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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body, h1, h2, h3, h4, h5, h6, p, ul, ol, figure, blockquote, dl, dd {
  margin: 0;
}

ul, ol {
  padding: 0;
  list-style: none;
}

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

button {
  font: inherit;
}

:root {
  --primary: #1B4965;
  --ink: #0D1B2A;
  --accent: #FF7F32;
  --accent-soft: #FFA500;
  --sky-blue: #B3C7D6;
  --mint: #EAF4F4;
  --dark: #222222;
  --data-blue: #00BFFF;
  --success: #2A9D8F;
  --bg: #F8F9FA;
  --white: #FFFFFF;
  --radius-sm: 12px;
  --radius-md: 20px;
  --radius-lg: 32px;
  --radius-pill: 999px;
  --shadow-soft: 0 8px 24px rgba(13, 27, 42, 0.08);
  --shadow-float: 0 16px 40px rgba(13, 27, 42, 0.12);
  --font-body: 'Noto Sans SC', 'PingFang SC', sans-serif;
  --font-number: 'Roboto Mono', 'SF Mono', monospace;
  --container: 1200px;
}

body {
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink);
  background: var(--bg);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--ink);
  margin-bottom: 0.5em;
}

a {
  color: var(--primary);
}

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

.skip-link {
  position: fixed;
  top: 16px;
  left: 16px;
  z-index: 999;
  transform: translateY(-160%);
  background: var(--accent);
  color: var(--white);
  font-weight: 700;
  font-size: 14px;
  line-height: 1;
  padding: 12px 20px;
  border-radius: var(--radius-pill);
  text-decoration: none;
  box-shadow: 0 4px 16px rgba(255, 127, 50, 0.35);
  transition: transform 0.2s ease;
}

.skip-link:focus {
  transform: translateY(0);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.site-header {
  position: fixed;
  top: 16px;
  left: 50%;
  transform: translateX(-50%);
  width: calc(100% - 32px);
  max-width: var(--container);
  z-index: 100;
}

.nav-shell {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  background: var(--primary);
  border-radius: var(--radius-pill);
  padding: 8px 10px 8px 18px;
  box-shadow: 0 12px 32px rgba(27, 73, 101, 0.3);
}

.nav-shell::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 32px;
  width: 64px;
  height: 3px;
  background: var(--accent);
  border-radius: 3px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--white);
  text-decoration: none;
  flex-shrink: 0;
}

.brand-mark {
  position: relative;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--accent);
  display: inline-block;
  overflow: hidden;
  flex-shrink: 0;
}

.brand-mark::after {
  content: '';
  position: absolute;
  inset: 7px;
  border-radius: 50%;
  background: var(--primary);
}

.brand-mark::before {
  content: '';
  position: absolute;
  top: 15px;
  left: -6px;
  width: 46px;
  height: 4px;
  background: var(--white);
  border-radius: 4px;
  transform: rotate(-30deg);
  z-index: 1;
}

.brand-text {
  font-weight: 900;
  font-size: 16px;
  letter-spacing: 0.01em;
  white-space: nowrap;
}

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

.nav-link {
  display: inline-block;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  color: rgba(255, 255, 255, 0.85);
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
  transition: background 0.2s ease, color 0.2s ease;
}

.nav-link:hover {
  background: rgba(255, 255, 255, 0.12);
  color: var(--white);
}

.nav-link[aria-current="page"] {
  background: var(--accent);
  color: var(--white);
  font-weight: 700;
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: none;
  background: rgba(255, 255, 255, 0.12);
  border-radius: 50%;
  cursor: pointer;
  padding: 0;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
}

.nav-toggle-bar {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--white);
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.site-footer {
  background: var(--dark);
  color: rgba(255, 255, 255, 0.65);
  margin-top: 60px;
}

.footer-decor {
  height: 6px;
  background: linear-gradient(90deg, var(--accent) 0%, var(--primary) 50%, var(--data-blue) 100%);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 40px;
  padding: 56px 0 40px;
}

.footer-brand-block,
.footer-nav-block,
.footer-legal-block,
.footer-contact-block {
  min-width: 0;
}

.footer-brand-block {
  padding-right: 16px;
}

.footer-brand-name {
  font-size: 20px;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--white);
  margin: 0 0 12px;
}

.footer-trust {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.55);
  max-width: 260px;
  margin: 0;
}

.footer-heading {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--sky-blue);
  margin: 0 0 16px;
}

.footer-links li + li,
.footer-contact li + li {
  margin-top: 10px;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.75);
  text-decoration: none;
  font-size: 14px;
  transition: color 0.2s ease, padding-left 0.2s ease;
}

.footer-links a:hover {
  color: var(--accent);
  padding-left: 4px;
}

.footer-contact li {
  display: flex;
  gap: 10px;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.7);
}

.contact-label {
  min-width: 36px;
  font-size: 12px;
  font-weight: 700;
  color: var(--sky-blue);
  flex-shrink: 0;
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px 24px;
  padding: 20px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 13px;
  color: rgba(255, 255, 255, 0.45);
}

.footer-copy,
.footer-icp {
  margin: 0;
}

.top-toggle {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.25);
  background: var(--primary);
  color: var(--white);
  font-size: 20px;
  line-height: 1;
  cursor: pointer;
  box-shadow: 0 12px 32px rgba(13, 27, 42, 0.22);
  opacity: 0;
  transform: translateY(12px) scale(0.9);
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease, background 0.2s ease;
  z-index: 90;
}

.top-toggle.is-visible {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: auto;
}

.top-toggle:hover {
  background: var(--accent);
  border-color: var(--accent);
}

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

#main-content {
  display: block;
}

.page-hero {
  padding: 180px 0 60px;
  background: linear-gradient(180deg, var(--mint) 0%, var(--bg) 100%);
}

.page-title {
  font-size: clamp(36px, 6vw, 64px);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 1.06;
  margin: 0 0 16px;
  color: var(--ink);
}

.page-intro {
  font-size: 17px;
  line-height: 1.8;
  color: var(--ink);
  opacity: 0.85;
  max-width: 640px;
  margin: 0;
}

.page-body {
  padding: 120px 0 80px;
}

.eyebrow {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 12px;
}

.section-title {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 900;
  letter-spacing: -0.03em;
  margin: 0 0 8px;
}

.section-subtitle {
  font-size: 16px;
  color: var(--sky-blue);
  margin: 0 0 24px;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  margin-bottom: 24px;
}

.breadcrumb a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s ease;
}

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

.breadcrumb .sep {
  color: var(--sky-blue);
}

.breadcrumb [aria-current="page"] {
  color: var(--ink);
  font-weight: 600;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius-pill);
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 14px;
  line-height: 1;
  text-decoration: none;
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, color 0.2s ease;
}

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

.btn:active {
  transform: translateY(0);
}

.btn-primary {
  background: var(--primary);
  color: var(--white);
  box-shadow: 0 6px 16px rgba(27, 73, 101, 0.22);
}

.btn-primary:hover {
  background: #163a56;
  box-shadow: 0 10px 24px rgba(27, 73, 101, 0.28);
}

.btn-accent {
  background: var(--accent);
  color: var(--white);
  box-shadow: 0 6px 16px rgba(255, 127, 50, 0.3);
}

.btn-accent:hover {
  background: #f5691a;
}

.btn-ghost {
  background: transparent;
  color: var(--primary);
  border-color: var(--primary);
}

.btn-ghost:hover {
  background: var(--primary);
  color: var(--white);
}

.btn-lg {
  padding: 16px 32px;
  font-size: 15px;
}

.card {
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 28px;
  border: 1px solid var(--mint);
  box-shadow: var(--shadow-soft);
  transition: box-shadow 0.25s ease, transform 0.25s ease;
}

.card:hover {
  box-shadow: var(--shadow-float);
  transform: translateY(-2px);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px;
  border-radius: var(--radius-pill);
  font-size: 12px;
  font-weight: 600;
  background: var(--mint);
  color: var(--primary);
}

.tag-accent {
  background: rgba(255, 127, 50, 0.12);
  color: #d95c16;
}

.tag-data {
  background: rgba(0, 191, 255, 0.12);
  color: #0077a8;
}

.tag-success {
  background: rgba(42, 157, 143, 0.12);
  color: var(--success);
}

.img-frame {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--mint);
}

.img-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.img-frame-16x9 {
  aspect-ratio: 16 / 9;
}

.img-frame-4x3 {
  aspect-ratio: 4 / 3;
}

.img-frame-1x1 {
  aspect-ratio: 1 / 1;
}

.data-number {
  font-family: var(--font-number);
  font-weight: 500;
  font-size: 1.25em;
  color: var(--data-blue);
  font-variant-numeric: tabular-nums;
}

@media (max-width: 900px) {
  .site-header {
    top: 12px;
    width: calc(100% - 24px);
  }

  .nav-shell {
    border-radius: 44px;
    padding: 8px 8px 8px 14px;
  }

  .site-nav {
    position: absolute;
    top: calc(100% + 12px);
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    gap: 4px;
    background: var(--primary);
    border-radius: 20px;
    padding: 12px;
    box-shadow: 0 16px 40px rgba(27, 73, 101, 0.32);
  }

  .site-nav[data-open] {
    display: flex;
  }

  .nav-link {
    padding: 12px 16px;
    font-size: 15px;
    color: var(--white);
  }

  .nav-toggle {
    display: flex;
  }

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

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

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

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .page-hero {
    padding: 160px 0 50px;
  }

  .page-body {
    padding: 104px 0 64px;
  }
}

@media (max-width: 600px) {
  .container {
    padding-left: 16px;
    padding-right: 16px;
  }

  .page-hero {
    padding: 140px 0 40px;
  }

  .page-body {
    padding: 96px 0 48px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 40px 0 28px;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }

  .top-toggle {
    right: 16px;
    bottom: 16px;
    width: 44px;
    height: 44px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .btn:hover,
  .card:hover {
    transform: none;
  }

  .skip-link {
    transition: none;
  }
}