```css

/* 球速体育 - 完整样式表 */
/* 包含：渐变Banner、圆角卡片、毛玻璃效果、响应式布局、暗色模式、滚动动画、hover动画 */

/* 基础重置与变量 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --bg-alt: #f4f6fc;
  --text: #1a1d2e;
  --text-muted: #555;
  --primary: #ff6f00;
  --primary-dark: #cc5800;
  --primary-light: #ffb74d;
  --border: #e0e3eb;
  --card-shadow: 0 4px 20px rgba(0,0,0,0.06);
  --radius: 12px;
  --radius-lg: 20px;
  --font: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
  --transition: 0.3s ease;
  --max-width: 1200px;
  --header-height: 64px;
  --glass-bg: rgba(255, 255, 255, 0.75);
  --glass-border: rgba(255, 255, 255, 0.3);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

/* 暗色模式 */
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f111a;
    --bg-alt: #181b2a;
    --text: #e8eaed;
    --text-muted: #9aa0a6;
    --border: #2d3142;
    --card-shadow: 0 4px 20px rgba(0,0,0,0.3);
    --glass-bg: rgba(15, 17, 26, 0.8);
    --glass-border: rgba(255, 255, 255, 0.08);
  }
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
}

/* 容器 */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
  width: 100%;
}

/* 链接 */
a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

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

/* 标题 */
h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.2;
}
h1 { font-size: 2.2rem; }
h2 { font-size: 1.8rem; margin-bottom: 1rem; }
h3 { font-size: 1.3rem; margin-bottom: 0.5rem; }

/* 区块 */
.section {
  padding: 60px 0;
  opacity: 0;
  transform: translateY(30px);
  animation: fadeInUp 0.6s ease forwards;
}
.section:nth-child(2) { animation-delay: 0.1s; }
.section:nth-child(3) { animation-delay: 0.2s; }
.section:nth-child(4) { animation-delay: 0.3s; }
.section:nth-child(5) { animation-delay: 0.4s; }
.section:nth-child(6) { animation-delay: 0.5s; }
.section:nth-child(7) { animation-delay: 0.6s; }
.section:nth-child(8) { animation-delay: 0.7s; }
.section:nth-child(9) { animation-delay: 0.8s; }
.section:nth-child(10) { animation-delay: 0.9s; }

@keyframes fadeInUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.bg-alt {
  background: var(--bg-alt);
}

/* 卡片 */
.card {
  background: var(--bg);
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  padding: 24px;
  border: 1px solid var(--border);
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
  position: relative;
  overflow: hidden;
}
.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--primary-light));
  opacity: 0;
  transition: opacity var(--transition);
}
.card:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.1);
}
.card:hover::before {
  opacity: 1;
}

/* 网格布局 */
.grid-2, .grid-3, .grid-4 {
  display: grid;
  gap: 24px;
}
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); }

/* 按钮 */
.btn {
  display: inline-block;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
  padding: 14px 32px;
  border-radius: 50px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
  position: relative;
  overflow: hidden;
  text-align: center;
}
.btn::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, rgba(255,255,255,0.2), transparent);
  opacity: 0;
  transition: opacity var(--transition);
}
.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(255, 111, 0, 0.4);
  text-decoration: none;
  color: #fff;
}
.btn:hover::after {
  opacity: 1;
}
.btn:active {
  transform: translateY(0);
}

/* 标签 */
.badge {
  display: inline-block;
  background: linear-gradient(135deg, #fff3e0, #ffe0b2);
  color: var(--primary-dark);
  padding: 6px 16px;
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 600;
  backdrop-filter: blur(4px);
  border: 1px solid rgba(255, 111, 0, 0.2);
  transition: transform var(--transition);
}
.badge:hover {
  transform: scale(1.05);
}

/* 头部 - 毛玻璃效果 */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
  height: var(--header-height);
  display: flex;
  align-items: center;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0;
  width: 100%;
}

/* Logo */
.logo {
  font-size: 1.5rem;
  font-weight: 800;
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  transition: color var(--transition);
}
.logo svg {
  width: 36px;
  height: 36px;
  filter: drop-shadow(0 2px 4px rgba(255, 111, 0, 0.3));
}
.logo:hover {
  color: var(--primary);
}

/* 导航 */
nav {
  display: flex;
  align-items: center;
  gap: 4px;
}
nav a {
  margin: 0 8px;
  font-weight: 500;
  color: var(--text);
  padding: 8px 12px;
  border-radius: 8px;
  transition: background var(--transition), color var(--transition);
  position: relative;
}
nav a::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: width var(--transition), left var(--transition);
  border-radius: 2px;
}
nav a:hover {
  color: var(--primary);
  background: rgba(255, 111, 0, 0.08);
  text-decoration: none;
}
nav a:hover::after {
  width: 60%;
  left: 20%;
}

/* Hero 区域 - 渐变Banner */
.hero {
  text-align: center;
  padding: 100px 0 70px;
  position: relative;
  background: linear-gradient(135deg, #0a0e27 0%, #1a1d3e 30%, #2a2050 60%, #0a0e27 100%);
  color: #fff;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 50%, rgba(255, 111, 0, 0.15) 0%, transparent 50%),
              radial-gradient(circle at 70% 50%, rgba(255, 183, 77, 0.1) 0%, transparent 50%);
  animation: heroGlow 8s ease-in-out infinite alternate;
}
@keyframes heroGlow {
  0% { transform: translate(0, 0) scale(1); }
  100% { transform: translate(-5%, -5%) scale(1.1); }
}
.hero .container {
  position: relative;
  z-index: 1;
}
.hero h1 {
  font-size: 2.8rem;
  margin-bottom: 16px;
  background: linear-gradient(135deg, #fff, #ffb74d);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero p {
  font-size: 1.2rem;
  color: rgba(255,255,255,0.8);
  max-width: 700px;
  margin: 0 auto 30px;
}
.hero-badges {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}
.hero-badges .badge {
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(4px);
}

/* FAQ */
.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 18px 0;
  cursor: pointer;
  transition: background var(--transition);
  border-radius: 8px;
  padding-left: 12px;
  padding-right: 12px;
}
.faq-item:hover {
  background: rgba(255, 111, 0, 0.03);
}
.faq-question {
  font-weight: 600;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 1.05rem;
  gap: 12px;
}
.faq-question span {
  font-size: 1.5rem;
  font-weight: 300;
  transition: transform var(--transition);
  color: var(--primary);
}
.faq-item.active .faq-question span {
  transform: rotate(45deg);
}
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding var(--transition);
  color: var(--text-muted);
  padding-top: 0;
  line-height: 1.7;
}
.faq-item.active .faq-answer {
  max-height: 300px;
  padding-top: 12px;
}

/* HowTo 步骤 */
.howto-step {
  display: flex;
  gap: 20px;
  margin-bottom: 24px;
  align-items: flex-start;
  padding: 16px;
  border-radius: var(--radius);
  transition: background var(--transition), transform var(--transition);
}
.howto-step:hover {
  background: var(--bg);
  transform: translateX(8px);
}
.howto-step-number {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  flex-shrink: 0;
  font-size: 1.1rem;
  box-shadow: 0 4px 12px rgba(255, 111, 0, 0.3);
}
.howto-step h3 {
  margin-bottom: 4px;
}

/* 页脚 */
footer {
  background: #0a0e27;
  color: #ccc;
  padding: 50px 0 30px;
  font-size: 0.9rem;
  position: relative;
}
footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--primary-light), var(--primary));
}
footer a {
  color: #aaa;
  transition: color var(--transition);
}
footer a:hover {
  color: #fff;
  text-decoration: none;
}
.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 30px;
}
.footer-grid h4 {
  color: #fff;
  margin-bottom: 14px;
  font-size: 1rem;
}
.footer-grid a {
  display: inline-block;
  margin-bottom: 6px;
}
.footer-bottom {
  border-top: 1px solid #222;
  padding-top: 24px;
  margin-top: 40px;
  text-align: center;
  font-size: 0.8rem;
}

/* 响应式 */
@media (max-width: 768px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
  .hero h1 { font-size: 2rem; }
  .hero { padding: 70px 0 50px; }
  .section { padding: 40px 0; }
  nav a { margin: 0 4px; font-size: 0.85rem; padding: 6px 8px; }
  .header-inner { flex-wrap: wrap; gap: 8px; }
  .logo { font-size: 1.2rem; }
  .logo svg { width: 28px; height: 28px; }
  .grid-2, .grid-3, .grid-4 { gap: 16px; }
  .card { padding: 18px; }
  .howto-step { flex-direction: column; gap: 12px; }
  .howto-step-number { width: 32px; height: 32px; font-size: 0.9rem; }
  .faq-item { padding: 14px 8px; }
  .footer-grid { gap: 20px; }
}

/* 小屏幕适配 */
@media (max-width: 480px) {
  .container { padding: 0 16px; }
  .hero h1 { font-size: 1.7rem; }
  .hero p { font-size: 1rem; }
  nav { gap: 2px; }
  nav a { font-size: 0.8rem; margin: 0 2px; padding: 4px 6px; }
  .btn { padding: 12px 24px; font-size: 0.9rem; }
}

/* 滚动条美化 */
::-webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-alt);
}
::-webkit-scrollbar-thumb {
  background: var(--primary);
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--primary-dark);
}

/* 选中文字样式 */
::selection {
  background: var(--primary);
  color: #fff;
}

/* 知识中心文章卡片 */
article.card {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
article.card a {
  align-self: flex-start;
  margin-top: auto;
  font-weight: 600;
}

/* 用户评价卡片 footer */
.card footer {
  margin-top: 12px;
  font-style: italic;
  color: var(--text-muted);
  background: none;
  padding: 0;
  border: none;
}

/* 返回顶部按钮样式 (由JS生成，这里补充) */
/* 已在JS中内联，此处不做覆盖 */

```