/* ============================================================
   观观练官网 · styles.css
   设计语言：精密暗房（复用 App 语义色板 ColorTokens.kt）
   强调色纪律：全局仅信号橙 accent；mint/amber/sky 仅语义场景
   ============================================================ */

:root {
  --bg0: #0A0C0F;
  --bg1: #13161B;
  --bg2: #191D24;
  --bg3: #21262E;
  --text: #F2F4F7;
  --muted: #A7AEB9;
  --faint: #6E7683;
  --accent: #FF7A2F;
  --accentText: #FFB27D;
  --accentSoft: rgba(255,122,47,.14);
  --gradStart: #FF9A55;
  --gradEnd: #F2571B;
  --onAccent: #1A0D04;
  --mint: #43E6A2;
  --amber: #F5C14B;
  --sky: #62A8F5;
  --danger: #F26D6D;
  --line: rgba(255,255,255,.07);
  --line2: rgba(255,255,255,.12);
  --radius-card: 24px;
  --radius-lg: 20px;
  --radius-md: 14px;
  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", "Source Han Sans SC", sans-serif;
  --nav-h: 68px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg0);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

::selection { background: var(--accent); color: var(--onAccent); }

/* 页面底色微光（避免纯黑死板） */
.page-bg {
  position: fixed; inset: 0; z-index: -2;
  background:
    radial-gradient(1200px 700px at 85% -10%, rgba(255,122,47,.07), transparent 60%),
    radial-gradient(900px 600px at -10% 40%, rgba(98,168,245,.04), transparent 55%),
    var(--bg0);
}

.container { max-width: 1140px; margin: 0 auto; padding: 0 24px; }
.container-narrow { max-width: 860px; }
.desktop-only { display: inline; }

/* ---------- 胶囊按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  border-radius: 999px; text-decoration: none; cursor: pointer;
  font-size: 15px; font-weight: 700; padding: 13px 26px;
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease, background .2s ease;
  -webkit-tap-highlight-color: transparent;
}
.btn-primary {
  background: linear-gradient(135deg, var(--gradStart), var(--gradEnd));
  color: var(--onAccent);
  box-shadow: 0 10px 32px rgba(255,122,47,.32), inset 0 1px 0 rgba(255,255,255,.25);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 16px 40px rgba(255,122,47,.45), inset 0 1px 0 rgba(255,255,255,.25); }
.btn-primary:active { transform: translateY(0); }
.btn-ghost {
  background: transparent; color: var(--text);
  border: 1px solid var(--line2);
}
.btn-ghost:hover { border-color: var(--accentText); color: var(--accentText); }
.btn-lg { font-size: 17px; padding: 16px 34px; }

/* ---------- 导航 ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  height: var(--nav-h);
  background: rgba(10,12,15,.72);
  backdrop-filter: blur(18px); -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: 1140px; margin: 0 auto; padding: 0 24px;
  height: 100%; display: flex; align-items: center; justify-content: space-between;
}
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--text); }
.brand-mark {
  width: 34px; height: 34px; border-radius: 10px; flex: none;
  display: grid; place-items: center;
  background: linear-gradient(135deg, var(--gradStart), var(--gradEnd));
  color: var(--onAccent); font-weight: 900; font-size: 19px;
  box-shadow: 0 4px 16px rgba(255,122,47,.35);
}
.brand-name { font-size: 20px; font-weight: 900; letter-spacing: 1px; }
.brand-name em { font-style: normal; color: var(--accent); }
.brand-tag {
  font-size: 11px; color: var(--muted);
  border: 1px solid var(--line2); border-radius: 999px; padding: 2px 9px; margin-left: 2px;
}
.nav-links { display: flex; align-items: center; gap: 30px; }
.nav-links a { color: var(--muted); text-decoration: none; font-size: 14px; font-weight: 500; transition: color .2s; }
.nav-links a:hover { color: var(--text); }
.nav-links .nav-cta {
  color: var(--onAccent); font-weight: 700;
  background: linear-gradient(135deg, var(--gradStart), var(--gradEnd));
  padding: 9px 20px; border-radius: 999px;
  box-shadow: 0 6px 20px rgba(255,122,47,.3);
}
.nav-links .nav-cta:hover { color: var(--onAccent); transform: translateY(-1px); }

/* ---------- Hero ---------- */
.hero { position: relative; padding: calc(var(--nav-h) + 64px) 0 96px; overflow: hidden; }
.hero-glow {
  position: absolute; right: -140px; top: 40px; width: 640px; height: 640px;
  background: radial-gradient(circle, rgba(255,122,47,.16), transparent 62%);
  pointer-events: none;
}
.hero-grid {
  position: absolute; inset: 0; opacity: .5; pointer-events: none;
  background-image:
    linear-gradient(rgba(255,255,255,.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.025) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 20%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 20%, transparent 75%);
}
.hero-inner {
  position: relative;
  display: grid; grid-template-columns: 1.15fr .85fr; gap: 48px; align-items: center;
}
.eyebrow {
  display: inline-block; font-size: 13px; font-weight: 700; color: var(--accentText);
  border: 1px solid rgba(255,122,47,.35); background: var(--accentSoft);
  border-radius: 999px; padding: 5px 14px; margin-bottom: 22px;
}
.hero h1 {
  font-size: clamp(44px, 6.2vw, 76px); font-weight: 900; line-height: 1.12; letter-spacing: 2px;
  margin-bottom: 24px;
}
.hero-sub { color: var(--muted); font-size: 17px; margin-bottom: 34px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 30px; }
.hero-chips { list-style: none; display: flex; flex-wrap: wrap; gap: 10px; }
.hero-chips li {
  font-size: 12px; color: var(--muted);
  border: 1px solid var(--line); border-radius: 999px; padding: 6px 13px;
}

/* 手机 mockup */
.hero-visual { position: relative; display: flex; justify-content: center; }
.phone {
  width: 292px; padding: 10px; border-radius: 46px;
  background: linear-gradient(160deg, #232933, #0D1014);
  border: 1px solid var(--line2);
  box-shadow: 0 40px 90px rgba(0,0,0,.55), inset 0 1px 0 rgba(255,255,255,.08);
}
.phone-notch {
  width: 92px; height: 22px; margin: 2px auto 8px; border-radius: 999px;
  background: #05060A;
}
.phone-screen {
  border-radius: 36px; overflow: hidden; aspect-ratio: 9 / 19;
  background: var(--bg0); position: relative;
}
.workout-mini {
  position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 14px;
  background:
    radial-gradient(ellipse 90% 60% at 50% 100%, rgba(255,122,47,.18), transparent 65%),
    radial-gradient(ellipse 70% 45% at 50% 20%, rgba(255,255,255,.05), transparent 60%),
    var(--bg0);
}
.wm-top {
  position: absolute; top: 16px; left: 18px; right: 18px;
  display: flex; justify-content: space-between;
  font-size: 11px; color: var(--muted);
}
.wm-time { color: var(--text); font-weight: 700; font-feature-settings: "tnum"; }
.wm-ring {
  width: 132px; height: 132px; border-radius: 50%;
  background: conic-gradient(var(--gradStart), var(--gradEnd) 74%, rgba(255,255,255,.08) 74%);
  display: grid; place-items: center;
  box-shadow: 0 0 46px rgba(255,122,47,.35);
}
.wm-ring-inner {
  width: 108px; height: 108px; border-radius: 50%;
  background: var(--bg0); display: flex; flex-direction: column; align-items: center; justify-content: center;
}
.wm-ring-inner strong { font-size: 40px; font-weight: 900; color: var(--accent); line-height: 1; font-feature-settings: "tnum"; }
.wm-ring-inner span { font-size: 11px; color: var(--muted); margin-top: 4px; }
.wm-action { font-size: 19px; font-weight: 900; }
.wm-sub { font-size: 11px; color: var(--faint); margin-top: -8px; }
.wm-progress { display: flex; gap: 5px; margin-top: 2px; }
.wm-progress i { width: 7px; height: 7px; border-radius: 50%; background: var(--bg3); }
.wm-progress i.on { background: linear-gradient(135deg, var(--gradStart), var(--gradEnd)); box-shadow: 0 0 8px rgba(255,122,47,.6); }

/* 悬浮徽标 */
.float-badge {
  position: absolute; background: var(--bg1);
  border: 1px solid var(--line2); border-radius: var(--radius-md);
  padding: 10px 14px; font-size: 12px; font-weight: 700;
  box-shadow: 0 16px 40px rgba(0,0,0,.5);
}
.float-badge small { display: block; color: var(--faint); font-weight: 400; margin-top: 2px; }
.fb-ai { left: -18px; top: 16%; animation: float 7s ease-in-out infinite; }
.fb-fx { right: -26px; bottom: 14%; animation: float 8s ease-in-out 1.2s infinite; }
@keyframes float { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-10px); } }

/* ---------- 通用 Section ---------- */
.section { padding: 110px 0; position: relative; }
.section + .section { border-top: 1px solid var(--line); }
.section-label {
  font-size: 13px; font-weight: 700; color: var(--accent); letter-spacing: 3px;
  display: flex; align-items: center; gap: 12px; margin-bottom: 16px;
}
.section-label::after { content: ""; height: 1px; width: 56px; background: linear-gradient(90deg, var(--accent), transparent); }
.section-title { font-size: clamp(30px, 4vw, 46px); font-weight: 900; line-height: 1.25; letter-spacing: 1px; margin-bottom: 18px; }
.section-sub { color: var(--muted); font-size: 16px; margin-bottom: 44px; }

/* ---------- 01 纯粹 · 私练 ---------- */
.split { display: grid; grid-template-columns: .9fr 1.1fr; gap: 64px; align-items: center; margin-top: 56px; }
.split-reverse { grid-template-columns: 1.05fr .95fr; }

.camera-card {
  position: relative; border-radius: var(--radius-card); overflow: hidden;
  aspect-ratio: 3 / 4; max-width: 400px; margin: 0 auto;
  background:
    radial-gradient(ellipse 100% 55% at 50% 100%, rgba(255,122,47,.22), transparent 60%),
    radial-gradient(ellipse 80% 45% at 50% 8%, rgba(255,255,255,.06), transparent 60%),
    #10141A;
  border: 1px solid var(--line);
  box-shadow: 0 30px 70px rgba(0,0,0,.45);
  display: flex; flex-direction: column; align-items: center; justify-content: flex-end; padding: 26px;
}
.cam-scrim { position: absolute; inset: 0; background: rgba(5,6,8,.35); pointer-events: none; }
.cam-body { font-size: 74px; filter: drop-shadow(0 10px 24px rgba(255,122,47,.35)); position: relative; }
.cam-count {
  position: relative; font-size: 64px; font-weight: 900; color: var(--accent);
  line-height: 1; font-feature-settings: "tnum";
  text-shadow: 0 0 30px rgba(255,122,47,.55);
}
.cam-action { position: relative; font-size: 17px; font-weight: 900; margin-top: 4px; }
.cam-footer { position: relative; display: flex; align-items: center; gap: 6px; margin-top: 18px; width: 100%; justify-content: center; }
.cam-footer em { font-style: normal; font-size: 11px; color: var(--faint); margin-left: 10px; }
.cam-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--bg3); }
.cam-dot.on { background: linear-gradient(135deg, var(--gradStart), var(--gradEnd)); box-shadow: 0 0 8px rgba(255,122,47,.6); }

.split-copy { display: flex; flex-direction: column; gap: 30px; }
.point { display: flex; gap: 18px; align-items: flex-start; }
.point-ico {
  width: 46px; height: 46px; flex: none; border-radius: 16px;
  background: var(--accentSoft); border: 1px solid rgba(255,122,47,.28);
  display: grid; place-items: center; font-size: 20px;
}
.point h3 { font-size: 18px; font-weight: 900; margin-bottom: 4px; }
.point p { color: var(--muted); font-size: 14.5px; }
.quote {
  border-left: 3px solid var(--accent); padding-left: 18px;
  font-size: 19px; font-weight: 900; color: var(--text); font-style: normal;
  margin-top: 6px;
}

/* ---------- 02 特效 ---------- */
.section-fx { background: linear-gradient(180deg, transparent, rgba(255,122,47,.04) 20%, rgba(255,122,47,.04) 80%, transparent); }
.fx-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.fx-card {
  position: relative; overflow: hidden;
  background: var(--bg1); border: 1px solid var(--line);
  border-radius: var(--radius-card); padding: 34px 28px 30px;
  transition: transform .25s ease, border-color .25s ease;
}
.fx-card:hover { transform: translateY(-4px); }
.fx-fire, .fx-electric { border-color: rgba(255,122,47,.22); }
.fx-electric { border-color: rgba(98,168,245,.22); }
.fx-glow {
  position: absolute; inset: -40% -30% auto; height: 80%; opacity: .5; pointer-events: none;
  background: radial-gradient(circle at 50% 20%, rgba(255,122,47,.22), transparent 60%);
}
.fx-electric .fx-glow { background: radial-gradient(circle at 50% 20%, rgba(98,168,245,.2), transparent 60%); }
.fx-emoji { display: block; font-size: 44px; margin-bottom: 18px; filter: drop-shadow(0 8px 20px rgba(255,122,47,.4)); }
.fx-electric .fx-emoji { filter: drop-shadow(0 8px 20px rgba(98,168,245,.4)); }
.fx-card h3 { font-size: 21px; font-weight: 900; margin-bottom: 8px; }
.fx-card p { color: var(--muted); font-size: 14px; }
.fx-vip {
  position: absolute; top: 18px; right: 18px;
  font-size: 11px; font-weight: 700; color: #3A2A08;
  background: linear-gradient(135deg, #FFD98A, #F5C14B);
  border-radius: 999px; padding: 4px 10px;
}
.fx-note {
  margin-top: 30px; display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; align-items: center;
  font-size: 13px; color: var(--accentText);
}
.fx-note span { border: 1px solid rgba(255,122,47,.3); background: var(--accentSoft); border-radius: 999px; padding: 8px 16px; }
.fx-note .fx-note-dim { color: var(--muted); border-color: var(--line); background: transparent; }

/* ---------- 03 AI 计划 ---------- */
.steps { list-style: none; display: flex; flex-direction: column; gap: 26px; }
.steps li, .install-steps li { display: flex; gap: 16px; align-items: flex-start; }
.step-no {
  width: 40px; height: 40px; flex: none; border-radius: 50%;
  display: grid; place-items: center;
  font-size: 15px; font-weight: 900; color: var(--onAccent);
  background: linear-gradient(135deg, var(--gradStart), var(--gradEnd));
  box-shadow: 0 6px 18px rgba(255,122,47,.3);
}
.steps h3 { font-size: 17px; font-weight: 900; margin-bottom: 2px; }
.steps p { color: var(--muted); font-size: 14px; }
.ai-fallback {
  margin-top: 30px; font-size: 13px; color: var(--mint);
  border: 1px solid rgba(67,230,162,.3); background: rgba(67,230,162,.07);
  border-radius: 999px; padding: 10px 18px; display: inline-block;
}

.plan-card {
  background: var(--bg1); border: 1px solid var(--line);
  border-radius: var(--radius-card); padding: 26px;
  box-shadow: 0 30px 70px rgba(0,0,0,.4);
  max-width: 420px; margin: 0 auto;
}
.plan-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 10px; margin-bottom: 20px; }
.plan-badge {
  display: inline-block; font-size: 11px; font-weight: 700; color: var(--accentText);
  background: var(--accentSoft); border-radius: 999px; padding: 3px 10px; margin-bottom: 8px;
}
.plan-head h3 { font-size: 19px; font-weight: 900; line-height: 1.3; }
.plan-meta { font-size: 12px; color: var(--faint); text-align: right; flex: none; padding-top: 4px; }
.plan-list { list-style: none; border-top: 1px solid var(--line); }
.plan-list li {
  display: flex; align-items: center; gap: 10px;
  padding: 11px 2px; border-bottom: 1px solid var(--line);
  font-size: 14.5px; font-weight: 500;
}
.plan-list li span { width: 26px; height: 26px; border-radius: 9px; background: var(--bg2); display: grid; place-items: center; font-size: 14px; }
.plan-list li em { margin-left: auto; font-style: normal; color: var(--faint); font-size: 12.5px; font-feature-settings: "tnum"; }
.plan-cta {
  margin-top: 20px; text-align: center;
  background: linear-gradient(135deg, var(--gradStart), var(--gradEnd));
  color: var(--onAccent); font-weight: 900; font-size: 16px;
  border-radius: 999px; padding: 14px;
  box-shadow: 0 10px 30px rgba(255,122,47,.32), inset 0 1px 0 rgba(255,255,255,.25);
}

/* ---------- 04 数据 ---------- */
.data-row { display: grid; grid-template-columns: 1.15fr .85fr; gap: 22px; }
.data-card {
  background: var(--bg1); border: 1px solid var(--line);
  border-radius: var(--radius-card); padding: 26px 26px 22px;
}
.data-card h3 { font-size: 16px; font-weight: 900; margin-bottom: 18px; }
.chart { width: 100%; height: 130px; display: block; }
.chart-line { fill: none; stroke: var(--accent); stroke-width: 2.4; stroke-linecap: round; stroke-linejoin: round; }
.chart-area { fill: url(#area); }
.chart-dot { fill: var(--accent); }
.data-note { margin-top: 14px; font-size: 13px; color: var(--faint); }
.data-note em { font-style: normal; font-weight: 700; }
.data-note .down { color: var(--mint); }
.dots { display: grid; grid-template-columns: repeat(7, 1fr); gap: 9px; max-width: 320px; }
.dots i { aspect-ratio: 1; border-radius: 50%; background: var(--bg3); }
.dots i.lit { background: linear-gradient(135deg, var(--gradStart), var(--gradEnd)); box-shadow: 0 0 10px rgba(255,122,47,.55); }

/* ---------- 下载 ---------- */
.section-download { background: linear-gradient(180deg, transparent, rgba(255,122,47,.05)); }
.download-card {
  display: flex; justify-content: space-between; align-items: center; gap: 30px; flex-wrap: wrap;
  background: var(--bg1); border: 1px solid rgba(255,122,47,.22);
  border-radius: var(--radius-card); padding: 34px 36px;
  box-shadow: 0 30px 80px rgba(0,0,0,.45);
}
.dl-left { display: flex; gap: 22px; align-items: center; }
.dl-icon { border-radius: 20px; box-shadow: 0 12px 32px rgba(0,0,0,.5); }
.dl-info h3 { font-size: 24px; font-weight: 900; margin-bottom: 6px; }
.dl-edition {
  font-size: 13px; font-weight: 700; color: var(--accentText);
  border: 1px solid rgba(255,122,47,.3); border-radius: 999px; padding: 2px 10px;
  vertical-align: 4px; margin-left: 6px;
}
.dl-meta { display: flex; flex-wrap: wrap; gap: 8px 18px; color: var(--muted); font-size: 13px; margin-bottom: 6px; }
.dl-req { color: var(--faint); font-size: 12px; }
.dl-right { text-align: center; }
.dl-tip { margin-top: 10px; font-size: 12px; color: var(--faint); }

.install-steps {
  list-style: none; display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px;
  margin-top: 44px;
}
.install-steps li { background: var(--bg1); border: 1px solid var(--line); border-radius: var(--radius-card); padding: 24px; align-items: flex-start; }
.install-steps h3 { font-size: 16px; font-weight: 900; margin-bottom: 4px; }
.install-steps p { color: var(--muted); font-size: 13.5px; }
.mini-note { text-align: center; margin-top: 36px; color: var(--muted); font-size: 14px; }

/* ---------- FAQ ---------- */
.faq {
  background: var(--bg1); border: 1px solid var(--line);
  border-radius: var(--radius-lg); padding: 20px 24px; margin-top: 14px;
}
.faq summary {
  list-style: none; cursor: pointer;
  font-size: 16px; font-weight: 700;
  display: flex; justify-content: space-between; align-items: center; gap: 14px;
  user-select: none;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+"; font-size: 20px; color: var(--accent); font-weight: 700;
  transition: transform .25s ease; flex: none;
}
.faq[open] summary::after { transform: rotate(45deg); }
.faq p { color: var(--muted); font-size: 14.5px; margin-top: 12px; padding-right: 24px; }

/* ---------- Footer ---------- */
.footer { border-top: 1px solid var(--line); padding: 56px 0 44px; }
.footer-inner { display: flex; flex-direction: column; align-items: center; gap: 12px; text-align: center; }
.footer-brand { display: flex; align-items: center; gap: 10px; }
.footer-slogan { color: var(--muted); font-size: 15px; }
.footer-meta { color: var(--faint); font-size: 12.5px; }

/* ---------- 滚动显现 ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s ease, transform .7s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .hero-inner { grid-template-columns: 1fr; text-align: center; }
  .hero-actions, .hero-chips { justify-content: center; }
  .eyebrow { margin-bottom: 18px; }
  .hero-visual { margin-top: 40px; }
  .fb-ai { left: 6%; }
  .fb-fx { right: 2%; }
  .split, .split-reverse { grid-template-columns: 1fr; gap: 48px; }
  .fx-row, .data-row, .install-steps { grid-template-columns: 1fr; }
  .download-card { justify-content: center; text-align: center; }
  .dl-left { flex-direction: column; }
  .nav-links a:not(.nav-cta) { display: none; }
  .desktop-only { display: none; }
  .section { padding: 84px 0; }
  .cam-footer em { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .float-badge { animation: none; }
  .btn, .fx-card, .faq summary::after { transition: none; }
}