:root {
  --bg: #0c0c0f;
  --bg-soft: #16161c;
  --bg-card: #1c1c24;
  --text: #f2f2f5;
  --text-muted: #a0a0b0;
  --accent: #ff2d55;
  --accent-soft: #ff5c7a;
  --line: rgba(255, 255, 255, 0.08);
  --max: 1120px;
  --radius: 12px;
  --shadow: 0 18px 40px rgba(0, 0, 0, 0.35);
  --font-display: "ZCOOL XiaoWei", "Noto Serif SC", serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--text);
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(255, 45, 85, 0.18), transparent 55%),
    radial-gradient(900px 500px at 90% 0%, rgba(120, 80, 255, 0.12), transparent 50%),
    linear-gradient(180deg, #101018 0%, var(--bg) 40%, #09090c 100%);
  line-height: 1.8;
  min-height: 100vh;
}

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

a {
  color: var(--accent-soft);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: #fff;
}

.container {
  width: min(100% - 2rem, var(--max));
  margin-inline: auto;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(14px);
  background: rgba(12, 12, 15, 0.82);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  color: #fff;
}

.brand img {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  object-fit: cover;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 1.45rem;
  letter-spacing: 0.04em;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1.1rem;
  align-items: center;
}

.nav a {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.nav a:hover,
.nav a.active {
  color: #fff;
}

.menu-toggle {
  display: none;
  width: 36px;
  height: 36px;
  padding: 0;
  margin: 0;
  flex-shrink: 0;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: #fff;
  cursor: pointer;
}

.menu-toggle span,
.menu-toggle i {
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  position: relative;
}

.menu-toggle span::before,
.menu-toggle span::after,
.menu-toggle i::before,
.menu-toggle i::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
}

.menu-toggle span::before,
.menu-toggle i::before {
  top: -6px;
}

.menu-toggle span::after,
.menu-toggle i::after {
  top: 6px;
}

/* Hero */
.hero {
  position: relative;
  padding: 3.5rem 0 2.5rem;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 2.5rem;
  align-items: center;
}

.hero-eyebrow {
  display: inline-block;
  color: var(--accent-soft);
  font-size: 0.9rem;
  letter-spacing: 0.12em;
  margin-bottom: 0.8rem;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.25;
  margin: 0 0 1rem;
  font-weight: 400;
}

.hero-lead {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin: 0 0 1.6rem;
  max-width: 36em;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.35rem;
  border-radius: 999px;
  font-weight: 600;
  border: 1px solid transparent;
  transition: transform 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), #ff6b8a);
  color: #fff;
}

.btn-ghost {
  border-color: var(--line);
  color: #fff;
  background: rgba(255, 255, 255, 0.03);
}

.hero-visual {
  position: relative;
}

.hero-visual img {
  width: 100%;
  border-radius: 18px;
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
  animation: floatY 6s ease-in-out infinite;
}

.hero-visual::after {
  content: "";
  position: absolute;
  inset: auto -8% -10% 20%;
  height: 40%;
  background: radial-gradient(circle, rgba(255, 45, 85, 0.35), transparent 70%);
  filter: blur(20px);
  z-index: -1;
  pointer-events: none;
}

@keyframes floatY {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(18px); }
  to { opacity: 1; transform: translateY(0); }
}

.reveal {
  animation: fadeUp 0.7s ease both;
}

/* Sections */
.section {
  padding: 3.2rem 0;
}

.section-head {
  margin-bottom: 1.8rem;
  max-width: 46rem;
}

.section-head h2 {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  margin: 0 0 0.7rem;
  font-weight: 400;
}

.section-head p {
  margin: 0;
  color: var(--text-muted);
}

.prose {
  color: var(--text-muted);
}

.prose h2,
.prose h3 {
  color: #fff;
  font-family: var(--font-display);
  font-weight: 400;
  margin-top: 2rem;
}

.prose p {
  margin: 0.9rem 0;
}

.prose ul,
.prose ol {
  padding-left: 1.2rem;
}

.prose li {
  margin: 0.4rem 0;
}

.shot-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.shot-grid.cols-4 {
  grid-template-columns: repeat(4, 1fr);
}

.shot-grid.cols-2 {
  grid-template-columns: repeat(2, 1fr);
}

.shot {
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform 0.25s ease, border-color 0.25s ease;
}

.shot:hover {
  transform: translateY(-4px);
  border-color: rgba(255, 45, 85, 0.4);
}

.shot img {
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  object-position: top;
}

.shot figcaption {
  padding: 0.85rem 1rem 1rem;
  color: var(--text-muted);
  font-size: 0.92rem;
}

.shot figcaption strong {
  display: block;
  color: #fff;
  margin-bottom: 0.25rem;
  font-weight: 600;
}

.feature-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  align-items: center;
  margin: 2rem 0;
}

.feature-row.reverse {
  direction: rtl;
}

.feature-row.reverse > * {
  direction: ltr;
}

.feature-copy h3 {
  font-family: var(--font-display);
  font-size: 1.55rem;
  margin: 0 0 0.8rem;
  font-weight: 400;
}

.feature-copy p {
  color: var(--text-muted);
  margin: 0 0 0.8rem;
}

.feature-media img {
  width: 100%;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin: 1rem 0 0;
}

.tag-list a,
.tag {
  display: inline-block;
  padding: 0.35rem 0.8rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.03);
  color: var(--text-muted);
  font-size: 0.88rem;
}

.tag-list a:hover {
  border-color: rgba(255, 45, 85, 0.5);
  color: #fff;
}

.faq details {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.9rem 1rem;
  margin-bottom: 0.7rem;
}

.faq summary {
  cursor: pointer;
  color: #fff;
  font-weight: 600;
}

.faq details p {
  color: var(--text-muted);
  margin: 0.7rem 0 0.2rem;
}

.breadcrumb {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 1.2rem;
}

.breadcrumb a {
  color: var(--text-muted);
}

.page-hero {
  padding: 2.2rem 0 0.5rem;
}

.page-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  margin: 0 0 0.8rem;
  font-weight: 400;
}

.page-hero p {
  color: var(--text-muted);
  margin: 0;
  max-width: 42rem;
}

.content-wrap {
  display: grid;
  grid-template-columns: 1fr 260px;
  gap: 2rem;
  padding-bottom: 3rem;
}

.side-nav {
  position: sticky;
  top: 5.5rem;
  align-self: start;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem;
}

.side-nav h3 {
  margin: 0 0 0.7rem;
  font-size: 0.95rem;
  color: #fff;
}

.side-nav a {
  display: block;
  color: var(--text-muted);
  padding: 0.35rem 0;
  font-size: 0.92rem;
}

.side-nav a:hover {
  color: #fff;
}

.error-page {
  min-height: 70vh;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 3rem 1rem;
}

.error-page h1 {
  font-family: var(--font-display);
  font-size: clamp(3rem, 10vw, 5rem);
  margin: 0;
  background: linear-gradient(135deg, #fff, var(--accent-soft));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.error-page p {
  color: var(--text-muted);
  max-width: 28rem;
  margin: 1rem auto 1.5rem;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--line);
  background: rgba(0, 0, 0, 0.35);
  padding: 2.5rem 0 1.5rem;
  margin-top: 1rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 1.5rem;
  margin-bottom: 1.5rem;
}

.footer-grid h3 {
  font-family: var(--font-display);
  margin: 0 0 0.8rem;
  font-size: 1.15rem;
  font-weight: 400;
}

.footer-grid p,
.footer-grid a {
  color: var(--text-muted);
  font-size: 0.92rem;
}

.footer-grid a {
  display: block;
  margin: 0.35rem 0;
}

.footer-bottom {
  border-top: 1px solid var(--line);
  padding-top: 1rem;
  color: var(--text-muted);
  font-size: 0.85rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  justify-content: space-between;
}

.toc-inline {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem 1.2rem;
  margin: 1.5rem 0;
}

.toc-inline h2 {
  margin: 0 0 0.6rem;
  font-size: 1.1rem;
  color: #fff;
}

.toc-inline ol {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--text-muted);
}

.toc-inline a {
  color: var(--accent-soft);
}

.stats-note {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin: 1.5rem 0;
}

.stats-note div {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem;
}

.stats-note strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.4rem;
  color: #fff;
  margin-bottom: 0.25rem;
}

.stats-note span {
  color: var(--text-muted);
  font-size: 0.9rem;
}

@media (max-width: 900px) {
  .hero-grid,
  .feature-row,
  .feature-row.reverse,
  .content-wrap,
  .footer-grid,
  .shot-grid,
  .shot-grid.cols-4,
  .stats-note {
    grid-template-columns: 1fr;
    direction: ltr;
  }

  .shot-grid.cols-2 {
    grid-template-columns: 1fr 1fr;
  }

  .side-nav {
    position: static;
  }

  .menu-toggle {
    display: inline-flex;
  }

  .nav {
    display: none;
  }

  .nav.open {
    display: flex;
    position: absolute;
    top: calc(100% + 2px);
    right: 0;
    left: auto;
    min-width: 200px;
    width: max-content;
    max-width: min(280px, calc(100vw - 2rem));
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0.55rem 0;
    background: rgba(18, 18, 24, 0.98);
    border: 1px solid var(--line);
    border-radius: 12px;
    box-shadow: var(--shadow);
    z-index: 120;
  }

  .nav.open a {
    padding: 0.65rem 1.1rem;
    white-space: nowrap;
  }

  .header-inner {
    flex-wrap: nowrap;
  }

  .hero {
    padding-top: 2rem;
  }

  .shot img {
    aspect-ratio: 3 / 4;
  }
}

@media (max-width: 560px) {
  .shot-grid.cols-2 {
    grid-template-columns: 1fr;
  }

  .brand-name {
    font-size: 1.2rem;
  }
}