/* ==========================================================================
   九游 Kinetic Arena — Site Kit 共享样式
   文件位置：/assets/site.css
   ========================================================================== */

/* 1. Reset 与设计变量
   ========================================================================== */

*, *::before, *::after {
  box-sizing: border-box;
}

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

body,
h1, h2, h3, h4, h5, h6,
p, figure, blockquote, dl, dd {
  margin: 0;
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  background:
    radial-gradient(1050px 420px at 88% -10%, rgba(0, 227, 154, 0.07), transparent 62%),
    radial-gradient(780px 380px at -5% 32%, rgba(20, 44, 67, 0.66), transparent 68%),
    var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

#main-content {
  flex: 1 0 auto;
}

[hidden] {
  display: none !important;
}

ul:not([class]),
ol:not([class]) {
  list-style: disc;
  padding-left: 1.5em;
  margin: 0 0 1rem;
}

ol:not([class]) {
  list-style: decimal;
}

:root {
  /* 品牌色板 */
  --deep-space-blue: #0B1B2A;
  --nebula-navy: #142C43;
  --kinetic-green: #00E39A;
  --voltage-orange: #FF7A2F;
  --mineral-grey: #7D8A96;
  --moss-green: #6B7F4D;
  --terracotta: #C97D5A;
  --warm-white: #F5F0E8;
  --graphite: #2E3A42;
  --safety-footer: #08131F;

  /* 语义标记 */
  --bg: var(--deep-space-blue);
  --bg-elevated: rgba(20, 44, 67, 0.82);
  --surface-glass: rgba(11, 27, 42, 0.62);
  --line: rgba(245, 240, 232, 0.14);
  --line-strong: rgba(245, 240, 232, 0.22);
  --line-green: rgba(0, 227, 154, 0.3);
  --line-orange: rgba(255, 122, 47, 0.32);
  --text: var(--warm-white);
  --text-secondary: rgba(245, 240, 232, 0.68);
  --text-muted: var(--mineral-grey);
  --shadow-deep: 0 24px 50px rgba(0, 0, 0, 0.28);

  /* 字体 */
  --font-display: "Archivo", "Helvetica Neue", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-data: "JetBrains Mono", "SFMono-Regular", Consolas, "Liberation Mono", monospace;

  /* 布局 */
  --container: 1280px;
  --gutter: clamp(16px, 3vw, 40px);
  --section-pad: clamp(3.5rem, 8vw, 6.5rem);

  /* 动效 */
  --dur-fast: 160ms;
  --dur: 280ms;
  --dur-slow: 520ms;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
}

::selection {
  background: rgba(0, 227, 154, 0.28);
  color: var(--warm-white);
}

/* 2. 基础排版
   ========================================================================== */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.2;
  color: var(--text);
}

h1 {
  font-size: clamp(2.4rem, 5.5vw, 4.5rem);
  font-weight: 900;
  letter-spacing: -0.012em;
}

h2 {
  font-size: clamp(1.55rem, 3vw, 2.25rem);
  letter-spacing: -0.012em;
}

h3 {
  font-size: 1.2rem;
  font-weight: 700;
}

p {
  margin-bottom: 1rem;
}

a {
  color: var(--kinetic-green);
  text-decoration: none;
  transition: color var(--dur-fast) ease;
}

a:hover {
  color: var(--text);
}

strong {
  font-weight: 700;
  color: var(--warm-white);
}

blockquote {
  margin: 1.5rem 0;
  padding: 0.25rem 0 0.25rem 1.25rem;
  border-left: 3px solid var(--kinetic-green);
  color: var(--text-secondary);
}

pre {
  margin: 1.25rem 0;
  padding: 1.2rem;
  background: #071018;
  border: 1px solid var(--line);
  border-radius: 4px;
  overflow-x: auto;
  font-family: var(--font-data);
  font-size: 0.85rem;
  line-height: 1.65;
}

code, kbd {
  font-family: var(--font-data);
  font-size: 0.88em;
  background: rgba(0, 227, 154, 0.08);
  border: 1px solid rgba(0, 227, 154, 0.16);
  padding: 0.12em 0.45em;
  border-radius: 3px;
}

pre code {
  background: none;
  border: 0;
  padding: 0;
}

.display-title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.6rem, 6vw, 5rem);
  line-height: 1.05;
  letter-spacing: -0.012em;
}

.text-secondary { color: var(--text-secondary); }
.text-muted { color: var(--text-muted); }
.text-green { color: var(--kinetic-green); }
.text-orange { color: var(--voltage-orange); }

.section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.7em;
  font-family: var(--font-data);
  font-size: 0.76rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--kinetic-green);
  margin-bottom: 0.65rem;
}

.section-kicker::before {
  content: "";
  width: 26px;
  height: 2px;
  background: var(--kinetic-green);
  flex: none;
}

.index-num {
  display: inline-flex;
  align-items: center;
  gap: 0.6em;
  font-family: var(--font-data);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  color: var(--voltage-orange);
}

.index-num::after {
  content: "";
  width: 28px;
  height: 1px;
  background: var(--voltage-orange);
  opacity: 0.55;
}

/* 3. 布局容器与章节
   ========================================================================== */

.container {
  width: min(100% - 2 * var(--gutter), var(--container));
  margin-inline: auto;
}

.section {
  position: relative;
  padding-block: var(--section-pad);
}

.section--tight {
  padding-block: clamp(2rem, 4vw, 3.25rem);
}

.section-intro {
  max-width: 62ch;
  color: var(--text-secondary);
  margin-bottom: 2.25rem;
}

.grid {
  display: grid;
  gap: clamp(16px, 2.4vw, 28px);
}

.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

/* 4. 按钮
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6em;
  padding: 0.85em 1.6em;
  border: 1px solid transparent;
  border-radius: 3px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.88rem;
  letter-spacing: 0.06em;
  line-height: 1.2;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: transform var(--dur-fast) ease, box-shadow var(--dur-fast) ease,
    background-color var(--dur-fast) ease, border-color var(--dur-fast) ease, color var(--dur-fast) ease;
}

.btn-primary {
  background-color: var(--kinetic-green);
  border-color: var(--kinetic-green);
  color: var(--deep-space-blue);
}

.btn-primary:hover {
  background-color: #2ce8b2;
  border-color: #2ce8b2;
  color: var(--deep-space-blue);
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(0, 227, 154, 0.3);
}

.btn-secondary {
  background-color: transparent;
  border-color: rgba(0, 227, 154, 0.5);
  color: var(--kinetic-green);
}

.btn-secondary:hover {
  background-color: rgba(0, 227, 154, 0.08);
  border-color: var(--kinetic-green);
  color: var(--kinetic-green);
  transform: translateY(-2px);
}

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

.btn--sm {
  padding: 0.55em 1.1em;
  font-size: 0.8rem;
}

/* 5. 卡片、标签与数据组件
   ========================================================================== */

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  padding: clamp(1.35rem, 3vw, 2rem);
  background: linear-gradient(160deg, rgba(20, 44, 67, 0.82), rgba(11, 27, 42, 0.94));
  border: 1px solid var(--line);
  transition: transform var(--dur) var(--ease-out), border-color var(--dur) ease, box-shadow var(--dur) ease;
}

.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 0;
  background: var(--kinetic-green);
  transition: height var(--dur) var(--ease-out);
}

.card:hover {
  transform: translateY(-4px);
  border-color: rgba(0, 227, 154, 0.45);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.3), 0 0 16px rgba(0, 227, 154, 0.07);
}

.card:hover::before {
  height: 100%;
}

.card__title {
  font-size: 1.05rem;
  margin-bottom: 0;
}

.card__text {
  color: var(--text-secondary);
  font-size: 0.92rem;
  margin-bottom: 0;
}

.card__meta {
  margin-top: auto;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.45em;
  padding: 0.3em 0.95em;
  border: 1px solid var(--line-green);
  background-color: rgba(0, 227, 154, 0.06);
  color: var(--kinetic-green);
  font-family: var(--font-data);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  border-radius: 999px;
  white-space: nowrap;
}

.tag--orange {
  border-color: var(--line-orange);
  background-color: rgba(255, 122, 47, 0.07);
  color: var(--voltage-orange);
}

.tag--muted {
  border-color: var(--line);
  background-color: transparent;
  color: var(--text-secondary);
}

.data-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.72rem 0;
  border-bottom: 1px dashed rgba(125, 138, 150, 0.3);
}

.data-row:last-of-type {
  border-bottom: 0;
}

.data-row__label {
  font-family: var(--font-data);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.data-row__value {
  font-family: var(--font-data);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text);
}

.data-row__value--accent { color: var(--kinetic-green); }
.data-row__value--warn { color: var(--voltage-orange); }

.stat {
  display: grid;
  gap: 0.35rem;
}

.stat__value {
  font-family: var(--font-data);
  font-size: clamp(1.9rem, 4vw, 3rem);
  font-weight: 700;
  line-height: 1.1;
  color: var(--kinetic-green);
}

.stat__value--orange {
  color: var(--voltage-orange);
}

.stat__label {
  font-size: 0.8rem;
  letter-spacing: 0.14em;
  color: var(--text-muted);
}

.steps {
  display: grid;
  gap: 1.5rem;
  margin: 0;
  padding: 0;
}

.step {
  position: relative;
  display: flex;
  gap: 1rem;
  padding: 1.25rem 1rem 1.25rem 1.5rem;
  background: rgba(20, 44, 67, 0.45);
  border: 1px solid var(--line);
  border-left: 3px solid var(--kinetic-green);
}

.step__num {
  font-family: var(--font-data);
  font-size: 0.78rem;
  color: var(--voltage-orange);
  letter-spacing: 0.12em;
  line-height: 1.6;
  flex: none;
}

.step__title {
  margin-bottom: 0.3rem;
  font-size: 1.02rem;
}

.step__text {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin: 0;
}

.table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-data);
  font-size: 0.84rem;
}

.table caption {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-align: left;
  margin-bottom: 0.5rem;
}

.table th,
.table td {
  padding: 0.7rem 0.9rem;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.table thead th {
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--kinetic-green);
  background: rgba(0, 227, 154, 0.04);
}

.table-striped tbody tr:nth-child(even) {
  background: rgba(20, 44, 67, 0.35);
}

/* 6. 框景、速度线与图片容器
   ========================================================================== */

.hero-frame {
  position: relative;
  padding: clamp(1.75rem, 5vw, 3.5rem);
  background:
    radial-gradient(540px 240px at 92% 0%, rgba(0, 227, 154, 0.12), transparent 60%),
    radial-gradient(420px 200px at 0% 100%, rgba(255, 122, 47, 0.08), transparent 58%),
    linear-gradient(150deg, rgba(20, 44, 67, 0.94), rgba(11, 27, 42, 0.98));
  border: 1px solid rgba(0, 227, 154, 0.22);
  box-shadow: var(--shadow-deep);
  overflow: hidden;
}

.hero-frame::before,
.hero-frame::after {
  content: "";
  position: absolute;
  width: 44px;
  height: 44px;
  pointer-events: none;
}

.hero-frame::before {
  top: 10px;
  left: 10px;
  border-top: 2px solid var(--kinetic-green);
  border-left: 2px solid var(--kinetic-green);
}

.hero-frame::after {
  bottom: 10px;
  right: 10px;
  border-bottom: 2px solid var(--voltage-orange);
  border-right: 2px solid var(--voltage-orange);
}

.frame-panel {
  position: relative;
  padding: clamp(1.25rem, 3vw, 2rem);
  background: rgba(11, 27, 42, 0.6);
  border: 1px solid var(--line);
  border-left: 3px solid var(--kinetic-green);
}

.speed-line {
  position: relative;
  height: 2px;
  margin-block: 1.5rem;
  background: linear-gradient(90deg, transparent, rgba(0, 227, 154, 0.35), rgba(255, 122, 47, 0.32), transparent);
  overflow: hidden;
}

.speed-line::after {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: -30%;
  width: 30%;
  background: linear-gradient(90deg, transparent, rgba(245, 240, 232, 0.8), transparent);
  animation: speed-scan 2.8s ease-in-out infinite;
}

@keyframes speed-scan {
  0% { transform: translateX(0); }
  60%, 100% { transform: translateX(430%); }
}

.speed-lines {
  position: relative;
  overflow: hidden;
}

.speed-lines::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background-image:
    repeating-linear-gradient(117deg, rgba(0, 227, 154, 0.05) 0 1px, transparent 1px 46px),
    repeating-linear-gradient(63deg, rgba(125, 138, 150, 0.05) 0 1px, transparent 1px 72px);
  pointer-events: none;
}

.media-frame {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, var(--nebula-navy), var(--deep-space-blue));
  border: 1px solid var(--line);
  aspect-ratio: 16 / 9;
}

.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* 7. 面包屑
   ========================================================================== */

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0 0 1.5rem;
  padding: 0;
  font-family: var(--font-data);
  font-size: 0.76rem;
  letter-spacing: 0.02em;
}

.breadcrumbs li {
  display: inline-flex;
  align-items: center;
}

.breadcrumbs li + li::before {
  content: "/";
  margin-right: 0.5rem;
  color: rgba(125, 138, 150, 0.6);
}

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

.breadcrumbs a:hover {
  color: var(--kinetic-green);
}

.breadcrumbs [aria-current="page"] {
  color: var(--kinetic-green);
}

/* 8. 折叠问答
   ========================================================================== */

.collapsible {
  border-bottom: 1px solid var(--line);
}

.collapsible__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem;
  width: 100%;
  padding: 1.15rem 0.15rem;
  background: none;
  border: 0;
  color: var(--text);
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.5;
  text-align: left;
  cursor: pointer;
  transition: color var(--dur-fast) ease;
}

.collapsible__trigger:hover {
  color: var(--kinetic-green);
}

.collapsible__trigger::after {
  content: "";
  flex: none;
  width: 9px;
  height: 9px;
  border-right: 2px solid var(--kinetic-green);
  border-bottom: 2px solid var(--kinetic-green);
  transform: translateY(-2px) rotate(45deg);
  transition: transform var(--dur) var(--ease-out);
}

.collapsible__trigger[aria-expanded="true"]::after {
  transform: translateY(0) rotate(225deg);
}

.collapsible__panel {
  max-width: 68ch;
  padding: 0 0.15rem 1.2rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.8;
}

/* 9. 滚动显现
   ========================================================================== */

html.js [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity var(--dur-slow) var(--ease-out), transform var(--dur-slow) var(--ease-out);
  transition-delay: var(--reveal-delay, 0ms);
}

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

/* 10. 无障碍与辅助工具
   ========================================================================== */

.skip-link {
  position: fixed;
  top: -100px;
  left: clamp(16px, 3vw, 40px);
  z-index: 1200;
  padding: 0.7rem 1.3rem;
  background: var(--kinetic-green);
  color: var(--deep-space-blue);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.85rem;
  border-radius: 3px;
  box-shadow: 0 8px 24px rgba(0, 227, 154, 0.3);
  transition: top var(--dur) var(--ease-out);
}

.skip-link:focus {
  top: 12px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

:focus-visible {
  outline: 2px solid var(--kinetic-green);
  outline-offset: 3px;
  border-radius: 2px;
}

/* 11. 头部
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: linear-gradient(180deg, rgba(11, 27, 42, 0.98), rgba(12, 25, 40, 0.95));
  border-bottom: 1px solid rgba(0, 227, 154, 0.2);
  box-shadow: 0 6px 28px rgba(0, 0, 0, 0.32);
}

.header-ticker {
  background: var(--safety-footer);
  border-bottom: 1px solid rgba(0, 227, 154, 0.12);
  font-family: var(--font-data);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  padding-block: 7px;
}

.header-ticker__inner {
  display: flex;
  align-items: center;
  gap: 0.9rem;
}

.ticker-pulse {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--kinetic-green);
  box-shadow: 0 0 10px var(--kinetic-green);
  animation: pulse-dot 1.9s ease-in-out infinite;
  flex: none;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.3; transform: scale(0.72); }
}

.ticker-text {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.header-inner {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 28px);
  min-height: 74px;
  padding-block: 12px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.9rem;
  color: var(--text);
  text-decoration: none;
  flex: none;
}

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

.brand-mark {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--kinetic-green), #00b294);
  color: var(--deep-space-blue);
  font-family: var(--font-data);
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: 0.02em;
  position: relative;
  flex: none;
}

.brand-mark::after {
  content: "";
  position: absolute;
  right: -5px;
  bottom: -5px;
  width: 16px;
  height: 16px;
  border-right: 2px solid var(--voltage-orange);
  border-bottom: 2px solid var(--voltage-orange);
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.brand-name {
  display: block;
  font-size: 0.68rem;
  letter-spacing: 0.26em;
  color: var(--text-muted);
  line-height: 1.4;
}

.brand-logo {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.12rem;
  line-height: 1.25;
  letter-spacing: 0.01em;
  white-space: nowrap;
}

.brand-tagline {
  display: block;
  font-family: var(--font-data);
  font-size: 0.64rem;
  letter-spacing: 0.14em;
  color: var(--kinetic-green);
  line-height: 1.4;
}

.main-nav {
  margin-inline-start: auto;
}

.main-nav-cta {
  display: none;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 0.15rem;
  margin: 0;
  padding: 0;
}

.nav-list__item {
  position: relative;
}

.nav-list a {
  display: inline-block;
  padding: 0.55rem 0.8rem;
  color: var(--text-secondary);
  font-size: 0.86rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  border-bottom: 2px solid transparent;
  transition: color var(--dur-fast) ease, border-color var(--dur-fast) ease;
}

.nav-list a:hover {
  color: var(--text);
}

.nav-list a[aria-current="page"] {
  color: var(--kinetic-green);
  border-bottom-color: var(--kinetic-green);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  flex: none;
}

.header-cta {
  flex: none;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 11px;
  background: transparent;
  border: 1px solid rgba(0, 227, 154, 0.35);
  border-radius: 4px;
  cursor: pointer;
  position: relative;
  z-index: 980;
  transition: border-color var(--dur-fast) ease, background-color var(--dur-fast) ease;
}

.nav-toggle:hover {
  border-color: var(--kinetic-green);
  background: rgba(0, 227, 154, 0.06);
}

.nav-toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--kinetic-green);
  transition: transform var(--dur) var(--ease-out), opacity var(--dur-fast) ease;
}

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

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

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

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.nav-overlay {
  position: fixed;
  inset: 0;
  z-index: 940;
  background: rgba(5, 12, 19, 0.76);
  backdrop-filter: blur(3px);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity var(--dur) ease, visibility 0s linear var(--dur);
}

.nav-overlay[data-open] {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transition: opacity var(--dur) ease, visibility 0s;
}

/* 12. 页脚
   ========================================================================== */

.site-footer {
  position: relative;
  margin-top: auto;
  background:
    radial-gradient(720px 260px at 100% 0%, rgba(0, 227, 154, 0.05), transparent 60%),
    var(--safety-footer);
  color: var(--text-muted);
  border-top: 1px solid rgba(0, 227, 154, 0.18);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent 0%, var(--kinetic-green) 24%, var(--voltage-orange) 58%, transparent 100%);
  opacity: 0.55;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.5fr 0.8fr 0.8fr 1.3fr;
  gap: clamp(1.5rem, 4vw, 3.5rem);
  padding-block: clamp(2.5rem, 6vw, 4.5rem);
}

.footer-brand {
  display: grid;
  gap: 0.9rem;
  align-content: start;
}

.footer-links {
  display: grid;
  align-content: start;
}

.footer-contact {
  display: grid;
  align-content: start;
}

.footer-list {
  display: grid;
  gap: 0.55rem;
  margin: 0;
  padding: 0;
}

.footer-list a {
  color: var(--text-muted);
  font-size: 0.9rem;
  transition: color var(--dur-fast) ease;
}

.footer-list a:hover {
  color: var(--kinetic-green);
}

.footer-heading {
  margin-bottom: 1rem;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text);
}

.footer-tagline {
  font-family: var(--font-data);
  font-size: 0.74rem;
  letter-spacing: 0.14em;
  color: var(--kinetic-green);
}

.footer-trust {
  font-size: 0.86rem;
  line-height: 1.75;
  color: var(--text-muted);
  max-width: 44ch;
}

.footer-contact__item {
  display: grid;
  gap: 0.12rem;
  margin-bottom: 0.85rem;
}

.footer-contact__label {
  font-family: var(--font-data);
  font-size: 0.62rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(125, 138, 150, 0.72);
}

.footer-contact__value {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.footer-bottom {
  border-top: 1px solid rgba(245, 240, 232, 0.08);
  padding-block: 1.15rem;
}

.footer-bottom-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
}

.footer-copy,
.footer-icp {
  margin: 0;
  font-size: 0.76rem;
  color: rgba(125, 138, 150, 0.85);
}

.footer-icp {
  letter-spacing: 0.04em;
}

/* 13. 响应式
   ========================================================================== */

@media (max-width: 1080px) {
  .grid-3 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .grid-4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 920px) {
  .header-cta {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .main-nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    z-index: 960;
    width: min(78vw, 340px);
    margin: 0;
    padding: clamp(5rem, 14vw, 6.5rem) 1.8rem 2.5rem;
    background: linear-gradient(180deg, rgba(11, 27, 42, 0.99), #0d1d2c);
    border-left: 1px solid rgba(0, 227, 154, 0.25);
    box-shadow: -18px 0 46px rgba(0, 0, 0, 0.38);
    transform: translateX(105%);
    visibility: hidden;
    transition: transform var(--dur) var(--ease-out), visibility 0s linear var(--dur);
    overflow-y: auto;
  }

  .main-nav[data-open] {
    transform: translateX(0);
    visibility: visible;
    transition: transform var(--dur) var(--ease-out), visibility 0s;
  }

  .main-nav-cta {
    display: block;
    margin-top: 1.6rem;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0.3rem;
  }

  .nav-list a {
    display: flex;
    align-items: center;
    min-height: 48px;
    padding: 0.7rem 0.9rem;
    font-size: 1rem;
    border-bottom: 1px solid var(--line);
    border-left: 3px solid transparent;
  }

  .nav-list a[aria-current="page"] {
    border-left-color: var(--kinetic-green);
    border-bottom-color: var(--line);
    background: rgba(0, 227, 154, 0.06);
  }

  .footer-inner {
    grid-template-columns: 1fr 1fr;
  }
}

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

  .brand-logo {
    font-size: 1rem;
  }

  .brand-mark {
    width: 42px;
    height: 42px;
    font-size: 1rem;
  }

  .header-ticker {
    display: none;
  }

  .footer-inner {
    grid-template-columns: 1fr;
  }

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
}

/* 14. 动态偏好与降级
   ========================================================================== */

@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;
    transition-delay: 0ms !important;
  }
}