/* ============================================================
   CCS GUIDE · 样式表
   1. 设计变量 / 基础
   2. 顶栏 / 通用组件
   3. 首页：首屏、当前教程、教程列表
   4. 教程页：头部、进度、步骤
   5. 灯箱 / 响应式 / 打印
   ============================================================ */

/* ---------- 1. 变量与基础 ---------- */
:root {
  --bg: #f3f2ec;
  --surface: #ffffff;
  --sunken: #eae8df;
  --ink: #101012;
  --ink-2: #34343b;
  --muted: #6a6971;
  --faint: #96959c;
  --line: #e2dfd5;
  --line-strong: #cfccc0;
  --volt: #d8ff3e;
  --volt-soft: #f6fbe0;
  --volt-line: #dfe9a8;
  --accent: #3047ff;
  --accent-soft: #eef0ff;
  --hot: #df451d;
  --hot-soft: #fff1ec;
  --ok: #0c7a51;
  --ok-soft: #e2f5ea;
  --font: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei UI", "Microsoft YaHei", "Segoe UI", system-ui, -apple-system, sans-serif;
  --mono: "JetBrains Mono", "Cascadia Code", "SFMono-Regular", Menlo, Consolas, monospace;
  --shadow: 6px 6px 0 var(--ink);
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-behavior: smooth; scroll-padding-top: 84px; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.75 var(--font);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
body.no-scroll { overflow: hidden; }
a { color: inherit; }
button, input { font: inherit; color: inherit; }
button { cursor: pointer; }
img { max-width: 100%; }
svg { flex: none; }
::selection { background: var(--volt); color: var(--ink); }
:focus-visible { outline: 2px solid var(--ink); outline-offset: 3px; border-radius: 4px; }

.wrap { width: 100%; max-width: 1200px; margin: 0 auto; padding-inline: 24px; }
.mono { font-family: var(--mono); }
.skip {
  position: absolute; left: 16px; top: -64px; z-index: 1000;
  padding: 8px 16px; border-radius: 999px;
  background: var(--volt); color: var(--ink); font-weight: 700; text-decoration: none;
}
.skip:focus { top: 12px; }

/* ---------- 2. 顶栏 ---------- */
.topbar {
  position: sticky; top: 0; z-index: 90;
  background: rgba(16, 16, 18, .95);
  -webkit-backdrop-filter: blur(14px) saturate(150%);
  backdrop-filter: blur(14px) saturate(150%);
  color: #ecebe6;
  border-bottom: 1px solid #29292f;
}
.topbar-inner {
  display: flex; align-items: center; gap: 14px;
  width: 100%; max-width: 1200px; min-height: 58px;
  margin: 0 auto; padding: 0 24px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; color: #fff; flex: none; }
.brand-mark {
  display: grid; place-items: center; width: 27px; height: 27px;
  border-radius: 8px; background: var(--volt);
}
.brand-mark svg { width: 17px; height: 17px; }
.brand-name { font: 700 12.5px var(--mono); letter-spacing: .14em; }
.bar-sep { width: 1px; height: 15px; background: #3a3a42; flex: none; }
.bar-crumb {
  min-width: 0; font-size: 13px; color: #a6a5ac;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.bar-crumb a { color: #a6a5ac; text-decoration: none; }
.bar-crumb a:hover { color: #fff; }
.bar-crumb strong { color: #ecebe6; font-weight: 600; }
.bar-nav { display: flex; gap: 2px; margin-left: 8px; }
.bar-nav a {
  padding: 5px 11px; border-radius: 999px;
  font-size: 13px; color: #b7b6bd; text-decoration: none;
}
.bar-nav a:hover { color: #fff; background: #26262c; }
.bar-spacer { flex: 1; }
.bar-pill {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 5px 12px; border: 1px solid #34343c; border-radius: 999px;
  background: #232329; font-size: 12px; color: #cfcecb; white-space: nowrap;
}
.bar-pill b { font: 700 12px var(--mono); color: var(--volt); }
.bar-link {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 4px 13px; border: 1px solid #3b3b44; border-radius: 999px;
  font-size: 13px; color: #deddd8; text-decoration: none; white-space: nowrap;
}
.bar-link:hover { border-color: var(--volt); color: var(--volt); }

/* ---------- 3. 首页 ---------- */
.hero {
  padding: 62px 0 58px;
  border-bottom: 1px solid var(--line);
  background-image: radial-gradient(circle at 1px 1px, rgba(16, 16, 18, .08) 1px, transparent 0);
  background-size: 24px 24px;
}
.kicker {
  display: inline-flex; align-items: center; flex-wrap: wrap; gap: 9px;
  margin: 0 0 20px;
  font: 600 11px/1 var(--mono); letter-spacing: .16em;
  text-transform: uppercase; color: var(--ink-2);
}
.kicker i { width: 9px; height: 9px; border-radius: 2px; background: var(--volt); box-shadow: 0 0 0 1.5px var(--ink); }
.kicker em { font-style: normal; color: var(--faint); }
.hero h1 {
  margin: 0;
  font-size: clamp(44px, 7.2vw, 92px);
  line-height: 1.08; letter-spacing: -.045em; font-weight: 800;
}
.hero h1 mark {
  background: linear-gradient(transparent 52%, var(--volt) 52% 82%, transparent 82%);
  color: inherit; padding: 0 .04em;
}
.hero-row {
  display: flex; align-items: flex-end; justify-content: space-between; gap: 40px;
  margin-top: 26px;
}
.lead { max-width: 630px; margin: 0; font-size: 16.5px; line-height: 1.9; color: var(--ink-2); }
.facts { display: flex; gap: 30px; flex: none; }
.facts div { text-align: right; }
.facts strong { display: block; font: 700 33px/1 var(--mono); letter-spacing: -.05em; }
.facts span { font: 600 10.5px/1.5 var(--mono); letter-spacing: .12em; color: var(--faint); text-transform: uppercase; }

/* 当前教程（大卡片） */
.feature {
  display: grid; grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr);
  gap: 34px; align-items: center;
  margin-top: 44px; padding: 34px;
  border-radius: 30px; background: var(--ink); color: #fff;
  text-decoration: none;
  box-shadow: 8px 8px 0 var(--volt);
  transition: transform .2s ease, box-shadow .2s ease;
}
.feature:hover { transform: translate(-3px, -3px); box-shadow: 11px 11px 0 var(--volt); }
.feature-label {
  display: flex; align-items: center; flex-wrap: wrap; gap: 9px;
  margin: 0 0 14px;
  font: 600 10.5px var(--mono); letter-spacing: .14em; text-transform: uppercase; color: #9b9aa2;
}
.feature-label b {
  padding: 3px 9px; border-radius: 999px;
  background: var(--volt); color: var(--ink); font-weight: 700; letter-spacing: .06em;
}
.feature h2 {
  margin: 0 0 10px;
  font-size: clamp(28px, 3.6vw, 44px); line-height: 1.12; letter-spacing: -.035em;
}
.feature p { margin: 0; max-width: 540px; font-size: 14px; line-height: 1.8; color: #b8b7be; }
.feature-meta {
  display: flex; flex-wrap: wrap; gap: 6px 16px; margin-top: 16px;
  font: 500 11.5px var(--mono); color: #8f8e96;
}
.feature-meta span { display: inline-flex; align-items: center; gap: 6px; }
.feature-meta i { width: 5px; height: 5px; border-radius: 50%; background: var(--volt); }
.feature-cta {
  display: inline-flex; align-items: center; gap: 10px;
  margin-top: 24px; padding: 11px 18px 11px 22px;
  border-radius: 999px; background: var(--volt); color: var(--ink);
  font-size: 14px; font-weight: 800;
}
.feature-cta svg { width: 26px; height: 26px; padding: 6px; border-radius: 50%; background: var(--ink); color: var(--volt); }
.feature:hover .feature-cta svg { transform: translateX(2px); }
.feature-cta svg { transition: transform .2s; }
.feature-visual { min-width: 0; }
.mini-window {
  padding: 9px; border-radius: 16px; background: #fff; color: var(--ink);
  box-shadow: 0 12px 40px rgba(0, 0, 0, .35);
  transform: rotate(-1.2deg);
}
.mini-bar { display: flex; align-items: center; gap: 5px; padding: 2px 5px 9px; font: 600 9.5px var(--mono); color: var(--faint); }
.mini-bar i { width: 7px; height: 7px; border-radius: 50%; background: #dedbd0; }
.mini-bar span { margin-left: auto; letter-spacing: .04em; }
.mini-row { display: flex; align-items: center; gap: 10px; padding: 11px; border: 1px solid var(--line); border-radius: 12px; background: #fbfaf6; }
.mini-avatar {
  display: grid; place-items: center; width: 27px; height: 27px; flex: none;
  border-radius: 8px; background: var(--ink); color: var(--volt); font: 700 12px var(--mono);
}
.mini-info { min-width: 0; }
.mini-name { font-size: 12px; font-weight: 700; line-height: 1.4; }
.mini-url { font: 500 9.5px var(--mono); color: var(--faint); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.mini-balance {
  margin-left: auto; flex: none; padding: 3px 9px; border-radius: 999px;
  background: var(--volt); font: 700 10.5px var(--mono); color: var(--ink); white-space: nowrap;
}
.mini-steps {
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 7px;
  margin: 16px 0 0; padding: 0; list-style: none;
}
.mini-steps li {
  display: flex; align-items: center; gap: 6px;
  padding: 7px 8px; border: 1px solid #34343c; border-radius: 9px;
  background: #19191d; font-size: 10.5px; color: #c3c2c9;
}
.mini-steps b { font: 700 9.5px var(--mono); color: var(--volt); }
.mini-steps span { min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* 教程列表 */
.section { padding-top: 74px; }
.section-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 20px; margin-bottom: 20px; }
.section-head h2 { margin: 0; font-size: clamp(30px, 3.8vw, 44px); line-height: 1.1; letter-spacing: -.04em; }
.section-head p { margin: 8px 0 0; font-size: 14px; color: var(--muted); }
.count {
  flex: none; padding: 5px 12px; border: 1px solid var(--line-strong); border-radius: 999px;
  background: var(--surface); font: 700 12px var(--mono); color: var(--ink-2); white-space: nowrap;
}
.toolbar { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-bottom: 20px; }
.search { position: relative; flex: 1 1 280px; max-width: 390px; }
.search svg {
  position: absolute; left: 15px; top: 50%; width: 17px; height: 17px;
  transform: translateY(-50%); fill: none; stroke: var(--faint); stroke-width: 1.8;
  stroke-linecap: round; stroke-linejoin: round;
}
.search input {
  width: 100%; height: 46px; padding: 0 16px 0 42px;
  border: 1px solid var(--line-strong); border-radius: 999px;
  background: var(--surface); font-size: 14px;
}
.search input::placeholder { color: var(--faint); }
.search input:focus { outline: none; border-color: var(--ink); box-shadow: 0 0 0 4px var(--volt-soft); }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chip {
  height: 40px; padding: 0 16px;
  border: 1px solid var(--line-strong); border-radius: 999px;
  background: var(--surface); font-size: 13px; font-weight: 600; color: var(--ink-2);
}
.chip:hover { border-color: var(--ink); }
.chip[aria-pressed="true"] { background: var(--ink); border-color: var(--ink); color: #fff; }

.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 310px), 1fr)); gap: 14px; }
.card {
  position: relative; display: flex; flex-direction: column; gap: 8px;
  min-height: 250px; padding: 24px;
  border: 1px solid var(--line-strong); border-radius: 24px;
  background: var(--surface); text-decoration: none;
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.card:hover { border-color: var(--ink); transform: translate(-2px, -2px); box-shadow: var(--shadow); }
.card-top { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.card-no { font: 700 11px var(--mono); letter-spacing: .12em; color: var(--faint); }
.card-topic { padding: 3px 10px; border-radius: 999px; background: var(--sunken); font-size: 11.5px; font-weight: 600; color: var(--ink-2); }
.card h3 { margin: 6px 0 0; font-size: 20px; line-height: 1.35; letter-spacing: -.025em; }
.card p { margin: 0; font-size: 13.5px; line-height: 1.8; color: var(--muted); }
.card-progress {
  align-self: flex-start; margin-top: 4px; padding: 2px 9px; border-radius: 999px;
  background: var(--volt-soft); border: 1px solid var(--volt-line);
  font: 700 10.5px var(--mono); color: var(--ink-2);
}
.card-foot { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-top: auto; padding-top: 16px; }
.card-meta { font: 500 11px var(--mono); color: var(--faint); }
.card-go {
  display: grid; place-items: center; width: 38px; height: 38px;
  border: 1px solid var(--line-strong); border-radius: 50%;
  transition: background .18s, border-color .18s;
}
.card-go svg { width: 16px; height: 16px; fill: none; stroke: currentColor; stroke-width: 2.2; stroke-linecap: round; stroke-linejoin: round; }
.card:hover .card-go { background: var(--volt); border-color: var(--ink); }
.card-coming {
  display: flex; flex-direction: column; justify-content: center; align-items: flex-start; gap: 8px;
  min-height: 250px; padding: 24px;
  border: 1.5px dashed var(--line-strong); border-radius: 24px; color: var(--muted);
}
.card-coming .plus {
  display: grid; place-items: center; width: 38px; height: 38px; margin-bottom: 4px;
  border: 1px solid var(--line-strong); border-radius: 50%;
  font: 400 20px/1 var(--mono); color: var(--faint);
}
.card-coming strong { font-size: 16px; color: var(--ink-2); }
.card-coming p { margin: 0; font-size: 13px; line-height: 1.8; }

.empty { padding: 44px 20px; text-align: center; border: 1.5px dashed var(--line-strong); border-radius: 24px; color: var(--muted); }
.empty p { margin: 0; }
.empty button {
  margin-top: 12px; height: 42px; padding: 0 20px;
  border: 0; border-radius: 999px; background: var(--ink); color: #fff; font-weight: 700;
}

/* 说明与页脚 */
.promise { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px; margin-top: 76px; }
.promise div { padding: 24px; border-radius: 24px; background: var(--ink); color: #c7c6cd; }
.promise strong { display: flex; align-items: center; gap: 9px; margin-bottom: 6px; font-size: 16px; color: #fff; }
.promise strong i { width: 8px; height: 8px; border-radius: 2px; background: var(--volt); }
.promise p { margin: 0; font-size: 13px; line-height: 1.8; }
footer {
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px 24px;
  margin-top: 44px; padding: 24px 0 56px;
  border-top: 1px solid var(--line);
  font-size: 12.5px; color: var(--muted);
}
footer span { font-weight: 700; color: var(--ink-2); white-space: nowrap; }
footer p { margin: 0; max-width: 780px; }

/* ---------- 4. 教程页 ---------- */
.tut-hero {
  padding: 34px 0 42px;
  border-bottom: 1px solid var(--line);
  background-image: radial-gradient(circle at 1px 1px, rgba(16, 16, 18, .06) 1px, transparent 0);
  background-size: 24px 24px;
}
.crumbs {
  display: flex; align-items: center; gap: 8px; margin-bottom: 26px;
  font: 600 10.5px var(--mono); letter-spacing: .12em; text-transform: uppercase; color: var(--faint);
}
.crumbs a { color: var(--muted); text-decoration: none; }
.crumbs a:hover { color: var(--ink); }
.tut-head { display: grid; grid-template-columns: minmax(0, 1fr) 272px; gap: 42px; align-items: start; }
.tut-intro h1 {
  margin: 0 0 12px;
  font-size: clamp(38px, 5.2vw, 64px); line-height: 1.08; letter-spacing: -.045em; font-weight: 800;
}
.tut-intro .lead { max-width: 660px; font-size: 16px; }
.meta-chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 18px; }
.meta-chips span {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 5px 11px; border: 1px solid var(--line-strong); border-radius: 999px;
  background: var(--surface); font-size: 12px; font-weight: 600; color: var(--ink-2);
}
.meta-chips svg { width: 13px; height: 13px; fill: none; stroke: var(--muted); stroke-width: 1.9; stroke-linecap: round; stroke-linejoin: round; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 24px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 46px; padding: 0 20px;
  border: 1.5px solid transparent; border-radius: 999px;
  font-size: 14px; font-weight: 700; text-decoration: none;
  transition: transform .16s, box-shadow .16s, border-color .16s, color .16s;
}
.btn svg { width: 17px; height: 17px; }
.btn-ink { background: var(--ink); border-color: var(--ink); color: #fff; }
.btn-ink:hover { transform: translateY(-1px); box-shadow: 4px 4px 0 var(--volt); }
.btn-ghost { background: transparent; border-color: var(--line-strong); color: var(--ink-2); }
.btn-ghost:hover { border-color: var(--ink); color: var(--ink); }
.btn-volt { background: var(--volt); border-color: var(--volt); color: var(--ink); }
.btn-volt:hover { background: #e4ff74; }

.progress-card {
  position: relative; overflow: hidden;
  padding: 22px; border-radius: 24px;
  background: var(--ink); color: #fff;
  box-shadow: 6px 6px 0 var(--volt);
}
.progress-card::after {
  content: ""; position: absolute; right: -34px; top: -34px;
  width: 118px; height: 118px; border-radius: 50%;
  background: rgba(216, 255, 62, .12);
}
.pc-label { margin: 0; font: 700 10px var(--mono); letter-spacing: .16em; text-transform: uppercase; color: #9a99a1; }
.pc-num { display: flex; align-items: baseline; gap: 3px; margin: 12px 0 14px; font: 700 54px/.9 var(--mono); letter-spacing: -.06em; }
.pc-num span { font-size: 19px; color: var(--volt); }
.pc-bar { height: 7px; border-radius: 99px; background: #2c2c33; overflow: hidden; }
.pc-bar i { display: block; width: 0; height: 100%; border-radius: inherit; background: var(--volt); transition: width .4s cubic-bezier(.2, .8, .2, 1); }
.pc-meta { margin: 10px 0 0; font-size: 12.5px; color: #c9c8cf; }
.pc-note { margin: 14px 0 0; padding-top: 13px; border-top: 1px solid #2c2c33; font-size: 11px; line-height: 1.7; color: #8c8b93; }

.tut-body {
  display: grid; grid-template-columns: 250px minmax(0, 1fr); gap: 42px;
  align-items: start; padding-top: 44px; padding-bottom: 8px;
}
.step-rail { position: sticky; top: 82px; min-width: 0; }
.rail-label { margin: 0 0 12px; font: 700 10.5px var(--mono); letter-spacing: .16em; text-transform: uppercase; color: var(--faint); }
.rail-list { margin: 0; padding: 0; list-style: none; border-left: 1px solid var(--line-strong); }
.rail-list li { margin: 0; }
.rail-list a {
  display: grid; grid-template-columns: 26px minmax(0, 1fr); gap: 7px;
  margin-left: -1px; padding: 9px 0 9px 14px;
  border-left: 2px solid transparent;
  font-size: 13px; line-height: 1.5; color: var(--muted); text-decoration: none;
}
.rail-list a:hover { color: var(--ink); }
.rail-list a.is-active { border-left-color: var(--ink); color: var(--ink); font-weight: 700; }
.rail-num { padding-top: 1px; font: 700 10.5px var(--mono); color: var(--faint); }
.rail-list a.is-active .rail-num { color: var(--ink); }
.rail-list a.is-done .rail-num { color: var(--ok); }
.rail-note { margin: 16px 0 0; font-size: 11.5px; line-height: 1.7; color: var(--faint); }

.steps { display: flex; flex-direction: column; gap: 18px; min-width: 0; }
.intro-note { padding: 20px 22px; border: 1px solid var(--line-strong); border-radius: 20px; background: var(--surface); }
.intro-note strong { display: block; margin-bottom: 4px; font: 700 10.5px var(--mono); letter-spacing: .14em; text-transform: uppercase; color: var(--faint); }
.intro-note p { margin: 0; font-size: 14px; line-height: 1.85; color: var(--ink-2); }
.step-card {
  scroll-margin-top: 82px;
  padding: 28px;
  border: 1px solid var(--line-strong); border-radius: 26px;
  background: var(--surface);
  transition: border-color .2s;
}
.step-card.is-done { border-color: var(--ink); }
.step-head { display: flex; align-items: flex-start; gap: 16px; }
.step-num {
  display: grid; place-items: center; flex: none;
  width: 54px; height: 54px;
  border: 1.5px solid var(--ink); border-radius: 16px;
  background: var(--volt); box-shadow: 3px 3px 0 var(--ink);
  font: 700 18px var(--mono); color: var(--ink);
}
.step-card.is-done .step-num { background: var(--ink); color: var(--volt); box-shadow: 3px 3px 0 var(--volt); }
.step-num svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 2.6; stroke-linecap: round; stroke-linejoin: round; }
.step-kicker { margin: 2px 0 4px; font: 700 10.5px var(--mono); letter-spacing: .14em; text-transform: uppercase; color: var(--faint); }
.step-head h2 { margin: 0; font-size: clamp(20px, 2.4vw, 26px); line-height: 1.35; letter-spacing: -.025em; }
.step-lead { margin: 18px 0 0; font-size: 15.5px; line-height: 1.85; color: var(--ink-2); }
.points { display: flex; flex-direction: column; gap: 9px; margin: 16px 0 0; padding: 0; list-style: none; }
.points li { position: relative; padding-left: 20px; font-size: 14.5px; line-height: 1.8; color: var(--ink-2); }
.points li::before {
  content: ""; position: absolute; left: 2px; top: .72em;
  width: 7px; height: 7px; border-radius: 2px;
  background: var(--volt); box-shadow: 0 0 0 1px var(--ink);
}
.points code, .callout code, .faq code {
  padding: 1px 5px; border-radius: 5px;
  background: var(--sunken); font: 500 .88em var(--mono); color: var(--ink);
  overflow-wrap: break-word; word-break: normal;
}

.shot { margin: 20px 0 0; }
.shot-btn {
  position: relative; display: block; width: 100%; padding: 0;
  border: 0; background: none; cursor: zoom-in;
}
.shot-btn img {
  display: block; width: 100%; height: auto;
  border: 1px solid var(--line-strong); border-radius: 16px;
  background: #fff;
}
.shot-btn::after {
  content: "点击放大"; position: absolute; right: 10px; bottom: 10px;
  padding: 5px 11px; border-radius: 999px;
  background: rgba(16, 16, 18, .84); color: #fff;
  font-size: 11.5px; font-weight: 600;
  opacity: 0; transform: translateY(4px); transition: opacity .18s, transform .18s;
}
.shot-btn:hover::after, .shot-btn:focus-visible::after { opacity: 1; transform: none; }
.shot figcaption { display: flex; align-items: flex-start; gap: 8px; margin-top: 9px; font-size: 12px; line-height: 1.7; color: var(--muted); }
.cap-no {
  flex: none; margin-top: 1px; padding: 1px 6px;
  border: 1px solid var(--volt-line); border-radius: 5px;
  background: var(--volt-soft); color: var(--ink);
  font: 700 10px var(--mono); letter-spacing: .06em;
}

.callout { margin: 18px 0 0; padding: 13px 16px; border-left: 4px solid var(--volt); border-radius: 4px 14px 14px 4px; background: var(--volt-soft); }
.callout strong { display: block; margin-bottom: 2px; font-size: 12.5px; letter-spacing: .01em; }
.callout p { margin: 0; font-size: 13.5px; line-height: 1.75; color: var(--ink-2); }
.callout.warn { border-left-color: var(--hot); background: var(--hot-soft); }
.callout.note { border-left-color: var(--accent); background: var(--accent-soft); }

.step-foot {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px;
  margin-top: 22px; padding-top: 18px;
  border-top: 1px dashed var(--line-strong);
}
.done-btn {
  display: inline-flex; align-items: center; gap: 7px;
  min-height: 40px; padding: 0 16px;
  border: 1.5px solid var(--line-strong); border-radius: 999px;
  background: var(--surface); font-size: 13px; font-weight: 700; color: var(--ink-2);
  transition: background .16s, border-color .16s, color .16s;
}
.done-btn:hover { border-color: var(--ink); color: var(--ink); }
.done-btn[aria-pressed="true"] { background: var(--volt); border-color: var(--ink); color: var(--ink); }
.done-btn svg { width: 15px; height: 15px; fill: none; stroke: currentColor; stroke-width: 2.6; stroke-linecap: round; stroke-linejoin: round; }
.next-link {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 13px; font-weight: 700; color: var(--ink-2); text-decoration: none;
  transition: gap .16s, color .16s;
}
.next-link:hover { gap: 10px; color: var(--ink); }
.next-link svg { width: 15px; height: 15px; fill: none; stroke: currentColor; stroke-width: 2.2; stroke-linecap: round; stroke-linejoin: round; }

.tut-foot { padding-top: 34px; padding-bottom: 0; }
.done-banner {
  display: flex; align-items: center; flex-wrap: wrap; gap: 16px;
  padding: 22px 24px; border-radius: 22px;
  background: var(--ink); color: #fff;
  box-shadow: 6px 6px 0 var(--volt);
}
.db-icon {
  display: grid; place-items: center; flex: none;
  width: 44px; height: 44px; border-radius: 14px;
  background: var(--volt); color: var(--ink);
}
.db-icon svg { width: 22px; height: 22px; }
.done-banner h2 { margin: 0; font-size: 19px; letter-spacing: -.02em; }
.done-banner p { margin: 2px 0 0; font-size: 13px; color: #b8b7be; }
.done-banner .btn { margin-left: auto; }

.faq { max-width: 840px; padding-top: 48px; }
@media (min-width: 1021px) { .tut-foot .faq { margin-left: 292px; } }
.faq h2 { margin: 0 0 6px; font-size: clamp(26px, 3.2vw, 36px); letter-spacing: -.035em; }
.faq details { border-bottom: 1px solid var(--line-strong); padding: 15px 0; }
.faq summary {
  display: flex; align-items: flex-start; justify-content: space-between; gap: 16px;
  cursor: pointer; list-style: none; font-size: 15px; font-weight: 700;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font: 400 20px/1 var(--mono); color: var(--muted); }
.faq details[open] summary::after { content: "–"; }
.faq p { margin: 8px 0 0; font-size: 14px; line-height: 1.85; color: var(--muted); }

/* ---------- 5. 灯箱 ---------- */
.lightbox {
  position: fixed; inset: 0; z-index: 300;
  display: grid; grid-template-rows: minmax(0, 1fr) auto;
  padding: 22px;
  background: rgba(10, 10, 12, .95);
}
.lb-stage { position: relative; display: grid; place-items: center; min-height: 0; }
.lb-img { max-width: min(1180px, 94vw); max-height: 80vh; border-radius: 12px; background: #fff; box-shadow: 0 30px 90px rgba(0, 0, 0, .55); }
.lb-close {
  position: absolute; top: 0; right: 0; z-index: 2;
  display: grid; place-items: center; width: 42px; height: 42px;
  border: 1px solid #3a3a42; border-radius: 50%;
  background: #1c1c21; color: #fff; font-size: 24px; line-height: 1;
}
.lb-close:hover { border-color: var(--volt); color: var(--volt); }
.lb-nav {
  position: absolute; top: 50%; transform: translateY(-50%);
  display: grid; place-items: center; width: 46px; height: 46px;
  border: 1px solid #3a3a42; border-radius: 50%;
  background: rgba(28, 28, 33, .9); color: #fff; font-size: 20px;
}
.lb-nav:hover { border-color: var(--volt); color: var(--volt); }
.lb-prev { left: 0; }
.lb-next { right: 0; }
.lb-cap { margin: 0; padding: 12px 64px 0; text-align: center; font-size: 13px; line-height: 1.7; color: #c9c8cf; }

.missing { max-width: 780px; padding-top: 90px; padding-bottom: 120px; }
.missing h1 { margin: 0 0 12px; font-size: clamp(34px, 5vw, 56px); line-height: 1.1; letter-spacing: -.04em; }
.missing .lead { margin-bottom: 24px; }

/* ---------- 6. 响应式 ---------- */
@media (max-width: 1020px) {
  .feature { grid-template-columns: 1fr; gap: 26px; }
  .feature-visual { max-width: 520px; }
  .tut-head { grid-template-columns: 1fr; gap: 26px; }
  .progress-card { max-width: 420px; }
  .tut-body { grid-template-columns: 1fr; gap: 24px; }
  .step-rail { position: static; }
  .rail-list { display: flex; gap: 8px; overflow-x: auto; max-width: 100%; padding: 2px 2px 6px; border-left: 0; scrollbar-width: none; }
  .rail-list::-webkit-scrollbar { display: none; }
  .rail-list li { flex: none; }
  .rail-list a {
    display: flex; align-items: center; gap: 7px;
    margin: 0; padding: 7px 13px;
    border: 1px solid var(--line-strong); border-radius: 999px;
    background: var(--surface); white-space: nowrap;
  }
  .rail-list a.is-active { background: var(--ink); border-color: var(--ink); color: #fff; }
  .rail-list a.is-active .rail-num { color: var(--volt); }
  .rail-note { display: none; }
  .promise { grid-template-columns: 1fr; }
  .facts { gap: 24px; }
}
@media (max-width: 820px) {
  .bar-nav { display: none; }
  .bar-crumb { max-width: 34vw; }
  .hero { padding-top: 46px; }
  .hero-row { flex-direction: column; align-items: flex-start; gap: 24px; }
  .facts div { text-align: left; }
  .feature { padding: 26px; border-radius: 26px; }
  .feature h2 { font-size: 30px; }
  .cards { grid-template-columns: 1fr; }
  .card, .card-coming { min-height: 0; }
  .section-head { flex-direction: column; align-items: flex-start; gap: 10px; }
  .search { max-width: none; flex-basis: 100%; }
  .step-card { padding: 22px; border-radius: 22px; }
}
@media (max-width: 620px) {
  .wrap { padding-inline: 16px; }
  .topbar-inner { padding: 0 16px; gap: 10px; }
  .brand-name { display: none; }
  .bar-sep { display: none; }
  .bar-crumb { max-width: none; font-size: 12px; }
  .bar-pill { padding: 4px 10px; font-size: 11px; }
  .bar-link { padding: 4px 10px; font-size: 12px; }
  .hero { padding: 36px 0 40px; }
  .hero h1 { font-size: clamp(38px, 11.5vw, 54px); }
  .lead { font-size: 15px; line-height: 1.85; }
  .facts { gap: 18px; }
  .facts strong { font-size: 26px; }
  .facts span { font-size: 9.5px; }
  .feature { margin-top: 30px; padding: 22px; }
  .feature h2 { font-size: 26px; }
  .feature-meta { gap: 4px 12px; }
  .mini-steps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .section { padding-top: 56px; }
  .tut-hero { padding-top: 26px; }
  .tut-intro h1 { font-size: clamp(32px, 9.4vw, 42px); }
  .crumbs { margin-bottom: 20px; }
  .progress-card { max-width: none; }
  .pc-num { font-size: 44px; }
  .step-card { padding: 18px; }
  .step-head { gap: 12px; }
  .step-num { width: 44px; height: 44px; border-radius: 13px; font-size: 15px; }
  .step-lead { font-size: 14.5px; }
  .points li { font-size: 14px; }
  .step-foot { align-items: flex-start; flex-direction: column; }
  .next-link { order: -1; }
  .done-banner { align-items: flex-start; }
  .done-banner .btn { margin-left: 0; }
  .faq { padding-top: 36px; }
  .lightbox { padding: 12px; }
  .lb-img { max-height: 76vh; border-radius: 8px; }
  .lb-nav { width: 38px; height: 38px; font-size: 17px; }
  .lb-prev { left: -4px; }
  .lb-next { right: -4px; }
  .lb-cap { padding: 10px 4px 0; font-size: 12px; }
  .lb-close { top: -4px; right: -4px; width: 36px; height: 36px; }
}
@media (hover: none) {
  .shot-btn::after { opacity: 1; transform: none; }
}
@media (max-width: 380px) {
  .bar-crumb { display: none; }
  .hero h1 { font-size: 36px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}
@media print {
  .topbar, .step-rail, .hero-actions, .step-foot, .done-banner, .lightbox, .toolbar, .card-coming { display: none !important; }
  body { background: #fff; }
  .step-card, .card { break-inside: avoid; border-color: #bbb; box-shadow: none; }
  .hero, .tut-hero { background: none; border-bottom: 1px solid #bbb; }
  .shot-btn img { border: 1px solid #ccc; }
  .shot-btn::after { display: none; }
  .tut-body { grid-template-columns: 1fr; }
  .feature { background: #fff; color: #000; box-shadow: none; border: 1px solid #bbb; }
  .feature p, .feature-meta, .feature-label { color: #444; }
  .feature-visual { display: none; }
}