/* 千懿 — AI Video Platform Corporate Site
   Visual direction: gray-black stone creative agency (inspired by Reep aesthetic) */

:root {
  --bg: #0e0e0f;
  --bg-elevated: #161618;
  --bg-stone: #1c1c1f;
  --bg-panel: #222226;
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.14);
  --text: #f2f0eb;
  --text-muted: #9a968c;
  --text-dim: #6e6a62;
  --accent: #c4a574;
  --accent-soft: rgba(196, 164, 116, 0.15);
  --accent-hot: #e8c99a;
  --success: #7d9b76;
  --font-display: "Syne", "Noto Sans SC", sans-serif;
  --font-body: "Outfit", "Noto Sans SC", sans-serif;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --header-h: 72px;
  --max: 1120px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 16px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

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

ul {
  list-style: none;
}

button {
  font: inherit;
  border: none;
  background: none;
  cursor: pointer;
  color: inherit;
}

.container {
  width: min(100% - 2.5rem, var(--max));
  margin-inline: auto;
}

.container-wide {
  width: min(100% - 2.5rem, 1280px);
  margin-inline: auto;
}

/* ——— Stone atmosphere ——— */
.stone-bg {
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(ellipse 80% 50% at 20% -10%, rgba(196, 164, 116, 0.12), transparent 55%),
    radial-gradient(ellipse 60% 40% at 90% 20%, rgba(90, 100, 110, 0.18), transparent 50%),
    radial-gradient(ellipse 50% 60% at 50% 100%, rgba(40, 42, 48, 0.9), transparent 60%),
    linear-gradient(180deg, #0a0a0b 0%, #121214 40%, #0e0e0f 100%);
}

.stone-grain {
  position: fixed;
  inset: 0;
  z-index: -1;
  opacity: 0.35;
  pointer-events: none;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.5'/%3E%3C/svg%3E");
  mix-blend-mode: overlay;
}

/* ——— Header ——— */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-h);
  transition: background 0.4s var(--ease), border-color 0.4s var(--ease), backdrop-filter 0.4s;
  border-bottom: 1px solid transparent;
}

.site-header.is-scrolled {
  background: rgba(14, 14, 15, 0.85);
  backdrop-filter: blur(16px);
  border-bottom-color: var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  z-index: 110;
}

.logo-mark {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: linear-gradient(145deg, var(--accent-hot), var(--accent) 50%, #8a7349);
  display: grid;
  place-items: center;
  position: relative;
  overflow: hidden;
}

.logo-mark::after {
  content: "";
  width: 14px;
  height: 14px;
  border: 2px solid var(--bg);
  border-radius: 3px;
  transform: rotate(45deg);
}

.logo span {
  background: linear-gradient(90deg, var(--text), var(--accent-hot));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.nav {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav a {
  font-size: 0.9rem;
  font-weight: 450;
  color: var(--text-muted);
  transition: color 0.25s;
  position: relative;
}

.nav a:hover,
.nav a.is-active {
  color: var(--text);
}

.nav a.is-active::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -6px;
  height: 1px;
  background: var(--accent);
}

.header-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 1.15rem;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--bg);
  background: var(--text);
  border-radius: 2px;
  transition: background 0.3s, transform 0.3s var(--ease);
}

.header-cta:hover {
  background: var(--accent-hot);
  transform: translateY(-1px);
}

.menu-toggle {
  display: none;
  width: 40px;
  height: 40px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  z-index: 110;
}

.menu-toggle span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--text);
  transition: transform 0.3s, opacity 0.3s;
}

.menu-toggle.is-open span:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg);
}

.menu-toggle.is-open span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.is-open span:nth-child(3) {
  transform: translateY(-6.5px) rotate(-45deg);
}

/* ——— Buttons ——— */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.9rem 1.6rem;
  font-size: 0.95rem;
  font-weight: 500;
  border-radius: 2px;
  transition: background 0.3s, color 0.3s, border-color 0.3s, transform 0.3s var(--ease);
}

.btn-primary {
  background: var(--accent);
  color: var(--bg);
}

.btn-primary:hover {
  background: var(--accent-hot);
  transform: translateY(-2px);
}

.btn-ghost {
  border: 1px solid var(--border-strong);
  color: var(--text);
}

.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent-hot);
}

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
}

/* ——— Hero ——— */
.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: calc(var(--header-h) + 2rem) 0 4.5rem;
  overflow: hidden;
}

.hero-visual {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-visual-layer {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, transparent 0%, rgba(14, 14, 15, 0.35) 45%, var(--bg) 92%),
    linear-gradient(90deg, rgba(14, 14, 15, 0.7) 0%, transparent 45%),
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='1600' height='900' viewBox='0 0 1600 900'%3E%3Cdefs%3E%3ClinearGradient id='g' x1='0' y1='0' x2='1' y2='1'%3E%3Cstop offset='0%25' stop-color='%232a2a30'/%3E%3Cstop offset='50%25' stop-color='%2318181c'/%3E%3Cstop offset='100%25' stop-color='%23383632'/%3E%3C/linearGradient%3E%3C/defs%3E%3Crect fill='url(%23g)' width='1600' height='900'/%3E%3Cpath d='M0 620 Q200 480 400 560 T800 500 T1200 580 T1600 480 V900 H0Z' fill='%23141416' opacity='0.9'/%3E%3Cpath d='M0 700 Q300 580 600 650 T1100 600 T1600 680 V900 H0Z' fill='%230e0e0f'/%3E%3C/svg%3E") center / cover no-repeat;
}

.hero-frame-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 80px 80px;
  mask-image: radial-gradient(ellipse 70% 60% at 70% 40%, black, transparent);
  animation: gridDrift 28s linear infinite;
}

@keyframes gridDrift {
  from { background-position: 0 0; }
  to { background-position: 80px 80px; }
}

.hero-orb {
  position: absolute;
  width: 420px;
  height: 420px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(196, 164, 116, 0.22), transparent 68%);
  top: 18%;
  right: 12%;
  filter: blur(40px);
  animation: orbPulse 8s ease-in-out infinite;
}

@keyframes orbPulse {
  0%, 100% { transform: scale(1); opacity: 0.7; }
  50% { transform: scale(1.15); opacity: 1; }
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 720px;
}

.brand-hero {
  font-family: var(--font-display);
  font-size: clamp(3.2rem, 9vw, 6.5rem);
  font-weight: 700;
  line-height: 0.95;
  letter-spacing: -0.04em;
  margin-bottom: 1.25rem;
  opacity: 0;
  animation: riseIn 1s var(--ease) 0.15s forwards;
}

.brand-hero em {
  font-style: normal;
  color: var(--accent);
}

.hero-headline {
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 3vw, 1.85rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.3;
  margin-bottom: 1rem;
  max-width: 28ch;
  opacity: 0;
  animation: riseIn 1s var(--ease) 0.35s forwards;
}

.hero-lead {
  color: var(--text-muted);
  font-size: 1.05rem;
  max-width: 42ch;
  margin-bottom: 2rem;
  opacity: 0;
  animation: riseIn 1s var(--ease) 0.5s forwards;
}

.hero .btn-group {
  opacity: 0;
  animation: riseIn 1s var(--ease) 0.65s forwards;
}

@keyframes riseIn {
  from {
    opacity: 0;
    transform: translateY(28px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-scroll {
  position: absolute;
  bottom: 1.5rem;
  right: 2rem;
  z-index: 2;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-dim);
  writing-mode: vertical-rl;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.hero-scroll::after {
  content: "";
  width: 1px;
  height: 48px;
  background: linear-gradient(var(--accent), transparent);
  animation: scrollLine 1.8s ease-in-out infinite;
}

@keyframes scrollLine {
  0%, 100% { transform: scaleY(0.4); opacity: 0.4; transform-origin: top; }
  50% { transform: scaleY(1); opacity: 1; transform-origin: top; }
}

/* ——— Sections ——— */
.section {
  padding: 6rem 0;
  position: relative;
}

.section-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1rem;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4.5vw, 3.1rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 1.25rem;
}

.section-desc {
  color: var(--text-muted);
  max-width: 54ch;
  font-size: 1.05rem;
}

.section-head {
  margin-bottom: 3.5rem;
}

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: start;
}

/* ——— About ——— */
.about-block p + p {
  margin-top: 1.1rem;
}

.about-block p {
  color: var(--text-muted);
  font-size: 1.05rem;
}

.about-meta {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  padding: 2rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-left: 2px solid var(--accent);
}

.about-meta dt {
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 0.35rem;
}

.about-meta dd {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
}

/* ——— Reveal on scroll ——— */
.reveal {
  opacity: 0;
  transform: translateY(36px);
  transition: opacity 0.8s var(--ease), transform 0.8s var(--ease);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }

/* ——— Services / Product ——— */
.service-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  border-top: 1px solid var(--border);
}

.service-item {
  display: grid;
  grid-template-columns: 4rem 1fr auto;
  gap: 1.5rem;
  align-items: start;
  padding: 2rem 0;
  border-bottom: 1px solid var(--border);
  transition: background 0.3s;
}

.service-item:hover {
  background: linear-gradient(90deg, var(--accent-soft), transparent);
  padding-left: 1rem;
  padding-right: 1rem;
  margin-inline: -1rem;
}

.service-num {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
}

.service-item h3 {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 650;
  letter-spacing: -0.02em;
  margin-bottom: 0.5rem;
}

.service-item p {
  color: var(--text-muted);
  max-width: 52ch;
}

.service-tag {
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-dim);
  padding-top: 0.25rem;
}

.flow-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-top: 3rem;
}

.flow-step {
  padding: 1.75rem 1.5rem;
  background: var(--bg-stone);
  border: 1px solid var(--border);
  position: relative;
}

.flow-step::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), transparent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.6s var(--ease);
}

.flow-step.is-visible::before,
.reveal.is-visible .flow-step::before {
  transform: scaleX(1);
}

.flow-step h4 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  margin: 0.75rem 0 0.5rem;
}

.flow-step p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.flow-step .step-i {
  font-size: 0.75rem;
  color: var(--accent);
  letter-spacing: 0.1em;
}

/* ——— Compliance note ——— */
.compliance {
  margin-top: 3rem;
  padding: 1.5rem 1.75rem;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
}

.compliance h4 {
  font-family: var(--font-display);
  font-size: 1rem;
  margin-bottom: 0.75rem;
  color: var(--accent-hot);
}

.compliance ul {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.compliance li {
  color: var(--text-muted);
  font-size: 0.95rem;
  padding-left: 1.1rem;
  position: relative;
}

.compliance li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--accent);
}

/* ——— Stats strip ——— */
.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  margin-top: 4rem;
}

.stat {
  background: var(--bg-elevated);
  padding: 2rem 1.5rem;
  text-align: center;
}

.stat strong {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--accent-hot);
  margin-bottom: 0.35rem;
}

.stat span {
  font-size: 0.85rem;
  color: var(--text-dim);
}

/* ——— CTA band ——— */
.cta-band {
  position: relative;
  padding: 5rem 0;
  overflow: hidden;
}

.cta-band::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(135deg, rgba(196, 164, 116, 0.12), transparent 50%),
    var(--bg-stone);
  border-block: 1px solid var(--border);
}

.cta-inner {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  flex-wrap: wrap;
}

.cta-inner h2 {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  max-width: 16ch;
  line-height: 1.15;
}

.cta-inner p {
  color: var(--text-muted);
  margin-top: 0.75rem;
  max-width: 36ch;
}

/* ——— Page hero (inner pages) ——— */
.page-hero {
  padding: calc(var(--header-h) + 4rem) 0 3.5rem;
  border-bottom: 1px solid var(--border);
}

.page-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 5vw, 3.75rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 1rem;
}

.page-hero p {
  color: var(--text-muted);
  max-width: 48ch;
  font-size: 1.1rem;
}

/* ——— Legal / prose ——— */
.prose {
  max-width: 720px;
  padding: 4rem 0 5rem;
}

.prose h2 {
  font-family: var(--font-display);
  font-size: 1.45rem;
  font-weight: 650;
  margin: 2.5rem 0 1rem;
  letter-spacing: -0.02em;
}

.prose h3 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  margin: 1.75rem 0 0.75rem;
}

.prose p,
.prose li {
  color: var(--text-muted);
  margin-bottom: 0.9rem;
}

.prose ul,
.prose ol {
  padding-left: 1.25rem;
  margin-bottom: 1rem;
}

.prose ul {
  list-style: disc;
}

.prose ol {
  list-style: decimal;
}

.prose li {
  margin-bottom: 0.45rem;
}

.prose a {
  color: var(--accent-hot);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.prose .updated {
  font-size: 0.9rem;
  color: var(--text-dim);
  margin-bottom: 2rem;
}

.prose .en-block {
  margin-top: 3rem;
  padding-top: 2.5rem;
  border-top: 1px solid var(--border);
}

.prose .en-block > h2:first-child {
  margin-top: 0;
}

/* ——— Contact ——— */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  padding: 4rem 0 5rem;
}

.contact-card {
  padding: 1.75rem 0;
  border-bottom: 1px solid var(--border);
}

.contact-card h3 {
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 0.5rem;
}

.contact-card a,
.contact-card p {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
}

.contact-card a:hover {
  color: var(--accent-hot);
}

.contact-aside {
  padding: 2rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  height: fit-content;
}

.contact-aside h3 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  margin-bottom: 1rem;
}

.contact-aside p {
  color: var(--text-muted);
  margin-bottom: 1rem;
  font-size: 0.95rem;
}

.contact-aside .entity {
  font-size: 0.9rem;
  color: var(--text-dim);
  line-height: 1.7;
  border-top: 1px solid var(--border);
  padding-top: 1.25rem;
  margin-top: 0.5rem;
}

/* ——— Footer ——— */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 3.5rem 0 2rem;
  background: var(--bg-elevated);
}

.footer-top {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 3rem;
}

.footer-brand .logo {
  margin-bottom: 1rem;
}

.footer-brand p {
  color: var(--text-muted);
  font-size: 0.95rem;
  max-width: 32ch;
}

.footer-col h4 {
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 1.1rem;
}

.footer-col a {
  display: block;
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 0.6rem;
  transition: color 0.25s;
}

.footer-col a:hover {
  color: var(--accent-hot);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--border);
  font-size: 0.85rem;
  color: var(--text-dim);
}

.footer-legal {
  display: flex;
  gap: 1.5rem;
}

.footer-legal a:hover {
  color: var(--accent);
}

/* ——— Mobile ——— */
@media (max-width: 900px) {
  .nav {
    position: fixed;
    inset: 0;
    background: rgba(14, 14, 15, 0.97);
    flex-direction: column;
    justify-content: center;
    gap: 1.75rem;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.35s, visibility 0.35s;
  }

  .nav.is-open {
    opacity: 1;
    visibility: visible;
  }

  .nav a {
    font-size: 1.35rem;
    font-family: var(--font-display);
    font-weight: 600;
  }

  .header-cta {
    display: none;
  }

  .menu-toggle {
    display: flex;
  }

  .split,
  .flow-steps,
  .stats,
  .contact-grid,
  .footer-top {
    grid-template-columns: 1fr;
  }

  .service-item {
    grid-template-columns: 3rem 1fr;
  }

  .service-tag {
    display: none;
  }

  .hero-scroll {
    display: none;
  }

  .cta-inner {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 560px) {
  .hero {
    padding-bottom: 3rem;
  }

  .section {
    padding: 4rem 0;
  }
}