/* ═══════════════════════════════════════════
   XUNSHE (迅蛇) — 深色黑红电竞主题
   主色板: 深黑 #0a0a0a | 电竞红 #ff0015 | 深灰卡 #1a1a26 | 亮白 #f0f0f5
   ═══════════════════════════════════════════ */

/* ── CSS 变量 ── */
:root {
  --bg-deep: #0a0a0a;
  --bg-card: #232325;
  --bg-card-hover: #2e2e2e;
  --bg-surface: #141414;
  --red-primary: #fc2436;
  --red-glow: rgba(255, 0, 21, 0.45);
  --red-dim: rgba(255, 0, 21, 0.18);
  --text-primary: #f0f0f5;
  --text-secondary: #bbbbbe;
  --text-muted: #7e7e80;
  --border-subtle: rgba(255, 255, 255, 0.06);
  --border-card: rgba(255, 255, 255, 0.08);
  --nav-bg: rgba(12, 12, 12, 0.72);
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 30px rgba(255, 0, 21, 0.3);
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --transition-fast: 0.2s ease;
  --transition-smooth: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  --font-cn: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
  --font-en: 'Rajdhani', 'Orbitron', 'Segoe UI', sans-serif;
  --max-width: 1280px;
  --nav-height: 70px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  color-scheme: dark;
}

body {
  font-family: var(--font-cn);
  background-color: var(--bg-deep);
  color: var(--text-primary);
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--red-primary);
}

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

ul, ol { list-style: none; }

button {
  cursor: pointer;
  border: none;
  font-family: inherit;
  font-size: inherit;
}

input, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

/* ── 滚动条 ── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-deep); }
::-webkit-scrollbar-thumb { background: #333; border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--red-primary); }

/* ═══════════════════════════════════════════
   顶部导航 — 滚动毛玻璃效果
   ═══════════════════════════════════════════ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  background: var(--nav-bg);
  backdrop-filter: blur(18px) saturate(140%);
  -webkit-backdrop-filter: blur(18px) saturate(140%);
  border-bottom: 1px solid var(--border-subtle);
  transition: all var(--transition-smooth);
  display: flex;
  align-items: center;
}

.navbar.scrolled {
  background: rgba(10, 10, 15, 0.92);
  border-bottom-color: rgba(255, 0, 21, 0.2);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.4);
}

.nav-inner {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-en);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
}

.nav-brand .brand-icon {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  font-weight: 900;
  color: #fff;
}

.nav-brand span {
  color: #fff;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
}

.nav-links a {
  display: block;
  padding: 8px 18px;
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: 20px;
  height: 2px;
  background: var(--red-primary);
  border-radius: 1px;
  transition: transform var(--transition-fast);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text-primary);
  background: rgba(255, 0, 21, 0.08);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  transform: translateX(-50%) scaleX(1);
}

/* 移动端汉堡菜单 */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all var(--transition-fast);
}

.nav-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* 语言切换 */
.lang-switch {
  display: flex;
  gap: 2px;
  margin-left: 12px;
  padding: 3px;
  background: var(--bg-card);
  border-radius: var(--radius-sm);
}

.lang-switch button {
  padding: 4px 10px;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-muted);
  background: transparent;
  border-radius: 4px;
  transition: all var(--transition-fast);
}

.lang-switch button.active {
  color: #fff;
  background: var(--red-primary);
}

.lang-switch button:hover:not(.active) {
  color: var(--text-secondary);
}

/* ═══════════════════════════════════════════
   页面容器
   ═══════════════════════════════════════════ */
.page-container {
  padding-top: var(--nav-height);
  min-height: 100vh;
}

.section {
  padding: 80px 24px;
}

.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

/* ═══════════════════════════════════════════
   标题样式
   ═══════════════════════════════════════════ */
.section-title {
  font-family: var(--font-en);
  font-size: 2.4rem;
  font-weight: 700;
  text-align: center;
  letter-spacing: 1px;
  margin-bottom: 12px;
}

.section-title .highlight {
  color: var(--red-primary);
}

.section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  font-size: 1rem;
  margin-bottom: 48px;
}

/* ═══════════════════════════════════════════
   按钮样式
   ═══════════════════════════════════════════ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  transition: all var(--transition-fast);
  letter-spacing: 0.5px;
}

.btn-primary {
  background: var(--red-primary);
  color: #fff;
  box-shadow: 0 4px 16px var(--red-glow);
}

.btn-primary:hover {
  background: #ff2222;
  box-shadow: 0 6px 24px rgba(255, 21, 41, 0.55);
  transform: translateY(-1px);
  color: #fff;
}

.btn-outline {
  background: transparent;
  color: var(--text-primary);
  border: 1.5px solid var(--border-card);
}

.btn-outline:hover {
  border-color: var(--red-primary);
  color: var(--red-primary);
  background: rgba(255, 0, 21, 0.06);
}

.btn-ghost {
  background: rgba(255,255,255,0.04);
  color: var(--text-secondary);
}

.btn-ghost:hover {
  background: rgba(255,255,255,0.08);
  color: var(--text-primary);
}

.btn-sm { padding: 8px 18px; font-size: 0.85rem; }
.btn-lg { padding: 16px 36px; font-size: 1.05rem; }

/* ═══════════════════════════════════════════
   SVG 图标 — 黑红配色
   ═══════════════════════════════════════════ */
.icon-svg {
  display: inline-block;
  width: 0.5em;
  height: 0.5em;
  vertical-align: middle;
  filter: brightness(0) saturate(100%) invert(1);
  opacity: 0.85;
  transition: filter var(--transition-fast), opacity var(--transition-fast);
}
.icon-svg-sm { width: 1em; height: 1em; }
.icon-svg-lg { width: 2em; height: 2em; }
.icon-svg-xl { width: 3em; height: 3em; }

/* 导航链接中图标 */
.nav-links a .icon-svg { margin-right: 4px; opacity: 0.6; }
.nav-links a:hover .icon-svg,
.nav-links a.active .icon-svg {
  opacity: 1;
  filter: brightness(0) saturate(100%) invert(17%) sepia(100%) saturate(7470%) hue-rotate(357deg);
}

/* 红色调图标（标题/重要区域） */
.icon-red {
  filter: brightness(0) saturate(100%) invert(17%) sepia(100%) saturate(7470%) hue-rotate(357deg) !important;
  opacity: 1 !important;
}

/* 白色调图标（深色按钮内） */
.icon-white {
  filter: brightness(0) invert(1) !important;
  opacity: 1 !important;
}

/* ═══════════════════════════════════════════
   卡片样式 — 悬停红色发光动画
   ═══════════════════════════════════════════ */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all var(--transition-smooth);
  position: relative;
}

.card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  opacity: 0;
  box-shadow: 0 0 30px var(--red-glow), inset 0 0 30px var(--red-dim);
  transition: opacity var(--transition-smooth);
  pointer-events: none;
  z-index: 1;
}

.card:hover {
  transform: translateY(-4px);
  border-color: rgba(255, 36, 54, 0.35);
  background: var(--bg-card-hover);
}

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

.card-body {
  padding: 24px;
  position: relative;
  z-index: 2;
}

/* ═══════════════════════════════════════════
   网格系统
   ═══════════════════════════════════════════ */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }

/* ═══════════════════════════════════════════
   页脚
   ═══════════════════════════════════════════ */
.footer {
  background: var(--bg-surface);
  border-top: 1px solid var(--border-subtle);
  padding: 48px 24px 24px;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
}

.footer-brand {
  font-family: var(--font-en);
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: 2px;
}

.footer-brand .brand-red {
  color: var(--red-primary);
}

.footer-desc {
  margin-top: 12px;
  color: var(--text-muted);
  font-size: 0.88rem;
  line-height: 1.6;
}

.footer-col h4 {
  font-size: 0.9rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 16px;
  color: var(--text-secondary);
}

.footer-col a {
  display: block;
  padding: 4px 0;
  color: var(--text-muted);
  font-size: 0.88rem;
  transition: color var(--transition-fast);
}

.footer-col a:hover {
  color: var(--red-primary);
}

.footer-bottom {
  max-width: var(--max-width);
  margin: 32px auto 0;
  padding-top: 20px;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* ═══════════════════════════════════════════
   视觉升级层 — 统一的质感（克制、低饱和）
   仅做视觉增强，不改变任何布局尺寸
   ═══════════════════════════════════════════ */
:root {
  --hairline: rgba(255, 255, 255, 0.09);
  --surface-1: rgba(255, 255, 255, 0.03);
  --surface-2: rgba(255, 255, 255, 0.06);
  --gradient-red: linear-gradient(135deg, #ff4050 0%, #f81b2e 48%, #c70d1e 100%);
  --shadow-soft: 0 14px 40px rgba(0, 0, 0, 0.45);
  --shadow-lift: 0 18px 48px rgba(0, 0, 0, 0.55), 0 0 0 1px rgba(252, 36, 54, 0.16);
}

/* ── 全局氛围：顶部红光 + 极淡网格，避免大面积纯黑 ── */
body {
  background:
    radial-gradient(1100px 620px at 50% -12%, rgba(252, 36, 54, 0.12), transparent 62%),
    radial-gradient(820px 520px at 95% 2%, rgba(150, 10, 24, 0.10), transparent 58%),
    var(--bg-deep);
  background-attachment: fixed;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.028) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.028) 1px, transparent 1px);
  background-size: 84px 84px;
  -webkit-mask-image: radial-gradient(ellipse 72% 46% at 50% 0%, #000 0%, transparent 76%);
  mask-image: radial-gradient(ellipse 72% 46% at 50% 0%, #000 0%, transparent 76%);
}

.page-container,
.footer {
  position: relative;
  z-index: 1;
}

/* ── 导航：加一条极细的红色分隔光带 ── */
.navbar::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(252, 36, 54, 0.5), transparent);
  opacity: 0.75;
  pointer-events: none;
}

.nav-brand img {
  transition: transform var(--transition-fast), filter var(--transition-fast);
}

.nav-brand:hover img {
  transform: translateY(-1px);
  filter: drop-shadow(0 4px 14px rgba(252, 36, 54, 0.35));
}

.nav-links a::after {
  width: 18px;
  background: var(--gradient-red);
  box-shadow: 0 0 10px rgba(252, 36, 54, 0.65);
}

.nav-links a:hover,
.nav-links a.active {
  background: linear-gradient(180deg, rgba(252, 36, 54, 0.14), rgba(252, 36, 54, 0.05));
  box-shadow: inset 0 0 0 1px rgba(252, 36, 54, 0.16);
}

.lang-switch {
  background: rgba(255, 255, 255, 0.045);
  border: 1px solid var(--border-subtle);
}

.lang-switch button.active {
  background: var(--gradient-red);
  box-shadow: 0 2px 10px rgba(252, 36, 54, 0.32);
}

/* ── 标题：统一的下划线光条与渐变强调字 ── */
.section-title {
  position: relative;
  padding-bottom: 18px;
}

.section-title::after {
  content: '';
  position: absolute;
  left: 50%;
  bottom: 0;
  transform: translateX(-50%);
  width: 64px;
  height: 3px;
  border-radius: 999px;
  background: linear-gradient(90deg, transparent, var(--red-primary), transparent);
}

.section-title .highlight {
  color: var(--red-primary);
  background: linear-gradient(120deg, #ff6b78, #fc2436 55%, #ff9aa2);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-subtitle {
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
}

/* ── 按钮：渐变主色 + 内侧高光，hover 轻微抬升 ── */
.btn {
  border-radius: 8px;
}

.btn-primary {
  background: var(--gradient-red);
  box-shadow: 0 8px 22px rgba(252, 36, 54, 0.26), inset 0 1px 0 rgba(255, 255, 255, 0.22);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #ff5564 0%, #ff2334 48%, #d60f21 100%);
  box-shadow: 0 12px 30px rgba(252, 36, 54, 0.4), inset 0 1px 0 rgba(255, 255, 255, 0.28);
  transform: translateY(-2px);
}

.btn-outline {
  background: rgba(255, 255, 255, 0.03);
}

.btn-outline:hover {
  background: rgba(252, 36, 54, 0.10);
  box-shadow: 0 8px 20px rgba(252, 36, 54, 0.16);
}

.btn-ghost {
  border: 1px solid transparent;
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.06);
  border-color: var(--border-card);
}

/* ── 卡片：顶部微高光 + 更柔和的投影 ── */
.card {
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.045), rgba(255, 255, 255, 0.012)),
    var(--bg-card);
  border-color: var(--hairline);
  box-shadow: var(--shadow-card);
}

.card:hover {
  border-color: rgba(252, 36, 54, 0.32);
  box-shadow: var(--shadow-lift);
}

/* ── 内页页头：标题下加一条短光条 ── */
.page-header {
  position: relative;
}

.page-header h1 {
  position: relative;
  padding-bottom: 14px;
  margin-bottom: 20px;
}

.page-header h1::after {
  content: '';
  position: absolute;
  left: 50%;
  bottom: 0;
  transform: translateX(-50%);
  width: 72px;
  height: 3px;
  border-radius: 999px;
  background: linear-gradient(90deg, transparent, var(--red-primary), transparent);
}

.page-header .section-subtitle {
  margin-bottom: 0;
}

/* ── 页脚：顶部红色光带 + 轻渐变 ── */
.footer {
  position: relative;
  background:
    radial-gradient(620px 220px at 50% 0%, rgba(252, 36, 54, 0.10), transparent 72%),
    var(--bg-surface);
  border-top: 1px solid transparent;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(252, 36, 54, 0.45), transparent);
  pointer-events: none;
}

.footer-col h4 {
  position: relative;
  padding-bottom: 10px;
}

.footer-col h4::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 24px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--red-primary), transparent);
}

.footer-col a {
  transition: color var(--transition-fast), transform var(--transition-fast);
}

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

/* ── 表单焦点 / 选中 / 滚动条 ── */
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
  outline: none;
  border-color: rgba(252, 36, 54, 0.55);
  box-shadow: 0 0 0 3px rgba(252, 36, 54, 0.14);
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid rgba(252, 36, 54, 0.65);
  outline-offset: 2px;
}

::selection {
  background: rgba(252, 36, 54, 0.35);
  color: #fff;
}

::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, #3c3c40, #2a2a2d);
}

/* ═══════════════════════════════════════════
   动画关键帧
   ═══════════════════════════════════════════ */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes pulseGlow {
  0%, 100% { box-shadow: 0 0 20px var(--red-glow); }
  50%      { box-shadow: 0 0 40px rgba(255, 0, 21, 0.6); }
}

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-10px); }
  to   { opacity: 1; transform: translateY(0); }
}

.animate-fade-in-up {
  animation: fadeInUp 0.7s ease forwards;
  opacity: 0;
}

.animate-delay-1 { animation-delay: 0.15s; }
.animate-delay-2 { animation-delay: 0.3s; }
.animate-delay-3 { animation-delay: 0.45s; }
.animate-delay-4 { animation-delay: 0.6s; }

/* ═══════════════════════════════════════════
   响应式
   ═══════════════════════════════════════════ */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  :root { --nav-height: 60px; }
  .section { padding: 48px 16px; }
  .section-title { font-size: 1.8rem; }

  .nav-links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    flex-direction: column;
    background: rgba(10, 10, 15, 0.96);
    backdrop-filter: blur(20px);
    padding: 16px;
    gap: 4px;
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: all var(--transition-smooth);
    border-bottom: 1px solid var(--border-subtle);
  }

  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  .nav-toggle { display: flex; }

  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; gap: 8px; text-align: center; }

  .lang-switch { margin-left: 0; }
}

/* ── 工具类 ── */
.text-center { text-align: center; }
.text-red { color: var(--red-primary); }
.text-muted { color: var(--text-muted); }
.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mt-4 { margin-top: 32px; }
.mt-5 { margin-top: 48px; }
.mb-2 { margin-bottom: 16px; }

/* ── 尊重系统「减少动态效果」设置 ── */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}
.mb-3 { margin-bottom: 24px; }
.hidden { display: none !important; }
.flex-center { display: flex; align-items: center; justify-content: center; }