/* ==========================================================
   完美体育 Site Kit — 共享样式
   文件：/assets/site.css
   设计语言：运动蓝图数据舱
   技术蓝图网格 / 切角面板 / 坐标索引 / 运动科技配色
   ========================================================== */

/* ---------- 1. 设计变量 ---------- */
:root {
  --color-primary: #0B1B3D;
  --color-accent: #FF6B35;
  --color-highlight: #00D4FF;
  --color-bg-alt: #F5F0E6;
  --color-text-dark: #1E1A17;
  --color-muted: #8A8580;
  --color-success: #6B8E23;
  --color-warning: #D2691E;
  --color-border: rgba(255, 255, 255, 0.12);
  --color-border-bright: rgba(0, 212, 255, 0.25);

  --font-headline: 'Archivo', 'Oswald', 'Noto Sans SC', 'Microsoft YaHei', -apple-system, 'Segoe UI', sans-serif;
  --font-body: -apple-system, 'Segoe UI', 'Roboto', 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
  --font-data: 'Roboto Mono', 'SF Mono', 'Cascadia Code', Menlo, Consolas, monospace;

  --header-height: 72px;
  --container-max: 1280px;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 40px;
  --space-5: 64px;
  --space-6: 96px;
  --ease: cubic-bezier(0.25, 0.1, 0.25, 1);
}

/* ---------- 2. 重置与基础 ---------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 16px);
  -webkit-text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--color-primary);
  background-image:
    linear-gradient(rgba(0, 212, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.04) 1px, transparent 1px);
  background-size: 28px 28px, 28px 28px;
  font-family: var(--font-body);
  color: rgba(255, 255, 255, 0.88);
  line-height: 1.7;
}

main {
  display: block;
  min-height: 60vh;
}

main:focus {
  outline: none;
}

a {
  color: inherit;
  text-decoration: none;
}

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

ul,
ol {
  list-style: none;
}

button,
input,
select,
textarea {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
}

button {
  cursor: pointer;
}

::selection {
  background: var(--color-accent);
  color: #FFFFFF;
}

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

/* ---------- 3. 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ---------- 4. 容器与辅助 ---------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-3);
}

.skip-link {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 2000;
  display: inline-flex;
  align-items: center;
  padding: 10px 20px;
  background: var(--color-accent);
  color: #FFFFFF;
  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: 0.04em;
  transform: translateY(-120%);
  transition: transform 0.2s var(--ease);
}

.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
  outline: none;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
}

.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0;
  height: 3px;
  z-index: 1500;
  background: linear-gradient(90deg, var(--color-accent), var(--color-highlight));
  box-shadow: 0 0 10px rgba(0, 212, 255, 0.35);
  pointer-events: none;
  transition: width 0.08s linear;
}

/* ---------- 5. 页头 ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(11, 27, 61, 0.42);
  border-bottom: 1px solid rgba(0, 212, 255, 0.08);
  transition: background-color 0.35s var(--ease), border-color 0.35s var(--ease), box-shadow 0.35s var(--ease);
}

.site-header[data-scrolled] {
  background: rgba(11, 27, 61, 0.95);
  border-bottom-color: var(--color-border-bright);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.35);
}

.site-header__inner {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  height: var(--header-height);
}

.site-header__inner::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 76px;
  height: 2px;
  background: var(--color-accent);
  pointer-events: none;
}

.site-header__brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  color: #FFFFFF;
  font-family: var(--font-headline);
  font-weight: 800;
  font-size: 1.22rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.site-header__brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--color-accent);
  color: #FFFFFF;
  font-family: var(--font-data);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0;
  clip-path: polygon(8px 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%, 0 8px);
}

.site-header__brand-text {
  font-weight: 800;
  letter-spacing: 0.08em;
}

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

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

.site-header__nav-item {
  flex-shrink: 0;
}

.site-header__nav-link {
  display: flex;
  align-items: baseline;
  gap: 6px;
  padding: 10px 12px;
  font-size: 0.94rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: rgba(255, 255, 255, 0.72);
  border-bottom: 2px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background-color 0.2s var(--ease);
  white-space: nowrap;
}

.site-header__nav-link .coord {
  font-size: 0.68rem;
  color: var(--color-highlight);
  opacity: 0.65;
  transition: opacity 0.2s var(--ease);
}

.site-header__nav-link:hover,
.site-header__nav-link:focus-visible {
  color: #FFFFFF;
  border-bottom-color: var(--color-highlight);
}

.site-header__nav-link:hover .coord,
.site-header__nav-link:focus-visible .coord {
  opacity: 1;
}

.site-header__nav-link[aria-current="page"] {
  color: #FFFFFF;
  border-bottom-color: var(--color-accent);
  background: linear-gradient(to top, rgba(255, 107, 53, 0.1), transparent 70%);
}

.site-header__nav-link[aria-current="page"] .coord {
  color: var(--color-accent);
  opacity: 1;
}

.site-header__action {
  flex-shrink: 0;
  white-space: nowrap;
  font-size: 0.82rem;
  padding: 8px 16px;
  text-transform: none;
  letter-spacing: 0.04em;
}

.site-header__toggle {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  min-width: 44px;
  min-height: 44px;
  color: #FFFFFF;
  flex-shrink: 0;
}

.site-header__toggle-icon {
  position: relative;
  display: block;
  width: 26px;
  height: 2px;
  background: currentColor;
  transition: background-color 0.25s var(--ease);
}

.site-header__toggle-icon::before,
.site-header__toggle-icon::after {
  content: '';
  position: absolute;
  left: 0;
  width: 26px;
  height: 2px;
  background: currentColor;
  transition: transform 0.25s var(--ease), top 0.25s var(--ease);
}

.site-header__toggle-icon::before {
  top: -7px;
}

.site-header__toggle-icon::after {
  top: 7px;
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-icon {
  background: transparent;
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-icon::before {
  top: 0;
  transform: rotate(45deg);
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-icon::after {
  top: 0;
  transform: rotate(-45deg);
}

.site-header__toggle-label {
  font-family: var(--font-data);
  font-size: 0.6rem;
  line-height: 1;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-highlight);
}

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 22px;
  font-family: var(--font-headline);
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  transition: background-color 0.25s var(--ease), color 0.25s var(--ease), transform 0.25s var(--ease), box-shadow 0.25s var(--ease);
  cursor: pointer;
}

.btn--primary {
  background: var(--color-accent);
  color: #FFFFFF;
  clip-path: polygon(8px 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%, 0 8px);
}

.btn--primary:hover,
.btn--primary:focus-visible {
  background: var(--color-highlight);
  color: var(--color-primary);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 212, 255, 0.25);
}

.btn--ghost {
  background: transparent;
  color: var(--color-highlight);
  border: 1px solid rgba(0, 212, 255, 0.5);
  clip-path: polygon(8px 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%, 0 8px);
}

.btn--ghost:hover,
.btn--ghost:focus-visible {
  background: rgba(0, 212, 255, 0.1);
  border-color: var(--color-highlight);
  color: #FFFFFF;
}

.section--alt .btn--ghost {
  color: var(--color-warning);
  border-color: rgba(210, 105, 30, 0.5);
}

.section--alt .btn--ghost:hover,
.section--alt .btn--ghost:focus-visible {
  background: rgba(210, 105, 30, 0.08);
  color: var(--color-text-dark);
}

/* ---------- 7. 页脚 ---------- */
.site-footer {
  flex-shrink: 0;
  position: relative;
  margin-top: auto;
  background: var(--color-primary);
  border-top: 1px solid rgba(0, 212, 255, 0.18);
}

.site-footer::before {
  content: '';
  position: absolute;
  top: -1px;
  left: 0;
  width: 120px;
  height: 3px;
  background: var(--color-accent);
  z-index: 1;
}

.site-footer__inner {
  padding-top: var(--space-5);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.4fr;
  gap: var(--space-4);
  padding-bottom: var(--space-4);
}

.site-footer__brand-col,
.site-footer__col {
  min-width: 0;
}

.site-footer__brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-headline);
  font-weight: 900;
  font-size: 1.3rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #FFFFFF;
}

.site-footer__brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  background: var(--color-accent);
  color: #FFFFFF;
  font-family: var(--font-data);
  font-size: 0.85rem;
  font-weight: 700;
  clip-path: polygon(8px 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%, 0 8px);
}

.site-footer__brand-text {
  font-weight: 900;
  letter-spacing: 0.06em;
}

.site-footer__trust {
  margin-top: var(--space-2);
  font-size: 0.87rem;
  line-height: 1.8;
  color: rgba(255, 255, 255, 0.55);
  max-width: 44ch;
}

.site-footer__heading {
  font-family: var(--font-data);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-highlight);
  margin-bottom: var(--space-2);
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  position: relative;
}

.site-footer__heading::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 32px;
  height: 2px;
  background: var(--color-accent);
}

.site-footer__list {
  display: grid;
  gap: 10px;
}

.site-footer__link {
  display: inline-block;
  color: rgba(255, 255, 255, 0.65);
  font-size: 0.92rem;
  line-height: 1.5;
  transition: color 0.2s var(--ease), padding-left 0.2s var(--ease);
}

.site-footer__link:hover,
.site-footer__link:focus-visible {
  color: var(--color-highlight);
  padding-left: 4px;
}

.site-footer__list--plain li {
  color: rgba(255, 255, 255, 0.62);
  font-size: 0.9rem;
  line-height: 1.8;
}

.site-footer__meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-2);
  padding: var(--space-2) 0 var(--space-3);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  font-family: var(--font-data);
  font-size: 0.78rem;
  color: rgba(255, 255, 255, 0.4);
}

.site-footer__copyright,
.site-footer__icp {
  letter-spacing: 0.04em;
}

/* ---------- 8. 页面骨架 ---------- */
.page-head {
  padding-top: calc(var(--header-height) + var(--space-4));
  padding-bottom: var(--space-3);
}

.page-head__title {
  font-family: var(--font-headline);
  font-size: clamp(2rem, 4.5vw, 3.4rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: #FFFFFF;
  max-width: 18ch;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: var(--space-2) 0;
  font-family: var(--font-data);
  font-size: 0.78rem;
  color: rgba(255, 255, 255, 0.5);
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.breadcrumb__link {
  color: var(--color-highlight);
  transition: color 0.2s var(--ease);
}

.breadcrumb__link:hover,
.breadcrumb__link:focus-visible {
  color: var(--color-accent);
}

.breadcrumb__sep {
  color: rgba(255, 255, 255, 0.25);
}

.breadcrumb__current {
  color: rgba(255, 255, 255, 0.85);
}

.section {
  padding-top: var(--space-5);
  padding-bottom: var(--space-5);
}

.section--alt {
  position: relative;
  background: var(--color-bg-alt);
  color: var(--color-text-dark);
}

.section--alt::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-accent), var(--color-highlight), transparent);
}

.section__header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.section__title {
  font-family: var(--font-headline);
  font-size: clamp(1.75rem, 3.6vw, 2.9rem);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: #FFFFFF;
  margin-top: var(--space-1);
}

.section--alt .section__title {
  color: var(--color-text-dark);
}

.section__desc {
  max-width: 52ch;
  font-size: 0.95rem;
  color: rgba(255, 255, 255, 0.65);
}

.section--alt .section__desc {
  color: rgba(30, 26, 23, 0.72);
}

.section__footer {
  margin-top: var(--space-4);
}

.prose {
  max-width: 72ch;
  font-size: 1rem;
  line-height: 1.85;
  color: rgba(255, 255, 255, 0.82);
}

.prose h2,
.prose h3 {
  font-family: var(--font-headline);
  font-weight: 800;
  letter-spacing: 0.02em;
  color: #FFFFFF;
  margin-top: 1.6em;
  margin-bottom: 0.5em;
}

.prose p {
  margin-bottom: 1em;
}

.prose ul {
  margin: 1em 0;
}

.prose li {
  position: relative;
  padding-left: 1.4em;
  margin-bottom: 0.5em;
}

.prose li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--color-accent);
}

.section--alt .prose {
  color: rgba(30, 26, 23, 0.82);
}

.section--alt .prose h2,
.section--alt .prose h3 {
  color: var(--color-text-dark);
}

/* ---------- 9. 网格 ---------- */
.grid {
  display: grid;
  gap: var(--space-3);
}

.grid--cols-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid--cols-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

/* ---------- 10. 数据面板与标签 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-data);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-highlight);
}

.eyebrow::before {
  content: '//';
  font-weight: 700;
  color: var(--color-accent);
}

.section--alt .eyebrow {
  color: var(--color-warning);
}

.panel {
  position: relative;
  padding: var(--space-3);
  background: linear-gradient(135deg, rgba(0, 212, 255, 0.07), transparent 55%);
  border: 1px solid var(--color-border);
  transition: border-color 0.3s var(--ease);
}

.panel::before {
  content: '';
  position: absolute;
  top: -1px;
  left: -1px;
  width: 18px;
  height: 18px;
  border-top: 2px solid var(--color-accent);
  border-left: 2px solid var(--color-accent);
}

.panel::after {
  content: '';
  position: absolute;
  bottom: -1px;
  right: -1px;
  width: 18px;
  height: 18px;
  border-bottom: 2px solid var(--color-highlight);
  border-right: 2px solid var(--color-highlight);
}

.panel:hover {
  border-color: rgba(0, 212, 255, 0.35);
}

.section--alt .panel {
  background: #FFFFFF;
  border-color: rgba(30, 26, 23, 0.12);
  box-shadow: 0 2px 12px rgba(30, 26, 23, 0.05);
}

.data-card {
  position: relative;
  padding: var(--space-3);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-accent);
  font-family: var(--font-data);
}

.data-card__label {
  display: block;
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.5);
  margin-bottom: 8px;
}

.data-card__value {
  display: block;
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-highlight);
}

.data-card__unit {
  font-size: 0.85rem;
  font-weight: 400;
  color: rgba(255, 255, 255, 0.45);
  margin-left: 4px;
}

.section--alt .data-card {
  background: #FFFFFF;
  border-color: rgba(30, 26, 23, 0.12);
  border-left-color: var(--color-accent);
}

.section--alt .data-card__label {
  color: var(--color-muted);
}

.section--alt .data-card__value {
  color: var(--color-primary);
}

.section--alt .data-card__unit {
  color: rgba(30, 26, 23, 0.5);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  font-family: var(--font-data);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-highlight);
  border: 1px solid currentColor;
  background: rgba(0, 212, 255, 0.06);
}

.tag--accent {
  color: var(--color-accent);
  background: rgba(255, 107, 53, 0.08);
}

.tag--success {
  color: #A3C44A;
  background: rgba(107, 142, 35, 0.12);
}

.tag--warning {
  color: #E0854A;
  background: rgba(210, 105, 30, 0.12);
}

/* ---------- 11. 图片容器 ---------- */
.image-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.06);
}

.image-frame::before {
  content: '';
  display: block;
  aspect-ratio: 16 / 9;
}

.image-frame--4-3::before {
  aspect-ratio: 4 / 3;
}

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

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

.image-frame--chamfered {
  clip-path: polygon(12px 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%, 0 12px);
}

.image-frame__caption {
  position: absolute;
  left: 0;
  bottom: 0;
  z-index: 1;
  padding: 4px 10px;
  background: var(--color-primary);
  font-family: var(--font-data);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-highlight);
}

.section--alt .image-frame {
  background: rgba(30, 26, 23, 0.08);
}

.section--alt .image-frame__caption {
  background: var(--color-bg-alt);
  color: var(--color-warning);
}

/* ---------- 12. 蓝图装饰 ---------- */
.coord {
  font-family: var(--font-data);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.42);
}

.section--alt .coord {
  color: rgba(30, 26, 23, 0.42);
}

.crosshair {
  position: absolute;
  width: 12px;
  height: 12px;
  opacity: 0.55;
  pointer-events: none;
}

.crosshair::before,
.crosshair::after {
  content: '';
  position: absolute;
  background: var(--color-highlight);
}

.crosshair::before {
  left: 50%;
  top: 0;
  width: 1px;
  height: 100%;
  transform: translateX(-50%);
}

.crosshair::after {
  top: 50%;
  left: 0;
  height: 1px;
  width: 100%;
  transform: translateY(-50%);
}

.hero-grid {
  position: relative;
  background-image:
    linear-gradient(rgba(0, 212, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.05) 1px, transparent 1px);
  background-size: 40px 40px;
}

/* ---------- 13. 滚动显现与章节高亮 ---------- */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.55s var(--ease), transform 0.55s var(--ease);
}

html.js [data-reveal].is-revealed {
  opacity: 1;
  transform: translateY(0);
}

html.js [data-reveal="section"] {
  opacity: 1;
  transform: none;
  box-shadow: inset 0 0 0 0 rgba(255, 107, 53, 0);
  transition: box-shadow 0.6s var(--ease);
}

html.js [data-reveal="section"].is-revealed {
  box-shadow: inset 3px 0 0 0 var(--color-accent);
}

/* ---------- 14. 响应式 ---------- */
@media (max-width: 1060px) {
  .site-header__nav-link {
    padding: 10px 8px;
    font-size: 0.88rem;
  }

  .site-header__action {
    display: none;
  }
}

@media (max-width: 960px) {
  .grid--cols-3 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .site-footer__brand-col {
    grid-column: 1 / -1;
  }
}

@media (max-width: 860px) {
  .site-header__toggle {
    display: inline-flex;
  }

  .site-header__inner {
    gap: var(--space-2);
  }

  .site-header__nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    margin-left: 0;
    background: var(--color-primary);
    border-bottom: 1px solid rgba(0, 212, 255, 0.18);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s var(--ease), border-color 0.35s var(--ease), box-shadow 0.35s var(--ease);
  }

  .site-header__nav[data-open] {
    max-height: calc(100vh - var(--header-height));
    overflow-y: auto;
    border-bottom-color: rgba(0, 212, 255, 0.4);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.45);
  }

  .site-header__nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--space-2);
  }

  .site-header__nav-item {
    border-bottom: 1px solid rgba(255, 255, 255, 0.07);
  }

  .site-header__nav-item:last-child {
    border-bottom: none;
  }

  .site-header__nav-link {
    justify-content: space-between;
    padding: 14px 12px;
    border-bottom: none;
    border-left: 3px solid transparent;
  }

  .site-header__nav-link:hover,
  .site-header__nav-link:focus-visible {
    border-bottom: none;
    border-left-color: var(--color-highlight);
    background: rgba(255, 255, 255, 0.05);
  }

  .site-header__nav-link[aria-current="page"] {
    border-bottom: none;
    border-left-color: var(--color-accent);
    background: linear-gradient(90deg, rgba(255, 107, 53, 0.12), transparent);
  }
}

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

  .site-footer__grid {
    grid-template-columns: 1fr;
    gap: var(--space-3);
  }

  .site-footer__brand-col {
    grid-column: auto;
  }

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

  .container {
    padding-inline: var(--space-2);
  }
}

@media (max-width: 480px) {
  .site-header__brand-text {
    font-size: 1rem;
  }

  .site-header__brand-mark {
    width: 34px;
    height: 34px;
    font-size: 0.72rem;
  }

  .site-header__toggle-label {
    display: none;
  }
}