/* ==========================================================================
   吹雪云 (cxy.lat) - 官方标准样式表
   ========================================================================== */

/* --- 全局 CSS 变量定义 --- */
:root {
  --font-primary: 'Plus Jakarta Sans', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  
  /* 主色调 (深色高端科技蓝调) */
  --bg-dark: #0a0e17;
  --bg-card: rgba(18, 25, 40, 0.75);
  --bg-card-hover: rgba(26, 36, 58, 0.9);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(0, 153, 255, 0.25);
  
  /* 文字颜色 */
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  
  /* 品牌高亮与渐变 */
  --primary-blue: #0099ff;
  --primary-cyan: #00b4d8;
  --btn-gradient: linear-gradient(135deg, #0099ff 0%, #00b4d8 100%);
  --btn-gradient-hover: linear-gradient(135deg, #0fa3ff 0%, #17c0e4 100%);
  --accent-purple: #7928ca;
  --glow-primary: rgba(0, 153, 255, 0.35);

  /* 阴影 */
  --shadow-card: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
  --shadow-hover: 0 20px 40px -15px rgba(0, 153, 255, 0.2);
  
  /* 尺寸与过渡 */
  --max-width: 1200px;
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* --- 重置与基础样式 --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: var(--font-primary);
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.6;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  background-image: 
    radial-gradient(circle at 50% 0%, rgba(0, 153, 255, 0.12) 0%, transparent 60%),
    radial-gradient(circle at 90% 40%, rgba(121, 40, 202, 0.08) 0%, transparent 50%);
  background-attachment: fixed;
}

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

img, svg {
  vertical-align: middle;
}

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

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* --- 通用按钮体系 --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 15px;
  line-height: 1;
  padding: 12px 24px;
  border-radius: 999px;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: center;
  user-select: none;
}

.btn-primary {
  background: var(--btn-gradient);
  color: #ffffff;
  box-shadow: 0 4px 18px var(--glow-primary);
  gap: 8px;
}

.btn-primary:hover {
  filter: brightness(1.08);
  transform: translateY(-2px);
  box-shadow: 0 8px 26px rgba(0, 153, 255, 0.45);
}

.btn-primary .btn-arrow {
  width: 16px;
  height: 16px;
  transition: transform var(--transition-fast);
}

.btn-primary:hover .btn-arrow {
  transform: translateX(4px);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.06);
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.3);
  transform: translateY(-2px);
}

.btn-header {
  background: var(--btn-gradient);
  color: #ffffff;
  font-size: 14px;
  padding: 8px 18px;
  border-radius: 999px;
  box-shadow: 0 2px 10px rgba(0, 153, 255, 0.3);
}

.btn-header:hover {
  filter: brightness(1.1);
  transform: translateY(-1px);
}

/* ==========================================================================
   顶部导航栏 (Header)
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 14, 23, 0.82);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-color);
  transition: background var(--transition-normal);
}

.header-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 20px;
  letter-spacing: -0.02em;
  color: #ffffff;
}

.logo-icon {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: var(--btn-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(0, 153, 255, 0.35);
}

.logo-icon svg {
  width: 20px;
  height: 20px;
}

.logo-text {
  background: linear-gradient(135deg, #ffffff 40%, #a5f3fc 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-link {
  color: var(--text-muted);
  font-size: 14px;
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav-link:hover {
  color: var(--primary-cyan);
}

/* ==========================================================================
   主视觉区 (Hero)
   ========================================================================== */
.hero-section {
  position: relative;
  padding: 90px 0 70px;
  text-align: center;
  overflow: hidden;
}

.hero-bg-glow {
  position: absolute;
  top: -120px;
  left: 50%;
  transform: translateX(-50%);
  width: 700px;
  height: 400px;
  background: radial-gradient(circle, rgba(0, 153, 255, 0.22) 0%, rgba(0, 180, 216, 0.08) 50%, transparent 75%);
  filter: blur(60px);
  z-index: 0;
  pointer-events: none;
}

.hero-container {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(0, 153, 255, 0.1);
  border: 1px solid rgba(0, 153, 255, 0.3);
  border-radius: 999px;
  margin-bottom: 24px;
}

.badge-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #10b981;
  box-shadow: 0 0 10px #10b981;
}

.badge-text {
  font-size: 13px;
  font-weight: 600;
  color: #38bdf8;
  letter-spacing: 0.02em;
}

.hero-title {
  font-size: 48px;
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.025em;
  max-width: 860px;
  margin-bottom: 22px;
  color: #ffffff;
}

.hero-title span {
  display: inline-block;
}

.hero-title-highlight {
  display: block;
  background: linear-gradient(135deg, #0099ff 0%, #00e5ff 60%, #a855f7 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-top: 6px;
}

.hero-subtitle {
  font-size: 17px;
  color: var(--text-muted);
  max-width: 660px;
  line-height: 1.7;
  margin-bottom: 36px;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 50px;
  flex-wrap: wrap;
}

.hero-cta-group .btn {
  padding: 14px 34px;
  font-size: 16px;
}

/* 核心数据展示 */
.hero-metrics {
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(18, 25, 40, 0.6);
  border: 1px solid var(--border-color);
  backdrop-filter: blur(12px);
  border-radius: 20px;
  padding: 20px 36px;
  gap: 36px;
  box-shadow: var(--shadow-card);
}

.metric-card {
  text-align: center;
}

.metric-value {
  font-size: 26px;
  font-weight: 800;
  color: #ffffff;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, #ffffff 40%, #38bdf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.metric-label {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 4px;
}

.metric-divider {
  width: 1px;
  height: 36px;
  background: var(--border-color);
}

/* ==========================================================================
   核心优势卡片 (Features)
   ========================================================================== */
.features-section {
  padding: 80px 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 50px;
}

.section-tag {
  font-size: 12px;
  font-weight: 700;
  color: var(--primary-cyan);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.section-title {
  font-size: 32px;
  font-weight: 800;
  line-height: 1.25;
  color: #ffffff;
  margin-bottom: 14px;
}

.section-desc {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.6;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 36px 30px;
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
  position: relative;
  backdrop-filter: blur(10px);
}

.feature-card:hover {
  transform: translateY(-6px);
  background: var(--bg-card-hover);
  border-color: var(--border-glow);
  box-shadow: var(--shadow-hover);
}

.feature-icon-wrapper {
  width: 56px;
  height: 56px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  transition: transform var(--transition-fast);
}

.feature-card:hover .feature-icon-wrapper {
  transform: scale(1.08);
}

.feature-icon-wrapper svg {
  width: 28px;
  height: 28px;
}

.icon-speed {
  background: rgba(0, 153, 255, 0.14);
  color: #0099ff;
  border: 1px solid rgba(0, 153, 255, 0.25);
}

.icon-cross {
  background: rgba(168, 85, 247, 0.14);
  color: #c084fc;
  border: 1px solid rgba(168, 85, 247, 0.25);
}

.icon-security {
  background: rgba(16, 185, 129, 0.14);
  color: #34d399;
  border: 1px solid rgba(16, 185, 129, 0.25);
}

.feature-title {
  font-size: 20px;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 12px;
}

.feature-desc {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 20px;
  flex-grow: 1;
}

.feature-list {
  list-style: none;
  border-top: 1px solid var(--border-color);
  padding-top: 18px;
}

.feature-list li {
  font-size: 13px;
  color: var(--text-muted);
  position: relative;
  padding-left: 18px;
  margin-bottom: 8px;
  line-height: 1.5;
}

.feature-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--primary-cyan);
  font-weight: bold;
}

.feature-list li:last-child {
  margin-bottom: 0;
}

/* ==========================================================================
   套餐引流横幅 (Banner)
   ========================================================================== */
.banner-section {
  padding: 40px 0 90px;
}

.banner-card {
  background: linear-gradient(135deg, rgba(0, 153, 255, 0.12) 0%, rgba(121, 40, 202, 0.12) 100%);
  border: 1px solid rgba(0, 153, 255, 0.25);
  border-radius: 24px;
  padding: 44px 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  backdrop-filter: blur(14px);
  gap: 30px;
}

.banner-tag {
  font-size: 12px;
  font-weight: 700;
  color: #38bdf8;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 8px;
  display: inline-block;
}

.banner-title {
  font-size: 26px;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 8px;
}

.banner-desc {
  font-size: 15px;
  color: var(--text-muted);
}

.btn-banner {
  background: var(--btn-gradient);
  color: #ffffff;
  padding: 14px 32px;
  font-size: 15px;
  border-radius: 999px;
  white-space: nowrap;
  box-shadow: 0 4px 20px var(--glow-primary);
}

.btn-banner:hover {
  filter: brightness(1.1);
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(0, 153, 255, 0.45);
}

/* ==========================================================================
   底部页脚 (Footer)
   ========================================================================== */
.site-footer {
  background: #06090f;
  border-top: 1px solid var(--border-color);
  padding: 60px 0 0;
  margin-top: auto;
}

.footer-container {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 50px;
}

.footer-logo {
  margin-bottom: 16px;
}

.footer-intro {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.7;
  max-width: 320px;
  margin-bottom: 16px;
}

.domain-tag {
  font-size: 13px;
  color: var(--text-dim);
}

.domain-tag span {
  color: #38bdf8;
  font-weight: 600;
}

.footer-title {
  font-size: 15px;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 18px;
  letter-spacing: 0.02em;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  font-size: 14px;
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: #ffffff;
  padding-left: 2px;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding: 24px 0;
}

.footer-bottom-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.copyright {
  font-size: 13px;
  color: var(--text-dim);
}

.footer-meta-links {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 13px;
  color: var(--text-dim);
}

.footer-meta-links a {
  color: var(--text-muted);
}

.footer-meta-links a:hover {
  color: #ffffff;
}

.footer-meta-links .sep {
  color: rgba(255, 255, 255, 0.15);
}

/* ==========================================================================
   二、弹窗与遮罩层规范 (严格还原设计图)
   ========================================================================== */

/* 1. 遮罩层 (Backdrop) */
.modal-backdrop {
  position: fixed;
  inset: 0;
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  /* 严格还原需求参数 */
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  background: rgba(0, 0, 0, 0.45);
  
  /* 默认隐藏，待 JS 延迟 300ms 丝滑淡入 */
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.35s cubic-bezier(0.16, 1, 0.3, 1),
              visibility 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

/* 激活状态 */
.modal-backdrop.is-visible {
  opacity: 1;
  visibility: visible;
}

/* 2. 弹窗卡片 (Modal Container) */
.modal-container {
  position: relative;
  background: #ffffff; /* 纯白背景 */
  border-radius: 16px; /* 圆角 16px */
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.25); /* 深层柔和阴影 */
  width: 100%;
  max-width: 440px; /* 最大宽度 440px */
  padding: 32px 28px 28px;
  box-sizing: border-box;
  text-align: center;
  color: #1f2937;
  
  /* 初始微缩放动效 */
  transform: scale(0.94) translateY(10px);
  transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

.modal-backdrop.is-visible .modal-container {
  transform: scale(1) translateY(0);
}

/* 右上角轻量关闭按钮“✕” */
.modal-close-btn {
  position: absolute;
  top: 16px;
  right: 18px;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: 500;
  color: #9ca3af;
  background: transparent;
  transition: all var(--transition-fast);
  cursor: pointer;
  line-height: 1;
}

.modal-close-btn:hover {
  color: #111827;
  background: #f3f4f6;
  transform: rotate(90deg);
}

/* 3. 警告标题与图标 */
.modal-header {
  margin-bottom: 18px;
}

.modal-alert-icon {
  font-size: 40px;
  line-height: 1;
  margin-bottom: 12px;
  animation: modalBounce 1.8s infinite ease-in-out;
}

@keyframes modalBounce {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-4px);
  }
}

.modal-title {
  font-size: 22px;
  font-weight: 700;
  color: #111827;
  letter-spacing: -0.01em;
  margin: 0;
  text-align: center;
}

/* 4. 公告正文 (行高舒适，字距清晰，保持视觉警示重点) */
.modal-body {
  margin-bottom: 26px;
}

.modal-text {
  font-size: 14.5px;
  line-height: 1.75;
  letter-spacing: 0.02em;
  color: #374151;
  text-align: justify;
  background: #fff8f1;
  border: 1px solid #fed7aa;
  border-radius: 12px;
  padding: 16px 18px;
  margin: 0;
}

/* 5. 核心行动按钮 (CTA) */
.modal-footer {
  display: flex;
  flex-direction: column;
}

.modal-cta-btn {
  display: block;
  width: 100%;
  padding: 15px 24px;
  /* 大圆角药丸按钮 */
  border-radius: 999px;
  /* 高亮亮蓝色渐变 #0099ff 到 #00b4d8 */
  background: linear-gradient(135deg, #0099ff 0%, #00b4d8 100%);
  color: #ffffff;
  font-size: 16px;
  font-weight: 700;
  text-align: center;
  box-shadow: 0 6px 20px rgba(0, 153, 255, 0.35);
  transition: all var(--transition-fast);
  cursor: pointer;
  letter-spacing: 0.02em;
  user-select: none;
}

/* 悬停微动效与亮度提升 */
.modal-cta-btn:hover {
  filter: brightness(1.12);
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(0, 153, 255, 0.5);
  color: #ffffff;
}

.modal-cta-btn:active {
  transform: translateY(0);
  filter: brightness(1.02);
}

/* ==========================================================================
   移动端与响应式适配 (Mobile-first responsive)
   ========================================================================== */
@media (max-width: 992px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 768px) {
  .nav-menu {
    display: none; /* 移动端精简顶部导航，聚焦 CTA */
  }

  .hero-section {
    padding: 60px 0 45px;
  }

  .hero-title {
    font-size: 34px;
  }

  .hero-subtitle {
    font-size: 15px;
    margin-bottom: 28px;
  }

  .hero-metrics {
    flex-direction: column;
    gap: 18px;
    padding: 20px 24px;
    width: 100%;
  }

  .metric-divider {
    width: 60px;
    height: 1px;
  }

  .features-grid {
    grid-template-columns: 1fr; /* 手机竖屏下单栏排列 */
    gap: 20px;
  }

  .banner-card {
    flex-direction: column;
    text-align: center;
    padding: 32px 24px;
  }

  .btn-banner {
    width: 100%;
  }

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

  .footer-bottom-inner {
    flex-direction: column;
    text-align: center;
    gap: 12px;
  }

  /* 移动端弹窗自适应留白 */
  .modal-container {
    padding: 28px 20px 24px;
    margin: 0 12px;
    border-radius: 16px;
  }

  .modal-alert-icon {
    font-size: 36px;
  }

  .modal-title {
    font-size: 20px;
  }

  .modal-text {
    font-size: 14px;
    padding: 14px 14px;
  }

  .modal-cta-btn {
    padding: 14px 20px;
    font-size: 15px;
  }
}