:root {
  --color-cream: #F5EFE0;
  --color-brown: #2B1D14;
  --color-orange: #F25C05;
  --color-navy: #1F3E5C;
  --color-sand: #D9D0C0;
  --color-stone: #8C7E6A;
  --color-yellow: #FFC300;
  --color-brick: #A33B20;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-display: "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", sans-serif;
  --font-mono: "SF Mono", "Courier New", Consolas, monospace;
  --header-w: 280px;
  --shadow-hard: 6px 6px 0 rgba(43, 29, 20, 1);
  --shadow-soft: 6px 6px 0 rgba(43, 29, 20, 0.12);
  --spacing: 16px;
  --spacing-lg: 32px;
  --spacing-xl: 64px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  background: var(--color-cream);
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-brown);
  background-color: var(--color-cream);
  background-image:
    linear-gradient(rgba(43, 29, 20, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(43, 29, 20, 0.035) 1px, transparent 1px);
  background-size: 24px 24px;
  min-height: 100vh;
  overflow-x: hidden;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  color: var(--color-brown);
  line-height: 1.25;
  font-weight: 900;
  text-wrap: balance;
}

h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  letter-spacing: -0.02em;
}

h2 {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  letter-spacing: -0.01em;
}

h3 {
  font-size: 1.375rem;
}

h4 {
  font-size: 1.125rem;
}

p {
  margin-bottom: 1rem;
}

a {
  color: var(--color-navy);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

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

:focus-visible {
  outline: 3px solid var(--color-orange);
  outline-offset: 2px;
}

.skip-link {
  position: fixed;
  top: -80px;
  left: 16px;
  z-index: 6000;
  background: var(--color-orange);
  color: var(--color-brown);
  padding: 12px 24px;
  text-decoration: none;
  font-weight: 700;
  font-size: 14px;
  border: 2px solid var(--color-brown);
  box-shadow: var(--shadow-hard);
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 16px;
  color: var(--color-brown);
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background-color: var(--color-orange);
  transform: scaleX(0);
  transform-origin: 0 0;
  z-index: 7000;
  pointer-events: none;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--header-w);
  height: 100vh;
  min-height: 520px;
  background: var(--color-brown);
  color: var(--color-cream);
  border-right: 3px solid var(--color-orange);
  z-index: 1000;
  overflow-y: auto;
  display: flex;
  padding: 28px 24px;
}

.site-header__inner {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.site-header__brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.site-header__brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: var(--color-orange);
  color: var(--color-brown);
  font-weight: 900;
  font-size: 22px;
  border: 2px solid var(--color-brown);
  font-family: var(--font-display);
  flex-shrink: 0;
}

.site-header__brand-name {
  font-size: 26px;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--color-cream);
  line-height: 1;
}

.site-header__slogan {
  display: block;
  color: var(--color-orange);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  border-left: 3px solid var(--color-orange);
  padding-left: 12px;
  margin-bottom: 4px;
}

.site-header__toggle {
  display: none;
  align-items: center;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  background: transparent;
  border: 2px solid var(--color-cream);
  cursor: pointer;
  padding: 8px;
  margin-left: auto;
  color: var(--color-cream);
  transition: color 0.2s ease, border-color 0.2s ease;
}

.site-header__toggle-bar {
  display: block;
  width: 22px;
  height: 2px;
  background: currentColor;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.site-header__toggle[aria-expanded="true"] {
  color: var(--color-orange);
  border-color: var(--color-orange);
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:first-child {
  transform: translateY(7px) rotate(45deg);
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:last-child {
  transform: translateY(-7px) rotate(-45deg);
}

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

.site-header__nav {
  display: block;
  margin-top: 8px;
}

.site-header__list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.site-header__item {
  margin: 0;
  padding: 0;
}

.site-header__link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  color: rgba(245, 239, 224, 0.8);
  text-decoration: none;
  font-size: 16px;
  font-weight: 500;
  border-left: 3px solid transparent;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease, padding-left 0.2s ease;
}

.site-header__link:hover {
  color: var(--color-cream);
  background: rgba(245, 239, 224, 0.06);
  border-left-color: var(--color-orange);
  padding-left: 18px;
}

.site-header__link[aria-current="page"] {
  background: var(--color-orange);
  border-left-color: var(--color-cream);
  color: var(--color-brown);
  font-weight: 700;
  box-shadow: 3px 3px 0 rgba(0, 0, 0, 0.25);
}

.site-header__num {
  font-family: var(--font-mono);
  font-size: 12px;
  min-width: 20px;
  color: rgba(245, 239, 224, 0.5);
}

.site-header__link:hover .site-header__num {
  color: var(--color-orange);
}

.site-header__link[aria-current="page"] .site-header__num {
  color: var(--color-brown);
}

.site-header__label {
  display: inline-block;
  line-height: 1.4;
}

.site-header__meta {
  margin-top: auto;
  display: flex;
  justify-content: space-between;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: rgba(245, 239, 224, 0.4);
  border-top: 1px solid rgba(245, 239, 224, 0.15);
  padding-top: 16px;
  letter-spacing: 0.08em;
}

.back-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-orange);
  border: 2px solid var(--color-brown);
  box-shadow: var(--shadow-hard);
  color: var(--color-brown);
  font-size: 20px;
  cursor: pointer;
  z-index: 2400;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 0.25s ease, visibility 0.25s ease, transform 0.25s ease;
}

.back-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-top:hover {
  background: var(--color-brown);
  color: var(--color-cream);
}

.site-footer {
  background: var(--color-brown);
  color: var(--color-cream);
  border-top: 6px solid var(--color-orange);
  padding: 64px 32px 32px;
  margin-left: var(--header-w);
}

.site-footer__grid {
  max-width: 1200px;
  margin-inline: auto;
  display: grid;
  grid-template-columns: 2.2fr 1fr 1fr 1.8fr;
  gap: 48px 32px;
}

.site-footer__brand {
  min-width: 0;
}

.site-footer__logo {
  font-size: 32px;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--color-cream);
  line-height: 1.2;
  display: inline-flex;
  align-items: center;
  gap: 12px;
}

.site-footer__logo::before {
  content: '';
  width: 14px;
  height: 14px;
  background: var(--color-orange);
  transform: skew(-12deg);
  display: inline-block;
  flex-shrink: 0;
}

.site-footer__slogan {
  color: var(--color-orange);
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.1em;
  margin-top: 12px;
  text-transform: uppercase;
}

.site-footer__desc {
  color: rgba(245, 239, 224, 0.7);
  font-size: 14px;
  line-height: 1.8;
  max-width: 320px;
  margin-top: 12px;
}

.site-footer__nav,
.site-footer__legal,
.site-footer__contact {
  min-width: 0;
}

.site-footer__heading {
  color: var(--color-orange);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(245, 239, 224, 0.15);
}

.site-footer__links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.site-footer__link {
  display: inline-block;
  color: rgba(245, 239, 224, 0.75);
  text-decoration: none;
  font-size: 14px;
  transition: color 0.15s ease, padding-left 0.15s ease;
}

.site-footer__link:hover {
  color: var(--color-orange);
  padding-left: 4px;
}

.site-footer__contact-line {
  font-size: 14px;
  color: rgba(245, 239, 224, 0.8);
  margin-bottom: 8px;
  line-height: 1.7;
}

.site-footer__note {
  font-size: 12px;
  color: rgba(245, 239, 224, 0.5);
  margin-top: 12px;
  line-height: 1.6;
}

.site-footer__bottom {
  max-width: 1200px;
  margin-inline: auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  border-top: 1px solid rgba(245, 239, 224, 0.15);
  padding-top: 24px;
  margin-top: 48px;
}

.site-footer__copyright,
.site-footer__icp {
  margin: 0;
  font-size: 12px;
  color: rgba(245, 239, 224, 0.5);
  font-family: var(--font-mono);
}

#main-content,
.main-content {
  outline: none;
  min-height: 60vh;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin-inline: auto;
  padding-inline: 24px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  background: var(--color-cream);
  color: var(--color-brown);
  border: 2px solid var(--color-brown);
  box-shadow: 4px 4px 0 var(--color-brown);
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
  line-height: 1.2;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease, color 0.15s ease;
}

.btn:hover {
  transform: translate(2px, 2px);
  box-shadow: 2px 2px 0 var(--color-brown);
  background: var(--color-brown);
  color: var(--color-cream);
}

.btn:active {
  transform: translate(4px, 4px);
  box-shadow: 0 0 0 var(--color-brown);
}

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

.btn-primary:hover {
  background: var(--color-brown);
  color: var(--color-cream);
}

.btn-outline {
  background: transparent;
  box-shadow: none;
  border-color: var(--color-brown);
  color: var(--color-brown);
}

.btn-outline:hover {
  background: var(--color-brown);
  color: var(--color-cream);
  transform: none;
  box-shadow: none;
}

.tag {
  display: inline-block;
  padding: 4px 10px;
  border: 1px solid currentColor;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  line-height: 1.6;
  text-transform: uppercase;
  background: transparent;
}

.tag--version {
  background: var(--color-yellow);
  border-color: var(--color-brown);
  color: var(--color-brown);
  font-weight: 700;
  box-shadow: 2px 2px 0 var(--color-brown);
}

.tag--orange {
  background: var(--color-orange);
  border-color: var(--color-brown);
  color: var(--color-brown);
}

.card {
  background: var(--color-cream);
  border: 2px solid var(--color-brown);
  box-shadow: var(--shadow-soft);
  padding: 24px;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.card:hover {
  transform: translate(4px, 4px);
  box-shadow: 2px 2px 0 rgba(43, 29, 20, 0.12);
}

.card--dark {
  background: var(--color-brown);
  color: var(--color-cream);
  border-color: var(--color-brown);
}

.card--dark h1,
.card--dark h2,
.card--dark h3,
.card--dark h4 {
  color: var(--color-cream);
}

.card--sand {
  background: var(--color-sand);
}

.section {
  padding-block: var(--spacing-lg);
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--color-orange);
  text-transform: uppercase;
}

.section-label::before {
  content: '';
  width: 28px;
  height: 2px;
  background: var(--color-orange);
  flex-shrink: 0;
}

.section-title {
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.15;
  margin-bottom: 16px;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-stone);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--color-stone);
  margin-bottom: 32px;
}

.breadcrumb a {
  color: var(--color-navy);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.breadcrumb a:hover {
  color: var(--color-orange);
  border-bottom-color: var(--color-orange);
}

.breadcrumb__sep {
  color: var(--color-sand);
  pointer-events: none;
}

.image-frame {
  position: relative;
  overflow: hidden;
  background: var(--color-sand);
  border: 2px solid var(--color-brown);
  box-shadow: 8px 8px 0 rgba(43, 29, 20, 0.12);
  aspect-ratio: 4 / 3;
}

.image-frame > img,
.image-frame > .image-placeholder {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

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

.image-frame--wide {
  aspect-ratio: 16 / 7;
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.divider {
  height: 0;
  border: none;
  border-top: 2px solid var(--color-brown);
  margin: var(--spacing-lg) 0;
  position: relative;
}

.divider::after {
  content: '';
  position: absolute;
  top: -4px;
  right: 0;
  width: 40px;
  height: 6px;
  background: var(--color-orange);
}

@media (min-width: 992px) {
  #main-content,
  .main-content {
    margin-left: var(--header-w);
  }
}

@media (max-width: 991px) {
  .site-header {
    position: sticky;
    top: 0;
    left: 0;
    width: 100%;
    height: auto;
    min-height: 0;
    border-right: none;
    border-bottom: 3px solid var(--color-orange);
    padding: 0 16px;
    display: block;
    overflow: visible;
  }

  .site-header__inner {
    flex-direction: row;
    align-items: center;
    height: 60px;
    gap: 12px;
  }

  .site-header__brand {
    margin-right: auto;
  }

  .site-header__brand-mark {
    width: 36px;
    height: 36px;
    font-size: 18px;
  }

  .site-header__brand-name {
    font-size: 22px;
  }

  .site-header__slogan {
    display: none;
  }

  .site-header__toggle {
    display: inline-flex;
  }

  .site-header__nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    margin: 0;
    padding: 16px 24px 24px;
    background: var(--color-brown);
    box-shadow: 0 16px 32px rgba(43, 29, 20, 0.3);
    border-bottom: 3px solid var(--color-orange);
  }

  .site-header__nav[data-open] {
    display: block;
    animation: navDrop 0.3s ease;
  }

  .site-header__meta {
    display: none;
  }

  .site-footer {
    margin-left: 0;
    padding: 40px 20px 28px;
  }

  .site-footer__grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px 24px;
  }

  #main-content,
  .main-content {
    margin-left: 0;
  }
}

@keyframes navDrop {
  from {
    opacity: 0;
    transform: translateY(-8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 767px) {
  .site-header__nav {
    padding: 12px 16px 16px;
  }

  .site-header__link {
    padding: 10px 8px;
    font-size: 15px;
  }

  .site-footer__grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .site-footer__brand .site-footer__desc {
    max-width: 100%;
  }

  .site-footer__bottom {
    flex-direction: column;
    align-items: flex-start;
  }

  .container {
    padding-inline: 16px;
  }

  .card {
    padding: 16px;
  }

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

@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;
  }
}