/* ============================================
   777电玩城CN官网 — 共享核心样式 /assets/site.css
   主题：数字竞技场 · 赛博游乐指挥部
   ============================================ */

/* ---------- 01 RESET & ROOT ---------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  /* 品牌色板 */
  --neon-purple: #9B30FF;
  --electric-blue: #00D9FF;
  --gold: #FFD700;
  --deep-space: #1A0B2E;
  --cream: #F8F0FF;
  --ink: #0D0518;
  --rose: #FF4D6D;
  --neon-green: #00FF88;

  /* 衍生色 */
  --purple-light: #C57BFF;
  --purple-dark: #4A1675;
  --blue-dim: rgba(0, 217, 255, 0.28);
  --border-purple: rgba(155, 48, 255, 0.32);
  --border-blue: rgba(0, 217, 255, 0.35);
  --border-white: rgba(255, 255, 255, 0.1);
  --text-white: #FFFFFF;
  --text-white-70: rgba(255, 255, 255, 0.72);
  --text-white-50: rgba(255, 255, 255, 0.52);
  --text-dark: #1A0B2E;
  --text-dark-65: rgba(26, 11, 46, 0.65);

  /* 字体 */
  --font-heading: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Noto Sans SC', 'Source Han Sans SC', sans-serif;
  --font-body: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Noto Sans SC', 'Roboto', sans-serif;

  /* 尺寸与动效 */
  --container-w: 1200px;
  --header-h: 74px;
  --radius: 6px;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --speed-fast: 0.2s ease;
  --speed-mid: 0.35s ease;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 20px);
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  background: var(--cream);
  color: var(--text-dark);
  font-family: var(--font-body);
  line-height: 1.7;
  font-size: 1rem;
  -webkit-font-smoothing: antialiased;
}

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

input, button, textarea, select {
  font: inherit;
  color: inherit;
}

ul, ol {
  list-style: none;
}

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

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 800;
  line-height: 1.25;
  text-wrap: balance;
}

p {
  margin-bottom: 1rem;
}

::selection {
  background: var(--neon-purple);
  color: #fff;
}

:focus-visible {
  outline: 3px solid var(--electric-blue);
  outline-offset: 3px;
  border-radius: 3px;
}

/* ---------- 02 CONTAINER & MAIN ---------- */
.container {
  width: min(100% - 2rem, var(--container-w));
  margin-inline: auto;
}

.main-content {
  min-height: 70vh;
  position: relative;
}

.section {
  padding-block: clamp(2.5rem, 6vw, 5rem);
  position: relative;
}

.section-dark {
  background: var(--deep-space);
  color: #fff;
}

.section-header {
  margin-bottom: 2rem;
}

.section-header--center {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.section-kicker {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.2em;
  color: var(--neon-purple);
  border: 1px solid rgba(155, 48, 255, 0.45);
  padding: 0.18rem 0.75rem;
  background: rgba(155, 48, 255, 0.06);
  clip-path: polygon(0 0, calc(100% - 8px) 0, 100% 8px, 100% 100%, 8px 100%, 0 calc(100% - 8px));
}

.section-title {
  font-size: clamp(1.6rem, 3.5vw, 2.6rem);
  font-weight: 900;
  margin-top: 0.55rem;
  letter-spacing: -0.01em;
}

.section-dark .section-title {
  color: #fff;
}

.section-subtitle {
  color: var(--text-dark-65);
  font-size: 1rem;
  max-width: 56ch;
  margin-top: 0.3rem;
}

.section-dark .section-subtitle {
  color: var(--text-white-70);
}

/* ---------- 03 BREADCRUMB ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.875rem;
  padding: 1.25rem 0;
  margin-bottom: 0.5rem;
}

.breadcrumb a {
  color: var(--electric-blue);
  transition: color var(--speed-fast);
}

.breadcrumb a:hover {
  color: var(--neon-purple);
  text-decoration: underline;
}

.breadcrumb .sep {
  color: var(--text-dark-65);
  opacity: 0.45;
}

.breadcrumb .current {
  color: var(--neon-purple);
  font-weight: 700;
}

/* ---------- 04 BUTTONS ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.7rem 1.6rem;
  border-radius: 4px;
  font-weight: 800;
  font-size: 0.95rem;
  line-height: 1;
  border: 1px solid transparent;
  cursor: pointer;
  transition:
    background var(--speed-fast),
    border-color var(--speed-fast),
    color var(--speed-fast),
    transform var(--speed-fast),
    box-shadow var(--speed-fast);
}

.btn-primary {
  background: var(--neon-purple);
  color: #fff;
  box-shadow: 0 0 22px rgba(155, 48, 255, 0.28);
}

.btn-primary:hover {
  background: #7b22ea;
  transform: translateY(-2px);
  box-shadow: 0 0 30px rgba(155, 48, 255, 0.42);
}

.btn-outline {
  border-color: var(--border-blue);
  color: var(--electric-blue);
  background: transparent;
}

.btn-outline:hover {
  background: var(--electric-blue);
  color: var(--ink);
  box-shadow: 0 0 22px rgba(0, 217, 255, 0.35);
}

.btn-gold {
  background: var(--gold);
  color: var(--ink);
  box-shadow: 0 0 20px rgba(255, 215, 0, 0.22);
}

.btn-gold:hover {
  background: #ffdf3d;
  transform: translateY(-2px);
}

/* ---------- 05 TAGS ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.72rem;
  font-weight: 800;
  line-height: 1;
  padding: 0.3rem 0.75rem;
  border-radius: 2px;
  border: 1px solid;
  letter-spacing: 0.06em;
}

.tag-purple {
  border-color: var(--neon-purple);
  color: var(--neon-purple);
}

.tag-cyan {
  border-color: var(--electric-blue);
  color: var(--electric-blue);
}

.tag-gold {
  border-color: var(--gold);
  color: var(--ink);
  background: var(--gold);
}

.tag-rose {
  border-color: var(--rose);
  color: var(--rose);
}

.tag-green {
  border-color: var(--neon-green);
  color: var(--neon-green);
  background: rgba(0, 255, 136, 0.08);
}

/* ---------- 06 CARDS ---------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.25rem;
}

.card {
  background: #fff;
  border: 1px solid rgba(26, 11, 46, 0.08);
  border-radius: var(--radius);
  padding: 1.5rem;
  position: relative;
  box-shadow: 0 6px 24px rgba(26, 11, 46, 0.05);
  transition:
    transform var(--speed-mid),
    box-shadow var(--speed-mid),
    border-color var(--speed-mid);
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 48px;
  background: linear-gradient(180deg, var(--neon-purple), var(--electric-blue));
  border-radius: 0 2px 2px 0;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 14px 36px rgba(155, 48, 255, 0.16);
  border-color: rgba(155, 48, 255, 0.3);
}

.card-title {
  font-size: 1.15rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
}

.card-text {
  color: var(--text-dark-65);
  font-size: 0.92rem;
}

.card-meta {
  margin-top: 1rem;
  font-size: 0.8rem;
  color: rgba(26, 11, 46, 0.45);
  letter-spacing: 0.04em;
}

/* ---------- 07 IMAGE FRAME ---------- */
.image-frame {
  position: relative;
  display: block;
  overflow: hidden;
  border-radius: var(--radius);
  background: var(--deep-space);
}

.image-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s var(--ease-out);
}

.image-frame:hover img {
  transform: scale(1.04);
}

.image-frame::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(155, 48, 255, 0.28), transparent 48%, rgba(0, 217, 255, 0.18));
  pointer-events: none;
  mix-blend-mode: screen;
}

.image-frame-16x9 {
  aspect-ratio: 16 / 9;
}

.image-frame-4x3 {
  aspect-ratio: 4 / 3;
}

.image-frame-1x1 {
  aspect-ratio: 1;
}

.image-frame-clip {
  clip-path: polygon(0 0, calc(100% - 22px) 0, 100% 22px, 100% 100%, 22px 100%, 0 calc(100% - 22px));
  border-radius: 0;
}

/* ---------- 08 HELPERS ---------- */
.data-highlight {
  color: var(--electric-blue);
  font-weight: 800;
  font-variant-numeric: tabular-nums;
}

.text-purple { color: var(--neon-purple); }
.text-blue { color: var(--electric-blue); }
.text-gold { color: var(--gold); }
.text-rose { color: var(--rose); }
.text-green { color: var(--neon-green); }

.bg-space { background: var(--deep-space); color: #fff; }
.bg-ink { background: var(--ink); color: #fff; }
.bg-cream { background: var(--cream); }

.divider-slice {
  height: 26px;
  border: 0;
  margin: 2.5rem 0;
  background: linear-gradient(90deg, transparent, rgba(155, 48, 255, 0.35) 30%, rgba(0, 217, 255, 0.35) 70%, transparent);
  clip-path: polygon(0 30%, 100% 0, 100% 70%, 0 100%);
}

/* ---------- 09 SKIP LINK ---------- */
.skip-link {
  position: fixed;
  top: -100px;
  left: 1rem;
  z-index: 5000;
  background: var(--gold);
  color: var(--ink);
  font-weight: 800;
  font-size: 0.9rem;
  padding: 0.65rem 1.2rem;
  border-radius: 4px;
  box-shadow: 0 4px 20px rgba(255, 215, 0, 0.35);
  transition: top var(--speed-fast);
}

.skip-link:focus {
  top: 1rem;
}

/* ---------- 10 SCROLL PROGRESS ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  height: 3px;
  z-index: 4000;
  background: linear-gradient(90deg, var(--neon-purple), var(--electric-blue) 55%, var(--gold) 100%);
  box-shadow: 0 0 12px rgba(0, 217, 255, 0.45);
  pointer-events: none;
}

/* ---------- 11 UTILITY STRIP ---------- */
.utility-strip {
  background: var(--ink);
  border-bottom: 1px solid rgba(155, 48, 255, 0.28);
  color: var(--text-white-70);
  font-size: 0.8rem;
  position: relative;
  z-index: 900;
}

.utility-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 38px;
  gap: 1rem;
}

.utility-status {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--neon-green);
  box-shadow: 0 0 8px var(--neon-green);
  animation: statusPulse 2.2s ease-in-out infinite;
}

@keyframes statusPulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.45; transform: scale(0.82); }
}

.utility-tools {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
}

.utility-link {
  color: var(--electric-blue);
  padding: 0.2rem 0.4rem;
  border: 1px solid rgba(0, 217, 255, 0.25);
  border-radius: 3px;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  transition: all var(--speed-fast);
}

.utility-link:hover {
  background: rgba(0, 217, 255, 0.12);
  border-color: var(--electric-blue);
}

.utility-divider {
  width: 1px;
  height: 14px;
  background: rgba(255, 255, 255, 0.16);
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.78rem;
  font-weight: 700;
}

.lang-active {
  color: var(--gold);
  padding: 0.15rem 0.45rem;
  background: rgba(255, 215, 0, 0.1);
  border: 1px solid rgba(255, 215, 0, 0.35);
  border-radius: 3px;
}

.lang-sep {
  color: rgba(255, 255, 255, 0.3);
}

.lang-option {
  opacity: 0.55;
  cursor: default;
}

/* ---------- 12 HEADER ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(26, 11, 46, 0.98);
  border-bottom: 1px solid var(--border-purple);
  box-shadow: 0 10px 36px rgba(13, 5, 24, 0.35);
}

.site-header::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: linear-gradient(90deg, var(--neon-purple) 0%, var(--electric-blue) 55%, var(--gold) 100%);
  opacity: 0.75;
}

.header-inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  min-height: var(--header-h);
}

/* ---------- 13 BRAND ---------- */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  flex-shrink: 0;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  background: linear-gradient(135deg, var(--neon-purple), var(--purple-dark));
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 12px 100%, 0 calc(100% - 12px));
  box-shadow: 0 0 24px rgba(155, 48, 255, 0.42);
  position: relative;
}

.brand-mark::after {
  content: '';
  position: absolute;
  right: 5px;
  top: 5px;
  width: 5px;
  height: 5px;
  background: var(--gold);
  clip-path: polygon(50% 0, 100% 100%, 0 100%);
}

.brand-mark-inner {
  color: #fff;
  font-weight: 900;
  font-size: 1.15rem;
  letter-spacing: 0.02em;
  line-height: 1;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.05;
}

.brand-text strong {
  font-size: 1.45rem;
  font-weight: 900;
  color: #fff;
  letter-spacing: 0.08em;
}

.brand-text small {
  font-size: 0.62rem;
  font-weight: 700;
  color: var(--electric-blue);
  letter-spacing: 0.4em;
  margin-top: 0.15rem;
  text-transform: uppercase;
}

/* ---------- 14 MAIN NAV ---------- */
.site-nav {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: flex-end;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 0.15rem;
}

.nav-link {
  display: inline-flex;
  align-items: baseline;
  gap: 0.35rem;
  padding: 0.55rem 0.75rem;
  border-radius: 4px;
  color: rgba(255, 255, 255, 0.82);
  font-size: 0.92rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  position: relative;
  transition:
    color var(--speed-fast),
    background var(--speed-fast);
}

.nav-index {
  font-size: 0.6rem;
  font-weight: 800;
  color: rgba(0, 217, 255, 0.72);
  letter-spacing: 0.06em;
}

.nav-link:hover {
  color: #fff;
  background: rgba(155, 48, 255, 0.16);
}

.nav-link[aria-current="page"] {
  color: var(--gold);
}

.nav-link[aria-current="page"]::after {
  content: '';
  position: absolute;
  left: 0.75rem;
  right: 0.75rem;
  bottom: 0.3rem;
  height: 2px;
  background: linear-gradient(90deg, var(--gold), var(--neon-purple));
  transform: skewX(-24deg);
}

.header-status {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 0.8rem;
  border: 1px solid var(--border-blue);
  background: rgba(0, 217, 255, 0.07);
  border-radius: 3px;
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.16em;
  color: var(--electric-blue);
  white-space: nowrap;
}

.header-status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--neon-green);
  box-shadow: 0 0 8px var(--neon-green);
  animation: statusPulse 2.2s ease-in-out infinite;
}

/* ---------- 15 NAV TOGGLE ---------- */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.55rem;
  background: transparent;
  border: 1px solid rgba(0, 217, 255, 0.5);
  color: #fff;
  padding: 0.55rem 1rem;
  border-radius: 4px;
  cursor: pointer;
  line-height: 1;
  font-size: 0.85rem;
  font-weight: 800;
  transition:
    border-color var(--speed-fast),
    background var(--speed-fast);
}

.nav-toggle:hover {
  border-color: var(--electric-blue);
  background: rgba(0, 217, 255, 0.14);
}

.nav-toggle-icon {
  position: relative;
  display: inline-block;
  width: 18px;
  height: 2px;
  background: currentColor;
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: '';
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background: currentColor;
  transition: transform var(--speed-fast), top var(--speed-fast);
}

.nav-toggle-icon::before {
  top: -6px;
}

.nav-toggle-icon::after {
  top: 6px;
}

.nav-toggle[aria-expanded="true"] {
  border-color: var(--neon-purple);
  background: rgba(155, 48, 255, 0.2);
}

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

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

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

/* ---------- 16 FOOTER ---------- */
.site-footer {
  position: relative;
  background: var(--deep-space);
  color: var(--text-white-70);
  padding-top: 4.5rem;
  overflow: hidden;
  margin-top: 4rem;
}

.site-footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--neon-purple), var(--electric-blue) 40%, var(--gold) 75%, var(--neon-purple));
  background-size: 200% 100%;
  animation: footerScan 10s linear infinite;
  z-index: 1;
}

@keyframes footerScan {
  0% { background-position: 0% 0; }
  100% { background-position: 200% 0; }
}

.footer-aurora {
  position: absolute;
  top: -140px;
  right: -100px;
  width: 420px;
  height: 420px;
  background: radial-gradient(circle, rgba(155, 48, 255, 0.28), transparent 65%);
  filter: blur(30px);
  pointer-events: none;
}

.footer-aurora::after {
  content: '';
  position: absolute;
  left: -260px;
  top: 120px;
  width: 300px;
  height: 300px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(0, 217, 255, 0.2), transparent 60%);
}

.footer-grid {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.3fr;
  gap: 2.8rem 2.2rem;
}

.footer-brand-col .brand-text strong {
  color: #fff;
}

.footer-trust {
  margin-top: 1rem;
  font-size: 0.85rem;
  line-height: 1.8;
  color: rgba(255, 255, 255, 0.6);
  max-width: 30ch;
}

.footer-badge {
  margin-top: 0.8rem;
}

.footer-col {
  min-width: 0;
}

.footer-heading {
  font-size: 0.95rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  color: #fff;
  margin-bottom: 1.1rem;
  padding-left: 0.8rem;
  position: relative;
}

.footer-heading::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.2rem;
  bottom: 0.2rem;
  width: 3px;
  background: linear-gradient(180deg, var(--neon-purple), var(--electric-blue));
  transform: skewX(-16deg);
  border-radius: 1px;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.footer-links a {
  display: inline-block;
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.9rem;
  transition:
    color var(--speed-fast),
    transform var(--speed-fast);
}

.footer-links a:hover {
  color: var(--electric-blue);
  transform: translateX(4px);
}

.footer-contact {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.contact-item {
  display: flex;
  flex-direction: column;
  gap: 0.12rem;
}

.contact-label {
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.18em;
  color: rgba(255, 255, 255, 0.45);
  text-transform: uppercase;
}

.contact-value {
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.86);
  word-break: break-all;
}

.contact-note {
  margin-top: 1rem;
  padding-top: 0.8rem;
  border-top: 1px dashed rgba(255, 255, 255, 0.15);
  font-size: 0.74rem;
  color: rgba(255, 255, 255, 0.45);
}

.footer-legal {
  position: relative;
  z-index: 2;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  margin-top: 3.5rem;
  padding: 1.3rem 0;
  border-top: 1px solid rgba(255, 255, 255, 0.09);
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.5);
}

.legal-copy {
  margin: 0;
}

.legal-icp {
  margin: 0;
  letter-spacing: 0.06em;
}

/* ---------- 17 BACK TO TOP ---------- */
.back-to-top {
  position: fixed;
  right: 1.3rem;
  bottom: 1.3rem;
  z-index: 1500;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.6rem 1rem;
  background: var(--ink);
  border: 1px solid rgba(155, 48, 255, 0.55);
  border-radius: var(--radius);
  color: #fff;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  cursor: pointer;
  box-shadow: 0 8px 28px rgba(13, 5, 24, 0.45);
  opacity: 0;
  visibility: hidden;
  transform: translateY(14px);
  transition:
    opacity var(--speed-mid),
    transform var(--speed-mid),
    visibility var(--speed-mid),
    border-color var(--speed-fast);
}

.back-to-top:hover {
  border-color: var(--electric-blue);
}

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

.back-to-top-icon {
  display: inline-block;
  width: 9px;
  height: 9px;
  border-left: 2px solid var(--electric-blue);
  border-top: 2px solid var(--electric-blue);
  transform: rotate(45deg);
}

/* ---------- 18 TOC & CHAPTER ---------- */
.chapter {
  border-left: 3px solid var(--neon-purple);
  padding-left: 1.5rem;
  margin: 2rem 0;
}

[data-toc] {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  padding-left: 1rem;
  border-left: 2px solid rgba(155, 48, 255, 0.2);
}

[data-toc] a {
  color: var(--text-dark-65);
  font-size: 0.88rem;
  font-weight: 600;
  border-left: 2px solid transparent;
  margin-left: -1rem;
  padding-left: 1rem;
  transition:
    color var(--speed-fast),
    border-color var(--speed-fast);
}

[data-toc] a:hover {
  color: var(--neon-purple);
}

[data-toc] a.is-active {
  color: var(--electric-blue);
  font-weight: 800;
  border-left-color: var(--electric-blue);
}

/* ---------- 19 RESPONSIVE ---------- */
@media (max-width: 1200px) {
  .header-inner {
    gap: 1rem;
  }

  .nav-link {
    padding: 0.5rem 0.55rem;
    font-size: 0.88rem;
  }
}

@media (max-width: 1024px) {
  .nav-index {
    display: none;
  }

  .header-status {
    display: none;
  }

  .utility-status-text {
    font-size: 0.74rem;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 2.4rem 2rem;
  }
}

@media (max-width: 920px) {
  .header-inner {
    gap: 1rem;
  }

  .nav-toggle {
    display: inline-flex;
    z-index: 4000;
  }

  .site-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 3000;
    background: rgba(13, 5, 24, 0.98);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-18px);
    transition:
      opacity 0.32s ease,
      transform 0.32s ease,
      visibility 0.32s ease;
  }

  .site-nav::before {
    content: '';
    position: absolute;
    top: -80px;
    right: -60px;
    width: 280px;
    height: 280px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(155, 48, 255, 0.32), transparent 65%);
    filter: blur(24px);
    pointer-events: none;
  }

  .site-nav::after {
    content: '';
    position: absolute;
    left: -80px;
    bottom: -60px;
    width: 240px;
    height: 240px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(0, 217, 255, 0.22), transparent 65%);
    filter: blur(24px);
    pointer-events: none;
  }

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

  .nav-list {
    flex-direction: column;
    gap: 0.4rem;
    text-align: center;
    padding: 2rem;
    position: relative;
    z-index: 1;
  }

  .nav-link {
    font-size: 1.6rem;
    font-weight: 800;
    padding: 0.65rem 1.6rem;
    color: rgba(255, 255, 255, 0.9);
    border-radius: var(--radius);
  }

  .nav-link:hover {
    background: rgba(155, 48, 255, 0.22);
  }

  .nav-link[aria-current="page"]::after {
    left: 1.6rem;
    right: 1.6rem;
    bottom: 0.45rem;
  }

  .nav-index {
    display: inline;
    font-size: 0.78rem;
  }
}

@media (max-width: 640px) {
  .utility-inner {
    flex-direction: column;
    align-items: flex-start;
    padding-block: 0.5rem;
    gap: 0.3rem;
  }

  .utility-tools {
    gap: 0.5rem;
  }

  .brand-mark {
    width: 46px;
    height: 46px;
  }

  .brand-mark-inner {
    font-size: 1rem;
  }

  .brand-text strong {
    font-size: 1.25rem;
  }

  .brand-text small {
    font-size: 0.55rem;
    letter-spacing: 0.3em;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

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

  .back-to-top {
    right: 1rem;
    bottom: 1rem;
    padding: 0.55rem 0.85rem;
  }

  .back-to-top-text {
    display: none;
  }

  .nav-link {
    font-size: 1.35rem;
  }
}

/* ---------- 20 MOTION REDUCTION ---------- */
@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;
  }

  .card:hover,
  .btn:hover,
  .footer-links a:hover {
    transform: none;
  }
}