/* ==========================================================================
   华体育竞技 · Multi-League Hub — 全站共享样式
   /assets/site.css
   ========================================================================== */

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

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

body {
  min-height: 100vh;
  font-family: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.7;
  letter-spacing: 0.01em;
  color: #F5F7FA;
  background-color: #0B0F1A;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: #00D4FF;
  text-decoration: none;
  transition: color 0.25s ease;
}

a:hover {
  color: #00FF87;
}

ul,
ol {
  list-style: none;
}

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

:focus-visible {
  outline: 2px solid #00FF87;
  outline-offset: 3px;
  border-radius: 2px;
}

/* ---------- CSS Variables ---------- */
:root {
  --color-bg: #0B0F1A;
  --color-surface: #141B2D;
  --color-dim: #1E2638;
  --color-line: #2A3650;
  --color-text: #F5F7FA;
  --color-text-secondary: #A0AAB8;
  --color-neon-green: #00FF87;
  --color-electric-blue: #00D4FF;
  --color-glass: rgba(255, 255, 255, 0.08);
  --gradient-accent: linear-gradient(135deg, #00FF87 0%, #00D4FF 100%);
  --font-primary: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-heading: 'Noto Sans SC', 'Helvetica Neue', sans-serif;
  --font-mono: 'Roboto Mono', 'SF Mono', Consolas, monospace;
  --content-width: 1320px;
  --content-pad: 2rem;
  --header-h: 72px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---------- Base Typography ---------- */
h1,
h2,
h3,
h4 {
  font-family: var(--font-heading);
  color: var(--color-text);
  line-height: 1.2;
}

h1 {
  font-size: clamp(3rem, 8vw, 6rem);
  font-weight: 300;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

h2 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 300;
  letter-spacing: -0.01em;
  line-height: 1.15;
}

h3 {
  font-size: 1.5rem;
  font-weight: 500;
}

h4 {
  font-size: 1.125rem;
  font-weight: 500;
}

/* ---------- Layout ---------- */
.container {
  width: 100%;
  max-width: var(--content-width);
  margin: 0 auto;
  padding-left: var(--content-pad);
  padding-right: var(--content-pad);
}

#main-content {
  padding-top: var(--header-h);
  min-height: 60vh;
}

.section {
  padding: 5rem 0;
}

.section--tight {
  padding: 2.5rem 0;
}

/* ---------- Skip Link ---------- */
.skip-link {
  position: fixed;
  top: -100%;
  left: 1rem;
  z-index: 3000;
  padding: 0.75rem 1.5rem;
  background: var(--color-neon-green);
  color: var(--color-bg);
  font-weight: 700;
  font-size: 0.9rem;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  transition: top 0.3s var(--ease);
}

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

/* ---------- Progress Bar ---------- */
.site-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  max-width: 100%;
  z-index: 2000;
  background: var(--gradient-accent);
  border-radius: 0 2px 2px 0;
  pointer-events: none;
  transition: width 0.1s linear;
}

/* ---------- Header ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-h);
  background: rgba(11, 15, 26, 0.72);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  backdrop-filter: blur(16px) saturate(140%);
  border-bottom: 1px solid rgba(42, 54, 80, 0.6);
  transition: background 0.3s ease, box-shadow 0.3s ease;
}

.site-header.is-scrolled {
  background: rgba(11, 15, 26, 0.95);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
}

.site-header::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent 0%, rgba(0, 255, 135, 0.4) 30%, rgba(0, 212, 255, 0.4) 70%, transparent 100%);
  pointer-events: none;
}

.site-header__inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

/* Brand */
.site-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.85rem;
  flex-shrink: 0;
}

.site-brand__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: var(--gradient-accent);
  color: var(--color-bg);
  font-size: 1.5rem;
  font-weight: 900;
  line-height: 1;
  border-radius: var(--radius-sm);
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  transition: filter 0.3s ease;
}

.site-brand:hover .site-brand__icon {
  filter: brightness(1.2);
}

.site-brand__meta {
  display: flex;
  flex-direction: column;
  line-height: 1.25;
}

.site-brand__name {
  font-family: var(--font-heading);
  font-size: 1.375rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--color-text);
}

.site-brand__en {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--color-electric-blue);
  white-space: nowrap;
}

/* Mobile Nav Toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-line);
  background: rgba(255, 255, 255, 0.04);
  flex-shrink: 0;
  transition: border-color 0.3s ease;
}

.nav-toggle:hover {
  border-color: var(--color-electric-blue);
}

.nav-toggle__line {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform 0.3s var(--ease), opacity 0.25s ease, background 0.3s ease;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
  background: var(--color-neon-green);
}

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

.nav-toggle[aria-expanded="true"] .nav-toggle__line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
  background: var(--color-neon-green);
}

/* Navigation */
.site-nav__list {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.site-nav__link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 0.85rem;
  font-size: 0.9rem;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  position: relative;
  transition: color 0.25s ease, background 0.25s ease;
}

.site-nav__link::after {
  content: '';
  position: absolute;
  left: 0.85rem;
  right: 0.85rem;
  bottom: 0.2rem;
  height: 2px;
  background: var(--gradient-accent);
  border-radius: 2px;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.35s var(--ease);
}

.site-nav__link:hover {
  color: var(--color-text);
}

.site-nav__link:hover::after {
  transform: scaleX(1);
}

.site-nav__link[aria-current="page"] {
  color: var(--color-neon-green);
}

.site-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
}

.site-nav__num {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  line-height: 1;
  color: var(--color-electric-blue);
  opacity: 0.9;
}

.site-nav__link[aria-current="page"] .site-nav__num {
  color: var(--color-neon-green);
}

/* ---------- Footer ---------- */
.site-footer {
  position: relative;
  background: var(--color-dim);
  border-top: 1px solid var(--color-line);
  overflow: hidden;
}

.site-footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-accent);
  opacity: 0.85;
}

.site-footer::after {
  content: '';
  position: absolute;
  bottom: -25%;
  right: -10%;
  width: 55%;
  height: 55%;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.06) 0%, transparent 65%);
  pointer-events: none;
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr;
  gap: 3rem;
  padding: 4rem 0 3rem;
  position: relative;
  z-index: 1;
}

/* Footer Brand */
.site-footer__brand {
  display: inline-flex;
  align-items: center;
  gap: 0.85rem;
  margin-bottom: 1.25rem;
}

.site-footer__brand-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 42px;
  height: 42px;
  padding: 0 0.35rem;
  background: var(--gradient-accent);
  color: var(--color-bg);
  font-size: 1.15rem;
  font-weight: 900;
  border-radius: var(--radius-sm) var(--radius-sm) var(--radius-sm) 2px;
  transition: filter 0.3s ease, transform 0.3s ease;
}

.site-footer__brand:hover .site-footer__brand-icon {
  filter: brightness(1.2);
  transform: rotate(-3deg);
}

.site-footer__brand-meta {
  display: flex;
  flex-direction: column;
  line-height: 1.3;
}

.site-footer__brand-name {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--color-text);
}

.site-footer__brand-en {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-electric-blue);
}

.site-footer__desc {
  max-width: 34ch;
  font-size: 0.88rem;
  line-height: 1.85;
  color: var(--color-text-secondary);
}

/* Footer Columns */
.site-footer__heading {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--color-neon-green);
}

.site-footer__heading-num {
  font-size: 0.62rem;
  color: var(--color-electric-blue);
}

.site-footer__links {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.site-footer__links a {
  display: inline-block;
  font-size: 0.92rem;
  color: var(--color-text-secondary);
  transition: color 0.25s ease, transform 0.25s ease;
}

.site-footer__links a:hover {
  color: var(--color-neon-green);
  transform: translateX(4px);
}

/* Contact list */
.site-footer__contact-list {
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}

.site-footer__contact-item {
  display: grid;
  grid-template-columns: 2.5rem 1fr;
  gap: 0.75rem;
  font-size: 0.88rem;
}

.site-footer__contact-label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-electric-blue);
  padding-top: 0.15rem;
}

.site-footer__contact-value {
  color: var(--color-text-secondary);
  line-height: 1.5;
  word-break: break-all;
}

/* Bottom Bar */
.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem 1.5rem;
  padding: 1.4rem 0;
  border-top: 1px solid rgba(42, 54, 80, 0.7);
  position: relative;
  z-index: 1;
}

.site-footer__copy {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
}

.site-footer__bottom-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1.25rem;
}

.site-footer__bottom-links a {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  transition: color 0.25s ease;
}

.site-footer__bottom-links a:hover {
  color: var(--color-neon-green);
}

.site-footer__icp {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--color-text-secondary);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 1.75rem;
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.3s var(--ease);
}

.btn--primary {
  background: var(--gradient-accent);
  color: var(--color-bg);
  font-weight: 700;
  border-radius: var(--radius-sm);
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 12px 100%, 0 calc(100% - 12px));
}

.btn--primary:hover {
  filter: brightness(1.15);
  color: var(--color-bg);
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(0, 255, 135, 0.2);
}

.btn--ghost {
  background: rgba(255, 255, 255, 0.05);
  border-color: var(--color-line);
  color: var(--color-text);
}

.btn--ghost:hover {
  border-color: var(--color-electric-blue);
  color: var(--color-electric-blue);
}

/* ---------- Breadcrumb ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  padding: 1.25rem 0;
  font-size: 0.85rem;
}

.breadcrumb__item {
  color: var(--color-text-secondary);
  transition: color 0.25s ease;
}

.breadcrumb__item:hover {
  color: var(--color-text);
}

.breadcrumb__sep {
  color: var(--color-line);
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

.breadcrumb__current {
  color: var(--color-neon-green);
}

/* ---------- Chapter / Section Header ---------- */
.chapter {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1.5rem;
  align-items: start;
  margin-bottom: 2.5rem;
}

.chapter__num {
  font-family: var(--font-mono);
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 300;
  line-height: 1;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.chapter__title {
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  font-weight: 300;
  color: var(--color-text);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.chapter__subtitle {
  margin-top: 0.25rem;
  font-size: 0.9rem;
  color: var(--color-text-secondary);
}

/* ---------- Content Map (Directory) ---------- */
.content-map {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1.25rem;
}

.content-map__card {
  position: relative;
  padding: 1.75rem;
  background: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  transition: border-color 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
  overflow: hidden;
}

.content-map__card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--gradient-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s var(--ease);
}

.content-map__card:hover {
  border-color: var(--color-neon-green);
  transform: translateY(-4px);
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.3);
}

.content-map__card:hover::after {
  transform: scaleX(1);
}

.content-map__num {
  display: block;
  margin-bottom: 0.75rem;
  font-family: var(--font-mono);
  font-size: 1.75rem;
  font-weight: 300;
  line-height: 1;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.content-map__title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 0.4rem;
}

.content-map__desc {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ---------- Glass Panel ---------- */
.glass-panel {
  background: var(--color-glass);
  border: 1px solid rgba(255, 255, 255, 0.1);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-radius: var(--radius-lg);
  padding: 2rem;
  position: relative;
}

/* ---------- Card ---------- */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  transition: border-color 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  border-color: var(--color-electric-blue);
  box-shadow: 0 8px 32px rgba(0, 212, 255, 0.08);
}

/* ---------- Data Chip ---------- */
.data-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.3rem 0.85rem;
  background: rgba(0, 212, 255, 0.07);
  border: 1px solid rgba(0, 212, 255, 0.25);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  color: var(--color-electric-blue);
  white-space: nowrap;
}

.data-chip--live {
  background: rgba(0, 255, 135, 0.08);
  border-color: rgba(0, 255, 135, 0.3);
  color: var(--color-neon-green);
}

/* ---------- Tag ---------- */
.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  color: var(--color-electric-blue);
  background: rgba(0, 212, 255, 0.06);
  border: 1px solid rgba(0, 212, 255, 0.25);
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

.tag:hover {
  background: rgba(0, 212, 255, 0.15);
  color: var(--color-text);
}

.tag--active {
  background: var(--gradient-accent);
  color: var(--color-bg);
  font-weight: 700;
  border-color: transparent;
}

/* ---------- Stat Line ---------- */
.stat-line {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--color-line);
}

.stat-line:last-child {
  border-bottom: none;
}

.stat-line__label {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
}

.stat-line__value {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: 0.03em;
  font-variant-numeric: tabular-nums;
}

/* ---------- Image Frame ---------- */
.image-frame {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-md);
  background: var(--color-surface);
  border: 1px solid var(--color-line);
}

.image-frame::before {
  content: '';
  display: block;
  padding-top: 56.25%;
}

.image-frame--portrait::before {
  padding-top: 125%;
}

.image-frame--square::before {
  padding-top: 100%;
}

.image-frame__content {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background:
    linear-gradient(135deg, rgba(0, 255, 135, 0.04) 0%, transparent 50%),
    linear-gradient(315deg, rgba(0, 212, 255, 0.04) 0%, transparent 50%),
    var(--color-surface);
}

/* ---------- Path (Skill Tree) ---------- */
.path {
  display: flex;
  flex-direction: column;
}

.path__node {
  position: relative;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1.25rem;
  padding: 0 0 2.25rem 0;
  border-left: 2px solid var(--color-line);
  margin-left: 9px;
  padding-left: 1.75rem;
}

.path__node:last-child {
  border-left-color: transparent;
  padding-bottom: 0;
}

.path__dot {
  position: absolute;
  left: -10px;
  top: 0.35rem;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--color-surface);
  border: 2px solid var(--color-line);
  transition: background 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.path__node--active .path__dot {
  background: var(--color-neon-green);
  border-color: var(--color-neon-green);
  box-shadow: 0 0 14px rgba(0, 255, 135, 0.5);
}

.path__content {
  min-width: 0;
}

/* ---------- Index List ---------- */
.index-list {
  display: flex;
  flex-direction: column;
}

.index-list__item {
  display: flex;
  align-items: baseline;
  gap: 1.25rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--color-line);
  transition: padding-left 0.3s ease;
}

.index-list__item:hover {
  padding-left: 0.5rem;
}

.index-list__num {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-neon-green);
  min-width: 2.5rem;
}

.index-list__link {
  font-size: 1.05rem;
  color: var(--color-text);
  transition: color 0.25s ease;
}

.index-list__link:hover {
  color: var(--color-neon-green);
}

/* ---------- Prose ---------- */
.prose {
  max-width: 72ch;
}

.prose p {
  margin-bottom: 1.25em;
  color: var(--color-text-secondary);
}

.prose a {
  color: var(--color-electric-blue);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.prose a:hover {
  color: var(--color-neon-green);
}

.prose ul {
  list-style: disc;
  padding-left: 1.5rem;
  margin: 1rem 0 1.5rem;
}

.prose ol {
  list-style: decimal;
  padding-left: 1.5rem;
  margin: 1rem 0 1.5rem;
}

.prose li {
  margin-bottom: 0.35rem;
  color: var(--color-text-secondary);
}

/* ---------- Scroll Reveal & Scroll Spy ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

[data-scroll-spy] {
  transition: border-color 0.4s ease, box-shadow 0.4s ease;
}

[data-scroll-spy].is-active {
  border-color: rgba(0, 255, 135, 0.35);
  box-shadow: 0 0 0 1px rgba(0, 255, 135, 0.06), 0 12px 48px rgba(0, 0, 0, 0.35);
}

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  :root {
    --content-pad: 1.5rem;
  }

  .site-footer__grid {
    grid-template-columns: 1fr 1fr;
    gap: 2.5rem;
  }

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

@media (max-width: 768px) {
  :root {
    --content-pad: 1.25rem;
    --header-h: 60px;
  }

  /* Mobile Nav */
  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    z-index: 999;
    background: rgba(11, 15, 26, 0.98);
    border-bottom: 1px solid var(--color-line);
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.4);
    padding: 1rem 1.5rem 2rem;
    transform: translateY(-110%);
    visibility: hidden;
    opacity: 0;
    transition: transform 0.4s var(--ease), visibility 0.4s, opacity 0.3s ease;
  }

  .site-nav[data-open] {
    transform: translateY(0);
    visibility: visible;
    opacity: 1;
  }

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

  .site-nav__link {
    display: flex;
    width: 100%;
    padding: 0.9rem 0.75rem;
    font-size: 1rem;
    border-bottom: 1px solid rgba(42, 54, 80, 0.5);
    border-radius: 0;
  }

  .site-nav__link::after {
    display: none;
  }

  .site-nav__link[aria-current="page"] {
    background: rgba(0, 255, 135, 0.06);
    padding-left: 1rem;
  }

  .site-nav__num {
    min-width: 1.75rem;
  }

  /* Header brand */
  .site-brand__en {
    display: none;
  }

  /* Footer */
  .site-footer__grid {
    grid-template-columns: 1fr;
    gap: 2.25rem;
    padding-top: 3rem;
  }

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

  .site-footer__bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.65rem;
    padding: 1.25rem 0;
  }

  /* Sections */
  .section {
    padding: 3rem 0;
  }

  .chapter {
    grid-template-columns: 1fr;
    gap: 0.35rem;
  }

  .chapter__num {
    font-size: 2.5rem;
  }
}

@media (max-width: 480px) {
  :root {
    --content-pad: 1rem;
  }

  .site-brand__name {
    font-size: 1.15rem;
  }

  .site-brand__icon {
    width: 38px;
    height: 38px;
    font-size: 1.25rem;
  }

  .content-map {
    grid-template-columns: 1fr;
  }
}

/* ---------- Reduced Motion ---------- */
@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;
  }

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

  .js-scroll-progress {
    display: none;
  }
}