:root {
  --blue-900: #0a3d6b;
  --blue-800: #0e4f8a;
  --blue-700: #1565a8;
  --blue-600: #1a7fd4;
  --blue-500: #2b9af0;
  --blue-100: #e8f4fc;
  --blue-50: #f3f9fd;
  --ink: #15202b;
  --muted: #5a6a7a;
  --line: #d7e4ef;
  --white: #ffffff;
  --soft: #f7fbfe;
  --accent: #00a8e8;
  --radius: 14px;
  --shadow: 0 12px 32px rgba(15, 70, 120, 0.08);
  --max: 1120px;
  --font: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --display: "Trebuchet MS", "PingFang 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(ellipse 80% 50% at 10% -10%, rgba(43, 154, 240, 0.18), transparent 55%),
    radial-gradient(ellipse 60% 40% at 100% 0%, rgba(0, 168, 232, 0.12), transparent 50%),
    linear-gradient(180deg, #f5fafd 0%, #eef6fb 40%, #f8fbfe 100%);
  line-height: 1.75;
  min-height: 100vh;
}

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

a {
  color: var(--blue-700);
  text-decoration: none;
}

a:hover {
  color: var(--blue-500);
  text-decoration: underline;
}

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

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  background: rgba(255, 255, 255, 0.88);
  border-bottom: 1px solid rgba(215, 228, 239, 0.9);
}

.header-inner {
  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);
  text-decoration: none;
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.15rem;
}

.brand:hover {
  text-decoration: none;
  color: var(--blue-700);
}

.brand img {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  object-fit: cover;
}

.nav {
  display: flex;
  align-items: center;
  gap: 0.15rem;
}

.nav a {
  color: var(--ink);
  padding: 0.45rem 0.75rem;
  border-radius: 999px;
  font-size: 0.95rem;
  text-decoration: none;
}

.nav a:hover,
.nav a.active {
  background: var(--blue-100);
  color: var(--blue-800);
  text-decoration: none;
}

.menu-toggle {
  display: none;
  border: 1px solid var(--line);
  background: var(--white);
  border-radius: 10px;
  padding: 0.45rem 0.7rem;
  cursor: pointer;
  font-size: 0.9rem;
  color: var(--blue-800);
}

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

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 18% 20%, rgba(0, 200, 255, 0.35), transparent 42%),
    radial-gradient(circle at 86% 10%, rgba(255, 180, 80, 0.22), transparent 38%),
    linear-gradient(135deg, #0a3d6b 0%, #1565a8 48%, #1a7fd4 100%);
  z-index: 0;
}

.hero-inner {
  position: relative;
  z-index: 1;
  color: var(--white);
  max-width: 720px;
  padding: 1rem 0 2rem;
}

.hero-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.2rem;
  animation: fadeUp 0.7s ease both;
}

.hero-brand img {
  width: 64px;
  height: 64px;
  border-radius: 16px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
}

.hero-brand span {
  font-family: var(--display);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 800;
  letter-spacing: 0.02em;
}

.hero h1 {
  margin: 0 0 0.85rem;
  font-size: clamp(1.35rem, 2.8vw, 1.85rem);
  font-weight: 650;
  line-height: 1.35;
  animation: fadeUp 0.7s ease 0.08s both;
}

.hero p {
  margin: 0 0 1.4rem;
  font-size: 1.05rem;
  opacity: 0.95;
  max-width: 560px;
  animation: fadeUp 0.7s ease 0.16s both;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  animation: fadeUp 0.7s ease 0.24s both;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.72rem 1.25rem;
  border-radius: 999px;
  font-weight: 600;
  border: 1px solid transparent;
  text-decoration: none;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-2px);
}

.btn-primary {
  background: var(--white);
  color: var(--blue-800);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.btn-primary:hover {
  color: var(--blue-700);
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.12);
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.45);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.22);
  color: var(--white);
}

.btn-blue {
  background: var(--blue-600);
  color: var(--white);
}

.btn-blue:hover {
  background: var(--blue-700);
  color: var(--white);
}

/* Layout blocks */
.section {
  padding: 3rem 0;
}

.section-alt {
  background: rgba(255, 255, 255, 0.55);
  border-block: 1px solid rgba(215, 228, 239, 0.7);
}

.section-head {
  margin-bottom: 1.75rem;
  max-width: 760px;
}

.section-head h2 {
  margin: 0 0 0.55rem;
  font-family: var(--display);
  font-size: clamp(1.4rem, 2.4vw, 1.85rem);
  color: var(--blue-900);
}

.section-head p {
  margin: 0;
  color: var(--muted);
  font-size: 1.02rem;
}

.prose {
  font-size: 1.02rem;
  color: #243444;
}

.prose p {
  margin: 0 0 1.05rem;
}

.prose h2,
.prose h3 {
  color: var(--blue-900);
  font-family: var(--display);
  margin: 1.8rem 0 0.7rem;
}

.prose ul,
.prose ol {
  padding-left: 1.25rem;
  margin: 0 0 1.1rem;
}

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

.toc {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.1rem 1.25rem;
  margin: 0 0 1.75rem;
  box-shadow: var(--shadow);
}

.toc strong {
  display: block;
  margin-bottom: 0.55rem;
  color: var(--blue-900);
}

.toc ol {
  margin: 0;
  padding-left: 1.2rem;
}

.toc a {
  font-weight: 500;
}

/* Feature / media grids */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.feature {
  display: grid;
  grid-template-columns: 1fr 1.05fr;
  gap: 1.25rem;
  align-items: center;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem;
  box-shadow: var(--shadow);
  transition: transform 0.25s ease;
}

.feature:hover {
  transform: translateY(-3px);
}

.feature.reverse {
  grid-template-columns: 1.05fr 1fr;
}

.feature.reverse .feature-media {
  order: 2;
}

.feature-media {
  border-radius: 12px;
  overflow: hidden;
  background: var(--blue-50);
  border: 1px solid var(--line);
}

.feature-media img {
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  object-position: top center;
  transition: transform 0.45s ease;
}

.feature:hover .feature-media img {
  transform: scale(1.03);
}

.feature-body h3 {
  margin: 0 0 0.5rem;
  font-size: 1.2rem;
  color: var(--blue-900);
}

.feature-body p {
  margin: 0 0 0.7rem;
  color: var(--muted);
  font-size: 0.98rem;
}

.feature-body .more {
  font-weight: 600;
  font-size: 0.92rem;
}

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

.shot {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform 0.25s ease;
}

.shot:hover {
  transform: translateY(-4px);
}

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

.shot figcaption {
  padding: 0.7rem 0.8rem 0.9rem;
  font-size: 0.88rem;
  color: var(--muted);
}

.shot figcaption strong {
  display: block;
  color: var(--blue-900);
  margin-bottom: 0.2rem;
  font-size: 0.95rem;
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  counter-reset: step;
}

.step {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.2rem;
  box-shadow: var(--shadow);
  position: relative;
}

.step::before {
  counter-increment: step;
  content: counter(step);
  display: inline-flex;
  width: 32px;
  height: 32px;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--blue-600);
  color: white;
  font-weight: 700;
  margin-bottom: 0.7rem;
}

.step h3 {
  margin: 0 0 0.4rem;
  font-size: 1.05rem;
  color: var(--blue-900);
}

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

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

.pill-list a,
.pill-list span {
  display: inline-block;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  background: var(--blue-100);
  color: var(--blue-800);
  font-size: 0.88rem;
  text-decoration: none;
}

.pill-list a:hover {
  background: var(--blue-600);
  color: white;
}

.note-box {
  background: linear-gradient(135deg, #eaf6ff, #f7fbfe);
  border-left: 4px solid var(--blue-500);
  border-radius: 0 12px 12px 0;
  padding: 1rem 1.15rem;
  margin: 1.25rem 0;
  color: #2a4055;
}

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

.page-hero h1 {
  margin: 0 0 0.55rem;
  font-family: var(--display);
  font-size: clamp(1.6rem, 3vw, 2.1rem);
  color: var(--blue-900);
}

.page-hero p {
  margin: 0;
  color: var(--muted);
  max-width: 680px;
}

.page-content {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.6rem 1.5rem 2rem;
  box-shadow: var(--shadow);
  margin-bottom: 3rem;
}

.breadcrumb {
  font-size: 0.9rem;
  color: var(--muted);
  margin-bottom: 0.85rem;
}

.breadcrumb a {
  color: var(--blue-700);
}

/* Error pages */
.error-wrap {
  min-height: 70vh;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 3rem 1rem;
}

.error-wrap h1 {
  font-size: clamp(3rem, 10vw, 5rem);
  margin: 0;
  color: var(--blue-700);
  font-family: var(--display);
}

.error-wrap p {
  color: var(--muted);
  margin: 0.8rem 0 1.4rem;
}

/* Footer */
.site-footer {
  background: linear-gradient(180deg, #0c426f, #083456);
  color: rgba(255, 255, 255, 0.88);
  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;
}

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

.site-footer a {
  color: rgba(255, 255, 255, 0.82);
  text-decoration: none;
  display: inline-block;
  margin-bottom: 0.35rem;
}

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

.footer-brand {
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
}

.footer-brand img {
  width: 48px;
  height: 48px;
  border-radius: 12px;
}

.copyright {
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  padding-top: 1rem;
  font-size: 0.88rem;
  color: rgba(255, 255, 255, 0.65);
}

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

@media (max-width: 980px) {
  .feature-grid {
    grid-template-columns: 1fr;
  }

  .feature,
  .feature.reverse {
    grid-template-columns: 140px 1fr;
  }

  .feature.reverse .feature-media {
    order: 0;
  }

  .feature-media img {
    aspect-ratio: 9 / 14;
  }

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

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

@media (max-width: 760px) {
  .menu-toggle {
    display: inline-flex;
  }

  .nav {
    display: none;
    position: absolute;
    left: 0;
    right: 0;
    top: 68px;
    background: rgba(255, 255, 255, 0.98);
    border-bottom: 1px solid var(--line);
    flex-direction: column;
    align-items: stretch;
    padding: 0.6rem 1rem 1rem;
    gap: 0.2rem;
  }

  .nav.open {
    display: flex;
  }

  .nav a {
    padding: 0.7rem 0.85rem;
  }

  .header-inner {
    position: relative;
  }

  .hero {
    padding: 2.4rem 0 1.8rem;
  }

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

  .feature-media img {
    aspect-ratio: 9 / 12;
    max-height: 420px;
    margin-inline: auto;
  }

  .shot-grid {
    grid-template-columns: 1fr;
    gap: 1.1rem;
    max-width: 420px;
    margin-inline: auto;
  }

  .shot img {
    aspect-ratio: 9 / 14;
    max-height: none;
  }

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

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

  .section {
    padding: 2.2rem 0;
  }

  .page-content {
    padding: 1.2rem 1rem 1.5rem;
  }
}

@media (max-width: 420px) {
  .shot-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
    max-width: 100%;
  }

  .shot img {
    aspect-ratio: 9 / 15;
  }
}