:root {
  --color-primary: #0A2540;
  --color-primary-deep: #0B1B2A;
  --color-accent: #FF6C2C;
  --color-accent-soft: rgba(255, 108, 44, 0.16);
  --color-info: #00C2D1;
  --color-info-soft: rgba(0, 194, 209, 0.16);
  --color-bg: #F5F7FA;
  --color-surface: #FFFFFF;
  --color-text: #2D3540;
  --color-text-light: #667085;
  --color-label-bg: #E3F0FF;
  --glass-bg: rgba(255, 255, 255, 0.72);
  --border-radius: 20px;
  --sidebar-w: 280px;
  --header-h: 68px;
  --gap: 24px;
  --max-width: 1280px;
  --shadow-sm: 0 8px 24px rgba(10, 37, 64, 0.08);
  --shadow-md: 0 16px 48px rgba(10, 37, 64, 0.14);
  --font-heading: "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --font-body: "Inter", "Noto Sans SC", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  overflow-x: hidden;
  background:
    radial-gradient(circle at 90% 8%, rgba(0, 194, 209, 0.1), transparent 34rem),
    radial-gradient(circle at 8% 92%, rgba(255, 108, 44, 0.08), transparent 26rem),
    linear-gradient(180deg, var(--color-bg) 0%, #EDF2F7 100%);
  background-attachment: fixed;
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img,
svg,
video {
  max-width: 100%;
  display: block;
}

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

a:hover {
  color: var(--color-info);
}

:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 3px;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  margin: 0 0 0.85rem;
  color: var(--color-primary);
  font-family: var(--font-heading);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

p {
  margin: 0 0 1rem;
}

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

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

.content-narrow {
  max-width: 760px;
  margin-inline: auto;
}

.section {
  padding-block: clamp(3.5rem, 8vw, 6.5rem);
}

.section-eyebrow {
  display: inline-block;
  margin-bottom: 0.35rem;
  color: var(--color-accent);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.24em;
}

.section-title {
  margin: 0 0 1rem;
  font-size: clamp(2rem, 5vw, 3.5rem);
  color: var(--color-primary);
}

.section-intro {
  max-width: 680px;
  margin: 0 0 2.5rem;
  color: var(--color-text-light);
  font-size: 1.05rem;
}

.grid {
  display: grid;
  gap: var(--gap);
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--gap);
}

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

.card,
.file-card {
  position: relative;
  background: var(--glass-bg);
  border: 1px solid rgba(255, 255, 255, 0.65);
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  padding: 1.5rem;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.card:hover,
.file-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.card-title,
.file-card__title {
  margin: 0 0 0.75rem;
  color: var(--color-primary);
  font-size: 1.25rem;
  font-weight: 800;
}

.card-text,
.file-card__text {
  margin: 0 0 1rem;
  color: var(--color-text-light);
}

.file-card {
  display: flex;
  flex-direction: column;
  height: 100%;
  overflow: hidden;
}

.file-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--color-accent), var(--color-info));
}

.file-card__media {
  margin: -1.5rem -1.5rem 1.25rem;
}

.file-card__body {
  display: flex;
  flex-direction: column;
  flex: 1;
}

.file-card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: auto;
  color: var(--color-text-light);
  font-size: 0.8rem;
}

.tag-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.22rem 0.8rem;
  border-radius: 999px;
  background: var(--color-label-bg);
  color: var(--color-primary);
  font-size: 0.75rem;
  font-weight: 600;
  white-space: nowrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  border: 0;
  border-radius: 999px;
  padding: 0.75rem 1.35rem;
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 700;
  line-height: 1.2;
  cursor: pointer;
  color: var(--color-surface);
  text-decoration: none;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
}

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

.btn-primary {
  background: var(--color-accent);
  box-shadow: 0 12px 24px rgba(255, 108, 44, 0.28);
}

.btn-primary:hover {
  background: #FF7E45;
  box-shadow: 0 16px 32px rgba(255, 108, 44, 0.36);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0 0 1.5rem;
  padding: 0;
  list-style: none;
  color: var(--color-text-light);
  font-size: 0.88rem;
}

.breadcrumb li + li::before {
  content: "/";
  margin-right: 0.5rem;
  color: var(--color-info);
}

.breadcrumb a {
  color: var(--color-primary);
  font-weight: 500;
}

.media-frame,
.file-card__media .media-frame {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  aspect-ratio: 16 / 10;
  border-radius: var(--border-radius);
  overflow: hidden;
  background: linear-gradient(135deg, var(--color-label-bg), var(--color-bg));
  color: rgba(10, 37, 64, 0.45);
  font-size: 0.85rem;
}

.media-frame--square {
  aspect-ratio: 1 / 1;
}

.media-frame--portrait {
  aspect-ratio: 4 / 5;
}

[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

[data-reveal="visible"] {
  opacity: 1;
  transform: none;
}

.skip-link {
  position: fixed;
  top: -100%;
  left: 1rem;
  z-index: 1400;
  padding: 0.65rem 1.2rem;
  border-radius: 0 0 0.75rem 0.75rem;
  background: var(--color-accent);
  color: var(--color-surface);
  font-size: 0.9rem;
  font-weight: 700;
  box-shadow: var(--shadow-sm);
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 0;
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1200;
  width: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-accent), var(--color-info));
  pointer-events: none;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1000;
  width: var(--sidebar-w);
  height: 100vh;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  background: rgba(10, 37, 64, 0.82);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  color: var(--color-surface);
  border-right: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 1px 0 30px rgba(10, 37, 64, 0.2);
  transition: background-color 0.3s ease;
}

.site-header[data-scrolled="true"] {
  background: rgba(11, 27, 42, 0.97);
}

.site-header-inner {
  position: relative;
  display: flex;
  flex-direction: column;
  width: 100%;
  height: 100%;
  padding: 1.5rem;
  overflow-y: auto;
}

.brand-block {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 2rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--color-surface);
}

.brand:hover {
  color: var(--color-surface);
}

.brand-mark {
  position: relative;
  display: inline-block;
  width: 48px;
  height: 48px;
  flex-shrink: 0;
  border-radius: 14px;
  background: linear-gradient(135deg, var(--color-accent), var(--color-info));
  box-shadow: 0 10px 20px rgba(0, 194, 209, 0.28);
  overflow: hidden;
}

.brand-mark::before {
  content: "";
  position: absolute;
  inset: 8px;
  border-radius: 10px;
  background: var(--color-primary);
}

.brand-mark::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 24px;
  height: 24px;
  border-radius: 10px 0 0 0;
  background: linear-gradient(135deg, transparent 50%, var(--color-accent) 50%);
}

.brand-copy {
  display: flex;
  flex-direction: column;
  line-height: 1.3;
}

.brand-name {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: 0.02em;
}

.brand-tagline {
  margin-top: 0.1rem;
  color: rgba(255, 255, 255, 0.68);
  font-size: 0.72rem;
  letter-spacing: 0.34em;
}

.nav-toggle {
  display: none;
}

.site-nav {
  display: flex;
  flex-direction: column;
  flex: 1;
  gap: 2rem;
}

.nav-list {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  padding: 0.72rem 0.9rem;
  border-radius: 12px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 0.95rem;
  font-weight: 500;
  line-height: 1.3;
  transition: background-color 0.2s ease, color 0.2s ease, transform 0.2s ease;
}

.nav-link::before {
  content: "";
  width: 6px;
  height: 6px;
  flex-shrink: 0;
  border-radius: 50%;
  background: var(--color-info);
  opacity: 0;
  transition: opacity 0.2s ease;
}

.nav-link:hover {
  color: var(--color-surface);
  background: rgba(255, 255, 255, 0.12);
  transform: translateX(4px);
}

.nav-link[aria-current="page"] {
  color: var(--color-surface);
  background: linear-gradient(135deg, rgba(0, 194, 209, 0.26), rgba(255, 108, 44, 0.2));
}

.nav-link[aria-current="page"]::before {
  opacity: 1;
}

.rail-extra {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: auto;
}

.rail-service {
  margin: 0;
  color: rgba(255, 255, 255, 0.55);
  font-size: 0.75rem;
}

#main-content {
  display: block;
  margin-left: var(--sidebar-w);
  padding-top: 2rem;
  padding-bottom: 4rem;
}

#main-content:focus {
  outline: none;
}

.site-footer {
  margin-left: var(--sidebar-w);
  padding: 4.5rem 0 2rem;
  position: relative;
  background: var(--color-primary-deep);
  color: rgba(255, 255, 255, 0.76);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--color-accent), var(--color-info), var(--color-primary));
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1.5fr;
  gap: clamp(1.5rem, 4vw, 3rem);
  width: min(calc(100% - var(--gap) * 2), var(--max-width));
  margin-inline: auto;
}

.footer-brand {
  max-width: 440px;
}

.footer-brand .brand {
  color: var(--color-surface);
}

.footer-brand .brand:hover {
  color: var(--color-surface);
}

.footer-description {
  margin: 1.1rem 0 1rem;
  color: rgba(255, 255, 255, 0.68);
  font-size: 0.95rem;
}

.trust-statement {
  margin: 1.25rem 0 0;
  padding-left: 1rem;
  border-left: 3px solid var(--color-info);
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.88rem;
  line-height: 1.7;
}

.footer-heading {
  margin-bottom: 1.1rem;
  color: var(--color-surface);
  font-size: 1rem;
  letter-spacing: 0.08em;
}

.footer-link-list {
  display: grid;
  gap: 0.65rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.footer-link {
  color: rgba(255, 255, 255, 0.74);
  font-size: 0.94rem;
  transition: color 0.2s ease, padding-left 0.2s ease;
}

.footer-link:hover {
  color: var(--color-info);
  padding-left: 4px;
}

.footer-contact {
  margin: 0.4rem 0;
  color: rgba(255, 255, 255, 0.66);
  font-size: 0.9rem;
}

.footer-legal {
  margin-top: 1rem;
  color: rgba(255, 255, 255, 0.46);
  font-size: 0.8rem;
  letter-spacing: 0.04em;
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.8rem 2rem;
  width: min(calc(100% - var(--gap) * 2), var(--max-width));
  margin: 3rem auto 0;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
}

.footer-copyright {
  margin: 0;
  color: rgba(255, 255, 255, 0.56);
  font-size: 0.85rem;
}

.footer-legal-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.footer-legal-links .footer-link {
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.56);
}

.footer-legal-links .footer-link:hover {
  color: var(--color-info);
}

@media (max-width: 1024px) {
  .site-header {
    width: auto;
    right: 0;
    height: var(--header-h);
    flex-direction: row;
    align-items: center;
    padding: 0 1rem;
    border-right: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.12);
    background: rgba(10, 37, 64, 0.9);
  }

  .site-header[data-scrolled="true"] {
    background: rgba(11, 27, 42, 0.98);
  }

  .site-header-inner {
    width: 100%;
    height: auto;
    padding: 0;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    overflow: visible;
  }

  .brand-block {
    flex: 1;
    justify-content: space-between;
    margin-bottom: 0;
  }

  .brand {
    min-width: 0;
  }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.45rem 1rem;
    border: 1px solid rgba(255, 255, 255, 0.28);
    border-radius: 999px;
    background: transparent;
    color: var(--color-surface);
    font-size: 0.88rem;
    font-weight: 600;
    cursor: pointer;
  }

  .nav-toggle:hover {
    background: rgba(255, 255, 255, 0.1);
  }

  .nav-toggle-icon {
    position: relative;
    display: inline-block;
    width: 18px;
    height: 14px;
    border-top: 2px solid var(--color-surface);
    border-bottom: 2px solid var(--color-surface);
  }

  .nav-toggle-icon::after {
    content: "";
    position: absolute;
    top: 4px;
    left: 0;
    right: 0;
    border-top: 2px solid var(--color-surface);
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    max-height: calc(100vh - var(--header-h));
    max-height: calc(100dvh - var(--header-h));
    margin: 0;
    padding: 1rem;
    background: rgba(10, 37, 64, 0.97);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 20px 44px rgba(10, 37, 64, 0.3);
    overflow-y: auto;
  }

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

  .nav-list {
    margin-bottom: 1rem;
  }

  .rail-extra {
    margin-top: 0.5rem;
  }

  #main-content {
    margin-left: 0;
    margin-top: var(--header-h);
    padding-top: 1.5rem;
  }

  .site-footer {
    margin-left: 0;
  }

  .grid-2,
  .grid-3,
  .archive-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 680px) {
  .grid-2,
  .grid-3,
  .archive-grid {
    grid-template-columns: 1fr;
  }

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

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

  .brand-mark {
    width: 40px;
    height: 40px;
    border-radius: 12px;
  }

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

  .brand-tagline {
    letter-spacing: 0.24em;
  }
}

@media (prefers-reduced-motion: reduce) {
  html,
  html:focus-within {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }

  [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }

  .btn,
  .card,
  .file-card,
  .nav-link {
    transform: none !important;
  }
}