/* ==========================================================================
   DUCATI ACCELERATOR / 杜卡迪网络加速 核心样式表
   设计美学: 1970 年代意大利赛车海报 (Rosso Corsa 竞技红)
   规范要求: 纯色、零圆角、1px 发丝分割线、无辉光、无渐变、无重阴影
   ========================================================================== */

/* 引入 Google 字体 Anton 与 Barlow */
@import url('https://fonts.googleapis.com/css2?family=Anton&family=Barlow:ital,wght@0,300;0,400;0,600;0,700;0,900;1,400&display=swap');

:root {
  --bg-carbon: #141414;
  --bg-card: #1c1c1c;
  --bg-card-alt: #181818;
  --red-ducati: #E30613;
  --text-white: #F2F2F0;
  --text-muted: #C9CBCF;
  --border-hairline: #2A2A2A;
  --border-active: #E30613;
  --font-display: 'Anton', 'Impact', 'Arial Black', sans-serif;
  --font-body: 'Barlow', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --max-width: 1240px;
}

/* 基础重置 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  border-radius: 0 !important; /* 严格要求：圆角为 0 */
  box-shadow: none !important; /* 严格要求：无重阴影、无辉光 */
  text-shadow: none !important;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  background-color: var(--bg-carbon);
  color: var(--text-white);
  font-family: var(--font-body);
  line-height: 1.6;
}

body {
  background-color: var(--bg-carbon);
  color: var(--text-white);
  min-height: 100vh;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.15s ease, background-color 0.15s ease;
}

img, svg {
  display: block;
  max-width: 100%;
}

/* 意大利赛车红色斜切条装饰 */
.racing-stripe {
  height: 6px;
  background-color: var(--red-ducati);
  width: 100%;
  display: block;
}

.racing-slash {
  display: inline-block;
  width: 28px;
  height: 12px;
  background-color: var(--red-ducati);
  transform: skew(-25deg);
  margin-right: 12px;
  vertical-align: middle;
}

/* 布局容器 */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

/* 发丝分割线 */
.hairline {
  border: 0;
  border-top: 1px solid var(--border-hairline);
  margin: 0;
  width: 100%;
}

/* 顶部通知条 / 赛车旗格纹感 */
.top-ticker {
  background-color: #0d0d0d;
  border-bottom: 1px solid var(--border-hairline);
  padding: 8px 0;
  font-size: 0.82rem;
  letter-spacing: 1.5px;
  color: var(--text-muted);
  text-transform: uppercase;
  font-weight: 600;
}

.top-ticker-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.top-ticker-highlight {
  color: var(--red-ducati);
  font-weight: 700;
}

/* 导航栏 */
.site-header {
  background-color: var(--bg-carbon);
  border-bottom: 1px solid var(--border-hairline);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}

/* 盾形徽章 Logo */
.brand-logo {
  display: flex;
  align-items: center;
  gap: 14px;
}

.shield-badge {
  width: 42px;
  height: 48px;
  background-color: var(--red-ducati);
  clip-path: polygon(0 0, 100% 0, 100% 70%, 50% 100%, 0 70%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-white);
  font-family: var(--font-display);
  font-size: 28px;
  line-height: 1;
  font-weight: 900;
  letter-spacing: -1px;
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 1.6rem;
  line-height: 1;
  letter-spacing: 1px;
  color: var(--text-white);
  text-transform: uppercase;
}

.brand-sub {
  font-size: 0.72rem;
  letter-spacing: 2.5px;
  color: var(--text-muted);
  text-transform: uppercase;
  font-weight: 700;
  margin-top: 3px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav-links a {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: 0.5px;
  position: relative;
  padding: 6px 0;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text-white);
}

.nav-links a.active::after,
.nav-links a:hover::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--red-ducati);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

/* 按钮规范 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 28px;
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.15s ease;
  line-height: 1;
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--red-ducati);
  color: var(--text-white);
  border-color: var(--red-ducati);
}

.btn-primary:hover {
  background-color: #b8050f;
  border-color: #b8050f;
  color: var(--text-white);
}

.btn-outline {
  background-color: transparent;
  color: var(--text-white);
  border-color: var(--border-hairline);
}

.btn-outline:hover {
  border-color: var(--red-ducati);
  color: var(--text-white);
  background-color: rgba(227, 6, 19, 0.08);
}

.btn-sm {
  padding: 10px 18px;
  font-size: 0.85rem;
}

.btn-lg {
  padding: 18px 36px;
  font-size: 1.05rem;
  font-family: var(--font-body);
}

/* 编号与小节标签 (01 / 02 / 03) */
.section-tag {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}

.section-num {
  font-family: var(--font-display);
  font-size: 1.5rem;
  color: var(--red-ducati);
  line-height: 1;
  letter-spacing: 1px;
}

.section-label {
  font-size: 0.85rem;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--text-muted);
  font-weight: 700;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 5vw, 3.6rem);
  text-transform: uppercase;
  line-height: 1.05;
  letter-spacing: 0.5px;
  color: var(--text-white);
  margin-bottom: 20px;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 680px;
  line-height: 1.7;
}

.section-header {
  margin-bottom: 48px;
}

/* ==================== HERO 区域 ==================== */
.hero-section {
  position: relative;
  padding: 80px 0 90px;
  border-bottom: 1px solid var(--border-hairline);
  background-color: var(--bg-carbon);
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 50px;
  align-items: center;
}

.hero-editorial-badge {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 6px 14px;
  background-color: #1f1f1f;
  border-left: 3px solid var(--red-ducati);
  font-size: 0.82rem;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--text-muted);
  font-weight: 700;
  margin-bottom: 24px;
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(3rem, 7vw, 5.2rem);
  line-height: 0.95;
  letter-spacing: -0.5px;
  text-transform: uppercase;
  color: var(--text-white);
  margin-bottom: 24px;
}

.hero-title .brand-red {
  color: var(--red-ducati);
  display: block;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 36px;
  max-width: 620px;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 40px;
}

.hero-meta-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  padding-top: 30px;
  border-top: 1px solid var(--border-hairline);
}

.hero-stat-item .stat-value {
  font-family: var(--font-display);
  font-size: 2.2rem;
  line-height: 1;
  color: var(--text-white);
  margin-bottom: 6px;
}

.hero-stat-item .stat-label {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-muted);
  font-weight: 600;
}

/* Hero 右侧海报式黑白图卡与红色切片 */
.hero-visual {
  position: relative;
  border: 1px solid var(--border-hairline);
  background-color: #0f0f0f;
  padding: 16px;
}

.hero-poster-frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--border-hairline);
}

.hero-img-mono {
  width: 100%;
  height: 480px;
  object-fit: cover;
  filter: grayscale(100%) contrast(140%) brightness(85%);
  display: block;
}

.hero-badge-overlay {
  position: absolute;
  top: 0;
  right: 0;
  background-color: var(--red-ducati);
  color: var(--text-white);
  padding: 12px 20px;
  font-family: var(--font-display);
  font-size: 1.2rem;
  letter-spacing: 1px;
  text-transform: uppercase;
}

.hero-corner-tag {
  position: absolute;
  bottom: 16px;
  left: 16px;
  background-color: rgba(20, 20, 20, 0.95);
  border: 1px solid var(--border-hairline);
  padding: 10px 16px;
  font-size: 0.8rem;
  color: var(--text-white);
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
}

/* ==================== 01 产品核心优势 (3个图文卡片) ==================== */
.features-section {
  padding: 90px 0;
  border-bottom: 1px solid var(--border-hairline);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-hairline);
  padding: 0;
  display: flex;
  flex-direction: column;
  transition: border-color 0.15s ease;
}

.feature-card:hover {
  border-color: var(--red-ducati);
}

.feature-card-media {
  position: relative;
  height: 200px;
  overflow: hidden;
  border-bottom: 1px solid var(--border-hairline);
  background-color: #0b0b0b;
}

.feature-card-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: grayscale(100%) contrast(130%) brightness(90%);
}

.feature-card-index {
  position: absolute;
  bottom: 0;
  left: 0;
  background-color: var(--red-ducati);
  color: var(--text-white);
  font-family: var(--font-display);
  font-size: 1.1rem;
  padding: 4px 14px;
  line-height: 1;
}

.feature-card-body {
  padding: 28px 24px;
  flex: 1;
}

.feature-title {
  font-family: var(--font-display);
  font-size: 1.6rem;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  margin-bottom: 12px;
  color: var(--text-white);
}

.feature-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* ==================== 02 流媒体与 AI 支持图卡 ==================== */
.media-ai-section {
  padding: 90px 0;
  border-bottom: 1px solid var(--border-hairline);
  background-color: #121212;
}

.media-ai-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.service-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-hairline);
  padding: 36px 32px;
  position: relative;
  display: flex;
  flex-direction: column;
}

.service-card-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 20px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--border-hairline);
}

.service-badge {
  background-color: var(--red-ducati);
  color: var(--text-white);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  padding: 4px 10px;
}

.service-title {
  font-family: var(--font-display);
  font-size: 2rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 12px;
}

.service-desc {
  font-size: 0.98rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 24px;
}

.service-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: auto;
}

.service-tag {
  background-color: #242424;
  border: 1px solid var(--border-hairline);
  padding: 6px 14px;
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 1px;
  color: var(--text-white);
  text-transform: uppercase;
}

/* ==================== 03 套餐价格对比表 ==================== */
.pricing-section {
  padding: 90px 0;
  border-bottom: 1px solid var(--border-hairline);
}

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

.price-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-hairline);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: border-color 0.15s ease;
}

.price-card:hover {
  border-color: var(--red-ducati);
}

.price-card.featured {
  background-color: #1e1e1e;
  border: 2px solid var(--red-ducati);
}

.popular-ribbon {
  position: absolute;
  top: 0;
  right: 0;
  background-color: var(--red-ducati);
  color: var(--text-white);
  font-size: 0.72rem;
  font-weight: 900;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  padding: 4px 12px;
}

.plan-tier {
  font-family: var(--font-display);
  font-size: 1.5rem;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 6px;
  color: var(--text-white);
}

.plan-subtitle {
  font-size: 0.82rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 24px;
}

.price-display {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 20px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-hairline);
}

.currency {
  font-family: var(--font-display);
  font-size: 1.6rem;
  color: var(--red-ducati);
}

.price-amount {
  font-family: var(--font-display);
  font-size: 3.4rem;
  line-height: 1;
  color: var(--text-white);
  letter-spacing: -1px;
}

.billing-period {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 600;
  text-transform: uppercase;
}

.plan-features {
  list-style: none;
  margin-bottom: 30px;
  flex: 1;
}

.plan-features li {
  font-size: 0.9rem;
  color: var(--text-muted);
  padding: 9px 0;
  border-bottom: 1px solid #232323;
  display: flex;
  align-items: center;
  gap: 8px;
}

.plan-features li strong {
  color: var(--text-white);
}

.plan-features li::before {
  content: '■';
  color: var(--red-ducati);
  font-size: 0.75rem;
}

/* ==================== 04 用户评价 ==================== */
.reviews-section {
  padding: 90px 0;
  border-bottom: 1px solid var(--border-hairline);
  background-color: #121212;
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-hairline);
  padding: 30px 26px;
  display: flex;
  flex-direction: column;
  position: relative;
}

.review-rating {
  color: var(--red-ducati);
  font-size: 1.1rem;
  letter-spacing: 3px;
  margin-bottom: 14px;
}

.review-text {
  font-size: 0.96rem;
  color: var(--text-white);
  line-height: 1.7;
  margin-bottom: 24px;
  flex: 1;
}

.review-author {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid var(--border-hairline);
  padding-top: 16px;
}

.author-name {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text-white);
}

.author-tag {
  font-size: 0.78rem;
  color: var(--text-muted);
  letter-spacing: 1px;
}

/* ==================== 05 常见问题 (FAQ) ==================== */
.faq-section {
  padding: 90px 0;
  border-bottom: 1px solid var(--border-hairline);
}

.faq-list {
  max-width: 900px;
  margin: 0 auto;
}

.faq-item {
  border: 1px solid var(--border-hairline);
  margin-bottom: 16px;
  background-color: var(--bg-card);
}

.faq-item summary {
  padding: 22px 28px;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-white);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: color 0.15s ease;
}

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

.faq-item summary::after {
  content: '+';
  font-family: var(--font-display);
  font-size: 1.6rem;
  color: var(--red-ducati);
  transition: transform 0.2s ease;
}

.faq-item[open] summary::after {
  content: '−';
}

.faq-item[open] summary {
  border-bottom: 1px solid var(--border-hairline);
  color: var(--red-ducati);
}

.faq-content {
  padding: 24px 28px;
  font-size: 0.98rem;
  color: var(--text-muted);
  line-height: 1.8;
  background-color: #171717;
}

/* ==================== FOOTER (页脚) ==================== */
/* 严格要求：页脚只保留这四个标题，内容打开新的页面展示 */
.site-footer {
  background-color: #0b0b0b;
  border-top: 2px solid var(--red-ducati);
  padding: 70px 0 40px;
}

.footer-top {
  display: grid;
  grid-template-columns: 1fr;
  text-align: center;
  margin-bottom: 40px;
}

.footer-brand {
  margin-bottom: 24px;
}

.footer-nav-four {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 36px;
  list-style: none;
  margin-bottom: 40px;
  padding-bottom: 30px;
  border-bottom: 1px solid var(--border-hairline);
}

.footer-nav-four li a {
  font-family: var(--font-display);
  font-size: 1.35rem;
  letter-spacing: 1.5px;
  color: var(--text-muted);
  text-transform: uppercase;
  padding: 8px 12px;
  border: 1px solid transparent;
  transition: all 0.15s ease;
}

.footer-nav-four li a:hover {
  color: var(--red-ducati);
  border-color: var(--red-ducati);
  background-color: #141414;
}

.footer-bottom {
  text-align: center;
  font-size: 0.85rem;
  color: #737373;
  letter-spacing: 1px;
  line-height: 1.8;
}

.footer-bottom p {
  margin-bottom: 6px;
}

/* 独立子页面排版 (关于我们, 服务条款, 隐私政策, 资讯中心) */
.page-hero {
  padding: 70px 0 50px;
  border-bottom: 1px solid var(--border-hairline);
  background-color: #121212;
}

.page-content-wrapper {
  padding: 70px 0 90px;
}

.editorial-article {
  max-width: 860px;
  margin: 0 auto;
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--text-white);
}

.editorial-article h2 {
  font-family: var(--font-display);
  font-size: 2.2rem;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  margin: 48px 0 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-hairline);
  color: var(--text-white);
}

.editorial-article h3 {
  font-size: 1.35rem;
  font-weight: 700;
  margin: 32px 0 14px;
  color: var(--red-ducati);
}

.editorial-article p {
  color: var(--text-muted);
  margin-bottom: 22px;
}

.editorial-article p strong {
  color: var(--text-white);
}

.editorial-article ul, .editorial-article ol {
  margin: 0 0 24px 24px;
  color: var(--text-muted);
}

.editorial-article li {
  margin-bottom: 10px;
}

.editorial-article blockquote {
  border-left: 3px solid var(--red-ducati);
  background-color: var(--bg-card);
  padding: 20px 24px;
  margin: 28px 0;
  font-style: italic;
  color: var(--text-white);
}

.editorial-article a {
  color: var(--red-ducati);
  text-decoration: underline;
  font-weight: 600;
}

.editorial-article a:hover {
  color: var(--text-white);
}

/* 资讯列表卡片 */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
}

.article-entry-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-hairline);
  padding: 32px;
  display: flex;
  flex-direction: column;
  transition: border-color 0.15s ease;
}

.article-entry-card:hover {
  border-color: var(--red-ducati);
}

.article-entry-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.8rem;
  color: var(--red-ducati);
  letter-spacing: 1.5px;
  text-transform: uppercase;
  font-weight: 700;
  margin-bottom: 12px;
}

.article-entry-title {
  font-family: var(--font-display);
  font-size: 1.7rem;
  line-height: 1.15;
  text-transform: uppercase;
  margin-bottom: 14px;
  color: var(--text-white);
}

.article-entry-title a:hover {
  color: var(--red-ducati);
}

.article-entry-excerpt {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 24px;
  flex: 1;
}

/* ==================== 响应式设计 (@media) ==================== */
@media (max-width: 1024px) {
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .top-ticker-inner {
    flex-direction: column;
    text-align: center;
    gap: 4px;
  }
  
  .nav-wrapper {
    flex-direction: column;
    height: auto;
    padding: 16px 0;
    gap: 16px;
  }

  .nav-links {
    flex-wrap: wrap;
    justify-content: center;
    gap: 16px;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .hero-img-mono {
    height: 320px;
  }

  .features-grid,
  .media-ai-grid,
  .pricing-grid,
  .reviews-grid,
  .articles-grid {
    grid-template-columns: 1fr;
  }

  .hero-meta-stats {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .footer-nav-four {
    flex-direction: column;
    gap: 16px;
  }

  .btn {
    width: 100%;
    padding: 16px 20px; /* 便于移动端手指大面积点击 */
  }

  .hero-cta-group {
    flex-direction: column;
  }
}