/* ============================================================
   群星云AI数据标注 · 官网样式
   视觉方向：小米官网产品页 —— 大留白、近黑标题、蓝主色、大圆角卡片
   ============================================================ */

:root {
  --blue: #2563eb;
  --blue-dark: #1d4ed8;
  --blue-soft: #eff6ff;
  --bg: #ffffff;
  --bg-alt: #f5f6f7;
  --ink: #1f2937;
  --ink-strong: #111827;
  --muted: #6b7280;
  --line: #e5e7eb;
  --green: #16a34a;
  --dark: #0d1117;
  --dark-card: #161b26;
  --dark-line: #2a3344;
  --radius: 20px;
  --shadow-app: 0 40px 80px -20px rgba(15, 23, 42, 0.28), 0 0 0 1px rgba(15, 23, 42, 0.06);
  --font: "PingFang SC", "MiSans", "Microsoft YaHei UI", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "Cascadia Code", "SF Mono", Consolas, "Courier New", monospace;
}

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

html { scroll-behavior: smooth; scroll-padding-top: 72px; }

body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  font-size: 17px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
strong { font-weight: 600; }

.container {
  width: min(1200px, calc(100% - 48px));
  margin-inline: auto;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border-radius: 999px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  border: none;
  transition: background 0.2s ease, color 0.2s ease, transform 0.15s ease, box-shadow 0.2s ease;
  white-space: nowrap;
}
.btn:active { transform: scale(0.98); }
.btn-primary {
  background: var(--blue);
  color: #fff;
  box-shadow: 0 8px 24px -8px rgba(37, 99, 235, 0.55);
}
.btn-primary:hover { background: var(--blue-dark); }
.btn-ghost {
  background: transparent;
  color: var(--ink-strong);
  box-shadow: inset 0 0 0 1.5px var(--line);
}
.btn-ghost:hover { box-shadow: inset 0 0 0 1.5px #c9cdd4; background: #fafafa; }
.btn-lg { padding: 16px 32px; font-size: 17px; }
.btn-sm { padding: 9px 20px; font-size: 14px; }

/* ---------- 导航 ---------- */
.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  transition: background 0.25s ease, box-shadow 0.25s ease, backdrop-filter 0.25s ease;
}
.nav.scrolled {
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  box-shadow: 0 1px 0 var(--line);
}
.nav-inner {
  width: min(1200px, calc(100% - 48px));
  margin-inline: auto;
  height: 64px;
  display: flex;
  align-items: center;
  gap: 32px;
}
.nav-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 17px;
  color: var(--ink-strong);
  flex-shrink: 0;
}
.brand-logo { border-radius: 7px; }
.brand-light { font-weight: 500; color: var(--ink); }
.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  margin-left: auto;
  font-size: 15px;
  color: var(--muted);
}
.nav-links a { transition: color 0.15s; }
.nav-links a:hover { color: var(--ink-strong); }
.nav-cta { flex-shrink: 0; }
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: none;
  border: none;
  cursor: pointer;
  margin-left: auto;
}
.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--ink-strong);
  margin-inline: auto;
  transition: transform 0.25s, opacity 0.25s;
}
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- 通用区块 ---------- */
.section { padding: 120px 0; }
.section-alt { background: var(--bg-alt); }
.section-dark {
  background: var(--dark);
  color: #e8eaed;
}
.section-head {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 64px;
}
.section-head h2 {
  font-size: clamp(30px, 4vw, 44px);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--ink-strong);
  line-height: 1.25;
  margin-bottom: 16px;
}
.section-dark .section-head h2 { color: #fff; }
.section-desc {
  font-size: 18px;
  color: var(--muted);
  line-height: 1.75;
}
.section-dark .section-desc { color: #9aa4b5; }
.eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 14px;
}
.eyebrow.light { color: #7aa2f7; }

/* ---------- Hero ---------- */
.hero {
  padding: 148px 0 100px;
  background:
    radial-gradient(1000px 480px at 50% -120px, rgba(37, 99, 235, 0.09), transparent 65%),
    linear-gradient(180deg, #fbfcfe 0%, #fff 55%);
  overflow: hidden;
}
.hero-copy {
  text-align: center;
  max-width: 820px;
}
.hero-title {
  font-size: clamp(48px, 8vw, 84px);
  font-weight: 800;
  letter-spacing: -0.035em;
  color: var(--ink-strong);
  line-height: 1.05;
  margin-bottom: 12px;
}
.hero-sub {
  font-size: clamp(20px, 2.6vw, 28px);
  font-weight: 500;
  color: var(--blue);
  margin-bottom: 24px;
  letter-spacing: -0.01em;
}
.hero-desc {
  font-size: 17px;
  color: var(--muted);
  max-width: 640px;
  margin: 0 auto 36px;
  line-height: 1.8;
}
.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}
.hero-stats {
  display: flex;
  justify-content: center;
  gap: 0;
  margin-bottom: 72px;
}
.hero-stats li {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 0 40px;
  border-right: 1px solid var(--line);
}
.hero-stats li:last-child { border-right: none; }
.hero-stats strong {
  font-size: 26px;
  font-weight: 700;
  color: var(--ink-strong);
  letter-spacing: -0.02em;
}
.hero-stats span { font-size: 13px; color: var(--muted); }

/* ---------- 软件界面模拟图 ---------- */
.hero-mockup {
  max-width: 1120px;
}
.app-window {
  background: #f3f4f6;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--shadow-app);
  font-size: 12px;
  color: #1f2937;
  user-select: none;
}
.app-titlebar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 36px;
  padding: 0 12px;
  background: #fff;
  border-bottom: 1px solid #e5e7eb;
}
.app-title {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  font-weight: 500;
  color: #374151;
}
.app-title svg { border-radius: 3px; }
.app-winbtns { display: flex; gap: 14px; align-items: center; }
.app-winbtns i {
  width: 10px; height: 10px;
  display: inline-block;
  border: 1.2px solid #9ca3af;
}
.app-winbtns i.close { border: none; position: relative; }
.app-winbtns i.close::before,
.app-winbtns i.close::after {
  content: "";
  position: absolute;
  left: 4px; top: -1px;
  width: 1.2px; height: 12px;
  background: #9ca3af;
}
.app-winbtns i.close::before { transform: rotate(45deg); }
.app-winbtns i.close::after { transform: rotate(-45deg); }
.app-menubar {
  display: flex;
  gap: 2px;
  padding: 0 8px;
  height: 28px;
  align-items: center;
  background: #fff;
  border-bottom: 1px solid #eceef1;
}
.app-menubar span {
  padding: 3px 10px;
  border-radius: 5px;
  color: #374151;
}
.app-menubar span.active { background: #e8effc; color: var(--blue); font-weight: 500; }
.app-toolbar {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 10px;
  background: #fafbfc;
  border-bottom: 1px solid #e5e7eb;
  flex-wrap: wrap;
}
.tb-btn {
  padding: 5px 12px;
  border-radius: 6px;
  background: #fff;
  border: 1px solid #e1e4e8;
  color: #374151;
  font-weight: 500;
  box-shadow: 0 1px 1px rgba(0,0,0,0.03);
}
.tb-btn.on {
  background: #e8effc;
  border-color: #b6ccf5;
  color: var(--blue);
}
.tb-btn.ai {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  background: linear-gradient(135deg, #2563eb, #4f46e5);
  border: none;
  color: #fff;
}
.tb-sep {
  width: 1px;
  height: 18px;
  background: #e1e4e8;
  margin: 0 4px;
}
.app-body {
  display: grid;
  grid-template-columns: 168px 1fr 196px;
  min-height: 0;
  background: #eceef1;
}
/* 左侧图片列表 */
.app-left, .app-right {
  background: #f7f8fa;
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  overflow: hidden;
}
.app-left { border-right: 1px solid #e1e4e8; }
.app-right { border-left: 1px solid #e1e4e8; gap: 6px; }
.panel-cap {
  font-size: 11px;
  font-weight: 600;
  color: #6b7280;
  letter-spacing: 0.04em;
  padding: 2px 2px 4px;
}
.thumb-list { display: flex; flex-direction: column; gap: 6px; }
.thumb {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 5px;
  border-radius: 8px;
  border: 1.5px solid transparent;
  background: #fff;
  box-shadow: 0 1px 2px rgba(0,0,0,0.04);
}
.thumb.current {
  border-color: var(--blue);
  background: #eff6ff;
}
.thumb .tick {
  font-size: 10px;
  color: #fff;
  background: var(--green);
  width: 14px; height: 14px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.thumb em {
  font-style: normal;
  font-size: 10.5px;
  color: #374151;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.ph {
  width: 34px; height: 24px;
  border-radius: 4px;
  flex-shrink: 0;
}
.ph-a { background: linear-gradient(135deg, #87b8e8, #6b86a6 60%, #8f959c); }
.ph-b { background: linear-gradient(135deg, #a5c8e8, #7a94b2 55%, #8f959c); }
.ph-c { background: linear-gradient(160deg, #93bde3, #6f89a8 50%, #9ca3af); }
.ph-d { background: linear-gradient(135deg, #87b8e8 40%, #2f6fd0 41%, #2f6fd0 55%, #8f959c 56%); }
.ph-e { background: linear-gradient(135deg, #c4d9ef, #7a94b2 60%, #8f959c); }
.ph-f { background: linear-gradient(135deg, #a8c6e6, #6b86a6 45%, #6f89a8); }
/* 中央画布 */
.app-canvas {
  position: relative;
  background: #3a3d41;
  aspect-ratio: 16 / 10;
  overflow: hidden;
}
.app-canvas .scene {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}
/* 检测框 */
.det {
  position: absolute;
  border: 2px solid;
  border-radius: 2px;
  opacity: 0;
  transform: scale(0.92);
  transform-origin: center;
}
.det-label {
  position: absolute;
  top: -20px;
  left: -2px;
  font-size: 10px;
  font-weight: 600;
  color: #fff;
  padding: 1px 7px;
  border-radius: 3px 3px 3px 0;
  white-space: nowrap;
  font-family: var(--font);
}
.det-car { left: 10.9%; top: 62.5%; width: 33.1%; height: 28%; border-color: #3b82f6; }
.det-car .det-label { background: #3b82f6; }
.det-person { left: 55.3%; top: 59%; width: 8.1%; height: 33%; border-color: #22c55e; }
.det-person .det-label { background: #22c55e; }
.det-dog { left: 71.9%; top: 77.5%; width: 13.75%; height: 14%; border-color: #f59e0b; }
.det-dog .det-label { background: #f59e0b; }
.det-light { left: 89.7%; top: 39.5%; width: 7.2%; height: 15.5%; border-color: #a855f7; }
.det-light .det-label { background: #a855f7; left: auto; right: -2px; border-radius: 3px 3px 0 3px; }
/* AI 完成后检测框入场 */
.hero-mockup.ai-play .det {
  animation: detIn 0.45s cubic-bezier(0.22, 1, 0.36, 1) forwards;
}
.hero-mockup.ai-play .det-car { animation-delay: 0.15s; }
.hero-mockup.ai-play .det-person { animation-delay: 0.45s; }
.hero-mockup.ai-play .det-dog { animation-delay: 0.75s; }
.hero-mockup.ai-play .det-light { animation-delay: 1.05s; }
@keyframes detIn {
  to { opacity: 1; transform: scale(1); }
}
.canvas-hint {
  position: absolute;
  left: 50%;
  bottom: 14px;
  transform: translateX(-50%);
  background: rgba(17, 24, 39, 0.78);
  color: #e5e7eb;
  font-size: 11px;
  padding: 5px 14px;
  border-radius: 999px;
  backdrop-filter: blur(6px);
  white-space: nowrap;
  opacity: 0;
  transition: opacity 0.4s ease 1.3s;
}
.hero-mockup.ai-play .canvas-hint { opacity: 1; }
/* 右侧面板 */
.class-list, .shape-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.class-list li, .shape-list li {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 5px 7px;
  background: #fff;
  border-radius: 6px;
  font-size: 11px;
  box-shadow: 0 1px 1px rgba(0,0,0,0.03);
  color: #374151;
}
.class-list i {
  width: 10px; height: 10px;
  border-radius: 3px;
  flex-shrink: 0;
}
.class-list span {
  margin-left: auto;
  color: #9ca3af;
  font-size: 10px;
  font-variant-numeric: tabular-nums;
}
.shape-list em {
  font-style: normal;
  font-size: 9px;
  font-weight: 700;
  color: #374151;
  border: 1.5px solid;
  border-radius: 3px;
  width: 16px; height: 16px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.stat-block {
  background: #fff;
  border-radius: 8px;
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  box-shadow: 0 1px 2px rgba(0,0,0,0.04);
}
.stat-row {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: #6b7280;
}
.stat-row b { color: #111827; font-size: 12px; }
.stat-row b.ok { color: var(--green); }
.stat-row.small b { font-size: 11px; }
.progress {
  height: 6px;
  border-radius: 999px;
  background: #e5e7eb;
  overflow: hidden;
}
.progress i {
  display: block;
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, #22c55e, #16a34a);
}
.app-status {
  display: flex;
  gap: 18px;
  align-items: center;
  height: 30px;
  padding: 0 14px;
  background: #fff;
  border-top: 1px solid #e5e7eb;
  font-size: 11px;
  color: #6b7280;
}
.app-status .tip { color: var(--blue); margin-left: auto; font-weight: 500; }

/* ---------- 三步上手 ---------- */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  counter-reset: step;
  margin-bottom: 40px;
}
.step-card {
  position: relative;
  background: #fff;
  border-radius: var(--radius);
  padding: 40px 32px 36px;
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.05), 0 0 0 1px rgba(15, 23, 42, 0.04);
  overflow: hidden;
}
.step-num {
  position: absolute;
  top: 22px;
  right: 26px;
  font-size: 44px;
  font-weight: 800;
  letter-spacing: -0.04em;
  color: rgba(37, 99, 235, 0.1);
  line-height: 1;
}
.step-icon {
  width: 56px; height: 56px;
  border-radius: 16px;
  background: var(--blue-soft);
  color: var(--blue);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
}
.step-icon svg { width: 30px; height: 30px; }
.step-card h3 {
  font-size: 20px;
  font-weight: 700;
  color: var(--ink-strong);
  margin-bottom: 10px;
}
.step-card p { font-size: 15px; color: var(--muted); line-height: 1.75; }
.steps-after {
  text-align: center;
  font-size: 16px;
  color: var(--muted);
}
.steps-after strong { color: var(--ink-strong); }

/* ---------- 功能网格 ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.feature-card {
  background: #fff;
  border-radius: var(--radius);
  padding: 36px 32px;
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.05), 0 0 0 1px rgba(15, 23, 42, 0.04);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 18px 40px -16px rgba(15, 23, 42, 0.16), 0 0 0 1px rgba(15, 23, 42, 0.05);
}
.feature-icon {
  width: 48px; height: 48px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}
.feature-icon svg { width: 26px; height: 26px; }
.feature-icon.blue { background: var(--blue-soft); color: var(--blue); }
.feature-icon.green { background: #ecfdf3; color: var(--green); }
.feature-card h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--ink-strong);
  margin-bottom: 10px;
}
.feature-card p { font-size: 15px; color: var(--muted); line-height: 1.75; }

/* ---------- 隐私 ---------- */
.privacy-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 56px;
}
.privacy-card {
  background: var(--dark-card);
  border: 1px solid var(--dark-line);
  border-radius: var(--radius);
  padding: 32px 28px;
}
.privacy-card h3 {
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 10px;
}
.privacy-card p { font-size: 14.5px; color: #9aa4b5; line-height: 1.75; }
.arch {
  max-width: 820px;
  margin: 0 auto;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--dark-line);
  border-radius: var(--radius);
  padding: 36px 28px;
}
.arch svg { width: 100%; height: auto; }

/* ---------- 快捷键 ---------- */
.key-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  max-width: 1000px;
  margin: 0 auto;
}
.key-item {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 14px 18px;
  font-size: 14px;
  color: var(--muted);
  transition: border-color 0.2s;
}
.key-item:hover { border-color: #b6ccf5; }
.key-item span:last-child { margin-left: auto; color: var(--ink); font-weight: 500; }
.key-item span + kbd { margin-left: 0; }
.key-item > span:not(:last-child) { margin-left: 0; }
kbd {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 28px;
  height: 28px;
  padding: 0 8px;
  border-radius: 7px;
  background: #f3f4f6;
  border: 1px solid #dfe2e7;
  box-shadow: 0 1.5px 0 #dfe2e7;
  font-family: var(--font);
  font-size: 12px;
  font-weight: 600;
  color: var(--ink-strong);
}

/* ---------- 对比表 ---------- */
.table-wrap {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.05), 0 0 0 1px rgba(15, 23, 42, 0.04);
  overflow-x: auto;
}
.compare-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 15px;
  min-width: 680px;
}
.compare-table th, .compare-table td {
  padding: 18px 22px;
  text-align: left;
  border-bottom: 1px solid var(--line);
  vertical-align: middle;
}
.compare-table thead th {
  font-size: 14px;
  font-weight: 600;
  color: var(--muted);
  background: #fafbfc;
}
.compare-table thead th.hl {
  color: var(--blue);
  background: var(--blue-soft);
  font-weight: 700;
}
.compare-table tbody th {
  font-weight: 600;
  color: var(--ink-strong);
  font-size: 14.5px;
  width: 160px;
}
.compare-table tbody td { color: var(--muted); }
.compare-table tbody td.hl {
  color: var(--ink-strong);
  font-weight: 600;
  background: rgba(37, 99, 235, 0.04);
}
.compare-table tbody tr:last-child th,
.compare-table tbody tr:last-child td { border-bottom: none; }

/* ---------- 路线图 ---------- */
.roadmap-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.roadmap-card {
  border-radius: var(--radius);
  padding: 32px 28px;
  background: #fff;
  border: 1.5px dashed #cfd5dd;
}
.roadmap-card .tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  color: var(--blue);
  background: var(--blue-soft);
  border-radius: 999px;
  padding: 4px 12px;
  margin-bottom: 16px;
}
.roadmap-card h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--ink-strong);
  margin-bottom: 8px;
}
.roadmap-card p { font-size: 15px; color: var(--muted); }

/* ---------- 下载 ---------- */
.download-card {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 48px;
  background: #fff;
  border-radius: 28px;
  padding: 64px;
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.05), 0 0 0 1px rgba(15, 23, 42, 0.04);
  align-items: center;
}
.download-copy h2 {
  font-size: clamp(28px, 3.5vw, 40px);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--ink-strong);
  margin-bottom: 12px;
  line-height: 1.25;
}
.download-copy .hero-actions {
  justify-content: flex-start;
  margin: 28px 0 16px;
}
.download-note { font-size: 14px; color: var(--muted); }
.download-specs {
  background: var(--bg-alt);
  border-radius: 20px;
  padding: 32px 30px;
}
.download-specs h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink-strong);
  margin-bottom: 18px;
}
.download-specs ul { display: flex; flex-direction: column; gap: 16px; }
.download-specs li {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}
.download-specs li:last-child { border-bottom: none; padding-bottom: 0; }
.download-specs span { font-size: 12.5px; color: var(--muted); }
.download-specs b { font-size: 14.5px; color: var(--ink-strong); font-weight: 600; line-height: 1.55; }

/* ---------- 页脚 ---------- */
.footer {
  background: var(--dark);
  color: #9aa4b5;
  padding: 72px 0 36px;
  font-size: 14px;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 64px;
  padding-bottom: 48px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  flex-wrap: wrap;
}
.footer-brand .nav-brand { color: #fff; margin-bottom: 16px; }
.footer-brand .brand-light { color: #c5cbd6; }
.footer-brand p { line-height: 1.8; font-size: 13.5px; }
.footer-links {
  display: flex;
  gap: 72px;
  flex-wrap: wrap;
}
.footer-links h4 {
  color: #fff;
  font-size: 13.5px;
  font-weight: 600;
  margin-bottom: 16px;
}
.footer-links div { display: flex; flex-direction: column; gap: 10px; }
.footer-links a {
  color: #9aa4b5;
  transition: color 0.15s;
}
.footer-links a:hover { color: #fff; }
.footer-bottom {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding-top: 28px;
  font-size: 12.5px;
  color: #6b7280;
  flex-wrap: wrap;
}

/* ---------- 滚动入场 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s cubic-bezier(0.22, 1, 0.36, 1), transform 0.7s cubic-bezier(0.22, 1, 0.36, 1);
}
.reveal.visible {
  opacity: 1;
  transform: none;
}
/* 交错延迟 */
.steps-grid .reveal:nth-child(2), .feature-grid .reveal:nth-child(2),
.privacy-grid .reveal:nth-child(2), .roadmap-grid .reveal:nth-child(2) { transition-delay: 0.1s; }
.steps-grid .reveal:nth-child(3), .feature-grid .reveal:nth-child(3),
.privacy-grid .reveal:nth-child(3), .roadmap-grid .reveal:nth-child(3) { transition-delay: 0.2s; }
.feature-grid .reveal:nth-child(4) { transition-delay: 0.08s; }
.feature-grid .reveal:nth-child(5) { transition-delay: 0.16s; }
.feature-grid .reveal:nth-child(6) { transition-delay: 0.24s; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
  .hero-mockup.ai-play .det { animation: none; opacity: 1; transform: none; }
  .canvas-hint { opacity: 1; transition: none; }
}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1024px) {
  .section { padding: 96px 0; }
  .feature-grid, .steps-grid, .privacy-grid, .roadmap-grid { grid-template-columns: repeat(2, 1fr); }
  .key-grid { grid-template-columns: repeat(3, 1fr); }
  .download-card { grid-template-columns: 1fr; padding: 48px 40px; gap: 36px; }
  .app-body { grid-template-columns: 140px 1fr 168px; }
}

@media (max-width: 860px) {
  .nav-links {
    position: fixed;
    inset: 64px 0 auto 0;
    background: rgba(255, 255, 255, 0.97);
    backdrop-filter: blur(16px);
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 12px 24px 20px;
    border-bottom: 1px solid var(--line);
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a {
    padding: 14px 4px;
    border-bottom: 1px solid var(--line);
    font-size: 16px;
    color: var(--ink-strong);
  }
  .nav-links a:last-child { border-bottom: none; }
  .nav-cta { display: none; }
  .nav-toggle { display: flex; }

  .hero { padding: 120px 0 72px; }
  .hero-stats { flex-wrap: wrap; gap: 24px 0; }
  .hero-stats li { padding: 0 24px; }
  .hero-stats li:nth-child(2) { border-right: none; }

  .app-body { grid-template-columns: 1fr; }
  .app-left, .app-right { display: none; }

  .steps-grid, .feature-grid, .privacy-grid, .roadmap-grid { grid-template-columns: 1fr; }
  .key-grid { grid-template-columns: repeat(2, 1fr); }
  .section-head { margin-bottom: 48px; }
}

@media (max-width: 560px) {
  .container { width: calc(100% - 32px); }
  body { font-size: 16px; }
  .hero-desc { font-size: 15.5px; }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .hero-actions .btn { width: 100%; }
  .hero-stats { flex-direction: column; align-items: center; gap: 18px; }
  .hero-stats li {
    border-right: none;
    padding: 0;
    width: 100%;
    align-items: center;
  }
  .key-grid { grid-template-columns: 1fr; }
  .app-status span:nth-child(3) { display: none; }
  .app-status .tip { display: none; }
  .download-card { padding: 36px 24px; }
  .footer-links { gap: 40px; }
  .section { padding: 72px 0; }
}