/* ========== Reset & Base ========== */
*,
*::before,
*::after {
  box-sizing: border-box;
}

* {
  margin: 0;
}

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

body {
  min-height: 100dvh;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--paper);
  background:
    radial-gradient(ellipse 80% 50% at 85% -10%, rgba(201, 247, 58, 0.08), transparent 60%),
    var(--primary-deep-cyan);
  overflow-x: hidden;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

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

ul,
ol {
  list-style: none;
  padding: 0;
}

p {
  margin: 0 0 1rem;
}

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

a {
  color: var(--accent-fluorescent-green);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

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

::selection {
  background: var(--accent-fluorescent-green);
  color: var(--ink);
}

:focus-visible {
  outline: 3px solid var(--accent-fluorescent-green);
  outline-offset: 3px;
}

/* ========== Variables ========== */
:root {
  --primary-deep-cyan: #062A33;
  --secondary-cyan-surface: #0C4050;
  --accent-fluorescent-green: #C9F73A;
  --support-fluorescent-dim: #B5E826;
  --dark-red: #8F2F2F;
  --signal-red: #E64A3D;
  --paper: #F4F7F5;
  --ink: #102A31;
  --muted: #7D9AA0;
  --data-green: #42E66C;
  --font-display: "Noto Sans SC", "HarmonyOS Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-editorial: "Source Serif SC", "Songti SC", "SimSun", serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", "SFMono-Regular", Consolas, monospace;
  --font-body: "Noto Sans SC", "HarmonyOS Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-pill: 999px;
}

/* ========== Utilities ========== */
.container,
.masthead-inner,
.nav-bar-inner,
.footer-bottom-inner {
  width: min(1200px, calc(100% - 48px));
  margin-inline: auto;
}

.container-narrow {
  width: min(880px, calc(100% - 48px));
  margin-inline: auto;
}

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

.muted {
  color: var(--muted);
}

.mono-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

.divider {
  height: 1px;
  border: none;
  margin: 24px 0;
  background: linear-gradient(90deg, rgba(201, 247, 58, 0.55), rgba(201, 247, 58, 0));
}

.divider-light {
  height: 1px;
  border: none;
  margin: 24px 0;
  background: rgba(244, 247, 245, 0.12);
}

.diagonal-stripe {
  height: 8px;
  border-radius: var(--radius-pill);
  background: repeating-linear-gradient(
    -45deg,
    var(--accent-fluorescent-green) 0,
    var(--accent-fluorescent-green) 8px,
    transparent 8px,
    transparent 16px
  );
}

/* ========== Typography Components ========== */
.section-label {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-editorial);
  font-size: 14px;
  letter-spacing: 0.12em;
  color: var(--accent-fluorescent-green);
}

.section-label::before {
  content: "";
  width: 26px;
  height: 2px;
  background: var(--accent-fluorescent-green);
  border-radius: 2px;
}

.section-title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(28px, 4.2vw, 46px);
  line-height: 1.14;
  letter-spacing: 0.01em;
  color: var(--paper);
}

.section-sub {
  font-size: 16px;
  line-height: 1.7;
  color: var(--muted);
  max-width: 640px;
}

.lead {
  font-size: 18px;
  line-height: 1.8;
  color: var(--paper);
}

/* ========== Buttons ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  border-radius: var(--radius-pill);
  border: 2px solid transparent;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  line-height: 1.4;
  cursor: pointer;
  white-space: nowrap;
  text-decoration: none;
  transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease, transform 0.15s ease;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

.btn-primary {
  background: var(--accent-fluorescent-green);
  color: var(--ink);
}

.btn-primary:hover {
  background: var(--support-fluorescent-dim);
  border-color: var(--support-fluorescent-dim);
  color: var(--ink);
}

.btn-outline {
  background: transparent;
  border-color: var(--accent-fluorescent-green);
  color: var(--accent-fluorescent-green);
}

.btn-outline:hover {
  background: rgba(201, 247, 58, 0.12);
  border-color: var(--support-fluorescent-dim);
  color: var(--support-fluorescent-dim);
}

.btn-danger {
  background: var(--signal-red);
  color: var(--paper);
}

.btn-danger:hover {
  background: var(--dark-red);
  color: var(--paper);
}

.btn-ghost {
  background: transparent;
  border-color: rgba(244, 247, 245, 0.3);
  color: var(--paper);
}

.btn-ghost:hover {
  background: rgba(244, 247, 245, 0.08);
  border-color: var(--paper);
  color: var(--paper);
}

.btn-sm {
  padding: 6px 14px;
  font-size: 13px;
}

.btn-lg {
  padding: 14px 30px;
  font-size: 17px;
}

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

/* ========== Tags ========== */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 12px;
  border-radius: var(--radius-pill);
  background: var(--secondary-cyan-surface);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.5;
  white-space: nowrap;
}

.tag::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
}

.tag-green {
  background: var(--accent-fluorescent-green);
  color: var(--ink);
}

.tag-red {
  background: var(--signal-red);
  color: var(--paper);
}

.tag-dim {
  color: var(--muted);
  background: rgba(12, 64, 80, 0.6);
}

/* ========== Breadcrumb ========== */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--muted);
}

.breadcrumb li {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.breadcrumb li + li::before {
  content: "→";
  color: var(--muted);
  opacity: 0.5;
}

.breadcrumb a {
  color: var(--muted);
}

.breadcrumb a:hover {
  color: var(--accent-fluorescent-green);
}

.breadcrumb [aria-current="page"] {
  color: var(--paper);
}

/* ========== Grid ========== */
.grid {
  display: grid;
  gap: 24px;
}

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

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

.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

.grid-gap-lg {
  gap: 40px;
}

/* ========== Panels & Sections ========== */
.panel {
  background: var(--secondary-cyan-surface);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.panel-paper {
  background: var(--paper);
  color: var(--ink);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.panel-paper .section-title,
.panel-paper .lead {
  color: var(--ink);
}

.section-cyan {
  background: var(--secondary-cyan-surface);
  border-radius: var(--radius-lg);
  padding: clamp(40px, 6vw, 72px);
}

.section-paper {
  background: var(--paper);
  color: var(--ink);
  border-radius: var(--radius-lg);
  padding: clamp(40px, 6vw, 72px);
}

.section-paper .section-title,
.section-paper .lead {
  color: var(--ink);
}

.section-paper .btn-outline {
  border-color: rgba(16, 42, 49, 0.45);
  color: var(--ink);
}

.section-paper .btn-outline:hover {
  background: rgba(16, 42, 49, 0.08);
  border-color: var(--ink);
}

/* ========== Figure / Image Containers ========== */
.figure {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background:
    linear-gradient(120deg, rgba(201, 247, 58, 0.06), transparent 45%),
    repeating-linear-gradient(-45deg, transparent 0 14px, rgba(201, 247, 58, 0.04) 14px 16px),
    var(--secondary-cyan-surface);
}

.figure > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.figure::after {
  content: "";
  position: absolute;
  inset: 0;
  border: 1px solid rgba(201, 247, 58, 0.25);
  border-radius: inherit;
  pointer-events: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.figure-16-9 {
  aspect-ratio: 16 / 9;
}

.figure-4-3 {
  aspect-ratio: 4 / 3;
}

.figure-1-1 {
  aspect-ratio: 1 / 1;
}

.figure-hover {
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.figure-hover:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.25);
}

.figure-hover:hover::after {
  border-color: var(--accent-fluorescent-green);
  box-shadow: inset 0 0 28px rgba(201, 247, 58, 0.08);
}

.figure-caption {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 4px 0;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--muted);
}

.figure-caption::before {
  content: "";
  width: 18px;
  height: 2px;
  flex-shrink: 0;
  background: var(--data-green);
  border-radius: 2px;
}

/* ========== Exhibit Label / Stats ========== */
.exhibit-label {
  display: inline-flex;
  flex-direction: column;
  gap: 2px;
  padding: 10px 14px;
  background: var(--secondary-cyan-surface);
  border-left: 3px solid var(--accent-fluorescent-green);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  color: var(--muted);
}

.exhibit-label strong {
  color: var(--paper);
  font-size: 13px;
  font-family: var(--font-display);
}

.stat {
  display: inline-flex;
  flex-direction: column;
  gap: 2px;
  font-family: var(--font-mono);
}

.stat-value {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--accent-fluorescent-green);
  font-variant-numeric: tabular-nums;
}

.stat-label {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

/* ========== Section Navigation ========== */
.section-nav {
  display: grid;
  gap: 4px;
  position: sticky;
  top: 72px;
}

.section-nav a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  font-size: 14px;
  color: var(--muted);
}

.section-nav a::before {
  content: "";
  width: 7px;
  height: 7px;
  flex-shrink: 0;
  border-radius: 50%;
  background: var(--secondary-cyan-surface);
  border: 1px solid var(--muted);
}

.section-nav a:hover {
  color: var(--paper);
  background: rgba(12, 64, 80, 0.45);
  text-decoration: none;
}

.section-nav a[aria-current="true"] {
  color: var(--accent-fluorescent-green);
}

.section-nav a[aria-current="true"]::before {
  background: var(--accent-fluorescent-green);
  border-color: var(--accent-fluorescent-green);
  box-shadow: 0 0 0 3px rgba(201, 247, 58, 0.2);
}

/* ========== Skip Link & Scroll Progress ========== */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  z-index: 500;
  pointer-events: none;
  background: transparent;
}

.scroll-progress::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, var(--accent-fluorescent-green), var(--data-green));
  transform: scaleX(var(--scroll-progress, 0));
  transform-origin: left center;
  transition: transform 0.1s linear;
}

.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 1000;
  padding: 10px 18px;
  background: var(--accent-fluorescent-green);
  color: var(--ink);
  border-radius: var(--radius-pill);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 14px;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 12px;
  text-decoration: none;
}

/* ========== Site Header / Masthead ========== */
.site-header {
  background: var(--primary-deep-cyan);
  color: var(--paper);
}

.masthead {
  border-bottom: 1px solid rgba(244, 247, 245, 0.08);
}

.masthead-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px 0 14px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--paper);
  text-decoration: none;
}

.brand:hover {
  text-decoration: none;
}

.brand-mark {
  position: relative;
  width: 42px;
  height: 42px;
  flex-shrink: 0;
  border-radius: 14px;
  background: var(--secondary-cyan-surface);
  border: 2px solid var(--accent-fluorescent-green);
  overflow: hidden;
}

.brand-mark::before {
  content: "";
  position: absolute;
  top: -8px;
  right: -8px;
  width: 26px;
  height: 26px;
  background: var(--accent-fluorescent-green);
  border-radius: 6px;
  transform: rotate(45deg);
}

.brand-mark::after {
  content: "";
  position: absolute;
  left: 5px;
  bottom: 5px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--signal-red);
  box-shadow: 0 0 10px rgba(230, 74, 61, 0.7);
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.25;
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 24px;
  letter-spacing: 0.05em;
  color: var(--paper);
  white-space: nowrap;
}

.brand-sub {
  font-family: var(--font-editorial);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--accent-fluorescent-green);
  white-space: nowrap;
}

.masthead-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted);
}

.masthead-icp {
  padding: 4px 10px;
  border: 1px solid rgba(125, 154, 160, 0.32);
  border-radius: var(--radius-pill);
  color: var(--muted);
  white-space: nowrap;
}

.masthead-legacy {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  background: rgba(201, 247, 58, 0.1);
  border: 1px solid rgba(201, 247, 58, 0.35);
  color: var(--accent-fluorescent-green);
  font-weight: 600;
  white-space: nowrap;
}

.masthead-legacy::after {
  content: "→";
  transition: transform 0.2s ease;
}

.masthead-legacy:hover {
  background: var(--accent-fluorescent-green);
  color: var(--ink);
  text-decoration: none;
}

.masthead-legacy:hover::after {
  transform: translateX(3px);
}

/* ========== Navigation Bar ========== */
.nav-bar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(6, 42, 51, 0.96);
  border-top: 1px solid rgba(201, 247, 58, 0.2);
  border-bottom: 1px solid rgba(201, 247, 58, 0.15);
  transition: box-shadow 0.25s ease;
}

.nav-bar.is-scrolled {
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.35);
}

.nav-bar-inner {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  min-height: 54px;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-list a {
  display: block;
  padding: 9px 18px;
  border-radius: var(--radius-pill);
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--paper);
  transition: background 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}

.nav-list a:hover {
  background: rgba(201, 247, 58, 0.1);
  color: var(--accent-fluorescent-green);
  text-decoration: none;
}

.nav-list a[aria-current="page"] {
  background: var(--accent-fluorescent-green);
  color: var(--ink);
  box-shadow: 0 0 0 3px rgba(201, 247, 58, 0.2), 0 4px 12px rgba(201, 247, 58, 0.22);
}

/* ========== Mobile Nav Toggle ========== */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  margin-left: auto;
  padding: 8px 16px 8px 14px;
  border-radius: var(--radius-pill);
  background: var(--secondary-cyan-surface);
  border: 1px solid rgba(201, 247, 58, 0.4);
  color: var(--paper);
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 600;
  line-height: 1.4;
  cursor: pointer;
  position: relative;
  z-index: 130;
  white-space: nowrap;
  transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.nav-toggle:hover {
  border-color: var(--accent-fluorescent-green);
  background: rgba(12, 64, 80, 0.9);
}

.nav-toggle[aria-expanded="true"] {
  background: var(--accent-fluorescent-green);
  border-color: var(--accent-fluorescent-green);
  color: var(--ink);
}

.nav-toggle-box {
  position: relative;
  width: 18px;
  height: 12px;
  flex-shrink: 0;
}

.nav-toggle-line {
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: var(--accent-fluorescent-green);
  transition: transform 0.25s ease, opacity 0.25s ease, background 0.2s ease;
}

.nav-toggle-line:nth-child(1) {
  top: 0;
}

.nav-toggle-line:nth-child(2) {
  top: 5px;
}

.nav-toggle-line:nth-child(3) {
  top: 10px;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(1) {
  transform: translateY(5px) rotate(45deg);
  background: var(--ink);
}

.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(-5px) rotate(-45deg);
  background: var(--ink);
}

/* ========== Nav Backdrop ========== */
.nav-backdrop {
  position: fixed;
  inset: 0;
  z-index: 90;
  background: rgba(4, 22, 27, 0.65);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

body.nav-open {
  overflow: hidden;
}

body.nav-open .nav-backdrop {
  opacity: 1;
  pointer-events: auto;
}

body.nav-open .back-to-top {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

/* ========== Footer ========== */
.site-footer {
  background: var(--ink);
  color: var(--paper);
  border-top: 2px solid var(--accent-fluorescent-green);
  margin-top: 64px;
}

.footer-main {
  display: grid;
  grid-template-columns: 2.2fr 1fr 1.6fr 1fr;
  gap: 40px;
  padding: 56px 0 44px;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.footer-col-brand {
  align-items: flex-start;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--paper);
  text-decoration: none;
}

.footer-brand:hover {
  text-decoration: none;
}

.footer-brand-mark {
  position: relative;
  width: 28px;
  height: 28px;
  flex-shrink: 0;
  border-radius: 9px;
  background: var(--secondary-cyan-surface);
  border: 1px solid var(--accent-fluorescent-green);
  overflow: hidden;
}

.footer-brand-mark::before {
  content: "";
  position: absolute;
  top: -5px;
  right: -5px;
  width: 16px;
  height: 16px;
  background: var(--accent-fluorescent-green);
  border-radius: 4px;
  transform: rotate(45deg);
}

.footer-brand-name {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 22px;
  letter-spacing: 0.04em;
  color: var(--paper);
  white-space: nowrap;
}

.footer-desc {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
  max-width: 320px;
  margin: 0;
}

.footer-trust {
  font-size: 13px;
  color: var(--muted);
  font-family: var(--font-mono);
  line-height: 1.6;
  border-left: 3px solid var(--data-green);
  padding-left: 12px;
  margin: 0;
}

.footer-heading {
  font-family: var(--font-editorial);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--accent-fluorescent-green);
}

.footer-links {
  display: grid;
  gap: 8px;
}

.footer-links a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--paper);
  font-size: 14px;
}

.footer-links a::before {
  content: "→";
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--accent-fluorescent-green);
  transition: transform 0.2s ease;
}

.footer-links a:hover {
  color: var(--accent-fluorescent-green);
  text-decoration: none;
}

.footer-links a:hover::before {
  transform: translateX(2px);
}

.footer-links a[aria-current="page"] {
  color: var(--accent-fluorescent-green);
}

.footer-contact {
  display: grid;
  gap: 10px;
  font-size: 14px;
}

.footer-contact li {
  display: flex;
  gap: 8px;
  line-height: 1.5;
}

.footer-contact-label {
  flex: 0 0 44px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted);
}

.footer-contact a {
  color: var(--paper);
}

.footer-contact a:hover {
  color: var(--accent-fluorescent-green);
}

.footer-contact-note {
  font-size: 12px;
  color: var(--muted);
  line-height: 1.6;
  border-top: 1px solid rgba(244, 247, 245, 0.1);
  padding-top: 10px;
  margin: 0;
}

.footer-bottom {
  border-top: 1px solid rgba(244, 247, 245, 0.08);
  padding: 16px 0;
}

.footer-bottom-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px 16px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--muted);
}

.footer-copyright,
.footer-icp {
  margin: 0;
  color: var(--muted);
}

/* ========== Back To Top ========== */
.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 300;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--accent-fluorescent-green);
  color: var(--ink);
  border: none;
  cursor: pointer;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s, background 0.2s ease;
}

.back-to-top:hover {
  background: var(--support-fluorescent-dim);
}

.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.back-to-top-icon {
  font-size: 20px;
  line-height: 1;
}

/* ========== Reveal ========== */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.js [data-reveal="left"] {
  transform: translateX(-20px);
}

.js [data-reveal="right"] {
  transform: translateX(20px);
}

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

/* ========== Responsive ========== */
@media (max-width: 900px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }

  .nav-toggle {
    display: inline-flex;
  }

  .nav-bar-inner {
    justify-content: flex-end;
    min-height: 52px;
  }

  .nav-list {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: min(320px, 84vw);
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    margin: 0;
    padding: 84px 16px 24px;
    background: var(--secondary-cyan-surface);
    border-left: 1px solid rgba(201, 247, 58, 0.25);
    box-shadow: -16px 0 40px rgba(0, 0, 0, 0.35);
    transform: translateX(100%);
    transition: transform 0.3s ease, visibility 0.3s;
    visibility: hidden;
    overflow-y: auto;
    z-index: 120;
  }

  .nav-bar[data-open] .nav-list {
    visibility: visible;
    transform: translateX(0);
  }

  .nav-list a {
    padding: 14px 16px;
    font-size: 16px;
    border-radius: 12px;
  }

  .nav-list a[aria-current="page"] {
    box-shadow: none;
  }

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

@media (max-width: 768px) {
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }

  .masthead-inner {
    padding: 14px 0 12px;
  }

  .brand-mark {
    width: 36px;
    height: 36px;
    border-radius: 12px;
  }

  .brand-name {
    font-size: 21px;
  }

  .brand-sub {
    font-size: 11px;
    letter-spacing: 0.12em;
  }
}

@media (max-width: 640px) {
  .masthead-icp {
    display: none;
  }

  .masthead-meta {
    gap: 8px;
  }

  .masthead-legacy {
    padding: 3px 10px;
    font-size: 11px;
  }

  .brand-mark {
    width: 32px;
    height: 32px;
    border-radius: 10px;
  }

  .brand-name {
    font-size: 19px;
  }

  .brand-sub {
    font-size: 10px;
    letter-spacing: 0.08em;
  }
}

@media (max-width: 560px) {
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

  .footer-main {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 40px 0 32px;
  }

  .footer-bottom-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }

  .back-to-top {
    right: 16px;
    bottom: 16px;
  }

  .site-footer {
    margin-top: 40px;
  }
}

/* ========== Reduced Motion ========== */
@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;
  }

  .scroll-progress::before {
    transition: none;
  }

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

  .back-to-top,
  .back-to-top.is-visible {
    transition: none;
  }
}