/* 主域名网站：首页用纸张底色加印章红；客户频道用客户自己的主色（页面里的 --accent）。
   字体只用系统字体：国内访问不到 Google Fonts，中文字体文件又太大。 */
:root {
  --paper: #f5f0e6;
  --paper-deep: #ece4d4;
  --card: #fffdf8;
  --ink: #1d1b18;
  --ink-soft: #4a453d;
  --muted: #7a7266;
  --line: #ddd3c2;
  --red: #c8431f;
  --red-deep: #9e3315;
  --accent: var(--red);
  --accent-soft: #e9a23b;
  --serif: "Source Han Serif SC", "Noto Serif CJK SC", "Songti SC", "STSong", "SimSun", serif;
  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC", "Source Han Sans SC", "Microsoft YaHei", sans-serif;
  --radius: 14px;
  --shadow: 0 1px 2px rgb(40 30 10 / 6%), 0 8px 24px -8px rgb(40 30 10 / 18%);
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: var(--sans); font-size: 16px; line-height: 1.75; }
a { color: inherit; }
img, video { display: block; max-width: 100%; }
h1, h2, h3 { margin: 0; line-height: 1.3; font-weight: 700; }
p { margin: 0; }
button { font: inherit; color: inherit; }
.wrap { width: min(1120px, 100%); margin-inline: auto; padding-inline: 20px; }

.eyebrow, .section-label { font-size: 13px; letter-spacing: .14em; color: var(--accent); font-weight: 600; }
.section-label { margin-bottom: 10px; }
h2 { font-family: var(--serif); font-size: clamp(26px, 4.2vw, 40px); letter-spacing: .01em; }
.lead { margin-top: 16px; max-width: 46em; color: var(--ink-soft); font-size: 17px; }

.button { display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: 0 22px; border-radius: 999px; border: 1.5px solid var(--ink); text-decoration: none; font-weight: 600; transition: transform .15s ease, background .15s ease; }
.button:hover { transform: translateY(-1px); }
.button.primary { background: var(--ink); color: var(--paper); }

.frame { position: relative; overflow: hidden; border-radius: 10px; background: var(--paper-deep); box-shadow: var(--shadow); margin: 0; }
.frame.landscape { aspect-ratio: 16 / 9; }
.frame.portrait { aspect-ratio: 9 / 16; }
.frame video, .frame img { width: 100%; height: 100%; object-fit: cover; }

/* ---------- 首页 ---------- */
.hero { background: radial-gradient(120% 90% at 85% 10%, #fbf6ec 0%, var(--paper) 60%); border-bottom: 1px solid var(--line); overflow: hidden; }
.nav { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.brand { font-family: var(--serif); font-weight: 700; font-size: 20px; text-decoration: none; }
.nav-links { display: flex; gap: 22px; align-items: center; font-size: 15px; }
.nav-links a { text-decoration: none; color: var(--ink-soft); }
.nav-links a.nav-cta { color: var(--red); font-weight: 600; }
.hero-body { display: grid; grid-template-columns: 1.05fr 1fr; gap: 48px; align-items: center; padding-top: 48px; padding-bottom: 88px; }
.hero h1 { margin-top: 18px; font-family: var(--serif); font-size: clamp(38px, 6.4vw, 68px); line-height: 1.18; letter-spacing: .01em; }
.subhead { margin-top: 22px; font-size: 18px; color: var(--ink-soft); max-width: 26em; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }
.hero-visual { position: relative; padding: 0 40px 64px 0; }
.hero-visual .frame.landscape { transform: rotate(-1.5deg); }
.hero-visual figcaption { position: absolute; left: 12px; bottom: 10px; padding: 2px 10px; border-radius: 999px; background: rgb(255 253 248 / 92%); font-size: 13px; color: var(--ink-soft); }
.hero-visual .frame.portrait { position: absolute; right: 0; bottom: 0; width: 34%; border: 5px solid var(--ink); border-radius: 20px; transform: rotate(3deg); }
.stamp { position: absolute; left: -22px; top: -26px; display: grid; place-items: center; width: 84px; height: 84px; border: 2.5px solid var(--red); border-radius: 50%; color: var(--red); font-family: var(--serif); font-weight: 700; font-size: 15px; line-height: 1.25; text-align: center; transform: rotate(-12deg); background: rgb(245 240 230 / 85%); }

.home main > section { margin-top: 96px; }

.compare { display: grid; grid-template-columns: 1fr auto 1.25fr; gap: 28px; align-items: center; margin-top: 40px; }
.doc { position: relative; padding: 28px 28px 24px; background: var(--card); border: 1px solid var(--line); border-radius: 6px; box-shadow: var(--shadow); transform: rotate(-1deg); }
.doc::before { content: ""; position: absolute; inset: 8px; border: 1px solid var(--line); border-radius: 3px; pointer-events: none; }
.doc-kicker { font-size: 12px; letter-spacing: .14em; color: var(--muted); }
.doc-title { margin-top: 4px; font-family: var(--serif); font-weight: 700; font-size: 18px; padding-bottom: 12px; border-bottom: 2px solid var(--ink); }
.doc ol { list-style: none; margin: 12px 0 0; padding: 0; columns: 2; column-gap: 20px; font-size: 13px; }
.doc li { display: grid; grid-template-columns: 22px 1fr; column-gap: 4px; break-inside: avoid; padding: 5px 0 6px; border-bottom: 1px dashed var(--line); }
.doc li span { color: var(--muted); font-variant-numeric: tabular-nums; }
.doc li i { grid-column: 2; display: block; height: 4px; margin-top: 4px; border-radius: 2px; background: var(--paper-deep); }
.doc li i + i { width: 62%; }
.arrow { display: grid; place-items: center; gap: 6px; color: var(--red); font-size: 13px; font-weight: 600; }
.arrow::before { content: ""; width: 54px; height: 54px; border-radius: 50%; background: var(--red) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23fff' stroke-width='2.4' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M5 12h14M13 6l6 6-6 6'/%3E%3C/svg%3E") center / 26px no-repeat; }
.result { display: block; text-decoration: none; }
.result .frame { margin-top: 8px; }
.result-meta { display: flex; justify-content: space-between; margin-top: 12px; font-size: 14px; color: var(--muted); }
.result-meta span { color: var(--red); font-weight: 600; }
.result:hover .frame { box-shadow: 0 0 0 3px var(--red), var(--shadow); }

.works h2 { margin-bottom: 8px; }
.work-group { margin-top: 44px; }
.work-group-head { display: flex; flex-wrap: wrap; align-items: baseline; gap: 6px 16px; margin-bottom: 18px; padding-bottom: 12px; border-bottom: 1px solid var(--line); }
.work-group-head h3 { font-family: var(--serif); font-size: 22px; }
.work-group-head p { color: var(--muted); font-size: 15px; }
.work-grid { display: grid; gap: 24px; }
.landscape .work-grid { grid-template-columns: repeat(3, 1fr); }
.portrait .work-grid { grid-template-columns: repeat(auto-fill, minmax(200px, 240px)); }
.work { margin: 0; }
.work figcaption { display: grid; gap: 2px; margin-top: 12px; }
.work .tag { font-size: 12px; color: var(--red); font-weight: 600; }
.work strong { font-size: 16px; line-height: 1.5; }
.work .meta { font-size: 13px; color: var(--muted); }
.works-note { margin-top: 28px; color: var(--muted); font-size: 14px; }

.audience-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 32px; }
.audience { padding: 26px; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); }
.audience h3 { font-family: var(--serif); font-size: 21px; padding-left: 12px; border-left: 3px solid var(--red); }
.audience p { margin-top: 12px; color: var(--ink-soft); font-size: 15px; }

.process { padding: 80px 0; background: var(--paper-deep); }
.steps { list-style: none; margin: 40px 0 0; padding: 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; counter-reset: step; }
.steps li { position: relative; padding-top: 18px; border-top: 2px solid var(--ink); }
.step-number { font-family: var(--serif); font-size: 40px; font-weight: 700; color: var(--red); line-height: 1; }
.steps h3 { margin-top: 12px; font-size: 19px; }
.steps p { margin-top: 8px; font-size: 15px; color: var(--ink-soft); }
.mini-review { display: flex; gap: 6px; margin-top: 16px; padding-bottom: 34px; }
.mini-review span { position: relative; flex: 1; aspect-ratio: 16 / 9; border-radius: 4px; background: var(--card); border: 1px solid var(--line); }
.mini-review span.active { border-color: var(--red); box-shadow: 0 0 0 2px rgb(200 67 31 / 20%); }
.mini-review b { position: absolute; left: 50%; top: calc(100% + 8px); transform: translateX(-30%); white-space: nowrap; padding: 4px 9px; border-radius: 8px; background: var(--ink); color: var(--paper); font-size: 11px; font-weight: 500; }
.mini-review b::after { content: ""; position: absolute; left: 30%; bottom: 100%; border: 5px solid transparent; border-bottom-color: var(--ink); }

.about { display: grid; grid-template-columns: 220px 1fr; gap: 48px; align-items: center; margin-bottom: 96px; }
.portrait-photo { aspect-ratio: 1; border-radius: 50%; background: repeating-linear-gradient(-45deg, var(--paper-deep) 0 10px, var(--paper) 10px 20px); border: 1px dashed var(--muted); display: grid; place-items: center; color: var(--muted); font-size: 14px; }
.about h2 { margin-bottom: 16px; }
.about p + p { margin-top: 12px; }
.about p { color: var(--ink-soft); max-width: 40em; }

.contact { background: var(--ink); color: var(--paper); padding: 80px 0; }
.contact-inner { display: grid; grid-template-columns: 1fr auto; gap: 48px; align-items: center; }
.contact h2 { color: var(--paper); }
.contact p { margin-top: 14px; color: #cfc6b6; max-width: 32em; }
.accounts { list-style: none; margin: 28px 0 0; padding: 0; display: grid; gap: 10px; }
.accounts li { display: flex; flex-wrap: wrap; gap: 4px 14px; font-size: 15px; }
.accounts span { color: #a99f8f; }
.qr { text-align: center; }
.qr-box { width: 168px; height: 168px; display: grid; place-items: center; border-radius: 12px; background: var(--paper); color: var(--muted); font-size: 14px; line-height: 1.5; }
.qr p { margin-top: 10px; font-size: 14px; }

.site-footer { padding: 32px 20px 40px; text-align: center; font-size: 12px; color: var(--muted); line-height: 2; }
.site-footer a { color: inherit; }
.home .site-footer { background: var(--ink); color: #8d8476; border-top: 1px solid #36322c; }

/* ---------- 首页上线前的占位页 ---------- */
.placeholder { min-height: 100vh; display: flex; flex-direction: column; }
.placeholder main { flex: 1; display: grid; place-content: center; gap: 8px; text-align: center; padding: 48px 20px; color: var(--ink-soft); }
.placeholder .brand { font-size: 28px; color: var(--ink); }

/* ---------- 客户频道 ----------
   配色跟成片一致：暖白底、白色卡片，文字用客户主色（--accent）调深，强调色用 --accent-soft。
   章节编号和要点卡片照搬成片里的编号条和安全要点卡片，员工看页面和看视频是同一套样子。 */
.client {
  --bg: #f3f1ec;
  --surface: #fff;
  --text: color-mix(in srgb, var(--accent) 70%, #0a0b1e);
  --text-soft: color-mix(in srgb, var(--accent) 35%, #4a4d5e);
  --text-muted: #85879b;
  --rule: color-mix(in srgb, var(--accent) 12%, transparent);
  --highlight: var(--accent-soft);
  --warn: #e0362c;
  --card-shadow: 0 1px 2px rgb(30 39 122 / 6%), 0 10px 28px -12px rgb(30 39 122 / 22%);
  background: var(--bg) linear-gradient(180deg, #f8f7f3 0, var(--bg) 480px) no-repeat;
  color: var(--text);
}
.client a { text-decoration: none; }
.client h2 { font-family: var(--sans); }
.client .site-footer { margin-top: 72px; color: var(--text-muted); border-top: 1px solid var(--rule); }

.client-bar { background: var(--surface); border-bottom: 1px solid var(--rule); }
.client-bar .wrap { display: flex; align-items: center; justify-content: space-between; gap: 16px; height: 64px; }
.client-logo { display: block; height: 30px; width: auto; }
.client-bar-label { font-size: 13px; letter-spacing: .14em; color: var(--text-muted); white-space: nowrap; }
.client-bar a:hover .client-bar-label { color: var(--text); }

.edition { display: inline-flex; align-items: center; gap: 6px; padding: 2px 12px 2px 10px; border-radius: 999px; border: 1px solid color-mix(in srgb, var(--highlight) 60%, transparent); background: color-mix(in srgb, var(--highlight) 12%, var(--surface)); color: color-mix(in srgb, var(--highlight) 55%, #5a3600); font-size: 13px; font-weight: 600; line-height: 1.8; white-space: nowrap; }
.edition::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--highlight); }

.channel-head { padding-top: 56px; padding-bottom: 40px; }
.channel-head .eyebrow { color: color-mix(in srgb, var(--highlight) 70%, #6b4000); letter-spacing: .16em; }
.channel-head h1 { margin-top: 12px; font-size: clamp(30px, 5.6vw, 48px); letter-spacing: .02em; }
.channel-head h1::after { content: ""; display: block; width: 56px; height: 5px; margin-top: 18px; border-radius: 3px; background: var(--highlight); }
.channel-desc { margin-top: 18px; max-width: 34em; color: var(--text-soft); font-size: 17px; }
.channel section + section { margin-top: 48px; }
.group-title { display: flex; align-items: baseline; gap: 12px; padding-bottom: 14px; font-size: 15px; letter-spacing: .1em; color: var(--text-soft); }
.group-title span { font-size: 13px; font-weight: 400; letter-spacing: 0; color: var(--text-muted); }
.video-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 20px; }
.video-row { display: grid; grid-template-columns: minmax(0, 420px) minmax(0, 1fr); gap: 36px; align-items: center; padding: 20px; border-radius: 16px; background: var(--surface); box-shadow: var(--card-shadow); transition: transform .2s ease, box-shadow .2s ease; }
.video-row:hover { transform: translateY(-2px); box-shadow: 0 0 0 2px color-mix(in srgb, var(--highlight) 70%, transparent), var(--card-shadow); }
.thumb { position: relative; aspect-ratio: 16 / 9; overflow: hidden; border-radius: 10px; background: var(--bg); }
.thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s ease; }
.play { position: absolute; left: 50%; top: 50%; width: 64px; height: 64px; margin: -32px 0 0 -32px; border-radius: 50%; background: var(--accent) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%23fff'%3E%3Cpath d='M8 5.5v13l11-6.5z'/%3E%3C/svg%3E") 56% center / 26px no-repeat; box-shadow: 0 8px 24px -6px rgb(0 0 0 / 40%); transition: background-color .2s ease, transform .2s ease; }
.video-row:hover .thumb img { transform: scale(1.03); }
.video-row:hover .play { background-color: var(--highlight); transform: scale(1.06); }
.video-text h3 { margin-top: 12px; font-size: clamp(21px, 2.8vw, 27px); }
.video-text p { margin-top: 10px; color: var(--text-soft); }
.video-text .video-meta { margin-top: 12px; font-size: 14px; color: var(--text-muted); font-variant-numeric: tabular-nums; }
.watch { display: inline-flex; align-items: center; min-height: 40px; margin-top: 18px; padding: 0 18px; border-radius: 999px; background: var(--accent); color: #fff; font-size: 15px; font-weight: 600; transition: background-color .2s ease; }
.video-row:hover .watch { background: color-mix(in srgb, var(--accent) 85%, #000); }

.crumb { padding-top: 18px; padding-bottom: 18px; font-size: 14px; }
.crumb a { color: var(--text-soft); }
.crumb a:hover { color: var(--text); }
/* 宽屏：左边视频、说明、要点和制作信息，右边章节吸顶；窄屏按视频、说明、章节、要点、制作信息排成一列。 */
.video-layout { display: grid; grid-template-columns: minmax(0, 1fr) 340px; grid-template-areas: "player chapters" "info chapters" "points chapters" "credits chapters"; gap: 28px 40px; align-items: start; }
.player-shell { grid-area: player; }
.player-shell video { width: 100%; aspect-ratio: 16 / 9; background: #000; border-radius: 14px; box-shadow: 0 30px 60px -30px rgb(20 24 80 / 55%); }
.video-info { grid-area: info; }
.chapter-panel { grid-area: chapters; position: sticky; top: 18px; max-height: calc(100vh - 36px); overflow: auto; scrollbar-width: thin; padding: 22px 14px 14px 20px; border-radius: 16px; background: var(--surface); box-shadow: var(--card-shadow); }
.key-points { grid-area: points; padding-top: 32px; border-top: 1px solid var(--rule); }
.credits { grid-area: credits; padding-top: 32px; border-top: 1px solid var(--rule); }

.video-info h1 { margin-top: 12px; font-size: clamp(24px, 3.6vw, 34px); letter-spacing: .01em; }
.video-info .video-meta { margin-top: 8px; font-size: 14px; color: var(--text-muted); }
.video-info .summary { margin-top: 10px; color: var(--text-soft); }
.controls-row { display: flex; flex-wrap: wrap; gap: 12px 20px; align-items: center; margin-top: 18px; }
.quality { display: inline-flex; align-items: center; gap: 4px; padding: 3px; border-radius: 999px; background: var(--surface); box-shadow: inset 0 0 0 1px var(--rule); font-size: 13px; color: var(--text-muted); }
.quality span { margin: 0 6px 0 10px; }
.quality button { border: 0; background: none; padding: 3px 12px; border-radius: 999px; color: var(--text-muted); cursor: pointer; }
.quality button[aria-pressed="true"] { color: #fff; background: var(--accent); }
.resume { border: 0; padding: 7px 16px; border-radius: 999px; background: var(--highlight); color: #2b1800; font-size: 13px; font-weight: 700; cursor: pointer; }
.panel-title { margin-bottom: 14px; font-size: 13px; font-weight: 700; letter-spacing: .16em; color: var(--text-soft); }

.chapters, .points, .credit-list { list-style: none; margin: 0; padding: 0; }
.chapters li { position: relative; }
/* 竖线：每一项画自己那一段，连起左边的编号块；看过的部分变成强调色。 */
.chapters li::before { content: ""; position: absolute; left: 16px; top: 0; bottom: 0; width: 2px; background: var(--rule); }
.chapters li:first-child::before { top: 50%; }
.chapters li:last-child::before { bottom: 50%; }
.chapters li.done::before { background: color-mix(in srgb, var(--accent) 55%, transparent); }
.chapters li.current::before { background: linear-gradient(color-mix(in srgb, var(--accent) 55%, transparent) 50%, var(--rule) 50%); }
.chapters li.current:first-child::before { background: var(--rule); }
.chapters button { display: grid; grid-template-columns: 34px minmax(0, 1fr) auto; align-items: center; column-gap: 12px; width: 100%; padding: 6px 8px 6px 0; border: 0; border-radius: 10px; background: none; text-align: left; cursor: pointer; }
/* 编号块照成片的编号条：没看到是白底灰字，看过是主色，当前这一步顶上加一道强调色。 */
.num { position: relative; z-index: 1; display: grid; place-items: center; width: 34px; height: 26px; overflow: hidden; border-radius: 6px; border: 1.5px solid color-mix(in srgb, var(--accent) 22%, transparent); background: var(--surface); color: var(--text-muted); font-size: 12px; font-weight: 700; font-variant-numeric: tabular-nums; transition: all .2s ease; }
.num:empty::after { content: ""; width: 6px; height: 6px; border-radius: 50%; background: currentColor; }
.chapter-text { display: grid; line-height: 1.4; }
.step { font-size: 12px; color: var(--text-muted); }
.chapter-title { font-size: 15px; color: var(--text-soft); }
.chapter-time { font-size: 13px; color: var(--text-muted); font-variant-numeric: tabular-nums; }
.chapters button:hover { background: color-mix(in srgb, var(--accent) 5%, transparent); }
.chapters button:hover .chapter-title { color: var(--text); }
.chapters li.done .num { border-color: transparent; background: color-mix(in srgb, var(--accent) 80%, #fff); color: #fff; }
.chapters li.current button { background: color-mix(in srgb, var(--highlight) 14%, transparent); }
.chapters li.current .num { border-color: transparent; background: var(--accent); color: #fff; box-shadow: inset 0 4px 0 var(--highlight); }
.chapters li.current .chapter-title { color: var(--text); font-weight: 700; }
.chapters li.current .step { color: color-mix(in srgb, var(--highlight) 60%, #6b4000); }

.key-points .hint { margin: -6px 0 16px; font-size: 13px; color: var(--text-muted); }
/* 要点卡片照成片里的安全要点卡：编号、警示三角、两行字。 */
.points { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px; }
.points button { position: relative; display: grid; align-content: start; gap: 6px; width: 100%; height: 100%; padding: 16px 16px 14px 22px; border: 0; border-radius: 12px; background: var(--surface); box-shadow: var(--card-shadow); text-align: left; cursor: pointer; transition: transform .15s ease, box-shadow .15s ease; }
.points button::before { content: ""; position: absolute; left: 12px; top: 16px; bottom: 16px; width: 3px; border-radius: 2px; background: var(--accent); }
.points button::after { content: ""; position: absolute; right: 14px; top: 14px; width: 24px; height: 22px; background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 22'%3E%3Cpath d='M12 1.5 23 20.5H1z' fill='%23e0362c' stroke='%23e0362c' stroke-width='2' stroke-linejoin='round'/%3E%3Cpath d='M12 7.5v6.5' stroke='%23fff' stroke-width='2.6' stroke-linecap='round'/%3E%3Ccircle cx='12' cy='17.2' r='1.5' fill='%23fff'/%3E%3C/svg%3E") center / contain no-repeat; }
.points button:hover { transform: translateY(-2px); box-shadow: 0 0 0 2px color-mix(in srgb, var(--highlight) 70%, transparent), var(--card-shadow); }
.point-num { font-size: 22px; font-weight: 800; line-height: 1.1; color: var(--text); font-variant-numeric: tabular-nums; }
.point-text { font-size: 16px; font-weight: 700; line-height: 1.5; color: var(--text); padding-right: 6px; }
.point-meta { font-size: 13px; color: var(--text-muted); font-variant-numeric: tabular-nums; }

/* 制作信息照成片片尾的名单：左边职务右对齐，右边姓名，中间一个强调色圆点。 */
.credit-list { display: grid; padding: 8px 24px; border-radius: 14px; background: var(--surface); box-shadow: var(--card-shadow); }
.credit-list li { display: grid; grid-template-columns: minmax(7.5em, 1fr) 10px minmax(0, 1.6fr); align-items: center; column-gap: 16px; padding: 12px 0; border-bottom: 1px solid var(--rule); }
.credit-list li:last-child { border-bottom: 0; }
.credit-role { justify-self: end; font-size: 14px; letter-spacing: .12em; color: var(--text-muted); white-space: nowrap; }
.credit-list li::before { content: ""; grid-column: 2; grid-row: 1; width: 6px; height: 6px; border-radius: 50%; background: var(--highlight); }
.credit-role { grid-column: 1; grid-row: 1; }
.credit-name { grid-column: 3; grid-row: 1; font-size: 16px; font-weight: 700; color: var(--text); }

@media (max-width: 900px) {
  .video-row { grid-template-columns: 1fr; gap: 6px; padding: 14px 14px 20px; }
  .video-layout { grid-template-columns: minmax(0, 1fr); grid-template-areas: "player" "info" "chapters" "points" "credits"; }
  .chapter-panel { position: static; max-height: none; overflow: visible; }
  .points { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 600px) {
  .client-bar .wrap { height: 56px; }
  .client-logo { height: 24px; }
  .channel-head { padding-top: 36px; padding-bottom: 28px; }
  .points { grid-template-columns: 1fr; gap: 10px; }
  .points button { grid-template-columns: 34px minmax(0, 1fr); column-gap: 10px; row-gap: 0; padding: 12px 44px 12px 22px; }
  .points button::before { top: 12px; bottom: 12px; }
  .points button::after { top: 50%; margin-top: -11px; }
  .point-num { grid-row: span 2; align-self: center; font-size: 20px; }
  .credit-list { padding: 4px 16px; }
  .credit-list li { grid-template-columns: 6.6em 8px minmax(0, 1fr); column-gap: 12px; }
  .credit-role { font-size: 13px; letter-spacing: .02em; }
  /* 手机上播放器吸顶，往下翻章节时视频还在眼前。 */
  .player-shell { position: sticky; top: 0; z-index: 2; margin-inline: -20px; background: #000; }
  .player-shell video { border-radius: 0; box-shadow: none; }
  .crumb { padding-top: 12px; padding-bottom: 12px; }
}

@media (max-width: 900px) {
  .hero-body { grid-template-columns: 1fr; gap: 40px; padding-top: 24px; padding-bottom: 56px; }
  .hero-visual { max-width: 560px; }
  .compare { grid-template-columns: 1fr; }
  .arrow { grid-auto-flow: column; }
  .arrow::before { transform: rotate(90deg); width: 44px; height: 44px; }
  .landscape .work-grid { grid-template-columns: 1fr 1fr; }
  .audience-grid { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr 1fr; gap: 32px 24px; }
  .contact-inner { grid-template-columns: 1fr; }
  .qr { justify-self: start; text-align: left; }
}

@media (max-width: 600px) {
  .nav-links a:not(.nav-cta) { display: none; }
  .home main > section { margin-top: 72px; }
  .hero-visual { padding-right: 28px; }
  .stamp { left: -6px; top: -20px; width: 70px; height: 70px; font-size: 13px; }
  .doc ol { columns: 1; }
  .landscape .work-grid { grid-template-columns: 1fr; }
  .portrait .work-grid { grid-template-columns: 1fr 1fr; gap: 14px; }
  .steps { grid-template-columns: 1fr; }
  .about { grid-template-columns: 1fr; gap: 24px; }
  .portrait-photo { width: 140px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .button, .thumb img, .play, .num, .video-row, .points button { transition: none; }
}