/* ============================================================
   lantian.online — 精装修版
   深色优先 · 暖色调 · 节间对比 · 细腻文字层次
   ============================================================ */

@import url('https://cdn.jsdelivr.net/npm/geist@1.3.1/dist/fonts/geist-sans/style.css');
@import url('https://cdn.jsdelivr.net/npm/geist@1.3.1/dist/fonts/geist-mono/style.css');

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* ══════════════════════════════════════════
   GLOBAL TOKENS
   深色默认，暖色调（非纯黑/纯白）
   ══════════════════════════════════════════ */

:root {
  color-scheme: dark;

  /* ── 背景层 ── */
  --bg-base:    #08080a;   /* 最深层，接近纯黑但带微冷 */
  --bg-raised:  #0e0d0b;   /* 稍亮，带微暖 */
  --bg-warm:    #111009;   /* 更暖的深色 */
  --bg-card:    rgba(255,255,255,0.04);
  --bg-card-h:  rgba(255,255,255,0.07);
  --bg-input:   rgba(255,255,255,0.06);

  /* 深色中的"亮节"——暖奶白 */
  --bg-light:   #f3f1ec;
  --bg-light-2: #eceae4;
  --bg-card-on-light:   #ffffff;
  --bg-card-on-light-h: #f8f6f1;

  /* ── 文字层（深色节） ── */
  /* 有明显暖奶色，绝非纯白 */
  --t-hi:     #dedad2;          /* 标题：可见的暖奶白，不是纯白 */
  --t-body:   rgba(210,206,196,0.72); /* 正文：更深的暖灰 */
  --t-muted:  rgba(200,196,186,0.50); /* 次要：明显偏灰 */
  --t-faint:  rgba(190,186,176,0.32); /* 标签/mono */

  /* ── 文字层（亮节，在深色主题的亮背景内） ── */
  --t-hi-inv:    #2a2620;        /* 暖深棕，不是纯黑 */
  --t-body-inv:  #5e5a52;        /* 暖中棕灰 */
  --t-muted-inv: #9c9890;        /* 暖浅灰 */
  --t-faint-inv: #c2beb6;        /* 最浅 */

  /* ── 边框/分割 ── */
  --border:     rgba(255,255,255,0.08);
  --border-mid: rgba(255,255,255,0.14);

  /* ── 阴影 ── */
  --shadow-card:
    rgba(255,255,255,0.07) 0px 0px 0px 1px,
    rgba(0,0,0,0.50) 0px 4px 20px;
  --shadow-card-h:
    rgba(255,255,255,0.12) 0px 0px 0px 1px,
    rgba(0,0,0,0.65) 0px 8px 32px,
    rgba(120,100,200,0.09) 0px 0px 0px 5px;
  --shadow-card-light:
    rgba(0,0,0,0.07) 0px 0px 0px 1px,
    rgba(0,0,0,0.05) 0px 2px 6px,
    rgba(0,0,0,0.04) 0px 10px 24px;
  --shadow-card-light-h:
    rgba(0,0,0,0.11) 0px 0px 0px 1px,
    rgba(0,0,0,0.08) 0px 8px 24px;

  /* ── Hero 光晕 ── */
  --glow-a: rgba(120, 80,220,0.22);
  --glow-b: rgba( 30,140,250,0.14);
  --glow-c: rgba(220, 60,150,0.09);

  /* ── Pill badge（深色） ── */
  --pill-bg:    rgba(80,140,240,0.14);
  --pill-text:  #8ab4f8;
  --pill-r-bg:  rgba(240,80,70,0.14);
  --pill-r-text:#ff9b94;

  /* ── Nav ── */
  --nav-bg: rgba(8,8,10,0.80);

  /* ── Accent ── */
  --accent: #7c6ff7;

  /* ── Focus ── */
  --focus: hsla(212,100%,50%,1);

  /* ── Fonts ── */
  --font-sans: 'Geist', -apple-system, 'PingFang SC', 'Microsoft YaHei', Arial, sans-serif;
  --font-mono: 'Geist Mono', ui-monospace, 'SFMono-Regular', Menlo, Monaco, monospace;

  /* ── Layout ── */
  --max-w:       720px;
  --pad-x:       20px;
  --gap-section: 88px;
}

/* ── 浅色主题 ── */
[data-theme="light"] {
  color-scheme: light;

  --bg-base:    #faf9f6;   /* 暖奶白，不是纯白 */
  --bg-raised:  #f3f1ec;
  --bg-warm:    #edeae3;
  --bg-card:    #ffffff;
  --bg-card-h:  #f7f5f0;

  --bg-light:   #faf9f6;
  --bg-light-2: #f3f1ec;
  --bg-card-on-light:   #ffffff;
  --bg-card-on-light-h: #f7f5f0;

  --t-hi:     #2c2820;        /* 浅色主题标题：暖深棕，不是纯黑 */
  --t-body:   #5a5650;        /* 暖中棕灰 */
  --t-muted:  #8e8a82;        /* 暖浅灰 */
  --t-faint:  #b2aea6;        /* 最浅 */

  --t-hi-inv:    #2c2820;
  --t-body-inv:  #5a5650;
  --t-muted-inv: #8e8a82;
  --t-faint-inv: #b2aea6;

  --border:     rgba(0,0,0,0.08);
  --border-mid: rgba(0,0,0,0.14);

  --shadow-card:
    rgba(0,0,0,0.06) 0px 0px 0px 1px,
    rgba(0,0,0,0.04) 0px 2px 4px,
    rgba(0,0,0,0.03) 0px 8px 20px,
    #fafaf8 0px 0px 0px 1px;
  --shadow-card-h:
    rgba(0,0,0,0.10) 0px 0px 0px 1px,
    rgba(0,0,0,0.07) 0px 8px 28px,
    rgba(100,80,220,0.05) 0px 0px 0px 4px;
  --shadow-card-light: var(--shadow-card);
  --shadow-card-light-h: var(--shadow-card-h);

  --glow-a: rgba(120, 80,220,0.07);
  --glow-b: rgba( 30,140,250,0.05);
  --glow-c: rgba(220, 60,150,0.04);

  --pill-bg:    #ebf3ff;
  --pill-text:  #2470d8;
  --pill-r-bg:  #fff0ef;
  --pill-r-text:#c93025;

  --nav-bg: rgba(250,249,246,0.85);
  --accent: #5b51e8;
}

/* ══════════════════════════════════════════
   BASE
   ══════════════════════════════════════════ */

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  font-feature-settings: "liga";
}

body {
  font-family: var(--font-sans);
  background: var(--bg-base);
  color: var(--t-hi);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background 0.35s, color 0.35s;
}

/* 全局噪声纹理（Film grain 质感） */
body::after {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 9999;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='300' height='300'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.78' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='300' height='300' filter='url(%23n)'/%3E%3C/svg%3E");
  background-size: 300px 300px;
  opacity: 0.042;
  mix-blend-mode: overlay;
}

/* ══════════════════════════════════════════
   LAYOUT
   ══════════════════════════════════════════ */

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--pad-x);
}

section {
  padding: var(--gap-section) 0;
  transition: background 0.35s;
}

/* 深色主题各节背景——有细微变化，制造节奏 */
:root #hero        { background: var(--bg-base); }
:root #metrics     { background: var(--bg-raised); }
:root #coop        { background: var(--bg-base); }
:root #methodology { background: var(--bg-warm); }
:root #ideas       { background: var(--bg-raised); }
:root #roles       { background: var(--bg-warm); }

/* 深色主题 "亮节"：关于我 → 暖奶白，形成视觉对比 */
:root #about {
  background: var(--bg-light);
  /* 覆盖此节内所有文字/卡片变量 */
  --t-hi:    var(--t-hi-inv);
  --t-body:  var(--t-body-inv);
  --t-muted: var(--t-muted-inv);
  --t-faint: var(--t-faint-inv);
  --bg-card:   var(--bg-card-on-light);
  --bg-card-h: var(--bg-card-on-light-h);
  --border:    rgba(0,0,0,0.08);
  --border-mid:rgba(0,0,0,0.14);
  --shadow-card:   var(--shadow-card-light);
  --shadow-card-h: var(--shadow-card-light-h);
  --pill-bg:    #ebf3ff;
  --pill-text:  #2470d8;
}

/* 浅色主题各节背景 */
[data-theme="light"] #hero        { background: var(--bg-base); }
[data-theme="light"] #metrics     { background: var(--bg-raised); }
[data-theme="light"] #about       { background: var(--bg-base); }
[data-theme="light"] #methodology { background: var(--bg-raised); }
[data-theme="light"] #coop        { background: var(--bg-base); }
[data-theme="light"] #ideas       { background: var(--bg-raised); }
[data-theme="light"] #roles       { background: var(--bg-base); }

/* ══════════════════════════════════════════
   NAV
   ══════════════════════════════════════════ */

nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--nav-bg);
  backdrop-filter: blur(16px) saturate(160%);
  -webkit-backdrop-filter: blur(16px) saturate(160%);
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s, background 0.35s;
}

nav.scrolled {
  border-bottom-color: var(--border);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
  padding: 0 var(--pad-x);
  max-width: var(--max-w);
  margin: 0 auto;
  gap: 12px;
}

.nav-brand {
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.3px;
  color: var(--t-hi);
  text-decoration: none;
  flex-shrink: 0;
  transition: color 0.35s;
}

.nav-links {
  display: flex;
  gap: 2px;
  list-style: none;
}

.nav-links a {
  font-size: 13px;
  font-weight: 500;
  color: var(--t-muted);
  text-decoration: none;
  padding: 5px 9px;
  border-radius: 6px;
  transition: color 0.15s, background 0.15s;
  -webkit-tap-highlight-color: transparent;
}

.nav-links a:hover {
  color: var(--t-hi);
  background: rgba(128,128,128,0.10);
}

/* 主题切换按钮 */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 1px solid var(--border-mid);
  background: var(--bg-card);
  color: var(--t-muted);
  cursor: pointer;
  font-size: 14px;
  flex-shrink: 0;
  transition: background 0.15s, color 0.15s, transform 0.1s;
  -webkit-tap-highlight-color: transparent;
  line-height: 1;
}

.theme-toggle:hover {
  background: var(--bg-raised);
  color: var(--t-hi);
}

.theme-toggle:active {
  transform: scale(0.90);
}

/* ══════════════════════════════════════════
   SECTION LABEL
   ══════════════════════════════════════════ */

.section-label {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.11em;
  color: var(--t-faint);
  text-transform: uppercase;
  margin-bottom: 36px;
  font-feature-settings: "tnum";
  transition: color 0.35s;
}

/* ══════════════════════════════════════════
   PILL BADGES
   ══════════════════════════════════════════ */

.pill {
  display: inline-block;
  background: var(--pill-bg);
  color: var(--pill-text);
  font-size: 11px;
  font-weight: 500;
  padding: 0 10px;
  height: 22px;
  line-height: 22px;
  border-radius: 9999px;
  transition: background 0.35s, color 0.35s;
}

.pill-red {
  background: var(--pill-r-bg);
  color: var(--pill-r-text);
}

.pill-green {
  background: rgba(40,200,120,0.13);
  color: #4cd596;
}

[data-theme="light"] .pill-green {
  background: #eafaf3;
  color: #1a8a57;
}

/* ══════════════════════════════════════════
   BUTTONS
   ══════════════════════════════════════════ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 44px;
  padding: 0 22px;
  border-radius: 7px;
  font-size: 14px;
  font-family: var(--font-sans);
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  border: none;
  transition: opacity 0.15s, background 0.15s, box-shadow 0.15s, transform 0.1s;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  white-space: nowrap;
}

.btn:active { transform: scale(0.97); }

.btn:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

/* 深色主题：主按钮用暖白背景，文字用暗色 */
.btn-primary {
  background: var(--t-hi);
  color: var(--bg-base);
}

.btn-primary:hover { opacity: 0.85; }

.btn-ghost {
  background: transparent;
  color: var(--t-hi);
  box-shadow: 0 0 0 1px var(--border-mid);
}

.btn-ghost:hover {
  background: var(--bg-raised);
}

/* ══════════════════════════════════════════
   HERO
   ══════════════════════════════════════════ */

#hero {
  padding-top: 96px;
  padding-bottom: var(--gap-section);
  text-align: center;
  position: relative;
  overflow: hidden;
}

/* Hero 背景光晕（Mesh gradient） */
#hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50%  -5%, var(--glow-a) 0%, transparent 68%),
    radial-gradient(ellipse 55% 45% at 92%  28%, var(--glow-b) 0%, transparent 60%),
    radial-gradient(ellipse 48% 38% at  8%  72%, var(--glow-c) 0%, transparent 55%);
  pointer-events: none;
}

.avatar-wrap {
  position: relative;
  z-index: 1;
  margin: 0 auto 28px;
  width: 88px;
  height: 88px;
  border-radius: 50%;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-raised);
  font-size: 36px;
  /* 三环光晕效果 */
  box-shadow:
    0 0 0 1px var(--border-mid),
    0 0 0 5px var(--bg-base),
    0 0 0 6px var(--border),
    0 12px 32px rgba(0,0,0,0.5);
  transition: box-shadow 0.35s;
}

.avatar-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 50%;
}

.hero-name {
  position: relative;
  z-index: 1;
  font-size: clamp(42px, 10vw, 62px);
  font-weight: 600;
  letter-spacing: -2.5px;
  line-height: 1.03;
  color: var(--t-hi);
  margin-bottom: 16px;
  transition: color 0.35s;
}

.hero-zh {
  position: relative;
  z-index: 1;
  font-size: 15px;
  font-weight: 400;
  color: var(--t-body);
  margin-bottom: 6px;
  letter-spacing: 0.04em;
  transition: color 0.35s;
}

.hero-en {
  position: relative;
  z-index: 1;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  color: var(--t-faint);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  margin-bottom: 40px;
  transition: color 0.35s;
}

.hero-cta {
  position: relative;
  z-index: 1;
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ══════════════════════════════════════════
   METRICS
   ══════════════════════════════════════════ */

.metrics-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
}

.metric-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 22px 18px;
  cursor: default;
  transition:
    transform    0.22s ease,
    box-shadow   0.22s ease,
    background   0.22s ease,
    border-color 0.22s ease;
}

.metric-card:hover {
  transform: translateY(-3px);
  background: var(--bg-card-h);
  border-color: var(--border-mid);
  box-shadow: 0 12px 32px rgba(0,0,0,0.35);
}

.metric-number {
  font-size: 30px;
  font-weight: 600;
  letter-spacing: -1.8px;
  line-height: 1;
  color: var(--t-hi);
  margin-bottom: 8px;
  transition: color 0.35s;
}

.metric-desc {
  font-size: 12px;
  font-weight: 400;
  color: var(--t-faint);
  line-height: 1.4;
  transition: color 0.35s;
}

/* ══════════════════════════════════════════
   ABOUT / TAG CARDS
   关于我节在深色主题下是亮背景
   变量已在 #about 节级覆盖，自动级联
   ══════════════════════════════════════════ */

.tags-grid {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.tag-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 22px 20px;
  display: flex;
  gap: 16px;
  align-items: flex-start;
  cursor: default;
  transition:
    transform    0.22s ease,
    box-shadow   0.22s ease,
    background   0.22s ease,
    border-color 0.22s ease;
}

.tag-card:hover {
  transform: translateY(-2px);
  background: var(--bg-card-h);
  border-color: var(--border-mid);
  box-shadow: var(--shadow-card-h);
}

.tag-icon {
  font-size: 22px;
  line-height: 1;
  flex-shrink: 0;
  margin-top: 2px;
}

.tag-title {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.3px;
  margin-bottom: 6px;
  color: var(--t-hi);
  transition: color 0.35s;
}

.tag-desc {
  font-size: 13px;
  font-weight: 400;
  color: var(--t-body);
  line-height: 1.72;
  transition: color 0.35s;
}

/* ══════════════════════════════════════════
   COOPERATION
   ══════════════════════════════════════════ */

.coop-grid {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 16px;
}

.coop-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 26px 22px;
  cursor: default;
  transition:
    transform    0.22s ease,
    box-shadow   0.22s ease,
    background   0.22s ease,
    border-color 0.22s ease;
}

.coop-card:hover {
  transform: translateY(-2px);
  background: var(--bg-card-h);
  border-color: var(--border-mid);
  box-shadow: var(--shadow-card-h);
}

.coop-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.coop-title {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.5px;
  color: var(--t-hi);
  margin-bottom: 10px;
  transition: color 0.35s;
}

.coop-desc {
  font-size: 13px;
  font-weight: 400;
  color: var(--t-body);
  line-height: 1.8;
  margin-bottom: 16px;
  transition: color 0.35s;
}

.coop-list {
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.coop-list-item {
  font-size: 12px;
  color: var(--t-muted);
  display: flex;
  align-items: flex-start;
  gap: 10px;
  line-height: 1.65;
  transition: color 0.35s;
}

.coop-list-item::before {
  content: "";
  display: block;
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--t-faint);
  flex-shrink: 0;
  margin-top: 7px;
}

.coop-scope {
  font-size: 12px;
  color: var(--t-muted);
  padding: 14px 18px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  line-height: 1.95;
  margin-bottom: 28px;
  transition: background 0.35s, color 0.35s, border-color 0.35s;
}

.coop-scope strong {
  color: var(--t-hi);
  font-weight: 600;
  transition: color 0.35s;
}

.coop-cta { text-align: center; }

/* ══════════════════════════════════════════
   IDEAS / QUOTES
   ══════════════════════════════════════════ */

.quotes-list {
  display: flex;
  flex-direction: column;
}

.quote-item {
  padding: 22px 0 22px 20px;
  border-left: 2px solid var(--border);
  margin-bottom: 2px;
  cursor: default;
  transition:
    border-color 0.2s ease,
    padding-left 0.2s ease;
}

.quote-item:hover {
  border-left-color: var(--accent);
  padding-left: 26px;
}

.quote-text {
  font-size: 19px;
  font-weight: 600;
  letter-spacing: -0.6px;
  line-height: 1.3;
  color: var(--t-hi);
  margin-bottom: 7px;
  transition: color 0.35s;
}

.quote-sub {
  font-size: 13px;
  font-weight: 400;
  color: var(--t-muted);
  line-height: 1.55;
  transition: color 0.35s;
}

/* ══════════════════════════════════════════
   METHODOLOGY — AI 进化方法论三位一体
   ══════════════════════════════════════════ */

:root #methodology { background: var(--bg-warm); }
[data-theme="light"] #methodology { background: var(--bg-raised); }

.method-title-main {
  font-size: clamp(24px, 6vw, 36px);
  font-weight: 600;
  letter-spacing: -1px;
  line-height: 1.15;
  color: var(--t-hi);
  margin-bottom: 8px;
  transition: color 0.35s;
}

.method-subtitle {
  font-size: 13px;
  color: var(--t-muted);
  margin-bottom: 40px;
  line-height: 1.6;
  transition: color 0.35s;
}

.method-layers {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.method-layer {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 24px 22px;
  margin-bottom: 2px;
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity 0.55s ease,
    transform 0.55s ease,
    background 0.22s ease,
    border-color 0.22s ease,
    box-shadow 0.22s ease;
  cursor: default;
}

.method-layer:last-child { margin-bottom: 0; }

.method-layer.visible {
  opacity: 1;
  transform: none;
}

.method-layer:hover {
  background: var(--bg-card-h);
  border-color: var(--border-mid);
  box-shadow: var(--shadow-card-h);
}

.method-layer-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.10em;
  text-transform: uppercase;
  color: var(--t-faint);
  background: var(--bg-input);
  padding: 3px 9px;
  border-radius: 99px;
  border: 1px solid var(--border);
  margin-bottom: 14px;
  transition: color 0.35s, background 0.35s, border-color 0.35s;
}

.method-layer-content {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.method-layer-icon {
  font-size: 26px;
  line-height: 1;
  flex-shrink: 0;
  margin-top: 2px;
}

.method-layer-name {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.5px;
  color: var(--t-hi);
  margin-bottom: 6px;
  transition: color 0.35s;
}

.method-layer-desc {
  font-size: 13px;
  color: var(--t-body);
  line-height: 1.75;
  transition: color 0.35s;
}

.method-connector {
  width: 1px;
  height: 18px;
  background: var(--border);
  margin: 0 0 0 33px;
  transition: background 0.35s;
}

/* ══════════════════════════════════════════
   ROLES
   ══════════════════════════════════════════ */

.roles-list { display: flex; flex-direction: column; }

.role-item {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 14px;
  font-weight: 400;
  color: var(--t-body);
  padding: 15px 0;
  border-bottom: 1px solid var(--border);
  cursor: default;
  transition: color 0.15s, padding-left 0.15s;
}

.role-item:last-child { border-bottom: none; }

.role-item:hover {
  color: var(--t-hi);
  padding-left: 5px;
}

.role-mono {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  color: var(--t-faint);
  text-transform: uppercase;
  letter-spacing: 0.07em;
  flex-shrink: 0;
  min-width: 22px;
  transition: color 0.35s;
}

/* ══════════════════════════════════════════
   FOOTER
   ══════════════════════════════════════════ */

footer {
  background: #060504;   /* 最深，形成页底收尾感 */
  padding: 64px 0 48px;
  border-top: 1px solid var(--border);
  transition: background 0.35s, border-color 0.35s;
}

[data-theme="light"] footer {
  background: var(--bg-warm);
}

.footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--pad-x);
}

.footer-name {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.96px;
  color: var(--t-hi);
  margin-bottom: 8px;
  transition: color 0.35s;
}

.footer-tagline {
  font-size: 13px;
  color: var(--t-muted);
  margin-bottom: 36px;
  line-height: 1.65;
  transition: color 0.35s;
}

.footer-wechat-box {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 24px 20px;
  text-align: center;
  margin-bottom: 36px;
  transition: background 0.35s, border-color 0.35s;
}

.footer-wechat-label {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--t-faint);
  margin-bottom: 14px;
  transition: color 0.35s;
}

.footer-qrcode {
  display: block;
  width: 144px;
  height: 144px;
  object-fit: contain;
  margin: 0 auto 14px;
  border-radius: 8px;
  border: 1px solid var(--border-mid);
}

.footer-wechat-hint {
  font-size: 13px;
  color: var(--t-muted);
  line-height: 1.6;
  transition: color 0.35s;
}

.footer-copy {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--t-faint);
  letter-spacing: 0.03em;
  transition: color 0.35s;
}

/* ══════════════════════════════════════════
   FADE-IN
   ══════════════════════════════════════════ */

.fade-in {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: none;
}

/* ══════════════════════════════════════════
   RESPONSIVE — TABLET 480px+
   ══════════════════════════════════════════ */

@media (min-width: 480px) {
  :root { --pad-x: 32px; --gap-section: 96px; }

  .metrics-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
  }

  .metric-number { font-size: 24px; letter-spacing: -1.1px; }

  .coop-grid { flex-direction: row; flex-wrap: wrap; gap: 10px; }
  .coop-card { flex: 1 1 220px; }
}

/* ══════════════════════════════════════════
   RESPONSIVE — DESKTOP 768px+
   ══════════════════════════════════════════ */

@media (min-width: 768px) {
  :root { --pad-x: 40px; --gap-section: 112px; }

  .avatar-wrap { width: 100px; height: 100px; }

  .tags-grid { flex-direction: row; flex-wrap: wrap; gap: 10px; }
  .tag-card { flex: 1 1 calc(50% - 5px); min-width: 220px; }

  .metric-number { font-size: 28px; letter-spacing: -1.3px; }
}