:root {
  --bg: #080a0c;
  --surface: #111417;
  --text: #f7f8f5;
  --muted: #9fa7ae;
  --line: rgba(255, 255, 255, 0.16);
  --accent: #39ef8b;
  --accent-ink: #07120c;
  color-scheme: dark;
  font-family: "Microsoft YaHei", "Noto Sans SC", Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-size: 16px;
  line-height: 1.55;
  letter-spacing: 0;
}

body,
a {
  font-family: inherit;
  letter-spacing: 0;
}

a {
  color: inherit;
  text-decoration: none;
}

a:focus-visible,
video:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
}

.case-header {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  width: min(100% - 64px, 1280px);
  margin: 0 auto;
  border-bottom: 1px solid var(--line);
}

.brand {
  font-size: 22px;
  font-weight: 900;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  color: rgba(255, 255, 255, 0.8);
  font-size: 14px;
  font-weight: 800;
}

.back-link svg {
  width: 18px;
  height: 18px;
}

.case-main {
  width: min(100% - 64px, 1280px);
  margin: 0 auto;
  padding: 74px 0 90px;
}

.case-intro {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.65fr);
  gap: 54px;
  align-items: end;
  margin-bottom: 38px;
}

.case-category {
  margin: 0 0 12px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 900;
}

.case-intro h1 {
  margin: 0;
  font-size: 58px;
  line-height: 1.08;
  letter-spacing: 0;
}

.case-intro > p {
  margin: 0;
  color: var(--muted);
}

.video-section {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.video-stage {
  position: relative;
  min-height: 520px;
  display: grid;
  place-items: center;
  overflow: hidden;
  background: #030405;
}

.video-stage video {
  display: block;
  width: 100%;
  max-height: 78vh;
  aspect-ratio: 16 / 9;
  background: #000;
}

.video-stage.is-portrait video {
  width: min(100%, 520px);
  aspect-ratio: 9 / 16;
}

.video-error {
  position: absolute;
  left: 50%;
  bottom: 26px;
  transform: translateX(-50%);
  width: max-content;
  max-width: calc(100% - 36px);
  margin: 0;
  padding: 10px 14px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 4px;
  background: #161a1e;
  color: #fff;
  font-size: 13px;
}

.case-controls {
  display: grid;
  grid-template-columns: 1fr 1fr;
}

.case-control {
  min-height: 118px;
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 22px 26px;
  border-right: 1px solid var(--line);
  background: var(--surface);
}

.case-control:last-child {
  border-right: 0;
}

.case-control.next {
  justify-content: flex-end;
  text-align: right;
}

.case-control svg {
  width: 24px;
  height: 24px;
  color: var(--accent);
}

.case-control span {
  display: grid;
  gap: 3px;
}

.case-control small {
  color: var(--muted);
  font-size: 11px;
}

.case-control strong {
  font-size: 16px;
}

.case-cta {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 34px;
  padding: 84px 0 0;
}

.case-cta p {
  margin: 0 0 8px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 900;
}

.case-cta h2 {
  margin: 0;
  font-size: 42px;
  line-height: 1.15;
  letter-spacing: 0;
}

.cta-button {
  min-height: 56px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 20px;
  border-radius: 4px;
  background: var(--accent);
  color: var(--accent-ink);
  font-weight: 900;
}

.cta-button svg {
  width: 18px;
  height: 18px;
}

@media (max-width: 760px) {
  .case-header,
  .case-main {
    width: 100%;
  }

  .case-header {
    min-height: 64px;
    padding: 0 18px;
  }

  .brand {
    font-size: 19px;
  }

  .back-link {
    font-size: 12px;
  }

  .case-main {
    padding: 48px 18px 68px;
  }

  .case-intro {
    grid-template-columns: 1fr;
    gap: 18px;
  }

  .case-intro h1 {
    font-size: 38px;
  }

  .video-stage {
    min-height: 0;
  }

  .video-stage video {
    max-height: 70vh;
  }

  .case-controls {
    grid-template-columns: 1fr;
  }

  .case-control,
  .case-control:last-child {
    min-height: 96px;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .case-control:last-child {
    border-bottom: 0;
  }

  .case-cta {
    align-items: stretch;
    flex-direction: column;
  }

  .case-cta h2 {
    font-size: 32px;
  }
}