/* ============================================================================
 * ModVerse 官网 - 自定义样式补充
 * 优先用 Tailwind utility class（已通过 Play CDN 注入），本文件只写：
 *   - CSS 变量 (:root)
 *   - Hero 渐变与背景层
 *   - 组件细节（按钮 hover、FAQ 折叠动画、卡片 hover）
 *   - 关键帧动画（fade-in）
 *   - 响应式微调（@media）
 * 命名约定：mv-* 前缀
 * ========================================================================== */

/* ---------- CSS 变量（与设计文档 §8.1 完全一致） ---------- */
:root {
  /* 色彩 token */
  --mv-bg:           #0F172A;   /* slate-900，主背景 */
  --mv-bg-alt:       #020617;   /* slate-950，深色 Hero 渐变端 */
  --mv-surface:      #1E293B;   /* slate-800，卡片 */
  --mv-surface-2:    #334155;   /* slate-700，悬浮态/分割线 */
  --mv-border:       #334155;   /* 边框 */
  --mv-text:         #E2E8F0;   /* slate-200，主文本 */
  --mv-text-muted:   #94A3B8;   /* slate-400，次文本 */
  --mv-primary:      #3B82F6;   /* blue-500 */
  --mv-primary-600:  #2563EB;   /* hover */
  --mv-primary-100:  #1E3A8A;   /* 弱化底色/badges */

  /* 圆角 */
  --mv-radius-sm:    8px;
  --mv-radius:       12px;      /* 卡片默认 */
  --mv-radius-lg:    16px;      /* Hero CTA、登录卡 */

  /* 间距 */
  --mv-section-py:   96px;      /* section 上下内边距（桌面） */
  --mv-container:    1200px;    /* 内容最大宽度 */
}

/* ---------- 全局 ---------- */
* { scroll-behavior: smooth; }

html, body {
  background: var(--mv-bg);
  color: var(--mv-text);
  font-family: 'Inter', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
  font-feature-settings: 'cv11', 'ss01';
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration: none; }

/* ---------- 通用容器 ---------- */
.mv-container {
  max-width: var(--mv-container);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

/* ---------- 顶部导航 ---------- */
.mv-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: rgba(15, 23, 42, 0.7);
  border-bottom: 1px solid var(--mv-border);
}

/* ---------- Hero ---------- */
.mv-hero {
  position: relative;
  overflow: hidden;
  padding-top: 96px;
  padding-bottom: 96px;
  background: radial-gradient(ellipse at top, var(--mv-bg-alt) 0%, var(--mv-bg) 70%);
}
.mv-hero__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  pointer-events: none;
  opacity: 0.6;
  z-index: 0;
}
.mv-hero__inner {
  position: relative;
  z-index: 1;
}
.mv-hero__title {
  font-size: clamp(2.25rem, 5vw, 3.5rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin-top: 1.5rem;
  background: linear-gradient(135deg, #F8FAFC 0%, #CBD5E1 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.mv-hero__subtitle {
  margin-top: 1.25rem;
  font-size: 1.0625rem;
  color: var(--mv-text-muted);
  max-width: 560px;
  line-height: 1.6;
}
.mv-hero__shot img {
  box-shadow: 0 30px 80px -20px rgba(0, 0, 0, 0.7),
              0 0 0 1px rgba(59, 130, 246, 0.15);
}

/* ---------- Badge（Hero 信任标识） ---------- */
.mv-badge {
  display: inline-flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0;
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px solid var(--mv-border);
  background: rgba(59, 130, 246, 0.08);
  color: var(--mv-text);
  font-size: 0.75rem;
  letter-spacing: 0.02em;
}
.mv-badge .font-mono { color: #93C5FD; }

/* ---------- 按钮 ---------- */
.mv-btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  border-radius: var(--mv-radius-lg);
  background: var(--mv-primary);
  color: #fff;
  font-weight: 600;
  text-decoration: none;
  transition: background-color 0.2s ease, transform 0.15s ease, box-shadow 0.2s ease;
  box-shadow: 0 6px 20px -4px rgba(59, 130, 246, 0.55);
  white-space: nowrap;
}
.mv-btn-primary:hover {
  background: var(--mv-primary-600);
  transform: translateY(-1px);
  box-shadow: 0 10px 28px -4px rgba(59, 130, 246, 0.7);
}
.mv-btn-primary:active {
  transform: translateY(0);
}
.mv-btn-primary:focus-visible {
  outline: 2px solid #93C5FD;
  outline-offset: 2px;
}

.mv-btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  border-radius: var(--mv-radius-lg);
  background: transparent;
  border: 1px solid var(--mv-border);
  color: var(--mv-text);
  font-weight: 500;
  text-decoration: none;
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
  white-space: nowrap;
}
.mv-btn-secondary:hover {
  background: var(--mv-surface);
  border-color: var(--mv-primary);
  color: #fff;
}
.mv-btn-secondary:focus-visible {
  outline: 2px solid #93C5FD;
  outline-offset: 2px;
}

.mv-trust {
  color: var(--mv-text-muted);
  font-size: 0.875rem;
}

/* ---------- 一句话简介 ---------- */
.mv-tagline {
  border-top: 1px solid var(--mv-border);
  border-bottom: 1px solid var(--mv-border);
  padding: 32px 0;
  background: rgba(2, 6, 23, 0.4);
}

/* ---------- Section 通用 ---------- */
.mv-section {
  padding-top: var(--mv-section-py);
  padding-bottom: var(--mv-section-py);
}
.mv-section__title {
  font-size: clamp(1.75rem, 3.5vw, 2.25rem);
  font-weight: 700;
  text-align: center;
  letter-spacing: -0.01em;
}
.mv-section__sub {
  margin-top: 12px;
  text-align: center;
  color: var(--mv-text-muted);
  font-size: 1rem;
}

/* ---------- 卡片 ---------- */
.mv-card {
  background: var(--mv-surface);
  border: 1px solid var(--mv-border);
  border-radius: var(--mv-radius);
  padding: 28px;
  transition: border-color 0.2s ease, transform 0.2s ease, background-color 0.2s ease;
}
.mv-card:hover {
  border-color: var(--mv-primary);
  transform: translateY(-4px);
  background: #22324a;
}
.mv-card--feature h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-top: 16px;
  color: var(--mv-text);
}
.mv-card--feature p {
  margin-top: 8px;
  color: var(--mv-text-muted);
  font-size: 0.9375rem;
  line-height: 1.6;
}
.mv-card__icon {
  width: 48px;
  height: 48px;
  display: block;
}

/* ---------- 截图 ---------- */
.mv-shot {
  margin: 0;
  background: var(--mv-surface);
  border: 1px solid var(--mv-border);
  border-radius: var(--mv-radius);
  overflow: hidden;
  transition: transform 0.25s ease, border-color 0.25s ease;
}
.mv-shot:hover {
  transform: translateY(-4px);
  border-color: var(--mv-primary);
}
.mv-shot img {
  display: block;
  width: 100%;
  height: auto;
}

/* ---------- FAQ ---------- */
.mv-faq__item {
  background: var(--mv-surface);
  border: 1px solid var(--mv-border);
  border-radius: var(--mv-radius);
  padding: 18px 22px;
  transition: border-color 0.2s ease, background-color 0.2s ease;
}
.mv-faq__item:hover {
  background: #22324a;
}
.mv-faq__item[open] {
  border-color: var(--mv-primary);
  background: rgba(59, 130, 246, 0.06);
}
.mv-faq__item summary {
  cursor: pointer;
  list-style: none;
  font-weight: 500;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  color: var(--mv-text);
}
.mv-faq__item summary::-webkit-details-marker { display: none; }
.mv-faq__item summary::marker { content: ''; }
.mv-faq__item summary::after {
  content: '+';
  color: var(--mv-text-muted);
  font-size: 1.25rem;
  font-weight: 400;
  line-height: 1;
  transition: transform 0.25s ease, color 0.2s ease;
  flex-shrink: 0;
}
.mv-faq__item[open] summary::after {
  content: '−';
  transform: rotate(180deg);
  color: var(--mv-primary);
}
.mv-faq__item p {
  margin-top: 14px;
  color: var(--mv-text-muted);
  font-size: 0.9375rem;
  line-height: 1.7;
}

/* ---------- Footer ---------- */
.mv-footer {
  background: var(--mv-bg-alt);
  border-top: 1px solid var(--mv-border);
  padding: 64px 0 32px;
}
.mv-footer h4 {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--mv-text);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.mv-footer ul {
  margin-top: 14px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  list-style: none;
  padding: 0;
}
.mv-footer a {
  color: var(--mv-text-muted);
  text-decoration: none;
  font-size: 0.9375rem;
  transition: color 0.15s ease;
}
.mv-footer a:hover {
  color: var(--mv-primary);
}
.mv-footer__contact {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--mv-border);
  display: flex;
  flex-wrap: wrap;
  gap: 24px 32px;
  font-size: 0.875rem;
  color: var(--mv-text-muted);
}
.mv-footer__contact a {
  color: var(--mv-text);
  font-weight: 500;
  transition: color 0.15s ease;
}
.mv-footer__contact a:hover { color: var(--mv-primary); }
.mv-footer__bottom {
  margin-top: 28px;
  padding-top: 22px;
  border-top: 1px solid var(--mv-border);
  text-align: center;
  font-size: 0.8125rem;
  color: var(--mv-text-muted);
}

/* ---------- 动画 ---------- */
@keyframes mv-fade-in {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}
.mv-hero__title,
.mv-hero__subtitle,
.mv-card,
.mv-faq__item,
.mv-shot {
  animation: mv-fade-in 0.6s ease-out backwards;
}
.mv-hero__title    { animation-delay: 0.05s; }
.mv-hero__subtitle { animation-delay: 0.15s; }
.mv-card:nth-child(1) { animation-delay: 0.10s; }
.mv-card:nth-child(2) { animation-delay: 0.18s; }
.mv-card:nth-child(3) { animation-delay: 0.26s; }
.mv-card:nth-child(4) { animation-delay: 0.34s; }
.mv-card:nth-child(5) { animation-delay: 0.42s; }
.mv-card:nth-child(6) { animation-delay: 0.50s; }

/* 用户开启 reduce-motion 时禁用动画，尊重可访问性偏好 */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ---------- 响应式 ---------- */
@media (max-width: 768px) {
  :root {
    --mv-section-py: 64px;
  }
  .mv-hero {
    padding-top: 56px;
    padding-bottom: 56px;
  }
  .mv-hero__title {
    font-size: 2.25rem;
  }
  .mv-hero__subtitle {
    font-size: 1rem;
  }
  .mv-btn-primary,
  .mv-btn-secondary {
    padding: 12px 22px;
    font-size: 0.9375rem;
  }
  .mv-card--feature {
    padding: 22px;
  }
  .mv-footer {
    padding-top: 48px;
  }
  .mv-footer__contact {
    flex-direction: column;
    gap: 12px;
  }
  .mv-footer__bottom {
    text-align: left;
  }
}

/* Hero 顶部小标签（CMS hero.eyebrow） */
.mv-eyebrow {
  display: block;
  color: #94A3B8;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.04em;
  margin-bottom: 10px;
}

/* Header 品牌名（CMS branding.siteName） */
.mv-brand-name {
  color: #F8FAFC;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.01em;
}

/* 截图区图注（CMS screenshots.items.N.caption） */
.mv-shot__caption {
  margin-top: 10px;
  color: #94A3B8;
  font-size: 14px;
  text-align: center;
}

/* Hero 信任徽章（CMS hero.trustBadges） */
.mv-badges {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-right: 12px;
}
.mv-badge-pill {
  display: inline-block;
  padding: 3px 10px;
  border: 1px solid #334155;
  border-radius: 999px;
  color: #94A3B8;
  font-size: 12px;
  white-space: nowrap;
}