:root {
  --bg: #f7f9ff;
  --text: #24324a;
  --text-strong: #172033;
  --text-muted: #647089;
  --line: rgba(126, 151, 196, .32);
  --line-purple: rgba(145, 105, 215, .36);
  --accent: #8f6fd6;
  --shadow: 0 20px 60px rgba(90, 113, 156, .18);
  --shadow-soft: 0 10px 30px rgba(90, 113, 156, .12);
  --font-sans: "IBM Plex Sans", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-serif: "Source Serif 4", Georgia, serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  background: var(--bg);
}

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--text);
  background:
    radial-gradient(circle at 12% 8%, rgba(190, 173, 236, .36), transparent 30%),
    radial-gradient(circle at 88% 10%, rgba(176, 215, 247, .44), transparent 32%),
    linear-gradient(180deg, #fbfcff 0%, #f3f7ff 42%, #f8f5ff 100%);
  min-height: 100vh;
}

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

img,
video {
  max-width: 100%;
  display: block;
}

button,
summary {
  font-family: inherit;
}

.container {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

/* V2V 展示区域使用更宽容器，减少页面左右留白 */
.v2v-container {
  width: min(1520px, calc(100% - 24px));
}

.site-nav {
  position: sticky;
  top: 0;
  z-index: 30;
  border-bottom: 1px solid var(--line);
  background: rgba(250, 252, 255, .78);
  backdrop-filter: blur(22px);
  box-shadow: 0 8px 24px rgba(90, 113, 156, .08);
}

.nav-inner {
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.nav-brand {
  display: flex;
  align-items: center;
  min-width: 120px;
}

.nav-logo {
  width: 128px;
  height: auto;
  object-fit: contain;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-link {
  padding: 9px 14px;
  color: var(--text-muted);
  border-radius: 999px;
  font-size: 14px;
  transition: color .18s ease, background .18s ease, box-shadow .18s ease;
}

.nav-link:hover {
  color: var(--accent);
  background: rgba(237, 230, 255, .75);
  box-shadow: inset 0 0 0 1px rgba(143, 111, 214, .18);
}

.nav-more {
  display: none;
  position: relative;
}

.nav-more-toggle {
  cursor: pointer;
  color: var(--text-muted);
  padding: 8px 12px;
  border: 1px solid var(--line-purple);
  border-radius: 999px;
  list-style: none;
  background: rgba(255, 255, 255, .72);
}

.nav-more-toggle::-webkit-details-marker {
  display: none;
}

.nav-more-menu {
  position: absolute;
  right: 0;
  top: calc(100% + 10px);
  min-width: 180px;
  padding: 10px;
  border-radius: 16px;
  background: rgba(255, 255, 255, .96);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.nav-more-menu a {
  display: block;
  padding: 10px 12px;
  color: var(--text-muted);
  border-radius: 10px;
}

.nav-more-menu a:hover {
  color: var(--accent);
  background: rgba(237, 230, 255, .75);
}

.hero {
  padding: 92px 0 70px;
}

.hero-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 42px;
  align-items: center;
  margin-top: 34px;
}

/* Demo video 占据整行，不再缩在右侧 */
.hero-copy {
  max-width: 960px;
}

.hero-demo-placeholder {
  width: 100%;
  min-height: 420px;
}

.eyebrow {
  color: var(--accent);
  font-weight: 800;
  letter-spacing: .08em;
  text-transform: uppercase;
  font-size: 13px;
  margin: 0 0 18px;
}

.title {
  margin: 0;
  font-family: var(--font-serif);
  color: var(--text-strong);
}

.hero-title-full {
  color: transparent;
  background: linear-gradient(90deg, #1b2235 0%, #4f4fc4 36%, #4d91d9 68%, #79bddf 100%);
  -webkit-background-clip: text;
  background-clip: text;
}

.hero-title-brand {
  font-size: clamp(76px, 10vw, 150px);
  display: block;
  color: #182033;
  letter-spacing: -.06em;
  line-height: .9;
}

.hero-title-gradient {
  display: block;
  margin-top: 18px;
  font-size: clamp(38px, 5vw, 72px);
  line-height: 1.02;
  color: transparent;
  background: linear-gradient(90deg, #7d5fd1 0%, #6d79d8 34%, #4f9cda 68%, #76bee2 100%);
  -webkit-background-clip: text;
  background-clip: text;
}

.affiliation {
  margin-top: 14px;
  color: #506079;
  font-weight: 700;
  line-height: 1.6;
}

.affiliation sup {
  color: var(--accent);
  font-weight: 900;
}

.author-note {
  display: block;
  margin-top: 4px;
  color: var(--text-muted);
  font-size: 14px;
  font-weight: 600;
}

.hero-summary {
  margin: 24px 0 0;
  max-width: 760px;
  color: var(--text-muted);
  font-size: 18px;
  line-height: 1.72;
}

.task-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 24px 0 0;
}

.task-pills span {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  padding: 6px 12px;
  border-radius: 999px;
  color: #4c5d7c;
  font-size: 13px;
  font-weight: 800;
  background: linear-gradient(180deg, #fff 0%, #eef4ff 100%);
  border: 1px solid rgba(126, 151, 196, .36);
  box-shadow: 0 8px 22px rgba(90, 113, 156, .1);
}

.links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.link-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 18px;
  border-radius: 999px;
  color: #fff;
  font-weight: 800;
  background: linear-gradient(135deg, #8f6fd6 0%, #5f9fd6 100%);
  box-shadow: 0 12px 28px rgba(105, 123, 200, .24);
  border: 1px solid rgba(255, 255, 255, .72);
  transition: transform .18s ease, box-shadow .18s ease, filter .18s ease;
}

.link-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 16px 36px rgba(105, 123, 200, .28);
  filter: saturate(1.08);
}

.link-btn-muted {
  color: #4d5c77;
  background: rgba(255, 255, 255, .78);
  border: 1px solid rgba(126, 151, 196, .32);
  box-shadow: 0 10px 24px rgba(90, 113, 156, .1);
}

.demo-video-frame {
  width: 100%;
  min-height: 420px;
  padding: 14px;
  border-radius: 28px;
  background: linear-gradient(180deg, rgba(255, 255, 255, .88), rgba(241, 246, 255, .88));
  border: 1px solid rgba(126, 151, 196, .36);
  box-shadow: var(--shadow);
}

.demo-video-inner {
  height: 100%;
  min-height: 392px;
  display: grid;
  place-items: center;
  text-align: center;
  border-radius: 20px;
  background: linear-gradient(135deg, rgba(143, 111, 214, .12), rgba(95, 159, 214, .16));
  border: 1px dashed rgba(126, 151, 196, .42);
}

.demo-play-icon {
  width: 68px;
  height: 68px;
  border-radius: 50%;
  background: linear-gradient(135deg, #8f6fd6, #5f9fd6);
  position: relative;
  box-shadow: 0 18px 42px rgba(90, 113, 156, .22);
}

.demo-play-icon:after {
  content: "";
  position: absolute;
  left: 28px;
  top: 22px;
  border-left: 18px solid #fff;
  border-top: 12px solid transparent;
  border-bottom: 12px solid transparent;
}

.demo-placeholder-title {
  margin: 18px 0 4px;
  font-weight: 800;
  color: var(--text-strong);
}

.demo-placeholder-copy {
  margin: 0;
  color: var(--text-muted);
}

.section {
  padding: 86px 0;
}

.section-centered {
  text-align: center;
}

.dark-showcase {
  background:
    radial-gradient(circle at 16% 0%, rgba(143, 111, 214, .14), transparent 34%),
    radial-gradient(circle at 84% 8%, rgba(95, 159, 214, .13), transparent 36%),
    #050604;
  border-top: 1px solid rgba(255, 255, 255, .08);
  border-bottom: 1px solid rgba(255, 255, 255, .08);
}

.dark-showcase .section-title {
  color: #f4efe4;
}

.dark-showcase .section-copy {
  color: rgba(244, 239, 228, .72);
}

.section-title {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(32px, 4vw, 52px);
  line-height: 1.05;
  letter-spacing: -.025em;
  color: var(--text-strong);
  text-align: center;
}

.section-title:after {
  content: "";
  display: block;
  width: 82px;
  height: 4px;
  margin: 18px auto 0;
  border-radius: 999px;
  background: linear-gradient(90deg, #a98bdc, #7da7d9);
}

.section-copy {
  max-width: 820px;
  margin: 22px auto 0;
  color: var(--text-muted);
  font-size: 17px;
  line-height: 1.72;
}

/* V2V case 使用更大空间显示 */
.video-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
  margin-top: 42px;
}

#v2v .video-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.video-item {
  position: relative;
  overflow: hidden;
  border-radius: 18px;
  background: rgba(10, 12, 18, .92);
  border: 1px solid rgba(126, 151, 196, .28);
  box-shadow: 0 10px 30px rgba(0, 0, 0, .24);
  cursor: pointer;
  transition: transform .22s ease, box-shadow .22s ease, border-color .22s ease;
}

.video-item:hover {
  transform: translateY(-4px);
  border-color: rgba(185, 155, 232, .72);
  box-shadow: 0 22px 54px rgba(0, 0, 0, .34);
}

.sample-card {
  isolation: isolate;
}

.sample-media-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  background: #090b0f;
}

.sample-video-pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  min-width: 0;
}

.sample-reference,
.sample-video-block {
  position: relative;
  overflow: hidden;
  background: #101522;
}

.sample-video-block video {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: #dce8f7;
  transition: transform .35s ease, filter .35s ease;
}

.sample-card:hover .sample-video-block video {
  transform: scale(1.035);
  filter: saturate(1.08) contrast(1.04);
}

.sample-video-block + .sample-video-block {
  border-left: 1px solid rgba(255, 255, 255, .14);
}

.sample-reference span,
.sample-video-block span {
  position: absolute;
  left: 10px;
  top: 10px;
  z-index: 2;
  padding: 5px 9px;
  border-radius: 999px;
  color: #fff;
  font-size: 11px;
  font-weight: 900;
  letter-spacing: .02em;
  background: rgba(0, 0, 0, .48);
  border: 1px solid rgba(255, 255, 255, .2);
  backdrop-filter: blur(12px);
}

.sample-output-block span {
  background: rgba(143, 111, 214, .78);
}

.sample-card:after {
  display: none;
}

.video-prompt {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: flex-start;
  gap: 8px;
  max-height: 0;
  padding: 0 14px;
  overflow: hidden;
  color: #f8f4ea;
  font-size: 14px;
  line-height: 1.45;
  font-weight: 800;
  text-align: left;
  background: linear-gradient(180deg, rgba(22, 23, 26, .96), rgba(10, 11, 13, .98));
  border-top: 1px solid rgba(255, 255, 255, 0);
  opacity: 0;
  transform: translateY(-4px);
  transition: max-height .24s ease, padding .24s ease, opacity .2s ease, transform .24s ease, border-color .24s ease;
}

.sample-card:hover .video-prompt {
  max-height: 116px;
  padding: 12px 14px 14px;
  opacity: 1;
  transform: translateY(0);
  border-top-color: rgba(255, 255, 255, .12);
}

.sample-badge {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  margin-right: 0;
  padding: 3px 7px;
  border-radius: 999px;
  color: #fff;
  background: linear-gradient(135deg, #8f6fd6, #5f9fd6);
  border: 1px solid rgba(255, 255, 255, .24);
  font-size: 11px;
  font-weight: 900;
}

.prompt-text {
  display: block;
  min-width: 0;
  overflow: visible;
  text-overflow: initial;
  white-space: normal;
}

#v2v .video-item {
  border-color: rgba(95, 159, 214, .38);
}

#v2v .video-item:hover {
  border-color: rgba(95, 159, 214, .78);
}

#rv2v .video-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
  align-items: start;
}

#rv2v .video-item {
  border-radius: 24px;
  background: linear-gradient(180deg, rgba(19, 21, 28, .98), rgba(8, 9, 13, .98));
  border: 1px solid rgba(151, 117, 224, .42);
  box-shadow: 0 18px 52px rgba(0, 0, 0, .36), inset 0 0 0 1px rgba(255, 255, 255, .035);
}

#rv2v .video-item:hover {
  border-color: rgba(178, 146, 246, .82);
  box-shadow: 0 26px 72px rgba(0, 0, 0, .48), 0 0 0 1px rgba(178, 146, 246, .22);
}

.rv2v-card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 13px 16px 0;
  color: rgba(244, 239, 228, .72);
  background: linear-gradient(180deg, rgba(19, 21, 28, .98), rgba(19, 21, 28, 0));
}

.rv2v-card-head span {
  font-size: 13px;
  font-weight: 800;
  letter-spacing: .02em;
}

.rv2v-card-head strong {
  padding: 4px 9px;
  border-radius: 999px;
  color: #fff;
  font-size: 11px;
  background: linear-gradient(135deg, #a47cee, #6f9de8);
  box-shadow: 0 8px 18px rgba(111, 157, 232, .22);
}

#rv2v .sample-media-grid.has-reference {
  display: grid;
  grid-template-columns: minmax(150px, .82fr) minmax(0, 1.9fr);
  gap: 10px;
  padding: 10px;
  background:
    radial-gradient(circle at 0% 0%, rgba(143, 111, 214, .16), transparent 36%),
    radial-gradient(circle at 100% 0%, rgba(95, 159, 214, .12), transparent 36%),
    #080a10;
}

#rv2v .sample-reference {
  min-height: 235px;
  border-radius: 18px;
  background: linear-gradient(180deg, rgba(255, 255, 255, .08), rgba(255, 255, 255, .03));
  border: 1px solid rgba(255, 255, 255, .12);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, .025), 0 12px 28px rgba(0, 0, 0, .22);
  display: flex;
  align-items: stretch;
  justify-content: center;
}

#rv2v .reference-stage {
  width: 100%;
  min-height: 235px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 10px;
  background: radial-gradient(circle at 50% 40%, rgba(255, 255, 255, .09), transparent 42%), #111620;
}

#rv2v .sample-reference img {
  width: 100%;
  height: 100%;
  max-height: 235px;
  aspect-ratio: auto;
  object-fit: contain;
  object-position: center;
  transition: transform .35s ease, filter .35s ease;
}

#rv2v .sample-card:hover .sample-reference img {
  transform: scale(1.025);
  filter: saturate(1.06) contrast(1.03);
}

#rv2v .sample-video-pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  min-height: 235px;
}

#rv2v .sample-video-block {
  border-radius: 18px;
  background: linear-gradient(180deg, #111722 0%, #080b12 100%);
  border: 1px solid rgba(255, 255, 255, .1);
  overflow: hidden;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, .025), 0 12px 28px rgba(0, 0, 0, .2);
}

#rv2v .sample-video-block video {
  width: 100%;
  height: 100%;
  min-height: 235px;
  aspect-ratio: auto;
  object-fit: cover;
  object-position: center;
  background: #101522;
}

#rv2v .sample-reference span,
#rv2v .sample-video-block span {
  left: 12px;
  top: 12px;
  padding: 6px 11px;
  border-radius: 999px;
  color: #fff;
  font-size: 12px;
  font-weight: 900;
  background: rgba(12, 14, 20, .62);
  border: 1px solid rgba(255, 255, 255, .22);
  box-shadow: 0 8px 18px rgba(0, 0, 0, .22);
  backdrop-filter: blur(16px);
}

#rv2v .sample-reference span {
  background: linear-gradient(135deg, rgba(65, 74, 91, .84), rgba(37, 42, 54, .84));
}

#rv2v .sample-output-block span {
  background: linear-gradient(135deg, rgba(164, 124, 238, .92), rgba(115, 142, 232, .92));
}

#rv2v .video-prompt {
  background: linear-gradient(180deg, rgba(18, 19, 25, .98), rgba(11, 12, 17, .98));
}

#rv2v .sample-card:hover .video-prompt {
  border-top-color: rgba(178, 146, 246, .22);
}

#rv2v .sample-badge {
  background: linear-gradient(135deg, #a47cee, #6f9de8);
}

.r2v-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
  margin-top: 44px;
}

.r2v-case {
  overflow: hidden;
  border-radius: 26px;
  background: linear-gradient(180deg, rgba(20, 22, 30, .98), rgba(8, 9, 13, .98));
  border: 1px solid rgba(120, 190, 205, .42);
  box-shadow: 0 18px 52px rgba(0, 0, 0, .36), inset 0 0 0 1px rgba(255, 255, 255, .035);
  transition: transform .22s ease, border-color .22s ease, box-shadow .22s ease;
}

.r2v-case:hover {
  transform: translateY(-4px);
  border-color: rgba(120, 220, 235, .78);
  box-shadow: 0 28px 76px rgba(0, 0, 0, .48), 0 0 0 1px rgba(120, 220, 235, .18);
}

/* R2V：输入图像和输出视频宽度相同，避免视频过大 */
.r2v-media-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  padding: 14px;
  background:
    radial-gradient(circle at 10% 0%, rgba(120, 190, 205, .12), transparent 36%),
    radial-gradient(circle at 100% 20%, rgba(143, 111, 214, .12), transparent 34%),
    #080a10;
}

.r2v-inputs {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.r2v-input {
  position: relative;
  overflow: hidden;
  margin: 0;
  min-height: 260px;
  border-radius: 18px;
  background: radial-gradient(circle at 50% 38%, rgba(255, 255, 255, .08), transparent 44%), #111620;
  border: 1px solid rgba(255, 255, 255, .11);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, .025), 0 12px 26px rgba(0, 0, 0, .22);
}

.r2v-input img {
  width: 100%;
  height: 100%;
  min-height: 260px;
  object-fit: contain;
  object-position: center;
  padding: 8px;
  transition: transform .35s ease, filter .35s ease;
}

.r2v-case:hover .r2v-input img {
  transform: scale(1.025);
  filter: saturate(1.06) contrast(1.03);
}

.r2v-input figcaption,
.r2v-output span {
  position: absolute;
  left: 12px;
  top: 12px;
  z-index: 2;
  padding: 6px 11px;
  border-radius: 999px;
  color: #fff;
  font-size: 12px;
  font-weight: 900;
  background: rgba(12, 14, 20, .62);
  border: 1px solid rgba(255, 255, 255, .22);
  box-shadow: 0 8px 18px rgba(0, 0, 0, .22);
  backdrop-filter: blur(16px);
}

.r2v-output {
  position: relative;
  overflow: hidden;
  min-height: 260px;
  border-radius: 18px;
  background: linear-gradient(180deg, #111722 0%, #080b12 100%);
  border: 1px solid rgba(120, 190, 205, .22);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, .025), 0 12px 28px rgba(0, 0, 0, .24);
}

.r2v-output video {
  width: 100%;
  height: 100%;
  min-height: 260px;
  object-fit: cover;
  object-position: center;
  background: #101522;
  transition: transform .35s ease, filter .35s ease;
}

.r2v-case:hover .r2v-output video {
  transform: scale(1.025);
  filter: saturate(1.08) contrast(1.04);
}

.r2v-output span {
  background: linear-gradient(135deg, rgba(99, 174, 191, .94), rgba(95, 159, 214, .94));
}

.section-framework {
  background:
    radial-gradient(circle at 20% 0%, rgba(185, 155, 232, .18), transparent 30%),
    radial-gradient(circle at 80% 10%, rgba(126, 184, 220, .18), transparent 32%);
}

.figure-panel {
  margin: 42px auto 0;
  padding: 16px;
  border-radius: 28px;
  background: linear-gradient(180deg, rgba(255, 255, 255, .92), rgba(241, 246, 255, .9));
  border: 1px solid rgba(126, 151, 196, .34);
  box-shadow: var(--shadow);
}

.framework-img {
  width: 100%;
  border-radius: 18px;
  border: 1px solid rgba(126, 151, 196, .22);
}

.media-caption {
  margin-top: 14px;
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.55;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-top: 32px;
}

.feature-card {
  padding: 24px;
  border-radius: 22px;
  text-align: left;
  background: linear-gradient(180deg, rgba(255, 255, 255, .92), rgba(244, 248, 255, .86));
  border: 1px solid rgba(126, 151, 196, .3);
  box-shadow: var(--shadow-soft);
}

.feature-card h3 {
  margin: 0 0 10px;
  color: var(--text-strong);
  font-size: 18px;
}

.feature-card p {
  margin: 0;
  color: var(--text-muted);
  line-height: 1.65;
}

.citation-card {
  position: relative;
  margin-top: 28px;
  border-radius: 22px;
  background: linear-gradient(180deg, rgba(255, 255, 255, .94), rgba(245, 248, 255, .92));
  border: 1px solid rgba(126, 151, 196, .32);
  box-shadow: var(--shadow-soft);
  overflow: hidden;
}

.citation-block {
  margin: 0;
  padding: 26px;
  overflow-x: auto;
  color: #35435c;
  font-size: 14px;
  line-height: 1.65;
  text-align: left;
}

.copy-citation-btn {
  position: absolute;
  top: 14px;
  right: 14px;
  padding: 7px 12px;
  border-radius: 999px;
  border: 1px solid rgba(143, 111, 214, .28);
  background: #f2edff;
  color: #7356b8;
  font-weight: 800;
  cursor: pointer;
  z-index: 2;
}

footer {
  padding: 54px 0 70px;
  color: var(--text-muted);
  text-align: center;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0), rgba(235, 241, 255, .72));
  border-top: 1px solid rgba(126, 151, 196, .22);
}

footer p {
  margin: 10px 0 0;
}

footer a {
  color: var(--accent);
  font-weight: 800;
}

.footer-brand-mark {
  width: 132px;
  height: auto;
  margin: 0 auto 18px;
  opacity: .88;
}

@media (max-width: 1180px) {
  #v2v .video-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .v2v-container {
    width: min(100% - 24px, 1180px);
  }
}

@media (max-width: 980px) {
  .video-grid,
  .feature-grid {
    grid-template-columns: 1fr 1fr;
  }

  .nav-links {
    display: none;
  }

  .nav-more {
    display: block;
  }

  #rv2v .video-grid {
    grid-template-columns: 1fr;
  }

  #rv2v .sample-media-grid.has-reference {
    grid-template-columns: minmax(140px, .75fr) minmax(0, 1.8fr);
  }

  .r2v-media-row {
    grid-template-columns: 1fr;
  }

  .r2v-input,
  .r2v-input img,
  .r2v-output,
  .r2v-output video {
    min-height: 220px;
  }
}

@media (max-width: 680px) {
  .container {
    width: min(100% - 28px, 1180px);
  }

  .v2v-container {
    width: min(100% - 16px, 1180px);
  }

  .nav-inner {
    height: 64px;
  }

  .nav-logo {
    width: 112px;
  }

  .hero {
    padding: 64px 0 48px;
  }

  .hero-title-brand {
    font-size: clamp(52px, 18vw, 82px);
  }

  .hero-title-gradient {
    font-size: clamp(30px, 10vw, 44px);
  }

  .hero-summary {
    font-size: 16px;
  }

  .hero-demo-placeholder {
    min-height: 300px;
  }

  .demo-video-frame {
    min-height: 300px;
  }

  .demo-video-inner {
    min-height: 272px;
  }

  .video-grid,
  .feature-grid,
  #v2v .video-grid {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 64px 0;
  }

    .section-title {
    font-size: clamp(30px, 10vw, 42px);
  }

  .section-copy {
    font-size: 15px;
  }

  .sample-video-pair {
    grid-template-columns: 1fr 1fr;
  }

  .video-prompt {
    max-width: none;
    border-radius: 0;
    transform: translateY(-4px);
  }

  .sample-card:hover .video-prompt {
    transform: translateY(0);
  }

  .sample-badge {
    font-size: 10px;
    padding: 3px 6px;
  }

  .prompt-text {
    font-size: 13px;
    line-height: 1.45;
  }

  .citation-block {
    padding: 56px 18px 22px;
    font-size: 12px;
  }

  #rv2v .sample-media-grid.has-reference {
    grid-template-columns: 1fr;
  }

  #rv2v .sample-reference {
    min-height: auto;
  }

  #rv2v .reference-stage {
    min-height: 0;
    max-height: 280px;
  }

  #rv2v .sample-reference img {
    height: auto;
    min-height: 0;
    max-height: 260px;
    object-fit: contain;
  }

  #rv2v .sample-video-pair {
    grid-template-columns: 1fr 1fr;
    min-height: 0;
  }

  #rv2v .sample-video-block video {
    min-height: 0;
    aspect-ratio: 16 / 9;
  }

  /* 移动端 R2V：先显示三张输入图，再显示输出视频 */
  .r2v-media-row {
    padding: 10px;
    gap: 10px;
    grid-template-columns: 1fr;
  }

  .r2v-inputs {
    grid-template-columns: 1fr 1fr 1fr;
    gap: 8px;
  }

  .r2v-input,
  .r2v-input img {
    min-height: 150px;
  }

  .r2v-input img {
    padding: 6px;
  }

  .r2v-output,
  .r2v-output video {
    min-height: 220px;
  }

  .r2v-input figcaption,
  .r2v-output span {
    left: 8px;
    top: 8px;
    padding: 4px 8px;
    font-size: 10px;
  }

  .r2v-case-no-head .r2v-media-row {
    border-radius: 26px;
  }

  .r2v-case-no-head {
    padding: 0;
  }

  .r2v-case-no-head .r2v-media-row {
    border-top: none;
  }
}

@media (max-width: 480px) {
  .container {
    width: min(100% - 20px, 1180px);
  }

  .v2v-container {
    width: min(100% - 12px, 1180px);
  }

  .hero {
    padding: 52px 0 42px;
  }

  .hero-title-brand {
    font-size: clamp(48px, 20vw, 72px);
  }

  .hero-title-gradient {
    margin-top: 14px;
    font-size: clamp(26px, 11vw, 38px);
  }

  .affiliation {
    font-size: 14px;
  }

  .author-note {
    font-size: 12px;
  }

  .task-pills {
    gap: 8px;
  }

  .task-pills span {
    min-height: 30px;
    padding: 5px 10px;
    font-size: 12px;
  }

  .links {
    gap: 10px;
  }

  .link-btn {
    min-height: 40px;
    padding: 0 15px;
    font-size: 14px;
  }

  .hero-demo-placeholder {
    min-height: 260px;
  }

  .demo-video-frame {
    min-height: 260px;
    padding: 10px;
    border-radius: 22px;
  }

  .demo-video-inner {
    min-height: 238px;
    border-radius: 16px;
  }

  .demo-play-icon {
    width: 56px;
    height: 56px;
  }

  .demo-play-icon:after {
    left: 23px;
    top: 18px;
    border-left-width: 15px;
    border-top-width: 10px;
    border-bottom-width: 10px;
  }

  .video-grid {
    gap: 16px;
  }

  #v2v .video-grid {
    gap: 14px;
  }

  .sample-video-pair {
    grid-template-columns: 1fr;
  }

  .sample-video-block + .sample-video-block {
    border-left: none;
    border-top: 1px solid rgba(255, 255, 255, .14);
  }

  .sample-video-block video {
    aspect-ratio: 16 / 9;
  }

  #rv2v .sample-video-pair {
    grid-template-columns: 1fr;
  }

  #rv2v .sample-video-block + .sample-video-block {
    border-left: none;
    border-top: none;
  }

  .video-prompt {
    display: block;
  }

  .sample-badge {
    display: inline-flex;
    margin-bottom: 7px;
  }

  .prompt-text {
    display: block;
  }

  .r2v-inputs {
    grid-template-columns: 1fr;
  }

  .r2v-input,
  .r2v-input img {
    min-height: 220px;
  }

  .r2v-output,
  .r2v-output video {
    min-height: 220px;
  }

  .feature-grid {
    gap: 14px;
  }

  .feature-card {
    padding: 20px;
  }

  footer {
    padding: 44px 0 56px;
  }
}