:root {
  color-scheme: light;
  --page: #f5f4f1;
  --paper: #fff;
  --ink: #3d2a20;
  --muted: #725d52;
  --rule: #d8d3cb;
  --accent: #8a9854;
  --shadow: 0 2px 14px rgb(53 41 32 / 7%);
  font-family: 'DM Sans', 'Manrope', Arial, sans-serif;
  color: var(--ink);
  background: var(--page);
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

* { box-sizing: border-box; }
body { min-width: 320px; margin: 0; background: var(--page); }
.guide { width: min(100% - 48px, 1200px); margin-inline: auto; padding: 56px 0 34px; }
.guide-header { margin: 0 auto 38px; text-align: center; }
.eyebrow { color: #857468; font-size: 11px; font-weight: 700; letter-spacing: 1.7px; }
h1 { margin: 16px 0 10px; font-size: clamp(42px, 7vw, 76px); line-height: 1.07; font-weight: 800; }
.guide-subtitle { margin: 0; color: #554239; font-size: clamp(21px, 3vw, 35px); font-weight: 500; }
.header-rule { display: block; width: 45px; height: 2px; margin: 23px auto 0; background: var(--accent); }
.video-list { display: grid; gap: 22px; }
.video-row { display: grid; grid-template-columns: minmax(0, 1.18fr) minmax(260px, .82fr); min-height: 300px; overflow: hidden; border: 1px solid #e5e1db; border-radius: 8px; background: var(--paper); box-shadow: var(--shadow); }
.video-frame { position: relative; min-width: 0; min-height: 300px; overflow: hidden; background: #e8e6df; }
.video-frame video { display: block; width: 100%; height: 100%; min-height: 300px; object-fit: cover; background: #e8e6df; }
.video-number { position: absolute; top: 14px; left: 16px; padding: 5px 8px; color: #fff; background: rgb(46 39 34 / 67%); font-size: 11px; font-weight: 700; }
.video-copy { align-self: center; padding: 30px clamp(24px, 5vw, 58px); }
.chapter-number { color: var(--accent); font-size: 42px; line-height: 1; font-weight: 800; }
.video-copy h2 { max-width: 400px; margin: 15px 0 17px; font-size: clamp(20px, 2.3vw, 29px); line-height: 1.25; font-weight: 700; }
.copy-rule { display: block; width: 100%; max-width: 300px; height: 1px; background: var(--rule); }
.video-copy p { max-width: 340px; margin: 17px 0 0; color: var(--muted); font-size: 17px; line-height: 1.65; }
.guide-footer { display: flex; align-items: center; justify-content: center; gap: 13px; margin: 30px 0 0; color: var(--muted); }
.guide-footer p { margin: 0; font-size: 14px; line-height: 1.5; }
.safety-icon { display: grid; width: 26px; height: 26px; flex: 0 0 auto; place-items: center; border: 1.5px solid var(--accent); border-radius: 50%; color: var(--accent); font-size: 16px; font-weight: 700; }
.loading,.load-error { grid-column: 1 / -1; padding: 32px; color: var(--muted); text-align: center; }

/* ── 视频播放按钮覆盖层 ── */
.video-frame { cursor: pointer; }
.video-play-btn {
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  background: transparent; border: none; cursor: pointer; padding: 0;
  /* 悬停时显示半透明遮罩 */
  transition: background 180ms ease;
}
.video-play-btn:hover { background: rgb(0 0 0 / 18%); }
.video-play-btn:focus-visible { outline: 3px solid var(--accent); outline-offset: -3px; }
.video-play-btn svg {
  width: 56px; height: 56px;
  fill: #fff; filter: drop-shadow(0 2px 8px rgb(0 0 0 / 50%));
  transition: transform 180ms ease;
}
.video-play-btn:hover svg { transform: scale(1.1); }

/* ── 全屏播放 Modal ── */
.video-modal {
  position: fixed; inset: 0; z-index: 1000;
  display: flex; align-items: center; justify-content: center;
}
.video-modal[hidden] { display: none; }
.video-modal-backdrop {
  position: absolute; inset: 0;
  background: rgb(0 0 0 / 82%);
  backdrop-filter: blur(4px);
}
.video-modal-content {
  position: relative; z-index: 1;
  width: min(92vw, 1100px);
  background: #000; border-radius: 6px;
  box-shadow: 0 24px 80px rgb(0 0 0 / 70%);
  overflow: hidden;
}
.video-modal-close {
  position: absolute; top: 12px; right: 12px; z-index: 2;
  width: 36px; height: 36px;
  display: grid; place-items: center;
  background: rgb(0 0 0 / 55%); border: none; border-radius: 50%;
  color: #fff; font-size: 15px; cursor: pointer;
  transition: background 150ms ease;
}
.video-modal-close:hover { background: rgb(0 0 0 / 80%); }
.video-modal-close:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }
.video-modal-player {
  display: block; width: 100%; max-height: 80vh;
  background: #000;
}

@media (min-width: 1400px) { .guide { padding-top: 72px; } .guide-header { margin-bottom: 48px; } }
@media (max-width: 680px) {
  .guide { width: min(100% - 28px, 480px); padding: max(28px, env(safe-area-inset-top)) 0 max(22px, env(safe-area-inset-bottom)); }
  .guide-header { margin-bottom: 25px; }
  .eyebrow { font-size: 9px; }
  h1 { margin-top: 12px; font-size: clamp(36px, 10vw, 54px); }
  .guide-subtitle { font-size: 21px; }
  .header-rule { margin-top: 17px; }
  .video-list { gap: 14px; }
  .video-row { grid-template-columns: 1fr; min-height: auto; }
  .video-frame,.video-frame video { min-height: 0; aspect-ratio: 1.38 / 1; }
  .video-frame video { object-fit: contain; }
  .video-copy { padding: 18px 20px 22px; }
  .chapter-number { font-size: 31px; }
  .video-copy h2 { margin: 8px 0 12px; font-size: 21px; }
  .video-copy p { margin-top: 11px; font-size: 15px; }
  .guide-footer { align-items: flex-start; justify-content: flex-start; margin: 22px 4px 0; }
  .guide-footer p { font-size: 12px; }
}