/* ══════════════════════════════════════════════════
   ai-video.css — AI 视频实验详情页样式
   暗色基调，紫色/蓝紫色高光，强调生成感与流动感
   ══════════════════════════════════════════════════ */

:root {
  --ai-acid: #b388ff;
  --ai-glow: rgba(179, 136, 255, 0.32);
  --ai-muted: rgba(255, 255, 255, 0.58);
  --ai-surface: rgba(255, 255, 255, 0.04);
  --ai-border: rgba(255, 255, 255, 0.1);
}

.case-page {
  color: #f0edf0;
  background: #08080a;
}

/* ── Hero ── */
.case-hero {
  position: relative;
  min-height: 96vh;
  display: grid;
  align-items: end;
  overflow: hidden;
  background: #050508;
}

.case-hero-video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
}

.case-hero-shade {
  position: absolute;
  inset: 0;
  z-index: 1;
  background:
    linear-gradient(90deg, rgba(5, 5, 8, 0.92), rgba(5, 5, 8, 0.48), rgba(5, 5, 8, 0.18)),
    linear-gradient(180deg, rgba(5, 5, 8, 0.08), rgba(5, 5, 8, 0.18), #08080a);
}

.case-hero-copy {
  position: relative;
  z-index: 2;
  width: min(1080px, calc(100% - 44px));
  margin: 0 auto 96px;
}

.case-hero h1 {
  max-width: 940px;
  margin-top: 14px;
  color: #fff;
  font-size: clamp(3.2rem, 7.5vw, 7.2rem);
  line-height: 0.95;
}

.case-subtitle {
  margin: 18px 0 0;
  color: var(--ai-acid);
  font-size: 1.32rem;
  font-weight: 700;
}

.case-lead {
  max-width: 760px;
  margin: 24px 0 0;
  color: rgba(255, 255, 255, 0.84);
  font-size: 1.2rem;
}

/* ── Section shared ── */
.case-section {
  width: min(var(--max), calc(100% - 44px));
  margin: 0 auto;
  padding: 104px 0;
  scroll-margin-top: 88px;
}

.section-index {
  color: var(--ai-acid);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0;
  line-height: 1.4;
  text-transform: uppercase;
}

/* ── Overview ── */
.overview-section {
  display: grid;
  grid-template-columns: minmax(240px, 0.9fr) minmax(0, 1.25fr);
  gap: 56px;
  align-items: start;
  border-bottom: 1px solid var(--ai-border);
}

.overview-copy {
  display: grid;
  gap: 18px;
}

.overview-copy h2 {
  color: #fff;
}

.overview-copy p {
  color: var(--ai-muted);
}

.overview-meta {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin: 0;
}

.overview-meta div {
  min-height: 120px;
  display: grid;
  align-content: start;
  gap: 10px;
  padding-top: 18px;
  border-top: 1px solid var(--ai-border);
}

.overview-meta dt {
  color: var(--ai-acid);
  font-size: 0.8rem;
  font-weight: 800;
  text-transform: uppercase;
}

.overview-meta dd {
  margin: 0;
  color: rgba(255, 255, 255, 0.88);
}

/* ── Concept ── */
.concept-section {
  display: grid;
  gap: 42px;
}

.concept-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.95fr);
  gap: 54px;
  align-items: end;
}

.concept-copy {
  display: grid;
  gap: 16px;
}

.concept-copy h2 {
  color: #fff;
  font-size: clamp(2.2rem, 4vw, 4rem);
  line-height: 1.05;
}

.concept-copy p {
  color: var(--ai-muted);
}

.concept-keywords {
  display: grid;
  gap: 18px;
}

.concept-keywords article {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 6px 18px;
  padding: 18px 0;
  border-top: 1px solid var(--ai-border);
}

.concept-keywords span {
  grid-row: 1 / 3;
  color: var(--ai-acid);
  font-weight: 800;
}

.concept-keywords h3 {
  color: #fff;
  margin: 0;
}

.concept-keywords p {
  color: var(--ai-muted);
  margin: 0;
}

.concept-image {
  margin: 0;
  overflow: hidden;
  border-radius: 8px;
  background: #111;
}

.concept-image video,
.concept-image img {
  width: 100%;
  aspect-ratio: 21 / 9;
  object-fit: cover;
}

/* ── System ── */
.system-section {
  display: grid;
  gap: 34px;
}

.system-heading {
  display: grid;
  gap: 16px;
  max-width: 760px;
}

.system-heading h2 {
  color: #fff;
}

.system-heading p {
  color: var(--ai-muted);
}

.system-feature {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(320px, 0.65fr);
  gap: 28px;
  align-items: end;
}

.system-feature video,
.system-feature img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 8px;
  background: #111;
}

.system-feature div {
  display: grid;
  gap: 14px;
  padding-bottom: 4px;
}

.system-feature h3 {
  color: #fff;
  margin: 0;
}

.system-feature p {
  color: var(--ai-muted);
  margin: 0;
}

/* ── Process ── */
.process-section {
  display: grid;
  gap: 36px;
  border-top: 1px solid var(--ai-border);
}

.process-copy {
  display: grid;
  gap: 16px;
  max-width: 760px;
}

.process-copy h2 {
  color: #fff;
}

.flow-steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.flow-steps article {
  min-height: 178px;
  display: grid;
  align-content: start;
  gap: 12px;
  padding: 18px;
  background: var(--ai-surface);
  border: 1px solid var(--ai-border);
  border-radius: 8px;
}

.flow-steps span {
  color: var(--ai-acid);
  font-size: 0.82rem;
  font-weight: 800;
}

.flow-steps h3 {
  color: #fff;
  margin: 0;
}

.flow-steps p {
  color: var(--ai-muted);
  margin: 0;
}

/* ── Outcome ── */
.outcome-section {
  width: 100%;
  padding: 112px max(22px, calc((100vw - var(--max)) / 2));
  color: #fff;
  background: #0b0b0e;
  scroll-margin-top: 88px;
}

.outcome-intro {
  display: grid;
  gap: 16px;
  max-width: 760px;
  margin-bottom: 34px;
}

.outcome-intro h2 {
  color: #fff;
}

.outcome-intro p {
  color: var(--ai-muted);
}

.outcome-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.outcome-card {
  position: relative;
  overflow: hidden;
  border-radius: 8px;
  background: #111;
  cursor: pointer;
  transition: transform 0.35s cubic-bezier(0.22, 1, 0.36, 1),
              box-shadow 0.35s cubic-bezier(0.22, 1, 0.36, 1);
}

.outcome-card:hover {
  transform: translateY(-6px) scale(1.02);
  box-shadow: 0 12px 40px rgba(179, 136, 255, 0.18);
}

.outcome-card-media {
  position: relative;
  overflow: hidden;
}

.outcome-card-media video {
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  display: block;
  pointer-events: none;
  transition: transform 0.5s cubic-bezier(0.22, 1, 0.36, 1);
}

.outcome-card:hover .outcome-card-media video {
  transform: scale(1.06);
}

/* 卡片遮罩 — 默认显示标签，hover 时加深 */
.outcome-card-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(8, 8, 10, 0.72) 0%, transparent 45%);
  transition: opacity 0.35s ease;
  pointer-events: none;
}

.outcome-card:hover .outcome-card-media::after {
  opacity: 0.6;
}

.outcome-card-label {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 2;
  padding: 14px 16px;
  color: #fff;
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  transform: translateY(0);
  transition: transform 0.35s cubic-bezier(0.22, 1, 0.36, 1);
}

.outcome-card:hover .outcome-card-label {
  transform: translateY(-4px);
}

/* ── Reflection ── */
.reflection-section {
  width: 100%;
  padding: 104px max(22px, calc((100vw - var(--max)) / 2));
  background: #f2edf5;
  scroll-margin-top: 88px;
}

.reflection-section .section-index {
  color: #7c4dff;
}

.reflection-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: 60px;
  align-items: start;
}

.reflection-heading {
  display: grid;
  gap: 16px;
}

.reflection-heading h2 {
  color: var(--ink);
}

.reflection-points {
  display: grid;
  gap: 22px;
}

.reflection-points article {
  display: grid;
  gap: 10px;
  padding-top: 18px;
  border-top: 1px solid #d0c8d8;
}

.reflection-points h3 {
  color: var(--ink);
  margin: 0;
}

.reflection-points p {
  color: var(--muted);
  margin: 0;
}

/* ── Responsive ── */
@media (max-width: 1100px) {
  .flow-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .outcome-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .outcome-card:hover {
    transform: translateY(-4px) scale(1.01);
  }
}

@media (max-width: 900px) {
  .overview-section,
  .concept-layout,
  .system-feature,
  .reflection-layout {
    grid-template-columns: 1fr;
  }

  .overview-meta {
    grid-template-columns: 1fr 1fr;
  }
}

/* ═══ Fullscreen Overlay ═══ */
.fullscreen-overlay {
  position: fixed;
  z-index: 9999;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.92);
  backdrop-filter: blur(12px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.35s cubic-bezier(0.22, 1, 0.36, 1);
}

.fullscreen-overlay.is-open {
  opacity: 1;
  pointer-events: auto;
}

.fullscreen-container {
  position: relative;
  width: min(90vw, 1200px);
  display: grid;
  gap: 16px;
}

.fullscreen-video {
  width: 100%;
  max-height: 85vh;
  border-radius: 8px;
  background: #000;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.6);
}

.fullscreen-label {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.9rem;
  font-weight: 600;
  text-align: center;
  letter-spacing: 0.04em;
}

.fullscreen-close {
  position: fixed;
  z-index: 1;
  top: 24px;
  right: 24px;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 50%;
  font-size: 1.1rem;
  cursor: pointer;
  transition: background 0.22s ease, transform 0.22s ease;
}

.fullscreen-close:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: scale(1.1);
}

@media (max-width: 720px) {
  .case-hero {
    min-height: 88vh;
  }

  .case-hero-copy {
    width: calc(100% - 32px);
    margin-bottom: 58px;
  }

  .case-hero h1 {
    font-size: 2.8rem;
  }

  .case-section {
    width: calc(100% - 32px);
    padding: 68px 0;
  }

  .overview-meta,
  .flow-steps,
  .outcome-grid {
    grid-template-columns: 1fr;
  }

  .concept-image video,
  .concept-image img {
    aspect-ratio: 4 / 3;
  }

  .outcome-section,
  .reflection-section {
    padding: 68px 16px;
  }
}