/* 幻火翼Code 官网 — 设计系统与全站样式
   双主题：浅色为默认，[data-theme="dark"] 切深色；火焰橙金主色 + 科技青点缀 */

:root {
  color-scheme: light;

  --bg: #ffffff;
  --bg-alt: #f5f7fb;
  --bg-elev: rgba(255, 255, 255, 0.82);

  --surface: rgba(15, 23, 42, 0.035);
  --surface-hover: rgba(15, 23, 42, 0.06);

  --border: rgba(15, 23, 42, 0.10);
  --border-strong: rgba(15, 23, 42, 0.18);
  --hover-border: rgba(15, 23, 42, 0.28);
  --hover-border-strong: rgba(15, 23, 42, 0.34);

  --text: #0f172a;
  --muted: #5a6b85;
  --dim: #6b7280;

  --flame-1: #c2410c;
  --flame-2: #b45309;
  --cyan: #0e7490;
  --info: #2563eb;
  --on-flame: #ffffff;

  --grad-flame: linear-gradient(135deg, var(--flame-1), var(--flame-2));
  --grad-flame-soft: linear-gradient(135deg, rgba(194, 65, 12, 0.12), rgba(180, 83, 9, 0.06));

  /* 火色/青色底纹与描边：浅底上取更深的一档，避免发灰发脏 */
  --flame-tint: rgba(194, 65, 12, 0.08);
  --flame-line: rgba(194, 65, 12, 0.26);
  --flame-line-strong: rgba(194, 65, 12, 0.32);
  --flame-ring: rgba(194, 65, 12, 0.26);
  --flame-ring-soft: rgba(194, 65, 12, 0.14);
  --flame-wash: rgba(194, 65, 12, 0.09);
  --cyan-tint: rgba(14, 116, 144, 0.09);
  --cyan-line: rgba(14, 116, 144, 0.26);

  --grid-line: rgba(15, 23, 42, 0.045);
  --sheen: rgba(15, 23, 42, 0.035);

  --glow-warm: rgba(255, 122, 24, 0.10);
  --glow-cool: rgba(14, 116, 144, 0.07);
  --glow-info: rgba(37, 99, 235, 0.06);

  --overlay: rgba(15, 23, 42, 0.78);
  --panel-bg: rgba(255, 255, 255, 0.86);
  --menu-bg: rgba(255, 255, 255, 0.98);
  --menu-shadow: 0 24px 40px -28px rgba(15, 23, 42, 0.28);
  --footer-bg: rgba(245, 247, 251, 0.75);

  --shot-border: rgba(15, 23, 42, 0.14);
  --shot-shadow: 0 8px 20px -14px rgba(15, 23, 42, 0.35);

  --brand-glow: 0 6px 18px -10px rgba(194, 65, 12, 0.5);

  --radius-sm: 10px;
  --radius: 16px;
  --radius-lg: 24px;

  --shadow: 0 20px 44px -28px rgba(15, 23, 42, 0.28);
  --shadow-flame: 0 12px 30px -14px rgba(194, 65, 12, 0.45);
  --shadow-flame-hover: 0 18px 38px -16px rgba(194, 65, 12, 0.5);
  --shadow-feature: 0 26px 62px -40px rgba(194, 65, 12, 0.6);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    "Liberation Mono", monospace;

  --maxw: 1200px;
  --header-h: 68px;
}

/* 深色令牌。除深色主题外，还供三处恒为深色的场景复用：
   首页 Hero 的 promo-hero.webp 是深色影像，截图灯箱是覆盖式深底，
   以及浮在 Hero 影像上的固定头部（未滚动、未展开移动菜单时）。
   这几种场景下只有深色令牌能保证白字可读，不随主题切换。 */
[data-theme="dark"],
.hero,
.lightbox,
body:has(.hero) .site-header:not(.is-scrolled):not(:has(.nav-links.is-open)) {
  color-scheme: dark;

  /* body 上的 color 已按浅色墨色解析并向下继承，深色场景需要重新植回 */
  color: var(--text);

  --bg: #070a12;
  --bg-alt: #0b1020;
  --bg-elev: rgba(9, 13, 24, 0.72);

  --surface: rgba(255, 255, 255, 0.045);
  --surface-hover: rgba(255, 255, 255, 0.075);

  --border: rgba(255, 255, 255, 0.10);
  --border-strong: rgba(255, 255, 255, 0.18);
  --hover-border: rgba(255, 255, 255, 0.28);
  --hover-border-strong: rgba(255, 255, 255, 0.34);

  --text: #e9edf6;
  --muted: #9aa5bb;
  --dim: #7b86a0;

  --flame-1: #ff7a18;
  --flame-2: #ffb020;
  --cyan: #22d3ee;
  --info: #1677ff;
  --on-flame: #1b0d00;

  --grad-flame: linear-gradient(135deg, var(--flame-1), var(--flame-2));
  --grad-flame-soft: linear-gradient(135deg, rgba(255, 122, 24, 0.20), rgba(255, 176, 32, 0.10));

  --flame-tint: rgba(255, 122, 24, 0.10);
  --flame-line: rgba(255, 140, 32, 0.28);
  --flame-line-strong: rgba(255, 140, 32, 0.34);
  --flame-ring: rgba(255, 140, 32, 0.30);
  --flame-ring-soft: rgba(255, 140, 32, 0.15);
  --flame-wash: rgba(255, 122, 24, 0.20);
  --cyan-tint: rgba(34, 211, 238, 0.10);
  --cyan-line: rgba(34, 211, 238, 0.28);

  --grid-line: rgba(255, 255, 255, 0.030);
  --sheen: rgba(255, 255, 255, 0.07);

  --glow-warm: rgba(255, 122, 24, 0.16);
  --glow-cool: rgba(34, 211, 238, 0.10);
  --glow-info: rgba(22, 119, 255, 0.10);

  --overlay: rgba(4, 6, 12, 0.88);
  --panel-bg: rgba(9, 13, 24, 0.82);
  --menu-bg: rgba(8, 11, 20, 0.97);
  --menu-shadow: 0 24px 40px -24px rgba(0, 0, 0, 0.9);
  --footer-bg: rgba(8, 11, 20, 0.62);

  --shot-border: rgba(255, 255, 255, 0.10);
  --shot-shadow: none;

  --brand-glow: 0 8px 20px -10px rgba(255, 140, 32, 0.8);

  --shadow: 0 22px 60px -26px rgba(0, 0, 0, 0.85);
  --shadow-flame: 0 12px 34px -14px rgba(255, 140, 32, 0.7);
  --shadow-flame-hover: 0 18px 44px -16px rgba(255, 140, 32, 0.95);
  --shadow-feature: 0 26px 62px -38px rgba(255, 140, 32, 0.95);
}

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

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

body {
  margin: 0;
  min-height: 100%;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* 全局背景：深空底色 + 主题辉光 + 网格线 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
  background:
    radial-gradient(900px 520px at 12% -8%, var(--glow-warm), transparent 62%),
    radial-gradient(820px 520px at 92% -4%, var(--glow-cool), transparent 58%),
    radial-gradient(1000px 700px at 50% 120%, var(--glow-info), transparent 60%),
    var(--bg);
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: radial-gradient(120% 90% at 50% 0%, #000 0%, transparent 78%);
  mask-image: radial-gradient(120% 90% at 50% 0%, #000 0%, transparent 78%);
}

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

[hidden] {
  display: none !important;
}

a {
  color: var(--flame-2);
}

h1,
h2,
h3,
h4 {
  line-height: 1.2;
  margin: 0;
  font-weight: 700;
  letter-spacing: -0.01em;
}

p {
  margin: 0;
}

:focus-visible {
  outline: 2px solid var(--flame-2);
  outline-offset: 3px;
  border-radius: 6px;
}

/* ---- 工具类 ---- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: 24px;
}

.narrow {
  max-width: 860px;
}

.mono {
  font-family: var(--font-mono);
}

.text-flame {
  background: var(--grad-flame);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.skip-link {
  position: absolute;
  top: -70px;
  left: 20px;
  z-index: 100;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  background: var(--flame-2);
  color: var(--on-flame);
  font-weight: 700;
  text-decoration: none;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 14px;
}

/* ---- 顶部导航 ---- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  height: var(--header-h);
  display: flex;
  align-items: center;
  border-bottom: 1px solid transparent;
  transition: background 0.25s ease, border-color 0.25s ease, backdrop-filter 0.25s ease;
}

.site-header.is-scrolled {
  background: var(--bg-elev);
  border-bottom-color: var(--border);
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
}

.site-header:has(.nav-links.is-open) {
  background: var(--bg-elev);
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
}

.nav {
  display: flex;
  align-items: center;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
  color: var(--text);
  font-weight: 700;
  flex: none;
}

.brand img {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  box-shadow: 0 0 0 1px var(--border), var(--brand-glow);
}

.brand__name {
  font-size: 18px;
  letter-spacing: 0.01em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
  margin: 0 0 0 auto;
  padding: 0;
}

.nav-links a {
  display: inline-block;
  padding: 9px 15px;
  border-radius: var(--radius-sm);
  color: var(--muted);
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
  transition: color 0.2s ease, background 0.2s ease;
}

.nav-links a:hover {
  color: var(--text);
  background: var(--surface);
}

.nav-links a.is-active {
  color: var(--text);
  font-weight: 600;
  background: var(--grad-flame-soft);
  box-shadow: inset 0 0 0 1px var(--flame-ring);
}

.nav-toggle {
  display: none;
  margin-left: auto;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  cursor: pointer;
  transition: background 0.2s ease;
}

.nav-toggle:hover {
  background: var(--surface-hover);
}

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 12px;
}

.nav-toggle__bars span {
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.25s ease, opacity 0.2s ease;
}

.nav-toggle__bars span:nth-child(1) {
  top: 0;
}

.nav-toggle__bars span:nth-child(2) {
  top: 5px;
}

.nav-toggle__bars span:nth-child(3) {
  top: 10px;
}

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

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

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) {
  transform: translateY(-5px) rotate(-45deg);
}

/* ---- 主题切换 ---- */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  padding: 0;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  transition: color 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

.theme-toggle:hover {
  color: var(--text);
  background: var(--surface);
  border-color: var(--border);
}

.theme-toggle svg {
  width: 18px;
  height: 18px;
}

/* 图标指「将要切换到的主题」：浅色下给月亮，深色下给太阳 */
.theme-toggle__icon--sun {
  display: none;
}

:root[data-theme="dark"] .theme-toggle__icon--moon {
  display: none;
}

:root[data-theme="dark"] .theme-toggle__icon--sun {
  display: block;
}

/* ---- 版块通用 ---- */
.section {
  position: relative;
  padding: clamp(64px, 7vw, 108px) 0;
}

.section--tight {
  padding-top: clamp(40px, 4vw, 64px);
}

.section-head {
  max-width: 720px;
  margin: 0 auto clamp(36px, 4.5vw, 60px);
  text-align: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--flame-2);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--flame-2));
}

.section-head h2 {
  font-size: clamp(26px, 3.3vw, 38px);
  margin: 14px 0 16px;
}

.section-head p {
  color: var(--muted);
  font-size: 16px;
  line-height: 1.75;
}

/* ---- 按钮 ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 26px;
  border-radius: 12px;
  border: 1px solid transparent;
  font-family: inherit;
  font-size: 15px;
  font-weight: 600;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  white-space: nowrap;
  transition: transform 0.16s ease, box-shadow 0.25s ease, background 0.25s ease,
    border-color 0.25s ease;
}

.btn svg {
  width: 18px;
  height: 18px;
  flex: none;
}

.btn--primary {
  background: var(--grad-flame);
  color: var(--on-flame);
  box-shadow: var(--shadow-flame);
}

.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-flame-hover);
}

.btn--ghost {
  background: var(--surface);
  border-color: var(--border-strong);
  color: var(--text);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.btn--ghost:hover {
  background: var(--surface-hover);
  border-color: var(--hover-border);
}

.btn[aria-disabled="true"],
.btn.is-disabled {
  background: var(--surface);
  border-color: var(--border);
  color: var(--dim);
  opacity: 0.72;
  cursor: not-allowed;
  pointer-events: none;
  box-shadow: none;
}

/* ---- 玻璃卡片 ---- */
.card {
  position: relative;
  padding: 26px 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  overflow: hidden;
  transition: transform 0.22s ease, border-color 0.22s ease, background 0.22s ease;
}

.card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(160deg, var(--sheen), transparent 46%);
  opacity: 0;
  transition: opacity 0.25s ease;
  pointer-events: none;
}

.card:hover {
  transform: translateY(-4px);
  border-color: var(--border-strong);
  background: var(--surface-hover);
}

.card:hover::before {
  opacity: 1;
}

.card__icon {
  width: 46px;
  height: 46px;
  margin-bottom: 18px;
  display: grid;
  place-items: center;
  border-radius: 13px;
  border: 1px solid var(--flame-line);
  background: var(--grad-flame-soft);
  color: var(--flame-2);
}

.card__icon svg {
  width: 22px;
  height: 22px;
}

.card h3 {
  font-size: 17px;
  margin-bottom: 9px;
}

.card p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

.cards {
  display: grid;
  gap: 20px;
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

/* 差异化能力：跨列大卡，火焰层级 */
.card--feature {
  grid-column: span 2;
  padding: 32px 30px;
  border-color: var(--flame-line-strong);
  background: radial-gradient(130% 150% at 0% 0%, var(--flame-wash), transparent 58%),
    var(--surface);
  box-shadow: var(--shadow-feature);
}

.card--feature::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--grad-flame);
  pointer-events: none;
}

.card--feature h3 {
  font-size: 20px;
}

.card--feature p {
  font-size: 15px;
}

/* 普通跨列卡：与火焰大卡同宽，用于让末行栅格填满 */
.card--wide {
  grid-column: span 2;
}

/* ---- Hero ---- */
.hero {
  position: relative;
  overflow: hidden;
  padding: calc(var(--header-h) + clamp(64px, 9vw, 116px)) 0 clamp(76px, 9vw, 128px);
}

.hero__media {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 24%;
  opacity: 0.52;
}

/* 影像自身是半透明的深色图：不垫不透明深底时，浅色主题下
   整条 Hero 会被白色页面透成灰雾，标题与正文失去对比 */
:root:not([data-theme="dark"]) .hero__media {
  background: #070a12;
}

/* 深色影像带与下方浅色版块之间用一条渐变收口，避免生硬直边 */
:root:not([data-theme="dark"]) .hero + .section::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 80px;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(7, 10, 18, 0.16), transparent);
}

.hero__media::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(56% 50% at 50% 48%, rgba(7, 10, 18, 0.94) 0%, rgba(7, 10, 18, 0.62) 52%, rgba(7, 10, 18, 0) 80%),
    linear-gradient(180deg, rgba(7, 10, 18, 0.88) 0%, rgba(7, 10, 18, 0.34) 32%, var(--bg) 96%);
}

.hero__inner {
  position: relative;
  z-index: 1;
  max-width: 840px;
  margin-inline: auto;
  text-align: center;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 7px 15px;
  border-radius: 999px;
  border: 1px solid var(--flame-line-strong);
  background: var(--flame-tint);
  color: var(--flame-2);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.05em;
}

.badge__dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--flame-2);
  box-shadow: 0 0 0 4px rgba(255, 176, 32, 0.18);
}

.hero h1 {
  font-size: clamp(38px, 6.6vw, 68px);
  line-height: 1.04;
  margin: 24px 0 18px;
  letter-spacing: -0.02em;
}

.hero__sub {
  font-size: clamp(17px, 2.1vw, 22px);
  font-weight: 600;
  color: var(--text);
  margin-bottom: 16px;
}

.hero__lead {
  max-width: 640px;
  margin: 0 auto 36px;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.8;
}

.hero__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  justify-content: center;
}

.hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 26px;
  justify-content: center;
  margin-top: 38px;
  color: var(--dim);
  font-family: var(--font-mono);
  font-size: 13px;
}

.hero__meta span {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.hero__meta span::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--cyan);
}

/* ---- 内页头部 ---- */
.page-hero {
  padding: calc(var(--header-h) + clamp(52px, 7vw, 88px)) 0 clamp(20px, 3vw, 34px);
  text-align: center;
}

.page-hero h1 {
  font-size: clamp(30px, 4.6vw, 46px);
  margin: 16px 0 18px;
  letter-spacing: -0.02em;
}

.page-hero p {
  max-width: 680px;
  margin-inline: auto;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
}

/* ---- 界面一览 ---- */
.viewport {
  display: grid;
  gap: clamp(28px, 4vw, 56px);
  grid-template-columns: minmax(0, 1fr) minmax(0, 2fr);
  align-items: center;
}

.viewport__copy h2 {
  font-size: clamp(26px, 3.3vw, 38px);
  margin: 14px 0 16px;
}

.viewport__copy > p {
  color: var(--muted);
  font-size: 16px;
  line-height: 1.75;
}

.viewport__list {
  display: grid;
  gap: 10px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.viewport__list li {
  position: relative;
  padding-left: 26px;
  color: var(--muted);
  font-size: 14.5px;
  line-height: 1.7;
}

.viewport__list li::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 0.62em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--flame-2);
}

.viewport__shot {
  display: block;
  width: 100%;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--surface);
  box-shadow: var(--shadow);
  cursor: zoom-in;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: transform 0.22s ease, border-color 0.22s ease, background 0.22s ease;
}

.viewport__shot:hover {
  transform: translateY(-4px);
  border-color: var(--border-strong);
  background: var(--surface-hover);
}

.viewport__shot img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 14px;
  border: 1px solid var(--shot-border);
  box-shadow: var(--shot-shadow);
}

/* ---- 截图放大查看 ---- */
body.is-locked {
  overflow: hidden;
}

.lightbox {
  position: fixed;
  inset: 0;
  z-index: 120;
  display: grid;
  place-items: center;
  padding: clamp(48px, 6vw, 76px) clamp(16px, 4vw, 48px);
}

.lightbox__backdrop {
  position: absolute;
  inset: 0;
  background: var(--overlay);
  backdrop-filter: blur(5px);
  -webkit-backdrop-filter: blur(5px);
}

.lightbox__dialog {
  position: relative;
  z-index: 1;
  display: grid;
  justify-items: center;
  gap: 14px;
  max-width: min(1180px, 100%);
  outline: none;
}

.lightbox__img {
  max-width: 100%;
  max-height: 74vh;
  width: auto;
  border-radius: 14px;
  border: 1px solid var(--border-strong);
  box-shadow: var(--shadow);
  background: var(--bg-alt);
}

.lightbox__close {
  position: fixed;
  z-index: 2;
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  padding: 0;
  border-radius: 50%;
  border: 1px solid var(--border-strong);
  background: var(--panel-bg);
  color: var(--text);
  cursor: pointer;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: background 0.2s ease, border-color 0.2s ease;
}

.lightbox__close svg {
  width: 20px;
  height: 20px;
}

.lightbox__close:hover {
  background: var(--surface-hover);
  border-color: var(--hover-border-strong);
}

.lightbox__close {
  top: clamp(14px, 3vw, 28px);
  right: clamp(14px, 3vw, 28px);
}

/* ---- 技术亮点 ---- */
.tech-grid {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.tech-item {
  padding: 22px 22px 20px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.tech-item__label {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--cyan);
  margin-bottom: 10px;
}

.tech-item h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

.tech-item p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

/* ---- 下载区 ---- */
.download {
  display: grid;
  gap: clamp(28px, 4vw, 52px);
  grid-template-columns: 1.05fr 1fr;
  align-items: center;
}

.download__media {
  position: relative;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--surface);
  padding: 12px;
  box-shadow: var(--shadow);
}

.download__media img {
  width: 100%;
  height: auto;
  border-radius: 14px;
}

/* 截图与配图是浅色界面，浅色主题下用描边 + 投影与白卡拉开层次 */
:root:not([data-theme="dark"]) .download__media img {
  border: 1px solid var(--shot-border);
  box-shadow: var(--shot-shadow);
}

.download__cards {
  display: grid;
  gap: 16px;
}

.dl-card {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 22px 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.dl-card__meta {
  display: grid;
  gap: 6px;
}

.dl-card__title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 17px;
  font-weight: 700;
}

.dl-card__title svg {
  width: 20px;
  height: 20px;
  color: var(--flame-2);
}

.dl-card__info {
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 13px;
}

.dl-card--soon {
  opacity: 0.62;
}

.dl-card--soon .dl-card__title svg {
  color: var(--muted);
}

.note {
  margin-top: 22px;
  color: var(--dim);
  font-size: 13px;
  line-height: 1.7;
}

/* ---- 特性页：模块 ---- */
.module + .module {
  margin-top: clamp(56px, 7vw, 96px);
}

.module-head {
  display: flex;
  gap: 20px;
  align-items: flex-start;
  max-width: 800px;
}

.module-icon {
  flex: none;
  width: 54px;
  height: 54px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  border: 1px solid var(--flame-line);
  background: var(--grad-flame-soft);
  color: var(--flame-2);
}

.module-icon svg {
  width: 26px;
  height: 26px;
}

.module-head h2 {
  font-size: clamp(22px, 2.8vw, 30px);
  margin: 9px 0 12px;
}

.module-head p {
  color: var(--muted);
  font-size: 15px;
  line-height: 1.8;
}

.points {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 30px;
}

.point {
  padding: 22px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.point__icon {
  width: 40px;
  height: 40px;
  margin-bottom: 14px;
  display: grid;
  place-items: center;
  border-radius: 11px;
  border: 1px solid var(--cyan-line);
  background: var(--cyan-tint);
  color: var(--cyan);
}

.point__icon svg {
  width: 20px;
  height: 20px;
}

.point h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

.point p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

.module-shot {
  margin: 28px 0 0;
  padding: 12px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--surface);
  box-shadow: var(--shadow);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.module-shot img {
  width: 100%;
  height: auto;
  border-radius: 14px;
  border: 1px solid var(--shot-border);
  box-shadow: var(--shot-shadow);
}

.module-shot figcaption {
  margin-top: 14px;
  padding: 0 6px 4px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
  text-align: center;
}

/* ---- 特性页：模块锚点导航 ---- */
.module {
  scroll-margin-top: calc(var(--header-h) + 84px);
}

.anchors {
  position: sticky;
  top: var(--header-h);
  z-index: 40;
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
  background: var(--bg-elev);
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
}

.anchors__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.anchors__list a {
  display: inline-block;
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--muted);
  font-size: 13.5px;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

.anchors__list a:hover {
  color: var(--text);
  background: var(--surface-hover);
  border-color: var(--border-strong);
}

/* ---- 特性页：交互示例 ---- */
.exchange {
  margin: 28px 0 0;
  padding: 24px 26px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.exchange__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 14px;
  margin-bottom: 18px;
}

.exchange__note {
  color: var(--dim);
  font-size: 12.5px;
}

.exchange__turn,
.exchange__result {
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.exchange__role {
  flex: none;
  padding: 3px 10px;
  border-radius: 999px;
  border: 1px solid var(--border-strong);
  background: var(--surface);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.5;
}

.exchange__text {
  margin: 0;
  color: var(--text);
  font-size: 15px;
  line-height: 1.7;
}

.exchange__flow {
  display: grid;
  gap: 8px;
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 13px;
}

.exchange__flow li {
  position: relative;
  padding-left: 20px;
  line-height: 1.7;
}

.exchange__flow li::before {
  content: "·";
  position: absolute;
  left: 6px;
  color: var(--flame-2);
}

.exchange__flow code {
  color: var(--flame-2);
}

.exchange__result {
  margin: 16px 0 0;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

/* ---- 回到顶部 ---- */
.to-top {
  position: fixed;
  right: clamp(16px, 2.5vw, 28px);
  bottom: clamp(16px, 2.5vw, 28px);
  z-index: 40;
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  padding: 0;
  border-radius: 50%;
  border: 1px solid var(--border-strong);
  background: var(--panel-bg);
  color: var(--text);
  cursor: pointer;
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: background 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.to-top:hover {
  background: var(--surface-hover);
  border-color: var(--hover-border-strong);
  transform: translateY(-2px);
}

.to-top svg {
  width: 20px;
  height: 20px;
}

/* ---- 行动号召 ---- */
.cta {
  text-align: center;
  padding: clamp(34px, 4.5vw, 52px) clamp(24px, 4vw, 40px);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--surface);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.cta h2 {
  font-size: clamp(20px, 2.6vw, 28px);
  margin-bottom: 12px;
}

.cta p {
  max-width: 520px;
  margin: 0 auto 26px;
  color: var(--muted);
  line-height: 1.8;
}

.cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  justify-content: center;
}

.ticks {
  list-style: none;
  padding: 0;
  margin: 20px 0 0;
  display: grid;
  gap: 11px;
}

.ticks li {
  position: relative;
  padding-left: 28px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.65;
}

.ticks li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--grad-flame-soft);
  border: 1px solid var(--flame-line-strong);
}

.ticks li::after {
  content: "";
  position: absolute;
  left: 5px;
  top: 11px;
  width: 6px;
  height: 3px;
  border-left: 1.6px solid var(--flame-2);
  border-bottom: 1.6px solid var(--flame-2);
  transform: rotate(-45deg);
}

/* ---- 版本变更 ---- */
.release {
  position: relative;
  padding-left: 30px;
  border-left: 2px solid var(--border);
}

.release::before {
  content: "";
  position: absolute;
  left: -8px;
  top: 6px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--grad-flame);
  box-shadow: 0 0 0 4px var(--flame-ring-soft);
}

.release__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 8px;
}

.release__ver {
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 700;
}

.release__date {
  color: var(--dim);
  font-family: var(--font-mono);
  font-size: 13px;
}

.release__tag {
  padding: 3px 11px;
  border-radius: 999px;
  border: 1px solid var(--flame-line-strong);
  background: var(--flame-tint);
  color: var(--flame-2);
  font-family: var(--font-mono);
  font-size: 12px;
}

.release__list {
  list-style: none;
  padding: 0;
  margin: 16px 0 0;
  display: grid;
  gap: 10px;
}

.release__list li {
  position: relative;
  padding-left: 20px;
  color: var(--muted);
  font-size: 15px;
}

.release__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
}

/* ---- 关于 / 联系 ---- */
.about-grid {
  display: grid;
  gap: 20px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.about-intro {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
  grid-template-columns: 1.3fr 1fr;
  align-items: start;
}

.about-intro__text p + p {
  margin-top: 16px;
}

.about-intro__text p {
  color: var(--muted);
  line-height: 1.85;
}

.contact-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 14px;
}

.contact-list li {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--muted);
  font-size: 15px;
}

.contact-list a {
  color: var(--text);
  text-decoration: none;
  border-bottom: 1px dashed var(--border-strong);
}

.contact-list a:hover {
  color: var(--flame-2);
}

.contact-list svg {
  width: 18px;
  height: 18px;
  color: var(--flame-2);
  flex: none;
}

/* ---- 上手步骤 / 系统要求 ---- */
.steps {
  display: grid;
  gap: 20px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin: 0;
  padding: 0;
  list-style: none;
}

.step {
  padding: 26px 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.step__num {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  margin-bottom: 16px;
  border-radius: 12px;
  border: 1px solid var(--flame-line);
  background: var(--grad-flame-soft);
  color: var(--flame-2);
  font-family: var(--font-mono);
  font-size: 17px;
  font-weight: 700;
}

.step h3 {
  margin-bottom: 9px;
  font-size: 17px;
}

.step p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

.requirements {
  margin-top: clamp(30px, 4vw, 46px);
  padding: 26px 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.requirements__title {
  margin-bottom: 16px;
  font-size: 15px;
}

.req-list {
  margin: 0;
}

.req {
  display: grid;
  grid-template-columns: 108px minmax(0, 1fr);
  gap: 18px;
  padding: 13px 0;
  border-top: 1px solid var(--border);
}

.req:first-child {
  padding-top: 0;
  border-top: 0;
}

.req:last-child {
  padding-bottom: 0;
}

.req dt {
  color: var(--flame-2);
  font-family: var(--font-mono);
  font-size: 13px;
}

.req dd {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.7;
}

/* ---- 常见问题 ---- */
.faq {
  display: grid;
  gap: 12px;
}

.faq__item {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: border-color 0.2s ease, background 0.2s ease;
}

.faq__item[open] {
  border-color: var(--border-strong);
  background: var(--surface-hover);
}

.faq__item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 22px;
  color: var(--text);
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

.faq__item summary::-webkit-details-marker {
  display: none;
}

.faq__item summary::after {
  content: "+";
  flex: none;
  color: var(--flame-2);
  font-family: var(--font-mono);
  font-size: 20px;
  line-height: 1;
  transition: transform 0.2s ease;
}

.faq__item[open] summary::after {
  transform: rotate(45deg);
}

.faq__item p {
  padding: 0 22px 20px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.75;
}

.faq__item code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  color: var(--flame-2);
}

/* ---- 页脚 ---- */
.site-footer {
  margin-top: clamp(40px, 6vw, 80px);
  border-top: 1px solid var(--border);
  background: var(--footer-bg);
  padding: clamp(44px, 5vw, 64px) 0 28px;
}

.footer-grid {
  display: grid;
  gap: 34px;
  grid-template-columns: 1.5fr 1fr 1fr;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 11px;
  margin-bottom: 14px;
}

.footer-brand img {
  width: 30px;
  height: 30px;
  border-radius: 8px;
}

.footer-brand span {
  font-size: 17px;
  font-weight: 700;
}

.footer-desc {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
  max-width: 360px;
}

.footer-col h3 {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--dim);
  margin-bottom: 16px;
  font-weight: 600;
}

.footer-col ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 11px;
}

.footer-col a {
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
  transition: color 0.2s ease;
}

.footer-col a:hover {
  color: var(--flame-2);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px 24px;
  margin-top: clamp(32px, 4vw, 48px);
  padding-top: 22px;
  border-top: 1px solid var(--border);
  color: var(--dim);
  font-size: 13px;
}

.footer-bottom a {
  color: var(--dim);
  text-decoration: none;
}

.footer-bottom a:hover {
  color: var(--muted);
}

.footer-bottom p {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 18px;
}

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

.beian img {
  width: auto;
  height: 16px;
}

/* ---- 响应式 ---- */
@media (max-width: 1199px) {
  .cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (max-width: 900px) {
  .download,
  .about-intro,
  .viewport {
    grid-template-columns: 1fr;
  }

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

  .footer-grid > :first-child {
    grid-column: 1 / -1;
  }
}

@media (max-width: 560px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .footer-grid > :first-child {
    grid-column: auto;
  }
}

@media (max-width: 767px) {
  :root {
    --header-h: 62px;
  }

  .container {
    padding-inline: 20px;
  }

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

  .nav-links {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 6px;
    margin: 0;
    padding: 14px 20px 20px;
    background: var(--menu-bg);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    box-shadow: var(--menu-shadow);
    transform: translateY(-10px);
    opacity: 0;
    visibility: hidden;
    transition: transform 0.24s ease, opacity 0.24s ease, visibility 0.24s ease;
  }

  .nav-links.is-open {
    transform: none;
    opacity: 1;
    visibility: visible;
  }

  .nav-links a {
    padding: 14px 16px;
    font-size: 16px;
  }

  .theme-toggle {
    width: 44px;
    height: 44px;
    margin-top: 6px;
  }

  .cards,
  .tech-grid,
  .about-grid,
  .points,
  .steps {
    grid-template-columns: 1fr;
  }

  .card--feature,
  .card--wide {
    grid-column: auto;
  }

  .req {
    grid-template-columns: 1fr;
    gap: 5px;
  }

  .anchors__list {
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    padding-bottom: 2px;
  }

  .anchors__list::-webkit-scrollbar {
    display: none;
  }

  .exchange {
    padding: 20px 18px;
  }

  .module-head {
    gap: 14px;
  }

  .module-icon {
    width: 46px;
    height: 46px;
    border-radius: 13px;
  }

  .module-icon svg {
    width: 22px;
    height: 22px;
  }

  .hero__cta .btn {
    flex: 1 1 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    transition-duration: 0.001ms !important;
  }
}