:root {
  --bg: #0c0c0f;
  --bg-soft: #15151a;
  --bg-card: #1a1a22;
  --text: #f2f2f5;
  --text-muted: #a8a8b3;
  --accent: #e11d48;
  --accent-soft: #fb7185;
  --line: rgba(255, 255, 255, 0.08);
  --radius: 14px;
  --shadow: 0 18px 50px rgba(0, 0, 0, 0.35);
  --max: 1120px;
  --font: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(225, 29, 72, 0.18), transparent 55%),
    radial-gradient(900px 500px at 100% 0%, rgba(251, 113, 133, 0.12), transparent 50%),
    var(--bg);
  color: var(--text);
  line-height: 1.75;
  font-size: 16px;
}

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% - 32px, var(--max));
  margin-inline: auto;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--accent);
  color: #fff;
  padding: 8px 12px;
  z-index: 1000;
}

.skip-link:focus {
  left: 12px;
  top: 12px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(14px);
  background: rgba(12, 12, 15, 0.85);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 68px;
  gap: 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: 0.02em;
}

.brand img {
  width: 36px;
  height: 36px;
  border-radius: 8px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav a {
  color: var(--text-muted);
  padding: 8px 12px;
  border-radius: 999px;
  font-size: 0.95rem;
}

.nav a:hover,
.nav a.active {
  color: #fff;
  background: rgba(225, 29, 72, 0.16);
}

.menu-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 0;
  border: 1px solid var(--line);
  background: var(--bg-soft);
  color: #fff;
  border-radius: 10px;
  cursor: pointer;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
}

.menu-toggle-bar {
  display: block;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: #fff;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.menu-toggle[aria-expanded="true"] .menu-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] .menu-toggle-bar:nth-child(2) {
  opacity: 0;
}

.menu-toggle[aria-expanded="true"] .menu-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.hero {
  padding: 56px 0 40px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 36px;
  align-items: center;
}

.hero-copy h1 {
  margin: 0 0 16px;
  font-size: clamp(1.8rem, 3.2vw, 2.6rem);
  line-height: 1.25;
  letter-spacing: 0.01em;
}

.hero-copy .lead {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin: 0 0 24px;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 20px;
  border-radius: 999px;
  font-weight: 600;
  border: 1px solid transparent;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), #be123c);
  color: #fff;
}

.btn-primary:hover {
  color: #fff;
  filter: brightness(1.08);
}

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

.hero-visual {
  position: relative;
  border-radius: 22px;
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
}

.hero-visual img {
  width: 100%;
  aspect-ratio: 4 / 5;
  object-fit: cover;
}

.section {
  padding: 56px 0;
}

.section-alt {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.02), transparent);
  border-block: 1px solid var(--line);
}

.section-head {
  margin-bottom: 28px;
  max-width: 760px;
}

.section-head h2 {
  margin: 0 0 10px;
  font-size: clamp(1.4rem, 2.4vw, 1.9rem);
}

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

.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.card img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.card-body {
  padding: 16px 18px 18px;
}

.card-body h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
}

.card-body p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.media-row {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 28px;
  align-items: center;
}

.media-row.reverse {
  grid-template-columns: 0.9fr 1.1fr;
}

.media-row.reverse .media-text {
  order: 2;
}

.media-row.reverse .media-img {
  order: 1;
}

.media-img {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.media-img img {
  width: 100%;
  aspect-ratio: 16 / 11;
  object-fit: cover;
}

.media-text h3 {
  margin: 0 0 12px;
  font-size: 1.35rem;
}

.media-text p {
  color: var(--text-muted);
  margin: 0 0 12px;
}

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

.prose h2,
.prose h3 {
  color: var(--text);
  margin-top: 1.6em;
}

.prose p {
  margin: 0 0 1em;
}

.prose ul,
.prose ol {
  padding-left: 1.2em;
  margin: 0 0 1em;
}

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

.toc {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
  margin-bottom: 28px;
}

.toc h2 {
  margin: 0 0 10px;
  font-size: 1.1rem;
}

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

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

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

.feature-list {
  display: grid;
  gap: 14px;
}

.feature-item {
  display: grid;
  grid-template-columns: 84px 1fr;
  gap: 14px;
  align-items: center;
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 12px;
}

.feature-item img {
  width: 84px;
  height: 84px;
  object-fit: cover;
  border-radius: 10px;
}

.feature-item h3 {
  margin: 0 0 4px;
  font-size: 1rem;
}

.feature-item p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.92rem;
}

.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tag-cloud a {
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.03);
  color: var(--text-muted);
  padding: 8px 14px;
  border-radius: 999px;
  font-size: 0.9rem;
}

.tag-cloud a:hover {
  border-color: rgba(225, 29, 72, 0.5);
  color: #fff;
}

.breadcrumb {
  padding: 18px 0 0;
  color: var(--text-muted);
  font-size: 0.9rem;
}

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

.page-hero {
  padding: 28px 0 10px;
}

.page-hero h1 {
  margin: 0 0 10px;
  font-size: clamp(1.6rem, 2.8vw, 2.2rem);
}

.page-hero p {
  margin: 0;
  color: var(--text-muted);
  max-width: 720px;
}

.site-footer {
  margin-top: 40px;
  border-top: 1px solid var(--line);
  background: #09090b;
  padding: 40px 0 28px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 28px;
  margin-bottom: 28px;
}

.footer-grid h3 {
  margin: 0 0 12px;
  font-size: 1rem;
}

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

.footer-grid ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-grid li {
  margin-bottom: 8px;
}

.footer-bottom {
  border-top: 1px solid var(--line);
  padding-top: 16px;
  color: var(--text-muted);
  font-size: 0.85rem;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  justify-content: space-between;
}

.error-page {
  min-height: 70vh;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 60px 0;
}

.error-page h1 {
  font-size: clamp(2.4rem, 6vw, 4rem);
  margin: 0 0 12px;
}

.error-page p {
  color: var(--text-muted);
  margin: 0 0 24px;
}

.internal-links {
  margin-top: 24px;
  padding: 18px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--bg-soft);
}

.internal-links h3 {
  margin: 0 0 10px;
  font-size: 1rem;
}

.internal-links ul {
  margin: 0;
  padding-left: 1.1em;
  color: var(--text-muted);
}

@media (max-width: 960px) {
  .hero-grid,
  .media-row,
  .media-row.reverse,
  .grid-2,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .media-row.reverse .media-text,
  .media-row.reverse .media-img {
    order: initial;
  }

  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 720px) {
  .menu-toggle {
    display: inline-flex;
    flex-shrink: 0;
  }

  .nav {
    display: none;
    position: absolute;
    left: 16px;
    right: 16px;
    top: 68px;
    flex-direction: column;
    align-items: stretch;
    background: #121218;
    border: 1px solid var(--line);
    border-radius: 14px;
    padding: 10px;
    box-shadow: var(--shadow);
  }

  .nav.open {
    display: flex;
  }

  .nav a {
    border-radius: 10px;
  }

  .hero {
    padding: 32px 0 24px;
  }

  .section {
    padding: 40px 0;
  }

  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

  .feature-item {
    grid-template-columns: 72px 1fr;
  }

  .feature-item img {
    width: 72px;
    height: 72px;
  }

  .footer-bottom {
    flex-direction: column;
  }
}