/* ═══════════ TOKENS ═══════════ */
:root {
  --bg: #0d2b36;
  --bg-deep: #08202a;
  --bg-lift: #143742;
  --bg-card: #184350;
  --text: #f5f2ee;
  --text-mute: #9bb1b8;
  --text-dim: #6e8a92;
  --accent: #0079c1;
  --accent-bright: #34a8e8;
  --accent-yellow: #f4c300;
  --divider: #1f4855;
  --max: 1180px;
  --font-cn: "PingFang SC", "Noto Sans SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-en: "Inter", "Helvetica Neue", "Helvetica", -apple-system, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-cn), var(--font-en);
  font-weight: 400;
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

.container { max-width: var(--max); margin: 0 auto; padding: 0 32px; }

/* ═══════════ NAV ═══════════ */
.topnav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 18px 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  backdrop-filter: blur(12px);
  background: rgba(8, 32, 42, 0.7);
  border-bottom: 1px solid var(--divider);
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-en);
  font-weight: 600;
  letter-spacing: 0.12em;
  font-size: 13px;
}
.s-logo {
  font-size: 22px;
  color: var(--accent);
  transform: rotate(-15deg);
  display: inline-block;
}
.brand-text { color: var(--text); }
.nav-links {
  list-style: none;
  display: flex;
  gap: 28px;
}
.nav-links a {
  color: var(--text-mute);
  text-decoration: none;
  font-size: 14px;
  transition: color 0.2s ease;
}
.nav-links a:hover { color: var(--accent-bright); }

/* ═══════════ HERO ═══════════ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding: 120px 32px 80px;
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  overflow: hidden;
}
.hero-bg img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 40%;
  filter: brightness(0.55) saturate(1.1);
}
.hero-bg-overlay {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 70% 50% at 30% 40%, rgba(0,121,193,0.25), transparent 60%),
    linear-gradient(180deg, rgba(8,32,42,0.45) 0%, rgba(13,43,54,0.85) 70%, var(--bg) 100%);
}
.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 1000px;
  margin: 0 auto;
}
.kicker {
  font-family: var(--font-en);
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--accent-bright);
  text-transform: uppercase;
  margin-bottom: 32px;
}
.hero-headline {
  font-size: clamp(40px, 7vw, 88px);
  line-height: 1.08;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 36px;
}
.hero-headline .cn { display: block; }
.hero-headline .en {
  display: block;
  font-family: var(--font-en);
  font-size: 0.4em;
  color: var(--accent-bright);
  font-weight: 300;
  letter-spacing: 0.04em;
  margin-top: 14px;
}
.hero-headline .en em { font-style: italic; font-weight: 400; }
.hero-sub {
  font-size: 19px;
  line-height: 1.7;
  color: var(--text-mute);
  max-width: 760px;
  margin-bottom: 28px;
}
.hero-sub strong { color: var(--text); }
.hero-meta {
  display: flex;
  gap: 16px;
  align-items: center;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  font-family: var(--font-en);
  margin-bottom: 56px;
}
.dot {
  width: 4px; height: 4px;
  background: var(--text-dim);
  border-radius: 50%;
}
.hero-cta {
  display: inline-block;
  padding: 14px 28px;
  border: 1px solid var(--accent);
  color: var(--accent-bright);
  text-decoration: none;
  font-size: 14px;
  letter-spacing: 0.06em;
  border-radius: 999px;
  transition: all 0.25s ease;
}
.hero-cta:hover {
  background: var(--accent);
  color: var(--bg-deep);
  transform: translateY(-2px);
}

/* ═══════════ SECTIONS ═══════════ */
.section {
  padding: 120px 0;
  border-top: 1px solid var(--divider);
}
.section-dark { background: var(--bg-deep); }
.section-kicker {
  font-family: var(--font-en);
  font-size: 11px;
  letter-spacing: 0.28em;
  color: var(--accent-bright);
  text-transform: uppercase;
  margin-bottom: 24px;
}
.section-title {
  font-size: clamp(32px, 4.5vw, 54px);
  line-height: 1.18;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 56px;
  max-width: 900px;
}
.section-title .cn { display: inline; }
.section-intro {
  font-size: 18px;
  color: var(--text-mute);
  max-width: 760px;
  margin-bottom: 64px;
}

/* ═══════════ BRIEF (品牌共识) ═══════════ */
.brief-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.brief-card {
  background: var(--bg-lift);
  border: 1px solid var(--divider);
  border-radius: 8px;
  padding: 32px;
  transition: border-color 0.25s ease, transform 0.25s ease;
}
.brief-card:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
}
.brief-card h3 {
  font-size: 18px;
  color: var(--accent-bright);
  margin-bottom: 16px;
  letter-spacing: 0.04em;
  font-weight: 600;
}
.brief-card p {
  color: var(--text-mute);
  font-size: 15px;
  line-height: 1.7;
}

/* ═══════════ SELLING POINTS ═══════════ */
.sp-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.sp-card {
  background: var(--bg-lift);
  border: 1px solid var(--divider);
  border-radius: 8px;
  padding: 32px 28px;
  position: relative;
  transition: all 0.25s ease;
}
.sp-card:hover {
  border-color: var(--accent);
  background: var(--bg-card);
}
.sp-num {
  font-family: var(--font-en);
  font-size: 11px;
  color: var(--accent-bright);
  letter-spacing: 0.18em;
  font-weight: 600;
  display: block;
  margin-bottom: 12px;
}
.sp-card h3 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 14px;
  letter-spacing: -0.01em;
}
.sp-claim {
  color: var(--text);
  font-size: 14px;
  line-height: 1.65;
  margin-bottom: 16px;
}
.sp-link {
  font-size: 13px;
  color: var(--text-dim);
  border-top: 1px solid var(--divider);
  padding-top: 14px;
  font-family: var(--font-en);
}
.sp-card-summary {
  background: linear-gradient(135deg, rgba(0,121,193,0.15), rgba(52,168,232,0.05));
  border-color: var(--accent);
}
.sp-card-summary .sp-num { color: var(--accent-yellow); }

/* ═══════════ VIDEO CARDS ═══════════ */
.vid {
  background: var(--bg-lift);
  border: 1px solid var(--divider);
  border-radius: 12px;
  padding: 40px;
  margin-bottom: 36px;
  transition: border-color 0.3s ease;
}
.vid:hover { border-color: var(--text-dim); }
.vid-body::after {
  content: "";
  display: block;
  clear: both;
}
.vid-hero {
  background: linear-gradient(135deg, rgba(0,121,193,0.20), rgba(52,168,232,0.06));
  border-color: var(--accent);
}
.vid-header {
  display: flex;
  align-items: flex-start;
  gap: 24px;
  margin-bottom: 28px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--divider);
}
.vid-num {
  font-family: var(--font-en);
  font-size: 14px;
  font-weight: 700;
  color: var(--bg-deep);
  background: var(--accent-bright);
  padding: 8px 14px;
  border-radius: 6px;
  letter-spacing: 0.05em;
  flex-shrink: 0;
}
.vid-header > div { flex: 1; }
.vid-title {
  font-size: 26px;
  font-weight: 700;
  margin-bottom: 6px;
  letter-spacing: -0.01em;
}
.vid-sub {
  font-family: var(--font-en);
  font-style: italic;
  font-size: 16px;
  color: var(--text-mute);
  font-weight: 400;
  letter-spacing: 0.02em;
}
.vid-meta {
  font-size: 13px;
  color: var(--text-dim);
  font-family: var(--font-en);
  letter-spacing: 0.04em;
}
.vid-badge {
  display: inline-block;
  padding: 3px 10px;
  background: var(--accent-yellow);
  color: var(--bg-deep);
  border-radius: 4px;
  font-weight: 700;
  font-size: 11px;
  letter-spacing: 0.08em;
  margin-left: 6px;
}
.vid-tag {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--accent-bright);
  background: rgba(0,121,193,0.15);
  border: 1px solid var(--accent);
  padding: 6px 12px;
  border-radius: 999px;
  white-space: nowrap;
  font-family: var(--font-en);
}
.hook {
  font-size: 16px;
  line-height: 1.75;
  color: var(--text-mute);
  margin-bottom: 24px;
  padding-left: 16px;
  border-left: 3px solid var(--accent);
}
.hook strong { color: var(--text); }

.beats {
  list-style: none;
  margin-bottom: 20px;
}
.beats li {
  padding: 12px 0;
  border-bottom: 1px dashed var(--divider);
  font-size: 15px;
  line-height: 1.65;
  color: var(--text-mute);
}
.beats li:last-child { border-bottom: none; }
.beats strong {
  display: inline-block;
  min-width: 92px;
  color: var(--accent-bright);
  font-family: var(--font-en);
  font-weight: 600;
  font-size: 14px;
}
.beats em {
  color: var(--text);
  font-style: normal;
  background: rgba(52,168,232,0.10);
  padding: 2px 8px;
  border-radius: 3px;
  font-size: 14px;
}
.why-ai {
  margin-top: 24px;
  padding: 16px 20px;
  background: var(--bg-card);
  border-radius: 6px;
  color: var(--text-mute);
  font-size: 14px;
  line-height: 1.7;
}
.why-ai strong { color: var(--accent-yellow); }

/* video pair (V1a + V1b) */
.vid-pair-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}
.vid-half h4 {
  font-size: 19px;
  margin-bottom: 12px;
  color: var(--text);
  font-weight: 700;
}
.vid-half h4 em {
  font-style: italic;
  font-family: var(--font-en);
  color: var(--text-dim);
  font-size: 14px;
  font-weight: 400;
  letter-spacing: 0.04em;
}

/* video frame (V2 placeholder) */
.video-frame {
  margin: 24px 0;
  border: 1px solid var(--divider);
  border-radius: 8px;
  overflow: hidden;
  background: var(--bg-deep);
  aspect-ratio: 16 / 9;
  display: flex;
  align-items: center;
  justify-content: center;
}
.video-frame video {
  width: 100%;
  height: 100%;
  display: block;
}
.video-placeholder {
  text-align: center;
  color: var(--text-mute);
}
.video-placeholder-text {
  font-size: 22px;
  color: var(--accent-bright);
  margin-bottom: 8px;
  font-weight: 600;
}
.video-placeholder-sub {
  font-size: 13px;
  color: var(--text-dim);
}

/* shotgrid (V2 colorway list) */
.shotgrid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 12px;
  margin-top: 20px;
}
.shot {
  background: var(--bg-card);
  padding: 18px 14px;
  border-radius: 6px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--text-mute);
}
.shot strong {
  color: var(--text);
  display: block;
  font-size: 15px;
  margin: 4px 0;
}
.shot-num {
  font-family: var(--font-en);
  font-size: 10px;
  color: var(--accent-bright);
  letter-spacing: 0.1em;
}

/* ref-row (A2/A3/A4 reference image rows — premium tight grid) */
.ref-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(0, 160px));
  gap: 10px;
  margin: 20px 0;
  justify-content: start;
}
.ref-row figure {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.ref-row img {
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  border-radius: 4px;
  border: 1px solid var(--divider);
}
.ref-row figcaption {
  font-size: 11px;
  color: var(--text-dim);
  font-family: var(--font-en);
  letter-spacing: 0.02em;
}

/* day-cycle (V6) */
.daycycle {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  margin: 20px 0;
}
.day-shot {
  background: var(--bg-card);
  padding: 14px;
  border-radius: 6px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 13px;
  border-left: 2px solid var(--accent);
}
.day-time {
  font-family: var(--font-en);
  font-size: 11px;
  color: var(--accent-bright);
  letter-spacing: 0.1em;
}
.day-shot strong {
  font-size: 15px;
  color: var(--text);
}
.day-desc {
  font-size: 12px;
  color: var(--text-dim);
}

/* ═══════════ CAMPAIGN GALLERY ═══════════ */
.campaign-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-bottom: 24px;
}
.campaign-fig {
  position: relative;
  overflow: hidden;
  border-radius: 6px;
  border: 1px solid var(--divider);
  background: var(--bg-deep);
  transition: transform 0.3s ease, border-color 0.3s ease;
}
.campaign-fig:hover {
  transform: translateY(-2px);
  border-color: var(--accent);
}
.campaign-fig img {
  width: 100%;
  display: block;
  aspect-ratio: 3 / 4;
  object-fit: cover;
}
.campaign-fig figcaption {
  padding: 12px 14px;
  background: var(--bg-lift);
  border-top: 1px solid var(--divider);
}
.campaign-fig figcaption strong {
  display: block;
  color: var(--text);
  font-size: 13px;
  margin-bottom: 4px;
  letter-spacing: 0.01em;
  line-height: 1.35;
}
.campaign-fig figcaption span {
  color: var(--text-mute);
  font-size: 11px;
  font-family: var(--font-en);
  line-height: 1.5;
  display: block;
}
.campaign-fig figcaption a {
  color: var(--accent-bright);
  text-decoration: none;
  border-bottom: 1px dashed var(--accent);
}
.campaign-fig figcaption a:hover { color: var(--text); }
.caption-note {
  font-size: 13px;
  color: var(--text-dim);
  font-style: italic;
  padding: 16px 0 0;
  border-top: 1px solid var(--divider);
  margin-top: 16px;
}

/* ═══════════ SUBHEAD (inside video cards) ═══════════ */
.subhead {
  font-size: 13px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent-bright);
  font-family: var(--font-en);
  font-weight: 600;
  margin: 28px 0 14px;
  padding-top: 8px;
  border-top: 1px dashed var(--divider);
}

/* ═══════════ COLOR ROW (A1 product references) ═══════════ */
.color-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 200px));
  gap: 12px;
  margin-bottom: 12px;
  justify-content: start;
}
.color-fig {
  background: linear-gradient(180deg, #000, var(--bg-deep));
  border-radius: 6px;
  overflow: hidden;
  border: 1px solid var(--divider);
  transition: transform 0.25s ease;
}
.color-fig:hover { transform: translateY(-3px); border-color: var(--accent); }
.color-fig img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: contain;
  background: #000;
  padding: 8px;
}
.color-fig figcaption {
  padding: 10px 8px;
  text-align: center;
  background: var(--bg-card);
  border-top: 1px solid var(--divider);
}
.color-fig figcaption strong {
  display: block;
  font-size: 13px;
  margin-bottom: 2px;
  color: var(--text);
}
.color-fig figcaption span {
  display: block;
  font-size: 11px;
  color: var(--text-dim);
  font-family: var(--font-en);
  letter-spacing: 0.04em;
}

/* ═══════════ VID-ANCHOR (single small ref image in R-tier cards) ═══════════ */
.vid-anchor {
  float: right;
  max-width: 220px;
  width: 35%;
  margin: 0 0 16px 24px;
  border-radius: 6px;
  overflow: hidden;
  border: 1px solid var(--divider);
}
.vid-anchor img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  display: block;
}
.vid-anchor figcaption {
  padding: 6px 10px;
  background: var(--bg-card);
  font-size: 11px;
  color: var(--text-dim);
  font-family: var(--font-en);
  letter-spacing: 0.02em;
}

/* ═══════════ DUAL-REF (A2 two-image side-by-side) ═══════════ */
.dual-ref {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 280px));
  gap: 14px;
  margin: 20px 0;
  justify-content: start;
}
.dual-ref figure {
  border-radius: 6px;
  overflow: hidden;
  border: 1px solid var(--divider);
  background: var(--bg-card);
}
.dual-ref img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  display: block;
}
.dual-ref figcaption {
  padding: 8px 12px;
  font-size: 11px;
  color: var(--text-mute);
  font-family: var(--font-en);
  letter-spacing: 0.02em;
  line-height: 1.55;
}

/* ═══════════ PHASE HEADERS (Phase A / Phase B dividers) ═══════════ */
.phase-header {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 28px 32px;
  margin: 48px 0 28px;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(0,121,193,0.08), rgba(8,32,42,0.4));
  border: 1px solid var(--divider);
  border-left: 4px solid var(--accent);
}
.phase-header.phase-b {
  background: linear-gradient(135deg, rgba(244,195,0,0.08), rgba(8,32,42,0.4));
  border-left-color: var(--accent-yellow);
}
.phase-header > div { flex: 1; }
.phase-tag {
  font-family: var(--font-en);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.22em;
  color: var(--bg-deep);
  background: var(--accent-bright);
  padding: 8px 14px;
  border-radius: 6px;
  white-space: nowrap;
  flex-shrink: 0;
}
.phase-header.phase-b .phase-tag { background: var(--accent-yellow); }
.phase-title {
  font-size: 26px;
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.01em;
  margin-bottom: 6px;
  color: var(--text);
}
.phase-desc {
  font-size: 14px;
  color: var(--text-mute);
  line-height: 1.65;
}
.phase-desc code {
  background: var(--bg-card);
  padding: 1px 8px;
  border-radius: 4px;
  font-family: var(--font-en);
  font-size: 12px;
  color: var(--accent-bright);
}
.phase-count {
  font-family: var(--font-en);
  font-size: 13px;
  font-weight: 600;
  color: var(--text-dim);
  letter-spacing: 0.08em;
  white-space: nowrap;
}

/* Phase A · R-prefixed video numbers (lower-cost, edit-only tier) */
.vid-num-r {
  background: var(--text-mute) !important;
  color: var(--bg-deep) !important;
}

/* ═══════════ FOOTER ═══════════ */
.footer {
  padding: 60px 0;
  background: var(--bg-deep);
  border-top: 1px solid var(--divider);
  text-align: center;
}
.footer-lockup {
  font-size: 14px;
  color: var(--text-mute);
  letter-spacing: 0.04em;
  margin-bottom: 16px;
}
.footer-lockup strong { color: var(--text); }
.footer-fineprint {
  font-size: 12px;
  color: var(--text-dim);
  line-height: 1.8;
}

/* ═══════════ RESPONSIVE ═══════════ */
@media (max-width: 900px) {
  .container { padding: 0 24px; }
  .topnav { padding: 14px 24px; }
  .nav-links { gap: 18px; }
  .nav-links a { font-size: 13px; }
  .hero { padding: 100px 24px 60px; }
  .section { padding: 80px 0; }
  .section-title { margin-bottom: 36px; }
  .brief-grid, .sp-grid {
    grid-template-columns: 1fr;
  }
  .vid { padding: 28px 20px; }
  .vid-header { flex-wrap: wrap; gap: 16px; }
  .vid-header > div { flex: 1 1 100%; order: 2; }
  .vid-tag { order: 1; }
  .vid-title { font-size: 22px; }
  .vid-pair-grid { grid-template-columns: 1fr; gap: 32px; }
  .shotgrid {
    grid-template-columns: repeat(2, 1fr);
  }
  .daycycle {
    grid-template-columns: repeat(2, 1fr);
  }
  .campaign-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .color-row {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .dual-ref {
    grid-template-columns: 1fr;
  }
  .vid-anchor {
    float: none;
    width: 100%;
    max-width: 280px;
    margin: 0 0 16px;
  }
  .phase-header {
    flex-direction: column;
    align-items: flex-start;
    padding: 20px 22px;
    gap: 14px;
  }
  .phase-title { font-size: 22px; }
  .campaign-grid {
    grid-template-columns: 1fr;
  }
  .color-row {
    grid-template-columns: repeat(2, 1fr);
  }
  .dual-ref {
    grid-template-columns: 1fr;
  }
  .beats strong { display: block; min-width: auto; margin-bottom: 4px; }
}

@media (max-width: 560px) {
  .brand-text { display: none; }
  .nav-links { gap: 14px; }
  .hero-headline { font-size: 38px; }
  .section-title { font-size: 28px; }
  .vid { padding: 24px 18px; }
  .vid-title { font-size: 19px; }
  .vid-sub { display: block; margin-top: 4px; font-size: 14px; }
}