/* ============ 华体会赛事 · 竞速终端 Site Kit ============ */
/* 文件：/assets/site.css */

/* ---------- 1. Reset ---------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--c-cloud);
  background-color: var(--c-space);
  background-image:
    linear-gradient(rgba(160, 180, 196, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(160, 180, 196, 0.035) 1px, transparent 1px);
  background-size: 32px 32px;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

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

ul, ol {
  list-style: none;
}

button {
  font: inherit;
  border: none;
  background: none;
  cursor: pointer;
  color: inherit;
  -webkit-appearance: none;
  appearance: none;
}

input, textarea, select {
  font: inherit;
}

main {
  display: block;
}

#main-content {
  display: block;
  min-height: 65vh;
}

/* ---------- 2. Variables ---------- */
:root {
  --c-space: #0A1A2F;
  --c-steel: #16273E;
  --c-neon: #00FF88;
  --c-orange: #FF6B35;
  --c-white: #FFFFFF;
  --c-cloud: #A0B4C4;
  --c-border: #2A3F55;
  --c-gold: #FFD700;

  --font-heading: Futura, "Century Gothic", "Microsoft YaHei", "PingFang SC", sans-serif;
  --font-body: Inter, -apple-system, "Helvetica Neue", "Microsoft YaHei", Arial, sans-serif;

  --shadow-card: 0 8px 24px rgba(0, 0, 0, 0.35);
  --shadow-hover: 0 16px 40px rgba(0, 0, 0, 0.5);
  --shadow-neon: 0 0 28px rgba(0, 255, 136, 0.15);

  --container-max: 1200px;
  --transition-fast: 180ms ease;
  --transition-base: 260ms ease;
}

/* ---------- 3. Typography ---------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  color: var(--c-white);
  letter-spacing: 0.01em;
}

h1 { font-size: 44px; }
h2 { font-size: 32px; }
h3 { font-size: 22px; }
h4 { font-size: 18px; }

p {
  margin-bottom: 1em;
}

/* ---------- 4. Layout Helpers ---------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: 24px;
}

.section {
  position: relative;
  padding: 72px 0;
}

.section-head {
  max-width: 720px;
  margin-bottom: 48px;
}

.section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-heading);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--c-neon);
  margin-bottom: 12px;
}

.section-kicker::before {
  content: "";
  width: 24px;
  height: 3px;
  background: var(--c-neon);
  clip-path: polygon(0 0, 100% 0, calc(100% - 4px) 100%, 0 100%);
}

.section-title {
  font-size: 36px;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--c-white);
  margin-bottom: 12px;
}

.section-desc {
  font-size: 17px;
  line-height: 1.6;
  color: var(--c-cloud);
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 24px;
}

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

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

.speed-line {
  display: block;
  position: relative;
  height: 3px;
  background: linear-gradient(90deg, var(--c-neon), transparent);
  overflow: visible;
}

.speed-line::after {
  content: "";
  position: absolute;
  right: -2px;
  top: -3px;
  width: 9px;
  height: 9px;
  background: var(--c-orange);
  transform: rotate(45deg);
}

.slanted-block {
  display: block;
  position: relative;
  min-height: 48px;
  background: var(--c-steel);
  border: 2px solid var(--c-border);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 16px 100%, 0 calc(100% - 16px));
}

.corner-mark {
  position: relative;
}

.corner-mark::before,
.corner-mark::after {
  content: "";
  position: absolute;
  width: 16px;
  height: 16px;
  pointer-events: none;
  z-index: 2;
  border-color: rgba(0, 255, 136, 0.55);
}

.corner-mark::before {
  top: -1px;
  left: -1px;
  border-top: 2px solid;
  border-left: 2px solid;
}

.corner-mark::after {
  right: -1px;
  bottom: -1px;
  border-right: 2px solid;
  border-bottom: 2px solid;
}

/* ---------- 5. Accessibility ---------- */
.sr-only {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: -60px;
  left: 16px;
  z-index: 999;
  background: var(--c-neon);
  color: #002B18;
  font-family: var(--font-heading);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  padding: 10px 20px;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 8px;
}

:focus-visible {
  outline: 2px solid var(--c-neon);
  outline-offset: 3px;
  border-radius: 1px;
}

/* ---------- 6. Scroll Progress ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--c-neon) 0%, var(--c-orange) 80%, var(--c-gold) 100%);
  box-shadow: 0 0 14px rgba(0, 255, 136, 0.4);
  z-index: 1000;
  pointer-events: none;
  transition: width 80ms linear;
}

/* ---------- 7. Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--c-space);
  border-bottom: 1px solid var(--c-border);
}

.header-signal {
  position: relative;
  height: 3px;
  background: linear-gradient(90deg, var(--c-neon) 0%, var(--c-orange) 60%, var(--c-gold) 100%);
  overflow: hidden;
}

.signal-bar {
  position: absolute;
  inset: 0;
  display: block;
  background: repeating-linear-gradient(
    -55deg,
    transparent 0,
    transparent 8px,
    rgba(255, 255, 255, 0.4) 8px,
    rgba(255, 255, 255, 0.4) 10px
  );
}

.header-inner {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: stretch;
  padding-top: 20px;
  padding-bottom: 0;
}

.header-brand {
  display: flex;
  justify-content: center;
  padding-bottom: 16px;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  position: relative;
}

.brand-shape {
  position: relative;
  width: 38px;
  height: 38px;
  background: var(--c-neon);
  clip-path: polygon(0 0, 100% 0, 82% 100%, 18% 100%);
  flex-shrink: 0;
}

.brand-shape::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 11px;
  height: 11px;
  background: var(--c-orange);
  transform: translate(-50%, -50%) rotate(45deg);
}

.brand-text {
  position: relative;
  display: flex;
  flex-direction: column;
  padding-bottom: 5px;
}

.brand-text::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--c-neon);
  clip-path: polygon(0 0, 100% 0, calc(100% - 8px) 100%, 0 100%);
}

.brand-name {
  font-family: var(--font-heading);
  font-size: 27px;
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: 0.05em;
  color: var(--c-white);
}

.brand-sub {
  font-family: var(--font-heading);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--c-cloud);
  margin-top: 2px;
}

/* ---------- 8. Navigation ---------- */
.site-nav {
  border-top: 1px solid var(--c-border);
  margin-top: 0;
}

.nav-list {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
}

.nav-item {
  flex-shrink: 0;
}

.nav-link {
  position: relative;
  display: block;
  padding: 14px 20px;
  font-family: var(--font-heading);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--c-cloud);
  transition: color var(--transition-fast);
}

.nav-link::before {
  content: "";
  position: absolute;
  top: 6px;
  right: 10px;
  bottom: 6px;
  left: 10px;
  background: rgba(0, 255, 136, 0.12);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--transition-base);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 20px;
  right: 20px;
  bottom: 0;
  height: 3px;
  background: var(--c-neon);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--transition-base);
}

.nav-link:hover,
.nav-link[aria-current="page"] {
  color: var(--c-white);
}

.nav-link:hover::before,
.nav-link[aria-current="page"]::before {
  transform: scaleX(1);
}

.nav-link:hover::after,
.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
}

.nav-link:hover .nav-num {
  color: var(--c-neon);
}

.nav-num {
  display: inline-block;
  font-size: 10px;
  font-weight: 700;
  color: var(--c-orange);
  margin-right: 6px;
  vertical-align: 2px;
  letter-spacing: 0;
  transition: color var(--transition-fast);
}

.nav-toggle {
  display: none;
  position: relative;
  width: 44px;
  height: 44px;
  border: 1px solid var(--c-border);
  background: var(--c-steel);
  align-items: center;
  justify-content: center;
  transition: border-color var(--transition-fast), background var(--transition-fast);
}

.nav-toggle:hover {
  border-color: var(--c-neon);
}

.nav-toggle[aria-expanded="true"] {
  border-color: var(--c-neon);
  background: rgba(0, 255, 136, 0.08);
}

.nav-toggle-box {
  position: relative;
  display: block;
  width: 18px;
  height: 14px;
}

.nav-toggle-line {
  position: absolute;
  left: 0;
  display: block;
  width: 100%;
  height: 2px;
  background: var(--c-neon);
  transition: transform 0.25s ease, top 0.25s ease, opacity 0.2s ease;
}

.nav-toggle-line:nth-child(1) { top: 0; }
.nav-toggle-line:nth-child(2) { top: 6px; }
.nav-toggle-line:nth-child(3) { top: 12px; }

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(1) {
  top: 6px;
  transform: rotate(45deg);
}

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

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(3) {
  top: 6px;
  transform: rotate(-45deg);
}

/* ---------- 9. Footer ---------- */
.site-footer {
  background: var(--c-space);
  margin-top: auto;
}

.footer-top {
  border-top: none;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1.3fr;
  gap: 48px;
  padding: 56px 0;
}

.footer-brand-col {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.brand-mark--footer {
  gap: 12px;
}

.brand-mark--footer .brand-shape {
  width: 32px;
  height: 32px;
}

.brand-mark--footer .brand-name {
  font-size: 24px;
}

.footer-statement {
  font-size: 15px;
  line-height: 1.7;
  color: var(--c-cloud);
  max-width: 320px;
}

.footer-nav-col {
  display: flex;
  flex-direction: column;
}

.footer-col-title {
  font-family: var(--font-heading);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--c-white);
  margin-bottom: 18px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--c-border);
  position: relative;
}

.footer-col-title::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 32px;
  height: 2px;
  background: var(--c-neon);
}

.footer-nav-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-nav-list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 15px;
  color: var(--c-cloud);
  line-height: 1.5;
  transition: color var(--transition-fast), transform var(--transition-fast);
}

.footer-nav-list a::before {
  content: "";
  width: 6px;
  height: 6px;
  background: var(--c-border);
  flex-shrink: 0;
  transform: rotate(0deg);
  transition: background var(--transition-fast), transform var(--transition-fast);
}

.footer-nav-list a:hover {
  color: var(--c-neon);
  transform: translateX(3px);
}

.footer-nav-list a:hover::before {
  background: var(--c-neon);
  transform: rotate(45deg);
}

.footer-contact-col {
  display: flex;
  flex-direction: column;
}

.footer-contact-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-contact-item {
  font-size: 14px;
  line-height: 1.55;
  color: var(--c-cloud);
  padding-left: 16px;
  position: relative;
}

.footer-contact-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 7px;
  height: 7px;
  background: var(--c-orange);
  clip-path: polygon(0 0, 100% 0, 100% 100%, 25% 100%);
}

.footer-bottom {
  border-top: 1px solid var(--c-border);
  background: rgba(0, 0, 0, 0.22);
  padding: 20px 0;
}

.footer-bottom-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-copy {
  font-size: 14px;
  color: var(--c-cloud);
}

.footer-icp {
  font-size: 13px;
  color: var(--c-cloud);
  letter-spacing: 0.05em;
}

/* ---------- 10. Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-heading);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.06em;
  line-height: 1;
  padding: 14px 28px;
  background-color: transparent;
  border: 2px solid transparent;
  border-radius: 0;
  cursor: pointer;
  text-decoration: none;
  transition: color var(--transition-fast), background-color var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
  position: relative;
}

.btn::after {
  content: "→";
  font-family: var(--font-heading);
  margin-left: 2px;
  transition: transform var(--transition-fast);
}

.btn:hover::after {
  transform: translateX(4px);
}

.btn-plain::after {
  content: none;
}

.btn-primary {
  background: var(--c-neon);
  border-color: var(--c-neon);
  color: #002B18;
  font-weight: 800;
}

.btn-primary:hover {
  background: #39FFA4;
  border-color: #39FFA4;
  box-shadow: 0 0 24px rgba(0, 255, 136, 0.35);
}

.btn-secondary {
  border-color: var(--c-neon);
  color: var(--c-neon);
}

.btn-secondary:hover {
  background: rgba(0, 255, 136, 0.1);
  border-color: var(--c-neon);
}

.btn-block {
  display: flex;
  width: 100%;
}

/* ---------- 11. Tags ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-heading);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  padding: 5px 12px;
  border: 1px solid var(--c-border);
  color: var(--c-cloud);
  line-height: 1.3;
}

.tag::before {
  content: "";
  width: 6px;
  height: 6px;
  background: var(--c-cloud);
  transform: rotate(45deg);
  flex-shrink: 0;
}

.tag-neon {
  color: var(--c-neon);
  border-color: rgba(0, 255, 136, 0.45);
}

.tag-neon::before {
  background: var(--c-neon);
}

.tag-orange {
  color: var(--c-orange);
  border-color: rgba(255, 107, 53, 0.45);
}

.tag-orange::before {
  background: var(--c-orange);
}

.tag-gold {
  color: var(--c-gold);
  border-color: rgba(255, 215, 0, 0.4);
}

.tag-gold::before {
  background: var(--c-gold);
}

/* ---------- 12. Cards ---------- */
.card {
  position: relative;
  background: var(--c-steel);
  border: 2px solid var(--c-border);
  padding: 24px;
  transition: transform var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
}

.card:hover {
  transform: translateY(-4px);
  border-color: rgba(0, 255, 136, 0.45);
  box-shadow: var(--shadow-hover);
}

.card-accent {
  clip-path: polygon(0 0, calc(100% - 20px) 0, 100% 20px, 100% 100%, 20px 100%, 0 calc(100% - 20px));
}

.card-accent::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 20px;
  height: 20px;
  background: var(--c-orange);
  clip-path: polygon(100% 0, 0 0, 100% 100%);
}

.card-title {
  font-family: var(--font-heading);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 8px;
  color: var(--c-white);
}

.card-body {
  font-size: 16px;
  line-height: 1.6;
  color: var(--c-cloud);
}

.card-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--c-cloud);
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px solid var(--c-border);
}

.card-meta::before {
  content: "";
  width: 10px;
  height: 2px;
  background: var(--c-neon);
  flex-shrink: 0;
}

/* ---------- 13. Research Board ---------- */
.board {
  position: relative;
  background: var(--c-steel);
  border: 2px solid var(--c-border);
  padding: 28px;
}

.board-title {
  font-family: var(--font-heading);
  font-size: 22px;
  font-weight: 700;
  color: var(--c-white);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.board-title::before {
  content: "#";
  color: var(--c-neon);
  font-size: 18px;
  font-weight: 800;
}

.board-summary {
  font-size: 16px;
  line-height: 1.7;
  color: var(--c-cloud);
  margin-bottom: 20px;
}

.board-evidence {
  border-left: 3px solid var(--c-neon);
  padding: 12px 16px;
  background: rgba(0, 255, 136, 0.05);
  margin-bottom: 16px;
  font-size: 15px;
  line-height: 1.6;
  color: var(--c-cloud);
}

.board-terms {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}

.board-links {
  border-top: 1px solid var(--c-border);
  padding-top: 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.board-links a {
  font-size: 14px;
  font-weight: 600;
  color: var(--c-neon);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-fast);
}

.board-links a:hover {
  border-bottom-color: var(--c-neon);
}

/* ---------- 14. Progress ---------- */
.progress-track {
  display: block;
  height: 8px;
  background: var(--c-space);
  border: 1px solid var(--c-border);
  padding: 1px;
}

.progress-fill {
  display: block;
  height: 100%;
  width: 65%;
  background: linear-gradient(90deg, var(--c-neon), var(--c-orange));
  transition: width var(--transition-base);
}

/* ---------- 15. Image Frames ---------- */
.image-frame {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background:
    repeating-linear-gradient(0deg, rgba(160, 180, 196, 0.06) 0, rgba(160, 180, 196, 0.06) 1px, transparent 1px, transparent 20px),
    repeating-linear-gradient(90deg, rgba(160, 180, 196, 0.06) 0, rgba(160, 180, 196, 0.06) 1px, transparent 1px, transparent 20px),
    var(--c-steel);
  border: 2px solid var(--c-border);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.image-frame:hover {
  border-color: rgba(0, 255, 136, 0.4);
}

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

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

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

.placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--c-cloud);
  background:
    radial-gradient(circle at center, rgba(0, 255, 136, 0.08), transparent 65%);
}

.image-caption {
  font-size: 13px;
  line-height: 1.5;
  color: var(--c-cloud);
  padding-top: 10px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.image-caption::before {
  content: "";
  width: 16px;
  height: 2px;
  background: var(--c-orange);
  flex-shrink: 0;
}

/* ---------- 16. Text Container ---------- */
.text-container {
  max-width: 760px;
  margin-inline: auto;
  font-size: 18px;
  line-height: 1.75;
  color: var(--c-cloud);
}

.text-container h1,
.text-container h2,
.text-container h3 {
  color: var(--c-white);
  margin: 2em 0 0.8em;
}

.text-container h2 { font-size: 28px; }
.text-container h3 { font-size: 20px; }

.text-container p {
  margin-bottom: 1.4em;
}

.text-container a {
  color: var(--c-neon);
  border-bottom: 1px solid rgba(0, 255, 136, 0.4);
  transition: border-color var(--transition-fast);
}

.text-container a:hover {
  border-bottom-color: var(--c-neon);
}

.text-container ul {
  margin: 1em 0 1.4em;
  padding-left: 0;
}

.text-container ul li {
  position: relative;
  padding-left: 24px;
  margin-bottom: 8px;
}

.text-container ul li::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 10px;
  width: 8px;
  height: 8px;
  background: var(--c-orange);
  transform: rotate(45deg);
}

/* ---------- 17. Breadcrumb ---------- */
.breadcrumb {
  margin-bottom: 24px;
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--c-cloud);
}

.breadcrumb-item {
  display: inline-flex;
  align-items: center;
}

.breadcrumb-item + .breadcrumb-item::before {
  content: "/";
  color: var(--c-border);
  margin-right: 8px;
}

.breadcrumb-item a {
  transition: color var(--transition-fast);
}

.breadcrumb-item a:hover {
  color: var(--c-neon);
}

.breadcrumb-item[aria-current="page"] {
  color: var(--c-white);
  font-weight: 600;
}

/* ---------- 18. Responsive ---------- */
@media (max-width: 1024px) {
  h1 { font-size: 38px; }

  .section { padding: 60px 0; }

  .grid-3 { grid-template-columns: repeat(2, 1fr); }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }
}

@media (max-width: 920px) {
  .header-inner {
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    padding-top: 10px;
    padding-bottom: 10px;
  }

  .header-brand {
    justify-content: flex-start;
    flex-shrink: 0;
    padding-bottom: 0;
  }

  .nav-toggle {
    display: inline-flex;
    margin-left: auto;
  }

  .site-nav {
    order: 3;
    width: 100%;
    border-top: none;
    margin-top: 0;
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    visibility: hidden;
    transition:
      max-height 0.35s ease,
      opacity 0.25s ease,
      visibility 0s linear 0.35s;
  }

  .site-nav[data-open] {
    visibility: visible;
    opacity: 1;
    max-height: 480px;
    border-top: 1px solid var(--c-border);
    margin-top: 12px;
    transition:
      max-height 0.35s ease,
      opacity 0.25s ease,
      visibility 0s linear 0s;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    padding: 8px 0;
  }

  .nav-link {
    padding: 14px 8px;
  }

  .nav-link::before {
    left: 0;
    right: 0;
    top: 4px;
    bottom: 4px;
  }

  .nav-link::after {
    left: 8px;
    right: auto;
    width: 28px;
    height: 3px;
  }
}

@media (max-width: 640px) {
  .container {
    padding-inline: 16px;
  }

  h1 { font-size: 32px; }
  h2 { font-size: 26px; }

  .section { padding: 48px 0; }

  .section-head { margin-bottom: 32px; }

  .section-title { font-size: 28px; }

  .grid-2,
  .grid-3 { grid-template-columns: 1fr; }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 40px 0;
  }

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

  .brand-name { font-size: 23px; }
  .brand-sub { letter-spacing: 0.2em; }
}

/* ---------- 19. 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;
  }

  .scroll-progress {
    transition: none !important;
  }

  .nav-toggle-line {
    transition: none !important;
  }
}