:root {
  --ink: #13151f;
  --ink-soft: #343846;
  --muted: #697183;
  --line: #e6e9ef;
  --paper: #ffffff;
  --paper-soft: #f7f8fb;
  --cyan: #16b7d9;
  --cyan-dark: #0786a5;
  --coral: #ff5f57;
  --yellow: #f5bd35;
  --green: #25b67a;
  --blue: #315dff;
  --shadow: 0 24px 70px rgba(25, 31, 46, 0.11);
  --radius: 8px;
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  width: 100%;
  max-width: 100%;
  overflow-x: hidden;
  scroll-behavior: smooth;
}

body {
  width: 100%;
  max-width: 100%;
  margin: 0;
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Microsoft YaHei", sans-serif;
  background:
    linear-gradient(rgba(19, 21, 31, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(19, 21, 31, 0.045) 1px, transparent 1px),
    linear-gradient(180deg, #ffffff 0%, #f7f8fb 42%, #ffffff 100%);
  background-size: 34px 34px, 34px 34px, auto;
  overflow-x: hidden;
}

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

img {
  display: block;
  width: 100%;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  width: min(var(--max), calc(100% - 48px));
  margin: 18px auto 0;
  padding: 12px 14px;
  border: 1px solid rgba(230, 233, 239, 0.82);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.88);
  box-shadow: 0 16px 40px rgba(25, 31, 46, 0.08);
  backdrop-filter: blur(16px);
  animation: slideDown 620ms ease both;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: 170px;
}

.brand-mark {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border-radius: 8px;
  color: #ffffff;
  font-weight: 900;
  background:
    linear-gradient(135deg, var(--cyan), var(--blue) 58%, var(--coral)),
    var(--cyan);
  box-shadow: 0 10px 24px rgba(22, 183, 217, 0.24);
}

.brand strong,
.brand em {
  display: block;
  line-height: 1.1;
}

.brand strong {
  font-size: 15px;
}

.brand em {
  margin-top: 4px;
  color: var(--muted);
  font-size: 12px;
  font-style: normal;
}

.nav-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  color: var(--muted);
  font-size: 14px;
}

.nav-links a,
.header-cta,
.button {
  border-radius: 8px;
  transition:
    transform 180ms ease,
    color 180ms ease,
    background-color 180ms ease,
    border-color 180ms ease,
    box-shadow 180ms ease;
}

.nav-links a {
  padding: 10px 12px;
}

.nav-links a:hover {
  color: var(--ink);
  background: var(--paper-soft);
}

.header-cta {
  padding: 10px 14px;
  color: #ffffff;
  font-size: 14px;
  font-weight: 800;
  background: var(--ink);
}

.header-cta:hover,
.button:hover {
  transform: translateY(-2px);
}

.section-shell {
  width: min(var(--max), calc(100% - 48px));
  margin: 0 auto;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.04fr) minmax(360px, 0.76fr);
  gap: 36px;
  align-items: center;
  min-height: 610px;
  padding: 58px 0 46px;
}

.hero-copy {
  min-width: 0;
  animation: riseIn 760ms ease both 120ms;
}

.role-line,
.section-heading span,
.contact-section span,
.tag {
  margin: 0;
  color: var(--cyan-dark);
  font-size: 13px;
  font-weight: 900;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 720px;
  margin-bottom: 22px;
  font-size: 58px;
  line-height: 1.06;
  overflow-wrap: break-word;
}

.title-line {
  display: inline;
}

.hero-lead {
  max-width: 680px;
  color: var(--ink-soft);
  font-size: 18px;
  line-height: 1.85;
  overflow-wrap: break-word;
}

.lead-line {
  display: inline;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 18px;
  border: 1px solid transparent;
  font-size: 14px;
  font-weight: 900;
}

.button.primary {
  color: #ffffff;
  background: var(--ink);
  box-shadow: 0 14px 34px rgba(19, 21, 31, 0.18);
}

.button.secondary {
  border-color: var(--line);
  color: var(--ink);
  background: var(--paper);
}

.button.primary:hover {
  background: var(--cyan-dark);
}

.button.secondary:hover {
  border-color: var(--ink);
}

.hero-panel {
  position: relative;
  overflow: hidden;
  min-width: 0;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    linear-gradient(135deg, rgba(22, 183, 217, 0.08), transparent 36%),
    linear-gradient(180deg, #ffffff, #fbfcff);
  box-shadow: var(--shadow);
  animation: riseIn 760ms ease both 260ms;
}

.hero-panel::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(110deg, transparent 0%, rgba(255, 255, 255, 0.68) 42%, transparent 78%);
  transform: translateX(-100%);
  animation: sheen 4.8s ease-in-out infinite 1.2s;
}

.panel-topline,
.signature-metric,
.hero-metric-grid article,
.card-header,
.data-list div,
.timeline-list li,
.proof-card figcaption {
  position: relative;
  z-index: 1;
}

.panel-topline {
  display: flex;
  justify-content: space-between;
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

.signature-metric {
  margin: 42px 0 30px;
  padding-bottom: 26px;
  border-bottom: 1px solid var(--line);
}

.signature-metric span {
  color: var(--muted);
  font-size: 14px;
  font-weight: 800;
}

.signature-metric strong {
  display: block;
  margin-top: 10px;
  font-size: 64px;
  line-height: 1;
}

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

.hero-metric-grid article {
  min-height: 96px;
  padding: 16px 0;
  border-top: 3px solid var(--ink);
}

.hero-metric-grid article:nth-child(2) {
  border-color: var(--coral);
}

.hero-metric-grid article:nth-child(3) {
  border-color: var(--cyan);
}

.hero-metric-grid article:nth-child(4) {
  border-color: var(--yellow);
}

.hero-metric-grid span {
  display: block;
  min-height: 40px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
  line-height: 1.45;
}

.hero-metric-grid strong {
  display: block;
  font-size: 28px;
  line-height: 1.15;
}

.metric-strip {
  display: flex;
  overflow: hidden;
  width: 100%;
  max-width: 100vw;
  border-top: 1px solid var(--ink);
  border-bottom: 1px solid var(--ink);
  background: var(--ink);
  color: #ffffff;
}

.marquee-track {
  display: flex;
  flex: 0 0 auto;
  gap: 12px;
  min-width: 100%;
  padding: 14px 6px;
  animation: marquee 34s linear infinite;
}

.marquee-track span {
  display: inline-flex;
  align-items: center;
  white-space: nowrap;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 8px;
  padding: 8px 12px;
  color: rgba(255, 255, 255, 0.92);
  font-size: 13px;
  font-weight: 800;
}

.section-heading {
  display: grid;
  grid-template-columns: 0.45fr 0.9fr 1fr;
  gap: 28px;
  align-items: end;
  margin-bottom: 34px;
}

.section-heading > *,
.platform-grid > *,
.case-grid > *,
.ai-grid > *,
.api-card > *,
.contact-section > * {
  min-width: 0;
}

.section-heading.compact {
  grid-template-columns: 0.45fr 1fr;
}

.section-heading h2,
.contact-section h2 {
  margin-bottom: 0;
  font-size: 38px;
  line-height: 1.16;
}

.section-heading p,
.contact-section p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.75;
}

.platform-section,
.case-section,
.ai-section,
.evidence-section,
.contact-section {
  padding: 96px 0 0;
}

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

.platform-card,
.case-card,
.ai-card,
.proof-card,
.contact-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 18px 48px rgba(25, 31, 46, 0.07);
}

.platform-card {
  position: relative;
  overflow: hidden;
  padding: 24px;
  animation: riseIn 680ms ease both;
}

.platform-card:nth-child(2) {
  animation-delay: 120ms;
}

.platform-card:nth-child(3) {
  animation-delay: 240ms;
}

.platform-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 5px;
  background: var(--ink);
}

.platform-card.zhihu::before {
  background: var(--blue);
}

.platform-card.xhs::before {
  background: var(--coral);
}

.platform-card.bili::before {
  background: var(--cyan);
}

.platform-card:hover,
.case-card:hover,
.ai-card:hover,
.proof-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 26px 70px rgba(25, 31, 46, 0.12);
}

.platform-card,
.case-card,
.ai-card,
.proof-card {
  transition:
    transform 220ms ease,
    box-shadow 220ms ease,
    border-color 220ms ease;
}

.card-header {
  display: flex;
  align-items: center;
  gap: 14px;
  min-height: 68px;
  margin-bottom: 22px;
}

.platform-icon {
  display: grid;
  flex: 0 0 auto;
  width: 48px;
  height: 48px;
  place-items: center;
  border-radius: 8px;
  color: #ffffff;
  font-weight: 900;
  background: var(--ink);
}

.zhihu .platform-icon {
  background: var(--blue);
}

.xhs .platform-icon {
  background: var(--coral);
}

.bili .platform-icon {
  background: var(--cyan-dark);
}

.card-header h3,
.ai-card h3,
.case-card h3 {
  margin-bottom: 6px;
  font-size: 20px;
  line-height: 1.25;
}

.card-header p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 13px;
}

.data-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--line);
}

.data-list div {
  min-height: 86px;
  padding: 14px;
  background: #ffffff;
}

.data-list dt {
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
}

.data-list dd {
  margin: 10px 0 0;
  font-size: 24px;
  font-weight: 900;
  line-height: 1.1;
}

.card-note {
  margin: 18px 0 0;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.7;
}

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 18px;
  color: var(--cyan-dark);
  font-size: 13px;
  font-weight: 900;
  line-height: 1.4;
}

.text-link::after {
  content: "";
  width: 7px;
  height: 7px;
  border-top: 2px solid currentColor;
  border-right: 2px solid currentColor;
  transform: rotate(45deg);
  transition: transform 180ms ease;
}

.text-link:hover::after {
  transform: translateX(3px) rotate(45deg);
}

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

.case-card {
  padding: 24px;
  background:
    linear-gradient(180deg, #ffffff, #fbfcff),
    var(--paper);
}

.case-number {
  display: inline-flex;
  margin-bottom: 28px;
  color: var(--coral);
  font-size: 13px;
  font-weight: 900;
}

.case-card:nth-child(2) .case-number {
  color: var(--cyan-dark);
}

.case-card:nth-child(3) .case-number {
  color: var(--green);
}

.case-card p,
.ai-card p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.8;
}

.ai-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 18px;
}

.ai-card {
  position: relative;
  overflow: hidden;
  min-height: 360px;
  padding: 28px;
}

.api-card {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(230px, 0.55fr);
  gap: 26px;
}

.ai-card::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 42%;
  height: 7px;
  background: linear-gradient(90deg, var(--cyan), var(--yellow), var(--coral));
}

.tag {
  display: inline-flex;
  margin-bottom: 16px;
  color: var(--coral);
}

.ai-card h3 {
  max-width: 560px;
  margin-bottom: 14px;
  font-size: 28px;
}

.timeline-list {
  display: grid;
  gap: 12px;
  align-content: center;
  padding: 0;
  margin: 0;
  list-style: none;
}

.timeline-list li {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper-soft);
}

.timeline-list strong,
.timeline-list span {
  display: block;
}

.timeline-list strong {
  margin-bottom: 8px;
  font-size: 14px;
}

.timeline-list span {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.55;
}

.source-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 30px;
}

.source-stack span {
  display: inline-flex;
  align-items: center;
  min-height: 38px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 12px;
  color: var(--ink-soft);
  font-size: 13px;
  font-weight: 900;
  background: var(--paper-soft);
}

.evidence-grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 18px;
}

.proof-card {
  grid-column: span 3;
  overflow: hidden;
  margin: 0;
  background: var(--paper);
}

.proof-card.large {
  grid-column: span 6;
}

.proof-card img {
  aspect-ratio: 16 / 9;
  height: auto;
  object-fit: cover;
  object-position: top;
  filter: saturate(0.95);
  transition:
    transform 520ms ease,
    filter 220ms ease;
}

.proof-card:hover img {
  transform: scale(1.025);
  filter: saturate(1.05);
}

.proof-card figcaption {
  display: grid;
  gap: 8px;
  padding: 16px 18px 18px;
  border-top: 1px solid var(--line);
}

.proof-card strong {
  font-size: 15px;
}

.proof-card span {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.6;
}

.contact-section {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.58fr);
  gap: 24px;
  align-items: stretch;
  padding-bottom: 88px;
}

.contact-section > div:first-child {
  padding: 34px 0;
}

.contact-card {
  display: grid;
  align-content: center;
  gap: 16px;
  padding: 28px;
  background: var(--ink);
  color: #ffffff;
}

.contact-card p {
  color: rgba(255, 255, 255, 0.72);
}

.link-list {
  display: grid;
  gap: 8px;
}

.link-list a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 38px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 8px;
  padding: 0 12px;
  color: rgba(255, 255, 255, 0.86);
  font-size: 13px;
  font-weight: 800;
  transition:
    border-color 180ms ease,
    background-color 180ms ease,
    transform 180ms ease;
}

.link-list a::after {
  content: "";
  width: 7px;
  height: 7px;
  border-top: 2px solid currentColor;
  border-right: 2px solid currentColor;
  transform: rotate(45deg);
}

.link-list a:hover {
  border-color: rgba(255, 255, 255, 0.38);
  background: rgba(255, 255, 255, 0.08);
  transform: translateX(2px);
}

.contact-card .button.primary {
  justify-self: start;
  color: var(--ink);
  background: #ffffff;
  box-shadow: none;
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-14px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes riseIn {
  from {
    opacity: 0;
    transform: translateY(22px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes sheen {
  0%,
  38% {
    transform: translateX(-100%);
  }
  62%,
  100% {
    transform: translateX(100%);
  }
}

@keyframes marquee {
  from {
    transform: translateX(0);
  }
  to {
    transform: translateX(-100%);
  }
}

@media (max-width: 980px) {
  .site-header {
    width: calc(100vw - 28px);
    max-width: var(--max);
  }

  .nav-links {
    display: none;
  }

  .section-shell {
    width: calc(100vw - 28px);
    max-width: var(--max);
  }

  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
    padding-top: 58px;
  }

  h1 {
    font-size: 42px;
  }

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

  .section-heading,
  .section-heading.compact,
  .ai-grid,
  .api-card,
  .contact-section {
    grid-template-columns: 1fr;
  }

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

  .section-heading h2,
  .contact-section h2 {
    font-size: 31px;
  }

  .platform-section,
  .case-section,
  .ai-section,
  .evidence-section,
  .contact-section {
    padding-top: 72px;
  }
}

@media (max-width: 640px) {
  .site-header {
    gap: 12px;
    margin-top: 10px;
  }

  .brand {
    min-width: 0;
  }

  .brand em {
    display: none;
  }

  .header-cta {
    padding-inline: 12px;
  }

  .hero {
    padding-top: 42px;
    gap: 24px;
  }

  h1 {
    font-size: 31px;
    line-height: 1.14;
    word-break: keep-all;
  }

  .title-line {
    display: block;
  }

  .role-line {
    font-size: 12px;
    line-height: 1.5;
  }

  .hero-lead {
    font-size: 15px;
    line-height: 1.75;
    word-break: break-all;
  }

  .lead-line {
    display: block;
  }

  h2,
  h3,
  p,
  .card-note,
  .section-heading p,
  .proof-card span {
    word-break: break-all;
  }

  .hero-actions,
  .hero-actions .button {
    width: 100%;
  }

  .signature-metric strong {
    font-size: 48px;
  }

  .hero-metric-grid,
  .data-list {
    grid-template-columns: 1fr;
  }

  .hero-panel,
  .platform-card,
  .case-card,
  .ai-card,
  .contact-card {
    padding: 20px;
  }

  .evidence-grid {
    grid-template-columns: 1fr;
  }

  .proof-card,
  .proof-card.large {
    grid-column: span 1;
  }

  .contact-section {
    padding-bottom: 62px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 1ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 1ms !important;
  }
}