/* 小蓝APP平台 xl-app.lol */
:root {
  --blue-50: #eef7ff;
  --blue-100: #d6ebff;
  --blue-200: #a8d4ff;
  --blue-400: #3d9fff;
  --blue-500: #1a7ef0;
  --blue-600: #0d63c9;
  --blue-700: #0a4ea0;
  --blue-800: #0b3d7a;
  --ink: #142033;
  --muted: #5a6b82;
  --line: #d9e6f5;
  --bg: #f4f8fc;
  --card: #ffffff;
  --accent: #00c2c8;
  --warn: #e8a317;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(13, 99, 201, 0.08);
  --max: 1120px;
  --font: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --display: "ZCOOL XiaoWei", "Noto Sans SC", "Microsoft YaHei", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background:
    radial-gradient(1200px 500px at 10% -10%, #dff1ff 0%, transparent 55%),
    radial-gradient(900px 420px at 100% 0%, #d8fbff 0%, transparent 50%),
    linear-gradient(180deg, #f7fbff 0%, var(--bg) 40%, #eef5fb 100%);
  line-height: 1.75;
  min-height: 100vh;
}

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

a {
  color: var(--blue-600);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--blue-400);
}

.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(255, 255, 255, 0.86);
  border-bottom: 1px solid rgba(217, 230, 245, 0.9);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 68px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  color: var(--ink);
  font-weight: 700;
}

.brand img {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  object-fit: cover;
  box-shadow: 0 4px 12px rgba(26, 126, 240, 0.25);
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.brand-text strong {
  font-family: var(--display);
  font-size: 1.15rem;
  letter-spacing: 0.02em;
}

.brand-text span {
  font-size: 0.72rem;
  color: var(--muted);
  font-weight: 500;
}

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

.nav a {
  color: var(--ink);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.35rem 0;
  position: relative;
}

.nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--blue-500), var(--accent));
  transition: width 0.25s ease;
}

.nav a:hover,
.nav a.active {
  color: var(--blue-600);
}

.nav a:hover::after,
.nav a.active::after {
  width: 100%;
}

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

.menu-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--blue-700);
  border-radius: 2px;
}

/* Hero */
.hero {
  padding: 3.2rem 0 2.4rem;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 2.2rem;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--blue-600);
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 0.75rem;
}

.hero h1 {
  font-family: var(--display);
  font-size: clamp(1.9rem, 3.4vw, 2.75rem);
  line-height: 1.25;
  margin: 0 0 1rem;
  letter-spacing: 0.01em;
}

.hero-lead {
  color: var(--muted);
  font-size: 1.05rem;
  margin: 0 0 1.4rem;
  max-width: 36rem;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.2rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.78rem 1.25rem;
  border-radius: 999px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: linear-gradient(135deg, var(--blue-500), var(--blue-700));
  color: #fff;
  box-shadow: 0 10px 24px rgba(26, 126, 240, 0.28);
}

.btn-primary:hover {
  color: #fff;
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.8);
  border-color: var(--line);
  color: var(--blue-700);
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.hero-tags span {
  font-size: 0.8rem;
  color: var(--blue-700);
  background: var(--blue-50);
  border: 1px solid var(--blue-100);
  padding: 0.28rem 0.7rem;
  border-radius: 999px;
}

.hero-visual {
  position: relative;
}

.hero-visual img {
  width: 100%;
  border-radius: 22px;
  box-shadow: var(--shadow);
  border: 1px solid rgba(255, 255, 255, 0.8);
  animation: floaty 5.5s ease-in-out infinite;
}

.hero-glow {
  position: absolute;
  inset: 12% -8% -8% 12%;
  background: radial-gradient(circle, rgba(0, 194, 200, 0.22), transparent 70%);
  z-index: -1;
  filter: blur(8px);
}

@keyframes floaty {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-8px);
  }
}

/* Sections */
.section {
  padding: 2.6rem 0;
}

.section-head {
  margin-bottom: 1.5rem;
}

.section-head h2 {
  font-family: var(--display);
  font-size: clamp(1.45rem, 2.4vw, 1.9rem);
  margin: 0 0 0.55rem;
}

.section-head p {
  margin: 0;
  color: var(--muted);
  max-width: 48rem;
}

.panel {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.35rem;
}

.prose {
  color: var(--ink);
}

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

.prose h3 {
  font-size: 1.2rem;
  margin: 1.6rem 0 0.7rem;
  color: var(--blue-800);
}

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

.prose li {
  margin-bottom: 0.4rem;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.1rem;
}

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

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 36px rgba(13, 99, 201, 0.12);
}

.feature-card img {
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  object-position: top center;
  background: var(--blue-50);
}

.feature-card .body {
  padding: 1rem 1.05rem 1.15rem;
}

.feature-card h3 {
  margin: 0 0 0.45rem;
  font-size: 1.05rem;
}

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

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.4rem;
  align-items: center;
}

.split.reverse .copy {
  order: 2;
}

.split img {
  border-radius: 16px;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  width: 100%;
  max-height: 560px;
  object-fit: cover;
  object-position: top center;
}

.toc {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.75rem;
}

.toc a {
  display: block;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.9rem 1rem;
  color: var(--ink);
  font-weight: 600;
  box-shadow: var(--shadow);
}

.toc a span {
  display: block;
  margin-top: 0.25rem;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 400;
}

.toc a:hover {
  border-color: var(--blue-200);
  color: var(--blue-700);
}

.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.9rem;
  counter-reset: step;
}

.step {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 1.1rem;
  position: relative;
}

.step::before {
  counter-increment: step;
  content: counter(step);
  display: inline-flex;
  width: 28px;
  height: 28px;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--blue-500), var(--accent));
  color: #fff;
  font-size: 0.85rem;
  font-weight: 700;
  margin-bottom: 0.6rem;
}

.step h3 {
  margin: 0 0 0.4rem;
  font-size: 1rem;
}

.step p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.faq details {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.9rem 1rem;
  margin-bottom: 0.7rem;
}

.faq summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--blue-800);
}

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

.related {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.related a {
  background: var(--blue-50);
  border: 1px solid var(--blue-100);
  color: var(--blue-700);
  padding: 0.45rem 0.85rem;
  border-radius: 999px;
  font-size: 0.9rem;
}

.page-hero {
  padding: 2.4rem 0 1.2rem;
}

.page-hero h1 {
  font-family: var(--display);
  font-size: clamp(1.7rem, 3vw, 2.3rem);
  margin: 0 0 0.7rem;
}

.page-hero p {
  margin: 0;
  color: var(--muted);
  max-width: 46rem;
}

.legal {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.6rem 1.5rem;
  box-shadow: var(--shadow);
}

.legal h2 {
  font-size: 1.2rem;
  color: var(--blue-800);
  margin: 1.5rem 0 0.6rem;
}

.legal h2:first-child {
  margin-top: 0;
}

.legal p,
.legal li {
  color: #334155;
}

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

.error-page .code {
  font-family: var(--display);
  font-size: clamp(4rem, 12vw, 7rem);
  line-height: 1;
  background: linear-gradient(135deg, var(--blue-500), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-bottom: 0.4rem;
}

.error-page h1 {
  margin: 0 0 0.7rem;
  font-size: 1.6rem;
}

.error-page p {
  color: var(--muted);
  margin: 0 0 1.4rem;
}

/* Footer */
.site-footer {
  margin-top: 3rem;
  background: linear-gradient(180deg, #0b3d7a 0%, #082f5e 100%);
  color: #dcebff;
  padding: 2.4rem 0 1.4rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 1.5rem;
  margin-bottom: 1.6rem;
}

.site-footer h3 {
  margin: 0 0 0.7rem;
  font-size: 1rem;
  color: #fff;
}

.site-footer p,
.site-footer a {
  color: #c7dcff;
  font-size: 0.92rem;
}

.site-footer a:hover {
  color: #fff;
}

.footer-links {
  display: grid;
  gap: 0.4rem;
}

.copyright {
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  padding-top: 1rem;
  font-size: 0.85rem;
  color: #9fbee8;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem;
}

/* Motion */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}

.reveal.show {
  opacity: 1;
  transform: none;
}

/* Mobile */
@media (max-width: 920px) {
  .site-header {
    position: relative;
  }

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

  .nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 210;
    background: rgba(255, 255, 255, 0.98);
    border-bottom: 1px solid var(--line);
    flex-direction: column;
    align-items: stretch;
    padding: 0.6rem 1rem 1rem;
    display: none;
  }

  .nav.open {
    display: flex;
  }

  .nav a {
    padding: 0.7rem 0.2rem;
    border-bottom: 1px solid #eef3f9;
  }

  .hero-grid,
  .split,
  .split.reverse .copy,
  .feature-grid,
  .toc,
  .steps,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .split.reverse .copy {
    order: 0;
  }

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

  .hero {
    padding-top: 1.8rem;
  }

  .hero-visual {
    order: -1;
  }

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

@media (max-width: 560px) {
  .feature-grid,
  .toc {
    grid-template-columns: 1fr;
  }

  .container {
    width: min(100% - 1.25rem, var(--max));
  }

  .panel,
  .legal {
    padding: 1.1rem;
  }
}