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

:root {
  --color-primary: #1a2a3a;
  --color-accent: #d4af37;
  --color-bg: #f7f7f5;
  --color-surface: #ffffff;
  --color-text: #14212e;
  --color-text-secondary: #4e5d6a;
  --color-border: #d9d2c5;
  --color-highlight: rgba(212,175,55,0.18);
  --color-glass: rgba(26,42,58,0.75);
  --color-inverse: #eef2f5;
  --font-heading: 'Noto Serif SC', 'Songti SC', serif;
  --font-body: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'JetBrains Mono', 'Roboto Mono', monospace;
  --content-max: 1280px;
  --header-h: 4.5rem;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  background: var(--color-bg);
  color: var(--color-text);
  -webkit-font-smoothing: antialiased;
}

#main-content {
  flex: 1;
  width: 100%;
}

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

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  line-height: 1.2;
  margin-top: 0;
  color: var(--color-text);
}

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

a:hover {
  text-decoration: none;
}

:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

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

.skip-link {
  position: absolute;
  left: -100%;
  top: 0;
  background: var(--color-accent);
  color: var(--color-primary);
  padding: 0.5rem 1rem;
  z-index: 200;
  text-decoration: none;
  border-radius: 0 0 0.25rem 0;
  transition: left var(--transition);
}

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

.site-header {
  position: relative;
  z-index: 100;
  background: var(--color-primary);
  color: var(--color-inverse);
  border-bottom: 1px solid var(--color-accent);
}

.site-header__bar {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.site-header__brand {
  flex-shrink: 0;
}

.brand {
  display: inline-flex;
  flex-direction: column;
  line-height: 1.2;
  text-decoration: none;
  color: inherit;
}

.brand__name {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: inherit;
}

.brand__sub {
  font-size: 0.7rem;
  font-family: var(--font-mono);
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--color-accent);
}

.site-nav__list {
  display: flex;
  gap: 0.35rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav__link {
  display: block;
  padding: 0.5rem 0.75rem;
  border-radius: 0.25rem;
  color: var(--color-inverse);
  text-decoration: none;
  font-size: 0.95rem;
  border: 1px solid transparent;
  transition:
    background-color var(--transition),
    color var(--transition),
    border-color var(--transition);
}

.site-nav__link:hover {
  color: var(--color-accent);
  border-color: rgba(212, 175, 55, 0.4);
  background: rgba(212, 175, 55, 0.08);
}

.site-nav__link[aria-current="page"] {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
  background: rgba(212, 175, 55, 0.12);
}

.site-header__aside {
  display: flex;
  align-items: center;
}

.site-nav__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  background: transparent;
  border: 1px solid rgba(238, 242, 245, 0.3);
  border-radius: 0.25rem;
  cursor: pointer;
  transition: border-color var(--transition);
}

.site-nav__toggle:hover {
  border-color: var(--color-accent);
}

.site-nav__toggle-line {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--color-inverse);
  transition:
    transform var(--transition),
    background-color var(--transition);
}

.site-nav__toggle:hover .site-nav__toggle-line {
  background: var(--color-accent);
}

.site-header__progress {
  position: absolute;
  bottom: -1px;
  left: 0;
  right: 0;
  height: 2px;
  background: transparent;
  pointer-events: none;
}

.site-header__progress span {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--color-accent), #f0d97a);
}

.side-tools {
  position: fixed;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  z-index: 90;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 0.5rem;
  background: var(--color-glass);
  border-radius: 0 1rem 1rem 0;
  border-left: 1px solid var(--color-accent);
  box-shadow: 0 0 16px rgba(26, 42, 58, 0.2);
  backdrop-filter: blur(8px);
}

.side-tools__link {
  display: block;
  padding: 0.5rem 0.75rem;
  color: var(--color-inverse);
  font-size: 0.875rem;
  text-decoration: none;
  border-radius: 0.25rem;
  border: 1px solid transparent;
  transition:
    background-color var(--transition),
    color var(--transition);
}

.side-tools__link:hover,
.side-tools__link:focus-visible {
  background: var(--color-highlight);
  color: var(--color-accent);
}

.site-footer {
  position: relative;
  background: var(--color-primary);
  color: var(--color-inverse);
  border-top: 1px solid var(--color-accent);
  padding: 3rem 1.5rem 1rem;
  font-size: 0.95rem;
}

.site-footer__frame {
  max-width: var(--content-max);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1.5fr;
  gap: 2rem;
  padding-bottom: 2rem;
}

.site-footer__brand .brand__name {
  color: var(--color-inverse);
  font-size: 1.5rem;
}

.site-footer__desc {
  margin: 1rem 0 0;
  color: rgba(238, 242, 245, 0.8);
  font-size: 0.9rem;
  max-width: 36em;
}

.site-footer__nav {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  justify-content: flex-start;
}

.site-footer__nav a {
  color: var(--color-inverse);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  padding: 0.15rem 0;
  width: fit-content;
  transition:
    color var(--transition),
    border-color var(--transition);
}

.site-footer__nav a:hover,
.site-footer__nav a:focus-visible {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

.site-footer__contact p {
  margin: 0.25rem 0;
  color: rgba(238, 242, 245, 0.75);
  font-family: var(--font-mono);
  font-size: 0.875rem;
}

.site-footer__meta {
  max-width: var(--content-max);
  margin: 1rem auto 0;
  padding-top: 1rem;
  border-top: 1px solid rgba(238, 242, 245, 0.15);
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 2rem;
  font-size: 0.875rem;
  color: rgba(238, 242, 245, 0.6);
}

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

.section {
  padding-block: 3rem;
}

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

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border: 1px solid var(--color-primary);
  background: transparent;
  color: var(--color-primary);
  font: inherit;
  font-size: 0.95rem;
  line-height: 1.4;
  border-radius: 0.25rem;
  text-decoration: none;
  cursor: pointer;
  transition:
    background-color var(--transition),
    color var(--transition),
    border-color var(--transition);
}

.btn:hover,
.btn:focus-visible {
  background: var(--color-primary);
  color: var(--color-inverse);
}

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

.btn--accent:hover,
.btn--accent:focus-visible {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-accent);
}

.btn--dark {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-inverse);
}

.btn--dark:hover,
.btn--dark:focus-visible {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-primary);
}

.breadcrumbs {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  padding-block: 1rem;
}

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

.breadcrumbs a:hover {
  text-decoration: underline;
}

.breadcrumbs__sep {
  margin: 0 0.5rem;
  color: var(--color-border);
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 1.5rem;
}

.grid__item {
  grid-column: span 4;
}

.grid__item--span-3 { grid-column: span 3; }
.grid__item--span-4 { grid-column: span 4; }
.grid__item--span-5 { grid-column: span 5; }
.grid__item--span-6 { grid-column: span 6; }
.grid__item--span-7 { grid-column: span 7; }
.grid__item--span-8 { grid-column: span 8; }
.grid__item--span-9 { grid-column: span 9; }
.grid__item--span-12 { grid-column: span 12; }

.image-frame {
  position: relative;
  overflow: hidden;
  background: var(--color-highlight);
  border: 1px solid var(--color-border);
  border-radius: 0.25rem;
  aspect-ratio: 16 / 10;
  min-height: 8rem;
}

.image-frame > * {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

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

.image-frame--wide {
  aspect-ratio: 21 / 9;
}

@media (max-width: 992px) {
  .site-header__bar {
    gap: 1rem;
    padding: 0 1rem;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-glass);
    border-bottom: 1px solid var(--color-accent);
    display: none;
    padding: 0.5rem 1rem 1.25rem;
    box-shadow: 0 12px 20px rgba(26, 42, 58, 0.3);
  }

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

  .site-nav__list {
    flex-direction: column;
    gap: 0.25rem;
  }

  .site-nav__link {
    padding: 0.75rem 0.5rem;
    border-radius: 0.25rem;
  }

  .site-nav__toggle {
    display: flex;
  }

  .site-header__aside {
    margin-left: auto;
  }

  .side-tools {
    display: none;
  }
}

@media (max-width: 768px) {
  .site-footer__frame {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .site-footer__meta {
    flex-direction: column;
    gap: 0.5rem;
  }

  .grid__item,
  .grid__item--span-3,
  .grid__item--span-4,
  .grid__item--span-5,
  .grid__item--span-6,
  .grid__item--span-7,
  .grid__item--span-8,
  .grid__item--span-9,
  .grid__item--span-12 {
    grid-column: 1 / -1;
  }
}

@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;
  }
}