/* Tutorial and video content share the homepage's type, spacing and color system. */
:root { --text-soft: #485443; --text-muted: var(--muted); --line-strong: #cbd7c3; --bg-raised: #fff; --bg-soft: #f1f5ed; --accent-ink: #fff; --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif; }
.guide-page h1, .video-page h1 { font-size: clamp(31px, 3.14vw, 40px); font-weight: 460; line-height: 1.65; letter-spacing: .01em; }
.guide-page h2, .video-page h2 { font-weight: 460; letter-spacing: -.015em; line-height: 1.5; }
.title-accent { color: var(--accent); }
.guide-hero, .page-intro { text-align: center; }
.guide-hero { width: min(1000px, calc(100% - 96px)); margin: auto; padding: 90px 0 68px; }
.guide-hero h1 { margin: 0 auto; }
.hero-lead, .lead { max-width: 680px; margin: 24px auto 0; color: var(--muted); font-size: 16px; line-height: 1.9; }
.platform-tabs { width: min(320px, 100%); margin: 38px auto 0; padding: 4px; display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 4px; border: 1px solid var(--line); border-radius: 8px; background: var(--bg-raised); }
.platform-tab { min-height: 38px; border: 0; border-radius: 5px; background: transparent; color: var(--muted); font: inherit; font-size: 13px; font-weight: 500; transition: background .2s, color .2s; }
.platform-tab:hover { color: var(--text); }
.platform-tab[aria-selected="true"] { color: #315b24; background: #e6efde; }
.guide-shell { width: min(1220px, calc(100% - 96px)); margin: auto; border-top: 1px solid var(--line); }
.guide-panel { width: min(1000px, 100%); margin: auto; padding: 68px 0 84px; }
.panel-header { display: grid; grid-template-columns: minmax(0,1fr) auto; gap: 36px; align-items: center; padding-bottom: 42px; border-bottom: 1px solid var(--line); }
.platform-label { color: var(--accent); font-size: 12px; font-weight: 450; letter-spacing: .04em; }
.panel-header h2 { margin-top: 12px; font-size: 29px; }
.panel-intro { max-width: 620px; margin-top: 16px; color: var(--muted); font-size: 16px; line-height: 1.9; }
.tutorial-outline { list-style: none; margin: 0; padding: 0; }
.tutorial-step { display: grid; grid-template-columns: 56px minmax(0,1fr) minmax(240px,.55fr); gap: 24px; align-items: start; padding: 36px 0; border-bottom: 1px solid var(--line); }
.step-index { color: var(--accent); padding-top: 5px; font-size: 13px; font-weight: 500; font-variant-numeric: tabular-nums; }
.tutorial-step h3 { font-size: 21px; font-weight: 500; line-height: 1.5; }
.tutorial-step p { margin-top: 10px; color: var(--muted); font-size: 15px; line-height: 1.85; }
.content-slot { min-height: 90px; display: flex; align-items: center; padding: 18px 20px; border: 1px dashed var(--line-strong); border-radius: 8px; background: var(--bg-soft); color: var(--muted); font-size: 13px; line-height: 1.8; }
.guide-chapter { padding: 46px 0; border-bottom: 1px solid var(--line); }
.guide-chapter:last-child { border-bottom: 0; }
.chapter-heading { display: grid; grid-template-columns: 56px minmax(0,1fr); gap: 24px; align-items: start; }
.chapter-heading .step-index { font-size: 15px; line-height: 1.6; }
.chapter-heading h3 { font-size: 24px; font-weight: 500; line-height: 1.5; }
.chapter-summary { max-width: 790px; margin-top: 12px; color: var(--muted); font-size: 16px; line-height: 1.9; }
.chapter-body { margin: 28px 0 0 80px; }
.instruction-list { margin: 0 0 28px; padding-left: 22px; display: grid; gap: 12px; color: var(--text-soft); font-size: 16px; line-height: 1.9; }
.instruction-list li { padding-left: 4px; }
.instruction-list li::marker { color: var(--accent); }
.instruction-list strong, .chapter-note strong { color: #365b28; font-weight: 550; }
.audio-device { padding: 2px 6px; border: 1px solid #c1d3b4; border-radius: 4px; background: #eaf2e3; color: #365b28; font-family: var(--font); font-size: .94em; overflow-wrap: anywhere; }
.chapter-note { margin: 0 0 28px; padding: 16px 18px; border-left: 2px solid #6baa49; border-radius: 0 6px 6px 0; background: var(--bg-soft); color: var(--text-soft); font-size: 15px; line-height: 1.9; }
.inline-action { display: inline-flex; margin-bottom: 28px; padding-bottom: 4px; border-bottom: 1px solid #587b44; color: var(--accent); font-size: 13px; font-weight: 500; }
.tutorial-media-grid { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 20px; align-items: start; }
.tutorial-media-grid-three { grid-template-columns: repeat(3,minmax(0,1fr)); }
.tutorial-media { display: block; margin: 0; overflow: hidden; border: 1px solid var(--line-strong); border-radius: 10px; background: var(--bg-raised); transition: border-color .2s; }
.tutorial-media:hover { border-color: #657166; }
.tutorial-media img { display: block; width: 100%; height: auto; }
.tutorial-media figcaption { padding: 12px 14px; border-top: 1px solid var(--line); color: var(--muted); font-size: 12px; line-height: 1.8; }
.tutorial-media-wide { grid-column: 1 / -1; }
.tutorial-media-compact { width: min(720px,100%); }
body.lightbox-open { overflow: hidden; }
.video-page main { width: min(1000px, calc(100% - 96px)); margin: auto; padding: 90px 0 84px; }
.page-intro { padding-bottom: 68px; }
.featured-demo { display: grid; grid-template-columns: minmax(0,1fr) 280px; align-items: center; gap: 72px; padding: 68px 0 80px; border-top: 1px solid var(--line); }
.demo-index { color: var(--accent); font-size: 13px; font-weight: 450; }
.demo-label { margin-top: 18px; color: var(--muted); font-size: 13px; font-weight: 450; }
.demo-title { margin-top: 14px; font-size: 29px; text-wrap: balance; }
.demo-description { max-width: 620px; margin-top: 18px; color: var(--muted); font-size: 16px; line-height: 1.9; }
.video-page .actions { margin-top: 28px; display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }
.more-demos { padding-top: 64px; border-top: 1px solid var(--line); }
.section-heading { display: flex; align-items: center; justify-content: space-between; gap: 32px; }
.section-heading h2 { font-size: 29px; }
.section-heading p { max-width: 460px; color: var(--muted); font-size: 15px; line-height: 1.9; }
.demo-grid { margin-top: 42px; display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 28px; }
.demo-card { min-width: 0; display: grid; grid-template-rows: 1fr auto; justify-items: center; }
.demo-card-header { width: 100%; min-height: 190px; padding: 24px 0 28px; border-top: 1px solid var(--line); }
.demo-card h2 { margin-top: 14px; font-size: 22px; }
.demo-card .demo-description { margin-top: 12px; font-size: 15px; }
.demo-link { display: inline-block; margin-top: 16px; color: var(--accent); font-size: 13px; text-underline-offset: 4px; }
.demo-link:hover { text-decoration: underline; }
.video-frame { width: 280px; max-width: 100%; aspect-ratio: 324 / 720; overflow: hidden; border: 1px solid var(--line-strong); border-radius: 12px; background: var(--bg-raised); box-shadow: 0 4px 12px rgba(24,40,19,.06), 0 24px 58px rgba(24,40,19,.10); }
/* Preserve Douyin's minimum layout and scale the original player to its frame. */
.video-frame iframe { display: block; width: 324px; height: 720px; border: 0; transform: scale(var(--video-scale,1)); transform-origin: top left; }
@media (max-width: 1080px) {
  .tutorial-step { grid-template-columns: 56px minmax(0,1fr); }
  .content-slot { grid-column: 2; }
  .demo-grid { grid-template-columns: repeat(2,minmax(0,280px)); justify-content: center; }
  .demo-card:last-child { grid-column: 1 / -1; }
}
@media (max-width: 850px) {
  .guide-hero, .guide-shell, .video-page main { width: calc(100% - 48px); }
  .featured-demo { grid-template-columns: 1fr; gap: 36px; }
  .featured-demo .demo-copy { text-align: center; }
  .featured-demo .demo-description { margin-left: auto; margin-right: auto; }
  .featured-demo .actions { justify-content: center; }
  .featured-demo .video-frame { margin: auto; }
}
@media (max-width: 600px) {
  .guide-hero { padding: 64px 0 48px; }
  .guide-page h1, .video-page h1 { font-size: clamp(22px,6.16vw,31px); }
  .hero-lead, .lead { font-size: 13px; }
  .guide-panel { padding: 48px 0 64px; }
  .panel-header { grid-template-columns: 1fr; gap: 24px; align-items: start; padding-bottom: 32px; }
  .panel-header h2, .section-heading h2 { font-size: 26px; }
  .panel-header .button { justify-self: start; }
  .panel-intro { font-size: 13px; }
  .chapter-heading, .tutorial-step { grid-template-columns: 30px minmax(0,1fr); gap: 14px; }
  .guide-chapter { padding: 34px 0; }
  .chapter-heading h3 { font-size: 21px; }
  .chapter-summary { font-size: 13px; }
  .chapter-body { margin: 24px 0 0; }
  .instruction-list { font-size: 15px; }
  .chapter-note { padding: 14px; font-size: 13px; }
  .tutorial-media-grid, .tutorial-media-grid-three { grid-template-columns: 1fr; gap: 18px; }
  .tutorial-media-wide { grid-column: auto; }
  .content-slot { grid-column: 1 / -1; }
  .video-page main { padding: 64px 0; }
  .page-intro { padding-bottom: 48px; }
  .featured-demo { padding: 44px 0 60px; }
  .demo-title { font-size: 25px; }
  .demo-description { font-size: 15px; }
  .more-demos { padding-top: 48px; }
  .section-heading { display: block; text-align: center; }
  .section-heading p { margin: 16px auto 0; font-size: 13px; }
  .demo-grid { grid-template-columns: minmax(0,280px); gap: 42px; }
  .demo-card:last-child { grid-column: auto; }
  .demo-card-header { min-height: 0; text-align: center; }
}
@media (max-width: 480px) { .guide-hero, .guide-shell, .video-page main { width: calc(100% - 36px); } }
    .image-lightbox {
      position: fixed;
      inset: 0;
      z-index: 80;
      display: grid;
      place-items: center;
      padding: 32px;
      background: rgba(0, 0, 0, .86);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
    }
    .image-lightbox-card {
      position: relative;
      width: min(1200px, 100%);
      max-height: calc(100svh - 64px);
      display: grid;
      grid-template-rows: minmax(0, 1fr) auto;
      overflow: hidden;
      border: 1px solid var(--line-strong);
      border-radius: 18px;
      background: var(--bg-raised);
      box-shadow: 0 30px 100px rgba(0, 0, 0, .7);
    }
    .image-lightbox-stage {
      min-height: 0;
      display: grid;
      place-items: center;
      overflow: auto;
      padding: 24px;
      background: #f1f5ed;
    }
    .image-lightbox-image {
      display: block;
      width: auto;
      max-width: 100%;
      height: auto;
      max-height: calc(100svh - 160px);
      object-fit: contain;
    }
    .image-lightbox-caption {
      padding: 16px 68px 17px 20px;
      border-top: 1px solid var(--line);
      color: var(--text-soft);
      font-size: 16px;
      line-height: 1.6;
    }
    .image-lightbox-close {
      position: absolute;
      right: 12px;
      bottom: 10px;
      z-index: 2;
      width: 42px;
      height: 42px;
      border: 1px solid var(--line-strong);
      border-radius: 50%;
      background: var(--bg-soft);
      color: var(--text);
      font: inherit;
      font-size: 25px;
      line-height: 1;
      cursor: pointer;
    }
    .image-lightbox-close:hover { border-color: var(--accent); color: var(--accent); }
@media (max-width: 600px) {
  .image-lightbox { padding: 10px; }
  .image-lightbox-card { max-height: calc(100svh - 20px); border-radius: 12px; }
  .image-lightbox-stage { padding: 10px; }
  .image-lightbox-image { max-height: calc(100svh - 112px); }
  .image-lightbox-caption { padding: 13px 58px 14px 14px; font-size: 13px; }
  .image-lightbox-close { right: 8px; bottom: 7px; width: 38px; height: 38px; }
}