768px) {
  .hero-char-wrap { display: none; }
}

/* ============================================================
   ① Hero Pipeline — 价值主张行
   ============================================================ */
.hero-sub { margin-bottom: var(--space-2); }
.hero-pipeline {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: var(--color-accent);
  letter-spacing: 0.14em;
  margin-bottom: var(--space-6);
}

/* ============================================================
   ② Nav Hamburger + 移动端全屏菜单
   ============================================================ */
.nav-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 0.4rem;
  z-index: 102;
}
.nav-hamburger span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--color-text-primary);
  transition: transform 0.3s cubic-bezier(0.16,1,0.3,1), opacity 0.3s;
  transform-origin: center;
}
.nav-hamburger.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav-hamburger.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

@media (max-width: 600px) {
  .nav-hamburger { display: flex; }
  .nav-links {
    position: fixed;
    inset: 0;
    background: rgba(var(--color-bg-rgb), 0.97);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--space-6);
    z-index: 99;
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links .nav-link {
    font-size: 1.1rem;
    letter-spacing: 0.18em;
    color: var(--color-text-secondary);
  }
}

/* ============================================================
   ③ Stats 4th item — 布局不受影响（flex 自适应）
   ============================================================ */
@media (max-width: 600px) {
  .stat-divider:last-of-type { display: none; }
}

/* ============================================================
   ④ SpotlightCard — 鼠标径向高光
   ============================================================ */
.exp-card { --mx: 50%; --my: 50%; }
.kn-source-card { --mx: 50%; --my: 50%; }
.exp-card::after,
.kn-source-card::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(
    220px circle at var(--mx) var(--my),
    rgba(var(--color-accent-rgb), 0.07),
    transparent 70%
  );
  opacity: 0;
  transition: opacity 0.35s;
  pointer-events: none;
  z-index: 0;
}
.exp-card:hover::after,
.kn-source-card:hover::after { opacity: 1; }
/* 子元素保持在高光层之上 */
.exp-card > *,
.kn-source-card > * { position: relative; z-index: 1; }

/* ============================================================
   ⑤ 证书 3D 倾斜 — 禁用 CSS transform，交由 JS 控制
   ============================================================ */
.cert-featured:hover { transform: none; }
.cert-thumb:hover    { transform: none; }
.cert-featured,
.cert-thumb { will-change: transform; }

/* ============================================================
   ⑥ Why Me 对比表
   ============================================================ */
.why-me { background: var(--color-bg-subtle); }
.why-table {
  width: 100%;
  max-width: 900px;
  border: 1px solid var(--color-line);
  overflow: hidden;
}
.why-table-header {
  display: grid;
  grid-template-columns: 1fr 1.6fr 1.6fr;
  background: var(--color-text-primary);
}
.why-table-row {
  display: grid;
  grid-template-columns: 1fr 1.6fr 1.6fr;
  border-top: 1px solid var(--color-line);
  transition: background 0.2s;
}
.why-table-row:hover { background: rgba(var(--color-accent-rgb), 0.03); }
.why-col {
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-small);
  display: flex;
  align-items: center;
}
.why-table-header .why-col {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  padding: 0.75rem var(--space-4);
}
.why-col--label {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  letter-spacing: 0.1em;
  color: var(--color-text-muted);
  border-right: 1px solid var(--color-line);
}
.why-table-header .why-col--label {
  color: rgba(244,244,242,0.25);
  border-right-color: rgba(255,255,255,0.08);
}
.why-col--other {
  color: var(--color-text-muted);
  border-right: 1px solid var(--color-line);
}
.why-table-header .why-col--other {
  color: rgba(244,244,242,0.4);
  border-right-color: rgba(255,255,255,0.08);
}
.why-col--me {
  color: var(--color-accent);
  font-weight: var(--weight-medium);
  background: rgba(var(--color-accent-rgb), 0.04);
}
.why-table-header .why-col--me {
  color: var(--color-accent-light);
  background: rgba(var(--color-accent-rgb), 0.18);
}
@media (max-width: 600px) {
  .why-table-header { grid-template-columns: 0.8fr 1.2fr 1.4fr; }
  .why-table-row    { grid-template-columns: 0.8fr 1.2fr 1.4fr; }
  .why-col          { padding: 0.6rem 0.75rem; font-size: var(--text-micro); }
  .why-table-header .why-col { padding: 0.5rem 0.75rem; }
}

/* ============================================================
   ⑦ 回到顶部按钮
   ============================================================ */
.back-to-top {
  position: fixed;
  bottom: var(--space-4);
  right: var(--space-4);
  width: 2.5rem;
  height: 2.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-line);
  color: var(--color-accent);
  cursor: pointer;
  z-index: 90;
  display: flex;
  align-items: center;
  justify-content: center;
  clip-path: polygon(0 0, calc(100% - 7px) 0, 100% 7px, 100% 100%, 7px 100%, 0 calc(100% - 7px));
  transition: border-color 0.25s, box-shadow 0.25s, transform 0.25s, background 0.25s;
}
.back-to-top[hidden] { display: none; }
.back-to-top:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-accent);
  transform: translateY(-3px);
  background: var(--color-accent-pale);
}

/* ============================================================
   ⑧ Footer 升级
   ============================================================ */
.footer { padding: var(--space-8) 0 var(--space-6); }
.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  padding-bottom: var(--space-4);
  margin-bottom: var(--space-4);
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}
.footer-name {
  font-family: var(--font-en);
  font-weight: var(--weight-thin);
  font-size: 1.6rem;
  letter-spacing: 0.12em;
  color: rgba(244,244,242,0.65);
}
.footer-role {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: rgba(244,244,242,0.28);
  letter-spacing: 0.12em;
}
.footer-cta {
  font-family: var(--font-mono);
  font-size: var(--text-small);
  color: rgba(var(--color-accent-rgb), 0.7);
  letter-spacing: 0.08em;
}
.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.footer-contacts {
  display: flex;
  gap: var(--space-2);
  align-items: center;
  flex-wrap: wrap;
}
.footer-contact-item {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: rgba(244,244,242,0.22);
  letter-spacing: 0.08em;
}
.footer-sep { color: rgba(244,244,242,0.1); font-size: var(--text-micro); }
.footer-right {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.footer-year {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: rgba(244,244,242,0.18);
  letter-spacing: 0.1em;
}
@media (max-width: 600px) {
  .footer-top    { flex-direction: column; align-items: flex-start; gap: var(--space-3); }
  .footer-bottom { flex-direction: column; align-items: flex-start; gap: var(--space-2); }
}

/* ============================================================
   全站视觉系统 v2
   方案 A：深色交替（Skills / Experience / Methodology → 深）
   方案 C：超大装饰字 + 全幅对角线
   ============================================================ */

/* ── Section 公共：内容层在装饰层之上 ── */
.about, .skills, .ai-power, .experience,
.certs, .method, .knowledge, .why-me {
  position: relative;
  overflow: hidden;
}
.about .container,
.ai-power .container,
.experience .container,
.certs .container,
.method .container,
.knowledge .container,
.why-me .container { position: relative; z-index: 1; }
.skills .skills-header,
.skills .marquee-wrapper { position: relative; z-index: 1; }

/* ── 超大装饰字 ::before 公共 ── */
.about::before, .skills::before, .ai-power::before,
.experience::before, .certs::before, .method::before,
.knowledge::before, .why-me::before {
  position: absolute;
  font-family: var(--font-en);
  font-weight: 800;
  font-size: clamp(8rem, 23vw, 28rem);
  letter-spacing: -0.04em;
  line-height: 0.88;
  pointer-events: none;
  z-index: 0;
  white-space: nowrap;
  user-select: none;
}

/* 各 section 的装饰字内容 + 位置 */
.about::before      { content: 'ABOUT';  bottom: -2rem; right: -1.5rem;  color: rgba(var(--color-accent-rgb), 0.07); }
.skills::before     { content: 'SKILL';  top: -2rem;    right: -1.5rem;  color: rgba(255,255,255,0.042); }
.ai-power::before   { content: 'A·I';   bottom: -2rem; left:  -0.5rem;  color: rgba(var(--color-accent-rgb), 0.065); }
.experience::before { content: 'EDIT';   top: -2rem;    right: -1.5rem;  color: rgba(255,255,255,0.038); }
.certs::before      { content: 'CERT';   bottom: -2rem; right: -1.5rem;  color: rgba(var(--color-accent-rgb), 0.07); }
.method::before     { content: 'METHOD'; top: -3rem;    left:  -1.5rem;  color: rgba(255,255,255,0.032);
                      font-size: clamp(5rem, 16vw, 19rem); }
.knowledge::before  { content: 'KNOW';   bottom: -2rem; right: -1.5rem;  color: rgba(var(--color-accent-rgb), 0.07); }
.why-me::before     { content: 'WHY';    top: -2rem;    right: -1rem;    color: rgba(var(--color-accent-rgb), 0.065); }

/* ── 全幅对角线 ::after（About / Experience / Knowledge）── */
.about::after, .experience::after, .knowledge::after {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}
.about::after {
  background:
    linear-gradient(135deg, transparent 54%,
      rgba(var(--color-accent-rgb),.05) 54%, rgba(var(--color-accent-rgb),.05) 54.6%, transparent 54.6%),
    linear-gradient(135deg, transparent 63%,
      rgba(var(--color-accent-rgb),.03) 63%, rgba(var(--color-accent-rgb),.03) 63.5%, transparent 63.5%);
}
.experience::after {
  background:
    linear-gradient(-135deg, transparent 54%,
      rgba(255,255,255,.04) 54%, rgba(255,255,255,.04) 54.6%, transparent 54.6%),
    linear-gradient(-135deg, transparent 63%,
      rgba(255,255,255,.024) 63%, rgba(255,255,255,.024) 63.5%, transparent 63.5%);
}
.knowledge::after {
  background:
    linear-gradient(135deg, transparent 48%,
      rgba(var(--color-accent-rgb),.045) 48%, rgba(var(--color-accent-rgb),.045) 48.6%, transparent 48.6%);
}

/* ════════════════════════════════════
   方案 A：深色 sections
   ════════════════════════════════════ */
.skills, .experience, .method {
  background: #0B1220;
  --color-accent:       #4A7FC1;
  --color-accent-rgb:   74, 127, 193;
  --color-accent-light: #7AAEE0;
  --color-accent-pale:  rgba(74,127,193,0.15);
}
.skills .section-label,
.experience .section-label,
.method .section-label { color: var(--color-accent); }
.skills .section-title,
.experience .section-title,
.method .section-title { color: rgba(244,244,242,0.92); }

/* Skills 深色 */
.skills {
  background-image: repeating-linear-gradient(
    0deg, rgba(255,255,255,.022) 0, rgba(255,255,255,.022) 1px,
    transparent 1px, transparent 30px);
}
.skills .marquee-track       { color: rgba(244,244,242,0.42); }
.skills .marquee-track .dot  { color: var(--color-accent); }

/* Experience 深色 */
.experience {
  background-image: repeating-linear-gradient(
    -45deg, rgba(255,255,255,.018) 0, rgba(255,255,255,.018) 1px,
    transparent 1px, transparent 24px);
}
.experience .exp-card {
  background: rgba(255,255,255,0.038);
  border-color: rgba(255,255,255,0.07);
}
.experience .exp-card:hover {
  background: rgba(255,255,255,0.062);
  border-color: rgba(var(--color-accent-rgb),0.4);
  box-shadow: 0 8px 32px rgba(var(--color-accent-rgb),0.15);
}
.experience .exp-number               { color: var(--color-accent); }
.experience .exp-title                { color: rgba(244,244,242,0.9); }
.experience .exp-desc                 { color: rgba(244,244,242,0.5); }
.experience .exp-desc strong          { color: var(--color-accent-light); }
.experience .tag                      { background: rgba(var(--color-accent-rgb),.15); color: var(--color-accent-light); border-color: rgba(var(--color-accent-rgb),.28); }
.experience .tag:hover                { background: var(--color-accent); color: #fff; }

/* Methodology 深色 */
.method {
  background-image:
    repeating-linear-gradient(45deg,  rgba(255,255,255,.016) 0, rgba(255,255,255,.016) 1px, transparent 1px, transparent 32px),
    repeating-linear-gradient(-45deg, rgba(255,255,255,.010) 0, rgba(255,255,255,.010) 1px, transparent 1px, transparent 32px);
}
.method .method-intro                 { color: rgba(244,244,242,0.42); }
.method .method-step                  { background: rgba(255,255,255,0.03); border-color: rgba(255,255,255,0.065); }
.method .method-step:hover            { border-color: rgba(var(--color-accent-rgb),.35); background: rgba(255,255,255,0.055); box-shadow: 0 8px 32px rgba(var(--color-accent-rgb),.1); }
.method .method-step-title            { color: rgba(244,244,242,0.88); }
.method .method-step-desc             { color: rgba(244,244,242,0.48); }
.method .method-step-desc strong      { color: var(--color-accent-light); }
.method .method-list li               { color: rgba(244,244,242,0.36); }
.method .method-connector             { color: rgba(255,255,255,0.16); }
.method .method-callout               { background: rgba(var(--color-accent-rgb),.1); border-left-color: var(--color-accent); }
.method .method-callout p             { color: rgba(244,244,242,0.58); }
.method .method-badge--hook           { color: var(--color-accent-light); background: rgba(var(--color-accent-rgb),.15); border-color: rgba(var(--color-accent-rgb),.3); }
.method .method-badge--value          { color: #a0c8f0; background: rgba(74,127,193,.12); border-color: rgba(74,127,193,.25); }

/* ════════════════════════════════════
   全站照片背景系统
   ════════════════════════════════════ */

/* 浅色 sections — 照片 + 浅色遮罩 */
.about {
  background:
    linear-gradient(rgba(244,244,242,0.87), rgba(244,244,242,0.87)),
    url('assets/sec-about.jpg') center/cover no-repeat;
}
.ai-power {
  background:
    linear-gradient(rgba(255,255,255,0.88), rgba(255,255,255,0.88)),
    url('assets/sec-ai.jpg') center/cover no-repeat;
}
.certs {
  background:
    linear-gradient(rgba(236,234,231,0.86), rgba(236,234,231,0.86)),
    url('assets/sec-certs.jpg') center/cover no-repeat;
}
.knowledge {
  background:
    linear-gradient(rgba(236,234,231,0.85), rgba(236,234,231,0.85)),
    url('assets/sec-knowledge.jpg') center/cover no-repeat;
}
.why-me {
  background:
    linear-gradient(rgba(236,234,231,0.87), rgba(236,234,231,0.87)),
    url('assets/sec-why.jpg') center/cover no-repeat;
}

/* 深色 sections — 照片 + 深色遮罩 */
.skills {
  background:
    linear-gradient(rgba(11,18,32,0.80), rgba(11,18,32,0.80)),
    url('assets/sec-skills.jpg') center/cover no-repeat;
}
.experience {
  background:
    linear-gradient(rgba(11,18,32,0.78), rgba(11,18,32,0.78)),
    url('assets/sec-experience.jpg') center/cover no-repeat;
}
.method {
  background:
    linear-gradient(rgba(11,18,32,0.80), rgba(11,18,32,0.80)),
    url('assets/sec-method.jpg') center/cover no-repeat;
}

/* ============================================================
   HERO DARK THEME
   深色 Hero：强视觉冲击 → Stats（深）→ About（浅）高对比翻转
   ============================================================ */

.hero {
  background: #0B1220;
  /* 在 hero 范围内把 accent 换成更亮的蓝，深色背景上才可见 */
  --color-accent:      #4A7FC1;
  --color-accent-rgb:  74, 127, 193;
  --color-accent-light:#7AAEE0;
  --color-accent-pale: rgba(74, 127, 193, 0.15);
}

/* 建筑背景图：深色背景下稍微透出轮廓 */
.hero .hero-bg-img {
  opacity: 0.13;
  filter: grayscale(40%);
}

/* 几何 SVG：CSS 覆盖 SVG 呈现属性，深色背景上加强可见度 */
.hero-geo polygon { opacity: 0.42; }
.hero-geo line    { opacity: 0.22; }

/* 聚光灯加强 */
.hero::after {
  background: radial-gradient(
    900px circle at var(--mx) var(--my),
    rgba(74, 127, 193, 0.13),
    transparent 60%
  );
}

/* ── Nav 在深色 Hero 上 ── */
.nav:not(.scrolled) .nav-brand          { color: rgba(244,244,242,0.88); }
.nav:not(.scrolled) .nav-link           { color: rgba(244,244,242,0.38); }
.nav:not(.scrolled) .nav-link:hover     { color: rgba(244,244,242,0.88); }
.nav:not(.scrolled) .nav-link.active    { color: var(--color-accent-light); }
.nav:not(.scrolled) .nav-hamburger span { background: rgba(244,244,242,0.72); }

/* ── Hero 文字颜色 ── */
.hero-name-en { color: rgba(244,244,242,0.96); }
.hero-name-zh { color: rgba(244,244,242,0.36); }
.hero-tagline { color: rgba(244,244,242,0.70); }
.hero-sub     { color: rgba(244,244,242,0.36); }

/* 滚动提示 */
.hero-scroll      { color: rgba(244,244,242,0.22); }
.hero-scroll-line { background: rgba(244,244,242,0.12); }

/* ── 按钮适配深色 ── */
.hero .btn-primary {
  background: rgba(244,244,242,0.96);
  color: #0B1220;
  border-color: rgba(244,244,242,0.96);
}
.hero .btn-primary:hover {
  background: var(--color-accent-light);
  border-color: var(--color-accent-light);
  color: #fff;
}
.hero .btn-outline {
  color: rgba(244,244,242,0.72);
  border-color: rgba(244,244,242,0.22);
}
.hero .btn-outline:hover {
  border-color: var(--color-accent-light);
  color: var(--color-accent-light);
}

/* ============================================================
   全站深色系统重写 — DARK MODE OVERHAUL v1
   调色板：Brittany Chiang 风格 × 何宏祥品牌
   Base #080E1A · Surface #0F172A · Accent #38BDF8 · Text #F1F5F9
   ============================================================ */

/* ── 1. 全局 CSS 变量覆盖 ── */
:root {
  --color-bg:            #080E1A;
  --color-bg-rgb:        8, 14, 26;
  --color-surface:       #0F172A;
  --color-bg-subtle:     #0D1525;

  --color-text-primary:  #F1F5F9;
  --color-text-rgb:      241, 245, 249;
  --color-text-secondary:#94A3B8;
  --color-text-muted:    #475569;

  --color-accent:        #38BDF8;
  --color-accent-rgb:    56, 189, 248;
  --color-accent-light:  #7DD3FC;
  --color-accent-pale:   rgba(56, 189, 248, 0.12);

  --color-line:          rgba(255,255,255,0.08);
  --color-line-strong:   rgba(255,255,255,0.15);

  --shadow-md:           0 4px 12px rgba(0,0,0,0.35);
  --shadow-accent:       0 8px 24px rgba(56,189,248,0.18);
}

/* ── 2. Stats 修复（原用 var(--color-text-primary) 作深色背景） ── */
.stats {
  background: #050A14;
  border-top-color: rgba(255,255,255,0.06);
}
.stat-number { color: #F1F5F9; }
.stat-label  { color: rgba(241,245,249,0.45); }
.stat-unit   { color: rgba(241,245,249,0.45); }
.stat-divider { border-color: rgba(255,255,255,0.07); }

/* ── 3. 浅色 sections → 深色照片遮罩（让照片纹理更明显）── */
.about {
  background:
    linear-gradient(rgba(8,14,26,0.72), rgba(8,14,26,0.72)),
    url('assets/sec-about.jpg') center/cover no-repeat;
}
.ai-power {
  background:
    linear-gradient(rgba(8,14,26,0.72), rgba(8,14,26,0.72)),
    url('assets/sec-ai.jpg') center/cover no-repeat;
}
.certs {
  background:
    linear-gradient(rgba(8,14,26,0.74), rgba(8,14,26,0.74)),
    url('assets/sec-certs.jpg') center/cover no-repeat;
}
.knowledge {
  background:
    linear-gradient(rgba(8,14,26,0.72), rgba(8,14,26,0.72)),
    url('assets/sec-knowledge.jpg') center/cover no-repeat;
}
.why-me {
  background:
    linear-gradient(rgba(8,14,26,0.72), rgba(8,14,26,0.72)),
    url('assets/sec-why.jpg') center/cover no-repeat;
}

/* ── 4. 深色 sections — 升级 accent 为电光蓝 ── */
.skills, .experience, .method {
  --color-accent:       #38BDF8;
  --color-accent-rgb:   56, 189, 248;
  --color-accent-light: #7DD3FC;
  --color-accent-pale:  rgba(56,189,248,0.12);
}

/* ── 5. Hero — 升级 accent + 聚光灯 ── */
.hero {
  --color-accent:      #38BDF8;
  --color-accent-rgb:  56, 189, 248;
  --color-accent-light:#7DD3FC;
  --color-accent-pale: rgba(56,189,248,0.12);
}
.hero::after {
  background: radial-gradient(
    900px circle at var(--mx) var(--my),
    rgba(56,189,248,0.09),
    transparent 60%
  );
}
.hero .btn-primary {
  background: #38BDF8;
  border-color: #38BDF8;
  color: #080E1A;
}
.hero .btn-primary:hover {
  background: #7DD3FC;
  border-color: #7DD3FC;
  color: #080E1A;
}
.hero .btn-outline {
  color: rgba(241,245,249,0.72);
  border-color: rgba(241,245,249,0.22);
}
.hero .btn-outline:hover {
  border-color: #38BDF8;
  color: #38BDF8;
}
.hero-name-en { color: rgba(241,245,249,0.96); }
.hero-name-zh { color: rgba(241,245,249,0.32); }
.hero-tagline { color: rgba(241,245,249,0.68); }
.hero-sub     { color: rgba(241,245,249,0.34); }
.hero-scroll      { color: rgba(241,245,249,0.2); }
.hero-scroll-line { background: rgba(241,245,249,0.1); }

/* ── 6. Nav — 统一深色适配 ── */
.nav:not(.scrolled) .nav-brand          { color: rgba(241,245,249,0.88); }
.nav:not(.scrolled) .nav-link           { color: rgba(241,245,249,0.38); }
.nav:not(.scrolled) .nav-link:hover     { color: rgba(241,245,249,0.88); }
.nav:not(.scrolled) .nav-link.active    { color: #38BDF8; }
.nav:not(.scrolled) .nav-hamburger span { background: rgba(241,245,249,0.72); }

/* ── 7. 所有卡片 → 磨砂玻璃统一风格 ── */
.exp-card,
.method-step,
.kn-source-card {
  background: rgba(255,255,255,0.04);
  border-color: rgba(255,255,255,0.08);
  backdrop-filter: blur(4px);
}
.exp-card:hover,
.method-step:hover,
.kn-source-card:hover {
  background: rgba(56,189,248,0.06);
  border-color: rgba(56,189,248,0.28);
  box-shadow: 0 8px 32px rgba(56,189,248,0.12);
}

/* About 卡片 */
.about .info-card,
.about .about-tag {
  background: rgba(255,255,255,0.04);
  border-color: rgba(255,255,255,0.08);
}

/* Certs 磨砂 */
.cert-item {
  background: rgba(255,255,255,0.04);
  border-color: rgba(255,255,255,0.07);
}
.cert-item:hover {
  border-color: rgba(56,189,248,0.3);
  box-shadow: 0 8px 24px rgba(56,189,248,0.1);
}

/* AI 工作流节点 */
.ai-step {
  background: rgba(255,255,255,0.04);
  border-color: rgba(255,255,255,0.08);
}
.ai-step:hover {
  border-color: rgba(56,189,248,0.28);
  background: rgba(56,189,248,0.06);
}

/* ── 8. Contact 修复 ── */
.contact {
  background: #050A14;
  color: #F1F5F9;
}
.contact .contact-title { color: #F1F5F9; }
.contact .contact-sub   { color: rgba(241,245,249,0.48); }
.contact .contact-wechat,
.contact .contact-email {
  color: rgba(241,245,249,0.72);
  border-color: rgba(255,255,255,0.12);
}
.contact .contact-wechat:hover,
.contact .contact-email:hover {
  border-color: #38BDF8;
  color: #38BDF8;
}

/* ── 9. Footer 修复 ── */
.footer {
  background: #050A14;
  border-top-color: rgba(255,255,255,0.06);
}

/* ── 10. Why Me 表头修复 ── */
.why-table-header {
  background: #0D1525;
}
.why-table-header .why-col--me {
  background: rgba(56,189,248,0.15);
}

/* ── 11. 装饰字 + 对角线全部隐藏 ── */
.about::before, .skills::before, .ai-power::before,
.experience::before, .certs::before, .method::before,
.knowledge::before, .why-me::before {
  display: none;
}
.about::after, .experience::after, .knowledge::after {
  display: none;
}

/* ── 12. 全站按钮统一 ── */
.btn-primary {
  background: #38BDF8;
  border-color: #38BDF8;
  color: #080E1A;
}
.btn-primary:hover {
  background: #7DD3FC;
  border-color: #7DD3FC;
  color: #080E1A;
}
.btn-outline {
  color: #38BDF8;
  border-color: rgba(56,189,248,0.4);
}
.btn-outline:hover {
  background: rgba(56,189,248,0.1);
  border-color: #38BDF8;
}