/* WordFlow 网站：设计变量、基础排版、通用组件、首页各区块。工作台另见 app.css。 */
:root {
  color-scheme: light;
  --ink-900: #111a2e;
  --ink-800: #1b2640;
  --ink-700: #2c3852;
  --ink-500: #5a6478;
  --ink-400: #808a9c;
  --ink-300: #aab1be;
  --line: #e6e1d6;
  --line-strong: #d6cfbf;
  --paper: #f7f4ed;
  --paper-2: #efeadf;
  --surface: #ffffff;
  --accent: #c8452f;
  --accent-700: #a5351f;
  --accent-soft: #fbece6;
  --teal: #1b6e66;
  --teal-soft: #e2f0ed;
  --amber: #a86a12;
  --amber-soft: #fbf0dc;
  --red: #b83227;
  --red-soft: #fae6e3;
  --green: #2a7a4b;
  --green-soft: #e3f2e8;
  --slate: #5f6b7d;
  --slate-soft: #eceef2;
  --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", "Segoe UI", sans-serif;
  --font-serif: "Songti SC", "STSong", "Noto Serif SC", "Source Han Serif SC", "SimSun", Georgia, serif;
  --font-mono: "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --radius: 14px;
  --radius-sm: 9px;
  --shadow-sm: 0 1px 2px rgba(17, 26, 46, .06), 0 1px 1px rgba(17, 26, 46, .04);
  --shadow: 0 10px 30px -12px rgba(17, 26, 46, .18), 0 2px 6px rgba(17, 26, 46, .05);
  --shadow-lg: 0 30px 60px -20px rgba(17, 26, 46, .28), 0 8px 18px -6px rgba(17, 26, 46, .10);
  --wrap: 1180px;
  --ease: cubic-bezier(.2, .7, .2, 1);
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink-800);
  font: 16px/1.7 var(--font-sans);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, input, select { font: inherit; color: inherit; }
::selection { background: rgba(200, 69, 47, .18); }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.wrap { width: min(var(--wrap), 100% - 40px); margin-inline: auto; }
.serif { font-family: var(--font-serif); }
.mono { font-family: var(--font-mono); }
.muted { color: var(--ink-500); }
.icon { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; flex: none; }

/* ---------------- 按钮 ---------------- */
.btn {
  --bg: var(--surface); --fg: var(--ink-800); --bd: var(--line-strong);
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  height: 44px; padding: 0 20px; border-radius: 999px;
  background: var(--bg); color: var(--fg); border: 1px solid var(--bd);
  font-weight: 600; font-size: 15px; letter-spacing: .01em; cursor: pointer; white-space: nowrap;
  transition: transform .18s var(--ease), box-shadow .18s var(--ease), background .18s, border-color .18s, color .18s;
}
.btn:hover { transform: translateY(-1px); box-shadow: var(--shadow); }
.btn:active { transform: translateY(0); box-shadow: none; }
.btn:focus-visible { outline: 3px solid rgba(200, 69, 47, .35); outline-offset: 2px; }
.btn[disabled] { opacity: .5; cursor: not-allowed; transform: none; box-shadow: none; }
.btn-primary { --bg: var(--accent); --fg: #fff; --bd: var(--accent); box-shadow: 0 6px 16px -6px rgba(200, 69, 47, .55); }
.btn-primary:hover { --bg: var(--accent-700); --bd: var(--accent-700); }
.btn-dark { --bg: var(--ink-900); --fg: #fff; --bd: var(--ink-900); }
.btn-dark:hover { --bg: var(--ink-700); }
.btn-ghost { --bg: transparent; --bd: transparent; }
.btn-ghost:hover { --bg: rgba(17, 26, 46, .05); box-shadow: none; }
.btn-lg { height: 54px; padding: 0 28px; font-size: 16px; }
.btn-sm { height: 34px; padding: 0 14px; font-size: 13.5px; }
.btn .icon { width: 18px; height: 18px; }

/* ---------------- 标签 ---------------- */
.chip {
  display: inline-flex; align-items: center; gap: 6px; height: 26px; padding: 0 10px; border-radius: 999px;
  font-size: 12.5px; font-weight: 600; background: var(--slate-soft); color: var(--slate); white-space: nowrap;
}
.chip-code { font-family: var(--font-mono); font-weight: 600; letter-spacing: .02em; background: var(--ink-900); color: #fff; }
.chip-a { background: var(--teal-soft); color: var(--teal); }
.chip-b { background: var(--amber-soft); color: var(--amber); }
.chip-c { background: var(--slate-soft); color: var(--slate); }
.chip-pass { background: var(--green-soft); color: var(--green); }
.chip-fail { background: var(--red-soft); color: var(--red); }
.chip-review { background: var(--amber-soft); color: var(--amber); }
.chip-nc { background: var(--slate-soft); color: var(--slate); }
.chip-accent { background: var(--accent-soft); color: var(--accent-700); }
.dot { width: 7px; height: 7px; border-radius: 50%; background: currentColor; flex: none; }

/* ---------------- 顶栏 ---------------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(247, 244, 237, .82); backdrop-filter: saturate(1.4) blur(14px); -webkit-backdrop-filter: saturate(1.4) blur(14px);
  border-bottom: 1px solid transparent; transition: border-color .2s, background .2s;
}
.site-header.scrolled { border-bottom-color: var(--line); }
.site-header .wrap { display: flex; align-items: center; height: 68px; gap: 28px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 700; font-size: 17px; letter-spacing: .01em; color: var(--ink-900); }
.brand-mark { width: 32px; height: 32px; }
.brand small { font-weight: 500; color: var(--ink-500); font-size: 13px; margin-left: 2px; }
.nav { display: flex; gap: 4px; margin-left: 8px; }
.nav a { padding: 8px 12px; border-radius: 8px; font-size: 14.5px; color: var(--ink-700); transition: background .15s, color .15s; }
.nav a:hover { background: rgba(17, 26, 46, .05); color: var(--ink-900); }
.header-cta { margin-left: auto; display: flex; gap: 10px; align-items: center; }
.menu-btn { display: none; }

/* ---------------- 首屏 ---------------- */
.hero { position: relative; overflow: hidden; padding: 72px 0 96px; }
.hero::before {
  /* 稿纸格：很淡的方格，暗示“写论文” */
  content: ""; position: absolute; inset: 0; z-index: -1;
  background-image:
    linear-gradient(rgba(200, 69, 47, .07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(200, 69, 47, .07) 1px, transparent 1px);
  background-size: 28px 28px;
  mask-image: radial-gradient(ellipse 70% 60% at 70% 40%, #000 20%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 70% 40%, #000 20%, transparent 75%);
}
.hero .wrap { display: grid; grid-template-columns: 1.02fr 1fr; gap: 56px; align-items: center; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 10px; padding: 6px 14px 6px 6px; border-radius: 999px;
  background: var(--surface); border: 1px solid var(--line); box-shadow: var(--shadow-sm); font-size: 13.5px; color: var(--ink-700);
}
.eyebrow b { background: var(--accent); color: #fff; border-radius: 999px; padding: 2px 10px; font-size: 12px; font-weight: 700; }
.hero h1 {
  font-family: var(--font-serif); font-weight: 900; color: var(--ink-900);
  font-size: clamp(38px, 5.2vw, 62px); line-height: 1.18; letter-spacing: .01em; margin: 22px 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: .06em; height: .16em; border-radius: 4px;
  background: rgba(200, 69, 47, .16); z-index: -1;
}
.lead { font-size: 18px; color: var(--ink-500); max-width: 34em; margin: 0 0 32px; }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.assure { display: flex; flex-wrap: wrap; gap: 10px 22px; margin-top: 30px; padding: 0; list-style: none; font-size: 14px; color: var(--ink-700); }
.assure li { display: inline-flex; align-items: center; gap: 7px; }
.assure .icon { width: 17px; height: 17px; color: var(--teal); }

/* 首屏右侧：排版前后的两页纸 */
.stage { position: relative; height: 560px; }
.sheet {
  position: absolute; width: 360px; height: 500px; background: var(--surface); border-radius: 6px;
  box-shadow: var(--shadow-lg); padding: 42px 38px; overflow: hidden;
}
.sheet-before { left: 0; top: 34px; transform: rotate(-5deg); filter: saturate(.7); opacity: .88; }
.sheet-after { right: 0; top: 0; transform: rotate(1.5deg); animation: float 7s ease-in-out infinite; }
@keyframes float { 0%, 100% { transform: rotate(1.5deg) translateY(0); } 50% { transform: rotate(1.2deg) translateY(-8px); } }
.sheet .tag { position: absolute; top: 14px; left: 16px; font-size: 11px; font-weight: 700; letter-spacing: .12em; color: var(--ink-400); }
.sheet-after .tag { color: var(--teal); }
.ln { height: 7px; border-radius: 4px; background: #e5e7ec; margin: 0 0 10px; }
.ln.s { width: 72%; } .ln.m { width: 88%; } .ln.xs { width: 40%; }
.ln.ind { margin-left: 2em; width: calc(100% - 2em); }
.sheet-before .ln:nth-child(3n) { margin-left: 14px; }
.sheet-before .ln.wavy { background: linear-gradient(90deg, #e5e7ec, #e5e7ec); position: relative; }
.sheet-before .ln.wavy::after {
  content: ""; position: absolute; left: 0; right: 30%; bottom: -5px; height: 4px;
  background: radial-gradient(circle at 3px -1px, transparent 3px, var(--red) 3.2px, var(--red) 4px, transparent 4.2px) 0 0/8px 4px repeat-x;
  opacity: .7;
}
.s-h1 { font-family: var(--font-serif); font-weight: 900; text-align: center; font-size: 19px; color: var(--ink-900); margin: 4px 0 18px; letter-spacing: .08em; }
.s-h2 { font-weight: 700; font-size: 13.5px; color: var(--ink-900); margin: 16px 0 10px; }
.sheet-before .s-h1 { text-align: left; font-family: var(--font-sans); font-size: 16px; font-weight: 700; letter-spacing: 0; }
.s-fig { height: 92px; margin: 16px 34px 8px; border-radius: 6px; background: linear-gradient(135deg, #edf1f6, #dfe6ef); position: relative; overflow: hidden; }
.s-fig::before { content: ""; position: absolute; left: 14%; bottom: 0; width: 72%; height: 60%; background:
  linear-gradient(to top, rgba(27, 110, 102, .35) 0 40%, transparent 40%) 0 100%/14% 100% no-repeat,
  linear-gradient(to top, rgba(27, 110, 102, .45) 0 70%, transparent 70%) 28% 100%/14% 100% no-repeat,
  linear-gradient(to top, rgba(27, 110, 102, .3) 0 55%, transparent 55%) 56% 100%/14% 100% no-repeat,
  linear-gradient(to top, rgba(200, 69, 47, .45) 0 90%, transparent 90%) 84% 100%/14% 100% no-repeat; }
.s-cap { text-align: center; font-size: 11px; color: var(--ink-500); margin-bottom: 14px; }
.s-foot { position: absolute; bottom: 18px; left: 0; right: 0; text-align: center; font-size: 11px; color: var(--ink-400); font-family: var(--font-serif); }
.note {
  position: absolute; z-index: 3; display: flex; align-items: center; gap: 8px; padding: 8px 12px 8px 8px;
  background: var(--surface); border: 1px solid var(--line); border-radius: 12px; box-shadow: var(--shadow);
  font-size: 12.5px; color: var(--ink-700); white-space: nowrap;
  opacity: 0; transform: translateY(8px); animation: pop .6s var(--ease) forwards;
}
.note .chip { height: 22px; font-size: 11px; padding: 0 8px; }
.note::before { content: ""; position: absolute; width: 28px; height: 1px; background: var(--line-strong); }
.note.l::before { right: 100%; top: 50%; }
.note.r::before { left: 100%; top: 50%; }
.n1 { top: 52px; right: 300px; animation-delay: .5s; }
.n2 { top: 186px; right: -6px; animation-delay: 1.1s; }
.n3 { top: 346px; right: 284px; animation-delay: 1.7s; }
.n4 { top: 470px; right: 40px; animation-delay: 2.3s; }
@keyframes pop { to { opacity: 1; transform: translateY(0); } }
.scan {
  position: absolute; left: 0; right: 0; height: 64px; top: -64px; pointer-events: none;
  background: linear-gradient(to bottom, transparent, rgba(27, 110, 102, .10), transparent);
  border-bottom: 1px solid rgba(27, 110, 102, .3); animation: scan 4.5s ease-in-out 0.3s infinite;
}
@keyframes scan { 0% { top: -64px; } 70%, 100% { top: 100%; } }

/* ---------------- 数字条 ---------------- */
.facts { border-block: 1px solid var(--line); background: var(--surface); }
.facts .wrap { display: grid; grid-template-columns: repeat(4, 1fr); }
.fact { padding: 28px 24px; border-left: 1px solid var(--line); }
.fact:first-child { border-left: 0; }
.fact b { display: block; font-family: var(--font-serif); font-size: 34px; line-height: 1.1; color: var(--ink-900); font-weight: 900; }
.fact b small { font-size: 16px; font-weight: 700; margin-left: 4px; color: var(--ink-500); }
.fact span { font-size: 14px; color: var(--ink-500); }

/* ---------------- 区块 ---------------- */
.section { padding: 104px 0; }
.section-alt { background: var(--surface); border-block: 1px solid var(--line); }
.section-head { max-width: 720px; margin: 0 0 52px; }
.section-head.center { margin-inline: auto; text-align: center; }
.kicker { font-size: 13px; font-weight: 700; letter-spacing: .14em; color: var(--accent); text-transform: uppercase; }
.section h2 {
  font-family: var(--font-serif); font-weight: 900; color: var(--ink-900);
  font-size: clamp(28px, 3.4vw, 40px); line-height: 1.25; margin: 10px 0 14px; letter-spacing: .01em;
}
.section-head p { color: var(--ink-500); font-size: 17px; margin: 0; }

/* 问题网格 */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.pit {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px;
  transition: transform .25s var(--ease), box-shadow .25s var(--ease), border-color .25s;
}
.section-alt .pit { background: var(--paper); }
.pit:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: var(--line-strong); }
.pit-head { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; }
.pit-ico { width: 42px; height: 42px; border-radius: 12px; display: grid; place-items: center; background: var(--accent-soft); color: var(--accent); }
.pit h3 { margin: 0; font-size: 17px; color: var(--ink-900); }
.pit h3 small { display: block; font-family: var(--font-mono); font-size: 11.5px; color: var(--ink-400); font-weight: 600; letter-spacing: .04em; }
.pit ul { margin: 0; padding: 0; list-style: none; font-size: 14.5px; color: var(--ink-700); }
.pit li { position: relative; padding-left: 16px; margin: 6px 0; }
.pit li::before { content: ""; position: absolute; left: 2px; top: .7em; width: 5px; height: 5px; border-radius: 50%; background: var(--line-strong); }

/* 流程 */
.flow { display: grid; grid-template-columns: repeat(6, 1fr); gap: 14px; counter-reset: step; position: relative; }
.flow::before { content: ""; position: absolute; top: 27px; left: 8%; right: 8%; height: 2px; background: repeating-linear-gradient(90deg, var(--line-strong) 0 6px, transparent 6px 12px); }
.flow-step { position: relative; text-align: center; padding: 0 6px; }
.flow-num {
  width: 56px; height: 56px; margin: 0 auto 16px; border-radius: 50%; display: grid; place-items: center; position: relative;
  background: var(--surface); border: 1px solid var(--line-strong); color: var(--ink-900); font-family: var(--font-serif); font-weight: 900; font-size: 20px;
  box-shadow: var(--shadow-sm);
}
.flow-step.paid .flow-num { background: var(--ink-900); color: #fff; border-color: var(--ink-900); }
.flow-step h3 { font-size: 16px; margin: 0 0 6px; color: var(--ink-900); }
.flow-step p { margin: 0; font-size: 13.5px; color: var(--ink-500); line-height: 1.6; }
.flow-free { display: flex; justify-content: center; gap: 12px; margin-top: 34px; font-size: 14px; color: var(--ink-500); align-items: center; }
.bracket { display: grid; grid-template-columns: 5fr 1fr; gap: 14px; margin-top: 26px; }
.bracket div { border-top: 2px solid var(--teal); padding-top: 10px; font-size: 13.5px; font-weight: 600; color: var(--teal); text-align: center; }
.bracket div + div { border-color: var(--ink-900); color: var(--ink-900); }

/* A/B/C */
.classes { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.klass { border-radius: var(--radius); padding: 30px; border: 1px solid var(--line); background: var(--surface); position: relative; overflow: hidden; }
.klass .letter { font-family: var(--font-serif); font-weight: 900; font-size: 64px; line-height: 1; position: absolute; right: 22px; top: 14px; opacity: .1; }
.klass h3 { margin: 14px 0 8px; font-size: 20px; color: var(--ink-900); }
.klass p { margin: 0 0 16px; color: var(--ink-500); font-size: 15px; }
.klass .eg { font-size: 13.5px; color: var(--ink-700); border-top: 1px dashed var(--line-strong); padding-top: 14px; }
.klass .eg div { display: flex; gap: 8px; align-items: baseline; margin: 6px 0; }
.klass .eg code { font-family: var(--font-mono); font-size: 12px; color: var(--ink-400); flex: none; }
.klass-a { border-top: 4px solid var(--teal); } .klass-a .letter { color: var(--teal); }
.klass-b { border-top: 4px solid var(--amber); } .klass-b .letter { color: var(--amber); }
.klass-c { border-top: 4px solid var(--slate); } .klass-c .letter { color: var(--slate); }
.callout {
  margin-top: 28px; display: flex; gap: 16px; align-items: center; padding: 20px 24px; border-radius: var(--radius);
  background: var(--ink-900); color: #e8ebf2; font-size: 15px;
}
.callout .icon { color: #f4a493; width: 26px; height: 26px; }
.callout b { color: #fff; }

/* 模板 */
.tpl-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.tpl {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; display: flex; flex-direction: column; gap: 10px;
  transition: transform .25s var(--ease), box-shadow .25s var(--ease);
}
.tpl:hover { transform: translateY(-3px); box-shadow: var(--shadow); }
.tpl-thumb { height: 120px; border-radius: 8px; background: var(--paper); border: 1px solid var(--line); position: relative; overflow: hidden; padding: 16px 22px; }
.tpl-thumb i { display: block; height: 5px; border-radius: 3px; background: #dfe2e8; margin: 0 0 7px; }
.tpl-thumb i.t { width: 46%; height: 7px; margin: 2px auto 12px; background: var(--ink-700); opacity: .75; }
.tpl-thumb i.h { width: 34%; background: var(--ink-500); opacity: .6; }
.tpl-thumb i.p { margin-left: 12px; }
.tpl h3 { margin: 4px 0 0; font-size: 16px; color: var(--ink-900); }
.tpl p { margin: 0; font-size: 13.5px; color: var(--ink-500); }
.tpl dl { margin: 4px 0 0; display: grid; grid-template-columns: auto 1fr; gap: 4px 10px; font-size: 12.5px; }
.tpl dt { color: var(--ink-400); }
.tpl dd { margin: 0; color: var(--ink-700); }
.tpl-note { margin-top: 22px; font-size: 14px; color: var(--ink-500); text-align: center; }

/* 隐私（深色区块） */
.dark { background: var(--ink-900); color: #c9cfdb; }
.dark h2 { color: #fff; }
.dark .kicker { color: #f4a493; }
.dark .section-head p { color: #9aa3b5; }
.privacy { display: grid; grid-template-columns: 1.1fr 1fr; gap: 48px; align-items: center; }
.device {
  border: 1px solid rgba(255, 255, 255, .12); border-radius: 18px; padding: 22px; background: linear-gradient(180deg, rgba(255,255,255,.05), rgba(255,255,255,.02));
}
.device-bar { display: flex; gap: 6px; margin-bottom: 18px; }
.device-bar i { width: 10px; height: 10px; border-radius: 50%; background: rgba(255, 255, 255, .18); }
.device-body { display: grid; grid-template-columns: 1fr auto 1fr; gap: 14px; align-items: center; }
.box { border-radius: 12px; padding: 16px; background: rgba(255, 255, 255, .06); border: 1px solid rgba(255, 255, 255, .1); font-size: 13.5px; }
.box b { display: block; color: #fff; font-size: 14.5px; margin-bottom: 4px; }
.box.engine { border-color: rgba(76, 190, 172, .5); background: rgba(27, 110, 102, .22); }
.arrow { color: #6b7488; font-size: 22px; }
.wire { margin-top: 16px; display: flex; align-items: center; gap: 12px; font-size: 13px; padding: 12px 14px; border-radius: 10px; border: 1px dashed rgba(255,255,255,.2); }
.wire code { font-family: var(--font-mono); color: #f4a493; font-size: 12px; word-break: break-all; }
.lists { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.lists h3 { margin: 0 0 12px; font-size: 15px; color: #fff; display: flex; align-items: center; gap: 8px; }
.lists ul { list-style: none; margin: 0; padding: 0; font-size: 14.5px; }
.lists li { padding: 9px 0; border-bottom: 1px solid rgba(255, 255, 255, .08); display: flex; gap: 10px; align-items: center; }
.lists .icon { width: 16px; height: 16px; }
.yes .icon { color: #6fd0bf; } .no .icon { color: #f08b78; }

/* 价格 */
.pricing { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; max-width: 900px; margin: 0 auto; }
.plan { border-radius: 20px; padding: 34px; background: var(--surface); border: 1px solid var(--line); display: flex; flex-direction: column; }
.plan.hl { background: var(--ink-900); color: #c9cfdb; border-color: var(--ink-900); box-shadow: var(--shadow-lg); position: relative; }
.plan.hl h3, .plan.hl .price { color: #fff; }
.plan h3 { margin: 0; font-size: 18px; color: var(--ink-900); }
.price { font-family: var(--font-serif); font-weight: 900; font-size: 40px; color: var(--ink-900); margin: 10px 0 4px; line-height: 1.2; }
.price small { font-size: 15px; font-family: var(--font-sans); font-weight: 500; color: var(--ink-400); margin-left: 6px; }
.plan ul { list-style: none; padding: 0; margin: 20px 0 28px; font-size: 15px; flex: 1; }
.plan li { display: flex; gap: 10px; align-items: flex-start; padding: 7px 0; }
.plan li .icon { width: 18px; height: 18px; margin-top: 4px; color: var(--teal); }
.plan.hl li .icon { color: #6fd0bf; }
.ribbon { position: absolute; top: 18px; right: 18px; }
.refund { max-width: 900px; margin: 22px auto 0; font-size: 13.5px; color: var(--ink-500); text-align: center; }

/* 常见问题 */
.faq { max-width: 820px; margin: 0 auto; }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary {
  list-style: none; cursor: pointer; padding: 22px 4px; font-size: 17px; font-weight: 600; color: var(--ink-900);
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-size: 24px; font-weight: 300; color: var(--ink-400); transition: transform .2s; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { margin: -6px 4px 22px; color: var(--ink-500); font-size: 15.5px; }

/* 结尾号召 */
.cta-band { padding: 0 0 104px; }
.cta-card {
  border-radius: 28px; padding: 64px; text-align: center; position: relative; overflow: hidden;
  background: radial-gradient(120% 140% at 0% 0%, #2a3554 0%, var(--ink-900) 55%); color: #c9cfdb;
}
.cta-card::after {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background-image: linear-gradient(rgba(255,255,255,.04) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.04) 1px, transparent 1px);
  background-size: 28px 28px;
}
.cta-card h2 { color: #fff; font-family: var(--font-serif); font-size: clamp(28px, 3.6vw, 42px); margin: 0 0 12px; position: relative; z-index: 1; }
.cta-card p { position: relative; z-index: 1; margin: 0 0 30px; }
.cta-card .btn { position: relative; z-index: 1; }

/* 页脚 */
.site-footer { border-top: 1px solid var(--line); padding: 40px 0 56px; font-size: 13.5px; color: var(--ink-500); }
.site-footer .wrap { display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; align-items: flex-start; }
.site-footer nav { display: flex; gap: 22px; flex-wrap: wrap; }
.site-footer a:hover { color: var(--ink-900); }

/* 出现动画 */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal { opacity: 1; transform: none; }
  .note { opacity: 1; transform: none; }
}

/* ---------------- 窄屏 ---------------- */
@media (max-width: 1080px) {
  .hero .wrap { grid-template-columns: 1fr; }
  .stage { height: 540px; max-width: 560px; margin: 0 auto; width: 100%; }
  .tpl-grid { grid-template-columns: repeat(2, 1fr); }
  .flow { grid-template-columns: repeat(3, 1fr); row-gap: 34px; }
  .flow::before, .bracket { display: none; }
  .privacy { grid-template-columns: 1fr; }
}
@media (max-width: 860px) {
  .nav, .header-cta .btn-ghost { display: none; }
  .grid-3, .classes, .pricing { grid-template-columns: 1fr; }
  .facts .wrap { grid-template-columns: repeat(2, 1fr); }
  .fact:nth-child(3) { border-left: 0; }
  .fact:nth-child(n+3) { border-top: 1px solid var(--line); }
  .section { padding: 76px 0; }
  .cta-card { padding: 44px 24px; }
}
@media (max-width: 600px) {
  .wrap { width: calc(100% - 32px); }
  .hero { padding: 40px 0 64px; }
  .stage { height: 450px; }
  .sheet { width: 270px; height: 390px; padding: 30px 26px; }
  .note { font-size: 11.5px; }
  .n1 { right: auto; left: 0; top: 10px; } .n2 { right: 0; top: 150px; } .n3 { right: auto; left: 6px; top: 280px; } .n4 { right: 0; top: 380px; }
  .note::before { display: none; }
  .tpl-grid, .lists { grid-template-columns: 1fr; }
  .flow { grid-template-columns: repeat(2, 1fr); }
  .lead { font-size: 16.5px; }
  .device-body { grid-template-columns: 1fr; }
  .arrow { transform: rotate(90deg); justify-self: center; }
}