/* =========================================================
   演物实验室 GeWu Lab — 设计系统
   纸感底色 + 朱砂强调 + 仪表读数，克制、可投屏、可打印
   ========================================================= */

:root {
  --paper: #f7f5ef;
  --paper-2: #fffefb;
  --paper-3: #f1ede3;
  --ink: #14181c;
  --ink-2: #343c45;
  --ink-3: #69727c;
  --ink-4: #9aa1a8;
  --line: #e3ddd0;
  --line-2: #cfc7b6;

  --accent: #c1442a;
  --accent-dark: #9e3520;
  --accent-soft: #fbebe5;
  --blue: #2b5f7a;
  --blue-soft: #e8f0f4;
  --green: #47703c;
  --gold: #b8860b;

  --radius-s: 8px;
  --radius: 14px;
  --radius-l: 22px;

  --shadow-s: 0 1px 2px rgba(20, 24, 28, 0.05);
  --shadow: 0 10px 30px -12px rgba(20, 24, 28, 0.18);
  --shadow-l: 0 30px 70px -30px rgba(20, 24, 28, 0.35);

  --serif: Georgia, "Songti SC", "SimSun", "STSong", serif;
  --sans: system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", "SFMono-Regular", "Cascadia Mono", Consolas, "Liberation Mono", monospace;

  --max: 1180px;
  --header-h: 68px;
}

* { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, canvas, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; color: inherit; }
h1, h2, h3, h4, p, figure { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

.skip-link {
  position: absolute; left: -9999px; top: 8px; z-index: 100;
  background: var(--ink); color: var(--paper); padding: 10px 16px; border-radius: 8px;
}
.skip-link:focus { left: 16px; }

/* ---------- 通用 ---------- */

.wrap { width: min(100% - 48px, var(--max)); margin-inline: auto; }
.wrap-narrow { width: min(100% - 48px, 780px); margin-inline: auto; }
.stack > * + * { margin-top: var(--gap, 16px); }
.mono { font-family: var(--mono); font-variant-numeric: tabular-nums; }
.muted { color: var(--ink-3); }
.small { font-size: 13px; }
.tiny { font-size: 12px; }
.center { text-align: center; }
.hr { height: 1px; background: var(--line); border: 0; margin: 0; }

.eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--mono); font-size: 12px; letter-spacing: 0.16em;
  text-transform: uppercase; color: var(--ink-3);
}
.eyebrow::before {
  content: ""; width: 26px; height: 1px; background: var(--accent); display: block;
}

.section { padding: 88px 0; }
.section--tight { padding: 56px 0; }
.section-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 32px; margin-bottom: 40px; flex-wrap: wrap; }
.section-title { font-size: clamp(26px, 3vw, 38px); line-height: 1.2; letter-spacing: -0.02em; font-weight: 700; }
.section-desc { color: var(--ink-3); max-width: 520px; margin-top: 12px; }

/* ---------- 按钮 ---------- */

.btn {
  --btn-bg: var(--ink);
  --btn-fg: var(--paper-2);
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 22px; border-radius: 999px; border: 1px solid transparent;
  background: var(--btn-bg); color: var(--btn-fg);
  font-size: 15px; font-weight: 600; letter-spacing: 0.01em;
  cursor: pointer; transition: transform 0.15s ease, background 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn[disabled] { opacity: 0.55; cursor: not-allowed; transform: none; }

.btn--primary { --btn-bg: var(--accent); }
.btn--primary:hover { --btn-bg: var(--accent-dark); box-shadow: 0 10px 24px -12px rgba(193, 68, 42, 0.8); }
.btn--ghost { --btn-bg: transparent; --btn-fg: var(--ink); border-color: var(--line-2); }
.btn--ghost:hover { --btn-bg: var(--paper-2); border-color: var(--ink); }
.btn--quiet { --btn-bg: transparent; --btn-fg: var(--ink-2); padding-inline: 12px; }
.btn--quiet:hover { --btn-bg: rgba(20, 24, 28, 0.05); }
.btn--lg { padding: 15px 30px; font-size: 16px; }
.btn--sm { padding: 8px 16px; font-size: 14px; }
.btn--block { width: 100%; }

.chip {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 4px 10px; border-radius: 999px;
  background: var(--paper-3); border: 1px solid var(--line);
  font-size: 12px; color: var(--ink-2); white-space: nowrap;
}
.chip--accent { background: var(--accent-soft); border-color: #efcabb; color: var(--accent-dark); }
.chip--ink { background: var(--ink); border-color: var(--ink); color: var(--paper-2); }

/* ---------- 顶部导航 ---------- */

.site-header {
  position: sticky; top: 0; z-index: 40;
  background: rgba(247, 245, 239, 0.96);
  backdrop-filter: saturate(180%) blur(18px);
  border-bottom: 1px solid var(--line);
}
.site-header__inner {
  height: var(--header-h);
  display: flex; align-items: center; gap: 28px;
}
.brand { display: flex; align-items: center; gap: 11px; flex-shrink: 0; }
.brand__mark {
  width: 34px; height: 34px; flex-shrink: 0;
  display: grid; place-items: center;
}
.brand__mark svg { width: 34px; height: 34px; display: block; }
.brand__text { display: flex; flex-direction: column; line-height: 1.15; }
.brand__name { font-weight: 700; letter-spacing: -0.01em; font-size: 16px; }
.brand__en { font-family: var(--mono); font-size: 10px; letter-spacing: 0.18em; color: var(--ink-3); text-transform: uppercase; }

.nav { display: flex; align-items: center; gap: 4px; margin-left: 8px; }
.nav a {
  padding: 8px 13px; border-radius: 8px; font-size: 14.5px; color: var(--ink-2);
  transition: background 0.15s, color 0.15s;
}
.nav a:hover { background: rgba(20, 24, 28, 0.05); color: var(--ink); }
.nav a.is-active { color: var(--ink); font-weight: 600; }
.nav a.is-active::after {
  content: ""; display: block; height: 2px; background: var(--accent);
  margin-top: 6px; border-radius: 2px;
}

.header-actions { margin-left: auto; display: flex; align-items: center; gap: 10px; }

.vip-pill {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 12px; font-weight: 600; color: var(--accent-dark);
  background: var(--accent-soft); border: 1px solid #efcabb;
  padding: 5px 11px; border-radius: 999px;
}
.vip-pill::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--accent); }

.user-menu { position: relative; }
.user-menu__btn {
  display: flex; align-items: center; gap: 8px; padding: 6px 10px 6px 6px;
  border: 1px solid var(--line); border-radius: 999px; background: var(--paper-2); cursor: pointer;
}
.avatar {
  width: 26px; height: 26px; border-radius: 50%; background: var(--ink); color: var(--paper);
  display: grid; place-items: center; font-size: 12px; font-weight: 600;
}
.user-menu__panel {
  position: absolute; right: 0; top: calc(100% + 8px); min-width: 200px;
  background: var(--paper-2); border: 1px solid var(--line); border-radius: 12px;
  box-shadow: var(--shadow); padding: 6px; display: none; z-index: 50;
}
.user-menu.is-open .user-menu__panel { display: block; }
.user-menu__panel a, .user-menu__panel button {
  display: flex; width: 100%; align-items: center; gap: 8px;
  padding: 9px 12px; border-radius: 8px; font-size: 14px; background: none; border: 0;
  cursor: pointer; text-align: left; color: var(--ink-2);
}
.user-menu__panel a:hover, .user-menu__panel button:hover { background: var(--paper-3); color: var(--ink); }

.nav-toggle { display: none; }

/* ---------- Hero ---------- */

.hero { position: relative; overflow: hidden; padding: 68px 0 84px; }
.hero::before {
  content: ""; position: absolute; inset: 0;
  background-image:
    linear-gradient(to right, rgba(20, 24, 28, 0.045) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(20, 24, 28, 0.045) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 70% 60% at 70% 40%, #000 0%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 70% 40%, #000 0%, transparent 75%);
  pointer-events: none;
}
.hero__grid { position: relative; display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 64px; align-items: center; }
.hero h1 {
  font-size: clamp(38px, 5.2vw, 64px); line-height: 1.08; letter-spacing: -0.035em; font-weight: 800;
  margin: 18px 0 22px;
}
.hero h1 em { font-style: normal; color: var(--accent); position: relative; white-space: nowrap; }
.hero h1 em::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 0.06em; height: 0.14em;
  background: var(--accent); opacity: 0.22; border-radius: 2px;
}
.hero__sub { font-size: 18px; color: var(--ink-2); max-width: 46ch; }
.hero__cta { display: flex; gap: 12px; margin-top: 32px; flex-wrap: wrap; }
.hero__stats { display: flex; gap: 36px; margin-top: 44px; flex-wrap: wrap; }
.hero__stat b { display: block; font-family: var(--mono); font-size: 26px; font-weight: 700; letter-spacing: -0.02em; }
.hero__stat span { font-size: 13px; color: var(--ink-3); }

.hero-stage {
  position: relative; background: var(--paper-2); border: 1px solid var(--line-2);
  border-radius: var(--radius-l); box-shadow: var(--shadow-l); overflow: hidden;
}
.hero-stage__bar {
  display: flex; align-items: center; gap: 8px; padding: 11px 14px;
  border-bottom: 1px solid var(--line); background: var(--paper-3);
}
.hero-stage__bar i { width: 8px; height: 8px; border-radius: 50%; background: var(--line-2); }
.hero-stage__bar span { margin-left: 6px; font-family: var(--mono); font-size: 11px; letter-spacing: 0.12em; color: var(--ink-3); text-transform: uppercase; }
.hero-stage canvas { width: 100%; height: 340px; display: block; }
.hero-stage__foot {
  display: flex; border-top: 1px solid var(--line); background: var(--paper-2);
}
.hero-stage__foot div { flex: 1; padding: 10px 14px; border-right: 1px solid var(--line); }
.hero-stage__foot div:last-child { border-right: 0; }
.hero-stage__foot small { display: block; font-family: var(--mono); font-size: 10px; letter-spacing: 0.1em; color: var(--ink-4); text-transform: uppercase; }
.hero-stage__foot b { font-family: var(--mono); font-size: 15px; font-weight: 600; }

/* ---------- 价值主张 ---------- */

.values { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.value { background: var(--paper-2); padding: 28px 24px; }
.value svg { width: 22px; height: 22px; color: var(--accent); margin-bottom: 16px; }
.value h3 { font-size: 16px; font-weight: 700; margin-bottom: 8px; letter-spacing: -0.01em; }
.value p { font-size: 14px; color: var(--ink-3); line-height: 1.7; }

/* ---------- 实验卡片 ---------- */

.lab-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }

.lab-card {
  position: relative; display: flex; flex-direction: column;
  background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}
.lab-card:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: var(--line-2); }
.lab-card__thumb {
  position: relative; aspect-ratio: 16 / 10; overflow: hidden;
  background: var(--paper-3); border-bottom: 1px solid var(--line);
}
.lab-card__thumb canvas { width: 100%; height: 100%; }
.lab-card__body { padding: 18px 20px 20px; display: flex; flex-direction: column; gap: 10px; flex: 1; }
.lab-card__kicker { display: flex; align-items: center; gap: 8px; font-size: 12px; color: var(--ink-3); }
.lab-card h3 { font-size: 18px; font-weight: 700; letter-spacing: -0.01em; display: flex; align-items: center; gap: 8px; }
.lab-card h3 span { font-family: var(--mono); font-size: 11px; color: var(--ink-4); letter-spacing: 0.06em; font-weight: 400; }
.lab-card p { font-size: 13.5px; color: var(--ink-3); line-height: 1.7; flex: 1; }
.lab-card__foot { display: flex; align-items: center; justify-content: space-between; gap: 10px; padding-top: 6px; }
.lab-card__topics { display: flex; gap: 6px; flex-wrap: wrap; }
.lab-card__topics span { font-size: 11px; color: var(--ink-3); background: var(--paper-3); border-radius: 4px; padding: 3px 7px; }
.lab-card__lock {
  position: absolute; top: 12px; right: 12px; z-index: 2;
  display: inline-flex; align-items: center; gap: 5px;
  background: rgba(20, 24, 28, 0.82); color: #fff; font-size: 11px;
  padding: 5px 9px; border-radius: 999px; backdrop-filter: blur(4px);
}
.lab-card__accent { position: absolute; left: 0; top: 0; bottom: 0; width: 3px; }

/* ---------- 价格 ---------- */

.price-grid { display: grid; grid-template-columns: 1fr 1.12fr 1fr 1fr; gap: 18px; align-items: stretch; }
.plan {
  display: flex; flex-direction: column; gap: 18px;
  background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px 24px; position: relative;
}
.plan--featured {
  border-color: var(--ink); box-shadow: var(--shadow); background: var(--ink); color: var(--paper);
}
.plan--featured .plan__price small, .plan--featured .plan__tagline, .plan--featured li { color: rgba(247, 245, 239, 0.72); }
.plan--featured .plan__name { color: #fff; }
.plan--featured li svg { color: #e8a58f; }
.plan.plan--featured li { color: rgba(247, 245, 239, 0.78); }
.plan__badge {
  position: absolute; top: -12px; left: 24px;
  background: var(--accent); color: #fff; font-size: 12px; font-weight: 600;
  padding: 4px 12px; border-radius: 999px; letter-spacing: 0.02em;
}
.plan__name { font-size: 15px; font-weight: 700; letter-spacing: 0.01em; }
.plan__price { display: flex; align-items: baseline; gap: 6px; font-family: var(--mono); }
.plan__price b { font-size: 40px; font-weight: 700; letter-spacing: -0.03em; line-height: 1; }
.plan__price small { font-size: 13px; color: var(--ink-3); font-family: var(--sans); }
.plan__was { font-size: 13px; color: var(--ink-4); text-decoration: line-through; font-family: var(--mono); }
.plan__tagline { font-size: 13px; color: var(--ink-3); min-height: 20px; }
.plan ul { display: flex; flex-direction: column; gap: 11px; flex: 1; }
.plan li { display: flex; gap: 9px; font-size: 13.5px; color: var(--ink-2); line-height: 1.55; }
.plan li svg { width: 15px; height: 15px; flex-shrink: 0; margin-top: 3px; color: var(--accent); }

.price-note { display: flex; gap: 24px; flex-wrap: wrap; margin-top: 28px; color: var(--ink-3); font-size: 13px; }
.price-note span { display: inline-flex; align-items: center; gap: 7px; }

/* ---------- 实验播放页 ---------- */

.lab-view {
  display: grid; grid-template-columns: 250px minmax(0, 1fr) 320px;
  gap: 0; border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--paper-2); overflow: hidden;
  min-height: 600px; height: clamp(600px, 72vh, 840px);
}
.lab-rail { border-right: 1px solid var(--line); background: var(--paper-3); padding: 18px 14px; }
.lab-rail__title { font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--ink-3); padding: 0 8px 12px; }
.chapter-link {
  display: flex; gap: 10px; width: 100%; text-align: left;
  padding: 10px 10px; border-radius: 9px; border: 1px solid transparent;
  background: none; cursor: pointer; color: var(--ink-2); font-size: 13.5px; line-height: 1.4;
  transition: background 0.15s, border-color 0.15s;
}
.chapter-link:hover { background: rgba(255, 255, 255, 0.7); }
.chapter-link.is-active { background: var(--paper-2); border-color: var(--line-2); box-shadow: var(--shadow-s); color: var(--ink); font-weight: 600; }
.chapter-link__no { font-family: var(--mono); font-size: 11px; color: var(--ink-4); padding-top: 2px; }
.chapter-link.is-active .chapter-link__no { color: var(--accent); }
.chapter-link.is-locked { color: var(--ink-4); }
.chapter-link__lock { margin-left: auto; color: var(--ink-4); flex-shrink: 0; }

.lab-main { display: flex; flex-direction: column; min-width: 0; }
.lab-stage-wrap { position: relative; flex: 1; min-height: 380px; background: var(--paper-2); }
.lab-stage-wrap canvas { position: absolute; inset: 0; width: 100%; height: 100%; }
.lab-stage-badge {
  position: absolute; left: 16px; top: 14px; z-index: 3;
  font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--ink-3); background: rgba(255, 254, 251, 0.9); border: 1px solid var(--line);
  padding: 4px 9px; border-radius: 5px;
}
.lab-hud {
  position: absolute; right: 14px; top: 12px; z-index: 3;
  display: flex; gap: 8px; flex-wrap: wrap; justify-content: flex-end; max-width: 70%;
}
.hud-item {
  background: rgba(255, 254, 251, 0.92); border: 1px solid var(--line);
  border-radius: 7px; padding: 5px 10px; text-align: right; min-width: 78px;
  backdrop-filter: blur(6px);
}
.hud-item small { display: block; font-family: var(--mono); font-size: 9.5px; letter-spacing: 0.1em; color: var(--ink-4); text-transform: uppercase; }
.hud-item b { font-family: var(--mono); font-size: 14px; font-weight: 600; font-variant-numeric: tabular-nums; }

.lab-side { border-left: 1px solid var(--line); background: var(--paper-2); display: flex; flex-direction: column; overflow-y: auto; }
.lab-side__head { padding: 18px 20px 14px; border-bottom: 1px solid var(--line); }
.lab-side__head h2 { font-size: 16px; font-weight: 700; letter-spacing: -0.01em; }
.lab-side__head p { font-size: 12.5px; color: var(--ink-3); margin-top: 6px; line-height: 1.6; }
.lab-controls { padding: 18px 20px; display: flex; flex-direction: column; gap: 20px; }
.lab-notes { margin-top: auto; padding: 16px 20px 22px; border-top: 1px solid var(--line); background: var(--paper-3); }
.lab-notes h3 { font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--ink-3); margin-bottom: 10px; }
.lab-notes p { font-size: 13px; color: var(--ink-2); line-height: 1.75; }
.lab-notes p + p { margin-top: 8px; }

/* 控件 */
.ctl { display: flex; flex-direction: column; gap: 7px; }
.ctl__top { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; }
.ctl__label { font-size: 13px; color: var(--ink-2); }
.ctl__val { font-family: var(--mono); font-size: 13px; font-weight: 600; color: var(--ink); font-variant-numeric: tabular-nums; }
.ctl__val i { font-style: normal; color: var(--ink-4); font-weight: 400; margin-left: 2px; }

input[type="range"] {
  -webkit-appearance: none; appearance: none; width: 100%; height: 22px; background: transparent; cursor: pointer;
}
input[type="range"]::-webkit-slider-runnable-track {
  height: 4px; border-radius: 999px; background: var(--paper-3); border: 1px solid var(--line);
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; width: 18px; height: 18px; border-radius: 50%;
  background: var(--paper-2); border: 2px solid var(--ink); margin-top: -8px;
  box-shadow: 0 1px 4px rgba(0,0,0,0.15); transition: transform 0.12s;
}
input[type="range"]::-webkit-slider-thumb:hover { transform: scale(1.08); }
input[type="range"]:focus-visible::-webkit-slider-thumb { border-color: var(--accent); }

.seg { display: flex; border: 1px solid var(--line-2); border-radius: 8px; overflow: hidden; }
.seg button {
  flex: 1; padding: 7px 6px; background: var(--paper-2); border: 0; cursor: pointer;
  font-size: 12.5px; color: var(--ink-3); transition: background 0.12s, color 0.12s;
}
.seg button + button { border-left: 1px solid var(--line-2); }
.seg button.is-on { background: var(--ink); color: var(--paper); font-weight: 600; }

.switch-row { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.switch {
  position: relative; width: 44px; height: 25px; border-radius: 999px; background: var(--line-2);
  border: 0; cursor: pointer; transition: background 0.18s; flex-shrink: 0; padding: 0;
}
.switch::after {
  content: ""; position: absolute; top: 3px; left: 3px; width: 19px; height: 19px;
  border-radius: 50%; background: #fff; transition: transform 0.18s; box-shadow: 0 1px 3px rgba(0,0,0,0.25);
}
.switch.is-on { background: var(--accent); }
.switch.is-on::after { transform: translateX(19px); }

.btn-row { display: flex; gap: 8px; }
.btn-row .btn { flex: 1; }

.chart-box { border: 1px solid var(--line); border-radius: 9px; background: var(--paper-2); padding: 6px; }
.chart-box canvas { width: 100%; height: 128px; }

.data-table { width: 100%; border-collapse: collapse; font-size: 12.5px; }
.data-table th, .data-table td { text-align: right; padding: 6px 4px; border-bottom: 1px solid var(--line); font-variant-numeric: tabular-nums; }
.data-table th { font-weight: 500; color: var(--ink-4); font-size: 11px; }
.data-table td:first-child, .data-table th:first-child { text-align: left; }
.data-table tr:last-child td { border-bottom: 0; }

/* 付费墙 */
.paywall {
  position: absolute; inset: 0; z-index: 5; display: grid; place-items: center;
  background: rgba(247, 245, 239, 0.72); backdrop-filter: blur(9px);
  padding: 24px; text-align: center;
}
.paywall__card {
  background: var(--paper-2); border: 1px solid var(--line-2); border-radius: var(--radius-l);
  box-shadow: var(--shadow); padding: 34px 30px; max-width: 420px;
}
.paywall__icon {
  width: 46px; height: 46px; margin: 0 auto 16px; border-radius: 50%;
  background: var(--accent-soft); color: var(--accent); display: grid; place-items: center;
}
.paywall h2 { font-size: 21px; font-weight: 700; letter-spacing: -0.02em; margin-bottom: 10px; }
.paywall p { font-size: 14px; color: var(--ink-3); line-height: 1.7; margin-bottom: 22px; }
.paywall .price-line { font-family: var(--mono); font-size: 13px; color: var(--ink-2); margin-bottom: 18px; }
.paywall .price-line b { font-size: 26px; letter-spacing: -0.02em; }

/* ---------- 表单 / 登录 ---------- */

.auth-wrap { display: grid; place-items: center; padding: 64px 0 96px; }
.auth-card {
  width: min(100%, 440px); background: var(--paper-2); border: 1px solid var(--line);
  border-radius: var(--radius-l); padding: 38px 34px; box-shadow: var(--shadow);
}
.auth-card h1 { font-size: 26px; font-weight: 700; letter-spacing: -0.02em; margin-bottom: 8px; }
.auth-card > p { color: var(--ink-3); font-size: 14px; margin-bottom: 26px; }

.field { display: flex; flex-direction: column; gap: 7px; margin-bottom: 16px; }
.field label { font-size: 13px; font-weight: 500; color: var(--ink-2); }
.field input, .field textarea, .field select {
  width: 100%; padding: 11px 14px; border: 1px solid var(--line-2); border-radius: 9px;
  background: var(--paper-2); font-size: 15px; transition: border-color 0.15s, box-shadow 0.15s;
}
.field input:focus, .field textarea:focus, .field select:focus {
  outline: none; border-color: var(--ink); box-shadow: 0 0 0 3px rgba(20, 24, 28, 0.08);
}
.field__hint { font-size: 12px; color: var(--ink-4); }
.form-error {
  background: #fdecea; border: 1px solid #f5c2ba; color: #8f2c1c;
  padding: 10px 14px; border-radius: 8px; font-size: 13px; margin-bottom: 16px;
}
.auth-alt { margin-top: 22px; font-size: 13.5px; color: var(--ink-3); text-align: center; }
.auth-alt a { color: var(--ink); text-decoration: underline; text-underline-offset: 3px; }
.demo-hint { margin-top: 18px; padding: 12px 14px; background: var(--paper-3); border-radius: 8px; font-size: 12px; color: var(--ink-3); line-height: 1.7; }
.demo-hint code { font-family: var(--mono); color: var(--ink); }

/* ---------- 会员中心 ---------- */

.account-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 24px; align-items: start; }
.panel { background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; }
.panel h2 { font-size: 16px; font-weight: 700; margin-bottom: 16px; }

.member-card {
  position: relative; overflow: hidden; border-radius: var(--radius);
  background: var(--ink); color: var(--paper); padding: 26px; min-height: 190px;
  display: flex; flex-direction: column; justify-content: space-between;
}
.member-card::after {
  content: ""; position: absolute; right: -60px; top: -60px; width: 220px; height: 220px;
  border-radius: 50%; border: 1px solid rgba(247,245,239,0.14);
}
.member-card--free { background: linear-gradient(135deg, #242a31, #14181c); }
.member-card__top { display: flex; justify-content: space-between; align-items: flex-start; gap: 16px; }
.member-card__plan { font-family: var(--mono); font-size: 11px; letter-spacing: 0.16em; text-transform: uppercase; color: rgba(247,245,239,0.6); }
.member-card__name { font-size: 24px; font-weight: 700; letter-spacing: -0.02em; margin-top: 6px; }
.member-card__meta { display: flex; gap: 28px; font-size: 12.5px; color: rgba(247,245,239,0.66); margin-top: 20px; }
.member-card__meta b { display: block; font-family: var(--mono); font-size: 15px; color: var(--paper); margin-top: 3px; }

.order-row { display: flex; align-items: center; gap: 14px; padding: 13px 0; border-bottom: 1px solid var(--line); font-size: 13.5px; }
.order-row:last-child { border-bottom: 0; }
.order-row__main { flex: 1; min-width: 0; }
.order-row__main b { font-weight: 600; }
.order-row__main small { display: block; color: var(--ink-4); font-family: var(--mono); font-size: 11px; margin-top: 2px; }
.status { font-size: 11px; padding: 3px 9px; border-radius: 999px; font-weight: 600; white-space: nowrap; }
.status--paid { background: #e8f2e6; color: #35602c; }
.status--pending { background: #fdf3dd; color: #8a6413; }
.status--closed, .status--refunded { background: var(--paper-3); color: var(--ink-3); }

.empty { text-align: center; padding: 40px 20px; color: var(--ink-4); font-size: 14px; }

/* ---------- 结算 ---------- */

.checkout { display: grid; grid-template-columns: 1fr 380px; gap: 28px; align-items: start; }
.summary { background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; position: sticky; top: calc(var(--header-h) + 20px); }
.summary__line { display: flex; justify-content: space-between; font-size: 14px; padding: 9px 0; color: var(--ink-2); }
.summary__total { display: flex; justify-content: space-between; align-items: baseline; border-top: 1px solid var(--line); margin-top: 10px; padding-top: 16px; }
.summary__total b { font-family: var(--mono); font-size: 30px; font-weight: 700; letter-spacing: -0.03em; }

.pay-methods { display: flex; flex-direction: column; gap: 10px; }
.pay-method {
  display: flex; align-items: center; gap: 12px; padding: 14px 16px;
  border: 1px solid var(--line-2); border-radius: 10px; background: var(--paper-2);
  cursor: pointer; transition: border-color 0.15s, background 0.15s;
}
.pay-method:hover { border-color: var(--ink-3); }
.pay-method.is-on { border-color: var(--ink); background: var(--paper-3); box-shadow: inset 0 0 0 1px var(--ink); }
.pay-method__logo { width: 30px; height: 30px; border-radius: 8px; display: grid; place-items: center; background: var(--paper-3); }
.pay-method__name { font-weight: 600; font-size: 14px; }
.pay-method__desc { font-size: 12px; color: var(--ink-4); }

.qr-box { display: grid; place-items: center; padding: 28px; border: 1px dashed var(--line-2); border-radius: 12px; background: var(--paper-3); }
.qr-box canvas { border-radius: 6px; background: #fff; padding: 8px; }
.qr-stub {
  width: 180px; height: 180px; display: grid; place-items: center; text-align: center;
  background: repeating-conic-gradient(#14181c 0% 25%, #fff 0% 50%) 0 0 / 16px 16px;
  border-radius: 8px; font-size: 11px; color: var(--ink-2);
}
.qr-stub span { background: var(--paper-2); padding: 8px 10px; border-radius: 6px; line-height: 1.5; }

/* ---------- FAQ ---------- */

.faq-list { border-top: 1px solid var(--line); }
.faq-item { border-bottom: 1px solid var(--line); }
.faq-item summary {
  list-style: none; cursor: pointer; padding: 22px 0; display: flex; align-items: center; justify-content: space-between; gap: 20px;
  font-size: 16px; font-weight: 600; letter-spacing: -0.005em;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; font-family: var(--mono); font-size: 20px; color: var(--ink-3); transition: transform 0.2s; }
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item p { padding: 0 0 22px; color: var(--ink-3); font-size: 14.5px; max-width: 72ch; line-height: 1.8; }

/* ---------- CTA 区块 ---------- */

.cta-band {
  background: var(--ink); color: var(--paper); border-radius: var(--radius-l);
  padding: 56px 48px; display: flex; align-items: center; justify-content: space-between; gap: 32px; flex-wrap: wrap;
  position: relative; overflow: hidden;
}
.cta-band::before {
  content: ""; position: absolute; right: -80px; top: -120px; width: 380px; height: 380px;
  border: 1px solid rgba(247,245,239,0.12); border-radius: 50%;
}
.cta-band h2 { font-size: clamp(24px, 3vw, 34px); letter-spacing: -0.03em; line-height: 1.2; max-width: 18ch; }
.cta-band p { color: rgba(247,245,239,0.65); margin-top: 10px; font-size: 15px; }
.cta-band .btn--primary { background: var(--paper); color: var(--ink); }
.cta-band .btn--primary:hover { background: #fff; }

/* ---------- 页脚 ---------- */

.site-footer { border-top: 1px solid var(--line); margin-top: 40px; padding: 56px 0 40px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr repeat(3, 1fr); gap: 40px; }
.footer-brand p { font-size: 13.5px; color: var(--ink-3); max-width: 30ch; margin-top: 14px; line-height: 1.75; }
.footer-col h3 { font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--ink-4); margin-bottom: 14px; }
.footer-col a { display: block; font-size: 13.5px; color: var(--ink-2); padding: 5px 0; }
.footer-col a:hover { color: var(--accent); }
.footer-bottom {
  display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap;
  border-top: 1px solid var(--line); margin-top: 44px; padding-top: 22px;
  font-size: 12px; color: var(--ink-4);
}

/* ---------- Toast / Modal ---------- */

.toast-root { position: fixed; right: 20px; bottom: 20px; z-index: 100; display: flex; flex-direction: column; gap: 10px; }
.toast {
  background: var(--ink); color: var(--paper); padding: 12px 18px; border-radius: 10px;
  font-size: 13.5px; box-shadow: var(--shadow-l); animation: toast-in 0.25s ease;
  max-width: 340px; line-height: 1.5;
}
.toast--error { background: #8f2c1c; }
@keyframes toast-in { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

.modal-backdrop {
  position: fixed; inset: 0; background: rgba(20, 24, 28, 0.45); backdrop-filter: blur(3px);
  display: grid; place-items: center; z-index: 90; padding: 20px; animation: fade 0.18s ease;
}
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }
.modal {
  background: var(--paper-2); border-radius: var(--radius-l); padding: 32px;
  width: min(100%, 460px); box-shadow: var(--shadow-l); position: relative;
}
.modal h2 { font-size: 20px; font-weight: 700; margin-bottom: 8px; }
.modal p { font-size: 14px; color: var(--ink-3); line-height: 1.7; margin-bottom: 20px; }
.modal__close { position: absolute; right: 18px; top: 16px; background: none; border: 0; cursor: pointer; color: var(--ink-3); }

/* ---------- 文章页 ---------- */

.prose { max-width: 72ch; }
.prose h2 { font-size: 22px; font-weight: 700; margin: 36px 0 12px; letter-spacing: -0.02em; }
.prose h3 { font-size: 17px; font-weight: 700; margin: 26px 0 8px; }
.prose p { color: var(--ink-2); margin: 12px 0; line-height: 1.85; }
.prose ul { list-style: disc; padding-left: 22px; color: var(--ink-2); margin: 12px 0; }
.prose li { margin: 6px 0; line-height: 1.8; }
.prose code { font-family: var(--mono); background: var(--paper-3); padding: 2px 6px; border-radius: 4px; font-size: 0.9em; }
.prose pre { background: var(--ink); color: #e8e4da; padding: 18px 20px; border-radius: 10px; overflow-x: auto; font-size: 13px; line-height: 1.6; }
.prose pre code { background: none; padding: 0; color: inherit; }

.page-head { padding: 56px 0 32px; border-bottom: 1px solid var(--line); margin-bottom: 40px; }
.page-head h1 { font-size: clamp(30px, 4vw, 44px); font-weight: 800; letter-spacing: -0.035em; line-height: 1.15; }
.page-head p { color: var(--ink-3); margin-top: 12px; max-width: 60ch; }

/* ---------- 目录筛选 ---------- */

.filters { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; margin-bottom: 28px; }
.filter-pill {
  padding: 8px 16px; border-radius: 999px; border: 1px solid var(--line-2);
  background: var(--paper-2); font-size: 13.5px; cursor: pointer; color: var(--ink-2);
  transition: all 0.15s;
}
.filter-pill:hover { border-color: var(--ink-3); }
.filter-pill.is-on { background: var(--ink); border-color: var(--ink); color: var(--paper); font-weight: 600; }
.filter-pill small { opacity: 0.55; margin-left: 5px; font-family: var(--mono); font-size: 11px; }
.search-input {
  margin-left: auto; padding: 9px 14px; border: 1px solid var(--line-2); border-radius: 999px;
  background: var(--paper-2); font-size: 13.5px; width: 220px;
}
.search-input:focus { outline: none; border-color: var(--ink); }

/* ---------- 响应式 ---------- */

@media (max-width: 1080px) {
  .lab-view { grid-template-columns: 210px minmax(0, 1fr); height: auto; min-height: 0; }
  .lab-stage-wrap { min-height: 420px; height: 420px; }
  .lab-side { grid-column: 1 / -1; border-left: 0; border-top: 1px solid var(--line); max-height: none; }
  .lab-rail { border-right: 1px solid var(--line); }
  .price-grid { grid-template-columns: repeat(2, 1fr); }
  .values { grid-template-columns: repeat(2, 1fr); }
  .lab-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 820px) {
  :root { --header-h: 60px; }
  .wrap, .wrap-narrow { width: calc(100% - 32px); }
  .hero { padding: 40px 0 56px; }
  .hero__grid { grid-template-columns: 1fr; gap: 36px; }
  .hero-stage canvas { height: 260px; }
  .section { padding: 56px 0; }
  .nav { display: none; }
  .nav-toggle { display: inline-grid; place-items: center; width: 38px; height: 38px; border: 1px solid var(--line-2); border-radius: 9px; background: var(--paper-2); cursor: pointer; }
  .site-header.is-open .nav {
    display: flex; position: absolute; left: 0; right: 0; top: var(--header-h);
    background: var(--paper-2); border-bottom: 1px solid var(--line);
    flex-direction: column; align-items: stretch; padding: 10px 16px 16px; margin: 0; gap: 2px;
  }
  .lab-grid { grid-template-columns: 1fr; }
  .values { grid-template-columns: 1fr; }
  .price-grid { grid-template-columns: 1fr; }
  .lab-view { grid-template-columns: 1fr; }
  .lab-rail { border-right: 0; border-bottom: 1px solid var(--line); display: flex; gap: 8px; overflow-x: auto; }
  .lab-rail__title { display: none; }
  .chapter-link { flex: 0 0 auto; width: auto; }
  .lab-stage-wrap { min-height: 320px; }
  .lab-hud { max-width: 92%; gap: 6px; }
  .hud-item { min-width: 62px; padding: 4px 8px; }
  .hud-item small { font-size: 9px; }
  .hud-item b { font-size: 12.5px; }
  .account-grid, .checkout { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .cta-band { padding: 36px 26px; }
  .search-input { margin-left: 0; width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  html { scroll-behavior: auto; }
}

@media print {
  .site-header, .site-footer, .lab-side, .lab-rail, .btn { display: none !important; }
  body { background: #fff; }
}

/* 卡片上的课本定位（章 · 节） */
.lab-card__where { font-size: 12px; color: var(--ink-3); white-space: nowrap; }
.lab-card__kicker { flex-wrap: wrap; }
.lab-card__thumb::after {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(20,24,28,0.04) 0%, rgba(20,24,28,0) 35%);
  pointer-events: none;
}

/* ---------- 全屏 + 控制面板折叠 ---------- */

.lab-view { position: relative; grid-template-columns: 250px minmax(0, 1fr) var(--side-w, 320px); transition: grid-template-columns 0.28s cubic-bezier(0.4, 0, 0.2, 1); }
.lab-view.hide-side { grid-template-columns: 250px minmax(0, 1fr) 0px; }
.lab-view.hide-side .lab-side { opacity: 0; transform: translateX(28px); pointer-events: none; }
.lab-side { transition: opacity 0.24s ease, transform 0.28s cubic-bezier(0.4, 0, 0.2, 1); }

/* 面板左边界中间的折叠按钮 */
.side-toggle {
  position: absolute; z-index: 6;
  top: 50%; transform: translateY(-50%);
  right: max(6px, calc(var(--side-w, 320px) - 13px));
  width: 26px; height: 46px;
  display: grid; place-items: center;
  font-size: 16px; line-height: 1; font-weight: 700;
  color: var(--ink-2);
  background: rgba(255, 254, 251, 0.96);
  border: 1px solid var(--line); border-radius: 8px;
  box-shadow: 0 2px 10px rgba(20, 24, 28, 0.08);
  cursor: pointer;
  transition: right 0.28s cubic-bezier(0.4, 0, 0.2, 1), background 0.15s, color 0.15s;
}
.side-toggle:hover { background: #fff; color: var(--ink); }
.side-toggle.is-hidden { background: var(--ink); color: var(--paper-2); border-color: var(--ink); }
.lab-view.hide-side { --side-w: 0px; }

/* 全屏：整个实验区进入全屏；隐藏左侧章节，保留画布和右侧控制面板 */
.lab-view:fullscreen {
  width: 100vw; height: 100vh; min-height: 0;
  border: 0; border-radius: 0;
  grid-template-columns: minmax(0, 1fr) var(--side-w, 320px);
  background: var(--paper);
}
.lab-view:fullscreen .lab-rail { display: none; }
.lab-view:fullscreen.hide-side { grid-template-columns: minmax(0, 1fr) 0px; }
.lab-view:fullscreen .lab-main, .lab-view:fullscreen .lab-side { height: 100vh; }
.lab-view:fullscreen .lab-stage-wrap { min-height: 0; height: 100%; }
.lab-view:fullscreen .lab-side { max-height: 100vh; overflow-y: auto; }

/* 全屏按钮（画布右下角） */
.lab-fs {
  position: absolute; right: 14px; bottom: 14px; z-index: 5;
  width: 38px; height: 38px; border-radius: 10px;
  display: grid; place-items: center; font-size: 17px; line-height: 1;
  color: var(--ink-2); background: rgba(255, 254, 251, 0.92);
  border: 1px solid var(--line); box-shadow: 0 2px 10px rgba(20, 24, 28, 0.08);
  cursor: pointer; transition: background 0.15s, color 0.15s, transform 0.15s;
}
.lab-fs:hover { background: #fff; color: var(--ink); transform: translateY(-1px); }
.lab-fs.is-on { background: var(--ink); color: var(--paper-2); border-color: var(--ink); }
/* ---------- 左侧：人教版目录（章节 → 小节） ---------- */

.lab-rail { display: flex; flex-direction: column; padding: 14px 10px 10px; }
.rail-body { flex: 1; min-height: 0; overflow-y: auto; padding-right: 2px; }
.rail-body::-webkit-scrollbar { width: 6px; }
.rail-body::-webkit-scrollbar-thumb { background: var(--line-2); border-radius: 3px; }

.rail-grade {
  font-family: var(--mono); font-size: 10px; letter-spacing: 0.14em;
  color: var(--ink-4); padding: 12px 8px 6px;
}
.rail-ch { margin-bottom: 2px; }
.rail-ch__btn {
  display: flex; align-items: center; gap: 7px; width: 100%;
  padding: 7px 8px; border: 0; border-radius: 8px; background: none;
  color: var(--ink-2); font-size: 13px; line-height: 1.35; text-align: left; cursor: pointer;
  transition: background 0.15s, color 0.15s;
}
.rail-ch__btn:hover { background: var(--paper); color: var(--ink); }
.rail-ch__caret { font-size: 10px; color: var(--ink-4); transition: transform 0.18s ease; }
.rail-ch.is-open .rail-ch__caret { transform: rotate(90deg); }
.rail-ch.is-open .rail-ch__btn { color: var(--ink); font-weight: 600; }
.rail-ch__title { flex: 1; min-width: 0; }
.rail-ch__count { font-size: 11px; color: var(--ink-4); }

.rail-secs { display: none; padding: 2px 0 6px 16px; }
.rail-ch.is-open .rail-secs { display: block; }
.rail-sec {
  display: flex; gap: 7px; align-items: baseline;
  padding: 6px 8px; border-radius: 7px;
  font-size: 12.5px; line-height: 1.45; color: var(--ink-3); text-decoration: none;
  transition: background 0.15s, color 0.15s;
}
.rail-sec:hover { background: var(--paper); color: var(--ink); }
.rail-sec.is-on { background: var(--accent-soft); color: var(--accent-dark); font-weight: 600; }
.rail-sec__no { font-family: var(--mono); font-size: 10.5px; color: var(--ink-4); flex-shrink: 0; }
.rail-sec.is-on .rail-sec__no { color: var(--accent-dark); }
.rail-sec.is-todo { opacity: 0.5; }
.rail-sec em { font-style: normal; font-size: 10.5px; color: var(--ink-4); margin-left: auto; }
/* 当前章标题块 */
.rail-current { padding: 4px 8px 10px; border-bottom: 1px solid var(--line); margin-bottom: 8px; }
.rail-current__grade { font-family: var(--mono); font-size: 10px; letter-spacing: 0.12em; color: var(--ink-4); }
.rail-current__title { font-size: 14px; font-weight: 700; color: var(--ink); line-height: 1.4; margin-top: 4px; }
.rail-current__count { font-size: 11.5px; color: var(--ink-3); margin-top: 4px; }
.rail-body .rail-secs { display: block; padding-left: 4px; }
/* 页脚版权与致谢（Three.js MIT / Poly Haven CC0） */
.footer-credits {
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px dashed rgba(20, 24, 28, 0.1);
  font-size: 11.5px;
  line-height: 1.8;
  color: var(--ink-4);
}
.footer-credits a { color: var(--ink-3); text-decoration: underline; text-underline-offset: 2px; }
.footer-credits a:hover { color: var(--accent); }

/* 注册页同意条款勾选 */
.consent {
  display: flex; align-items: flex-start; gap: 9px;
  margin: 4px 0 14px; font-size: 13px; line-height: 1.65; color: var(--ink-3);
  cursor: pointer;
}
.consent input[type="checkbox"] {
  width: 15px; height: 15px; margin-top: 3px; flex: none; accent-color: var(--accent); cursor: pointer;
}
.consent a { color: var(--accent); text-decoration: underline; text-underline-offset: 2px; }