/* ==========================================================================
   CordCloud 瑞士工业制图风格 (Swiss Engineering Blueprint Theme)
   规范要求：
   1. 画布：暖纸色 #F2EFE7 背景、近黑墨色 #17150F 文字
   2. 信号橙强调色：#E4572E 仅用于辅助线、编号与主按钮
   3. 字体：Space Grotesk 700 收紧字距（标题）、IBM Plex Sans（正文）、IBM Plex Mono（标签与数字）
   4. 76px 极细网格线背景，FIG 章节编号
   5. 直角、2px 黑边、无圆角、无阴影、无渐变，极简原生纯 CSS
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500;600;700&family=IBM+Plex+Sans:wght@400;500;600;700&family=Space+Grotesk:wght@700&display=swap');

:root {
  --bg-paper: #F2EFE7;
  --text-ink: #17150F;
  --accent-orange: #E4572E;
  --grid-line: rgba(23, 21, 15, 0.08);
  --border-dark: #17150F;
  --border-light: rgba(23, 21, 15, 0.2);
  --white: #FFFFFF;
  --font-heading: 'Space Grotesk', -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-body: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, "SF Mono", Consolas, monospace;
  --grid-size: 76px;
}

/* 基础重置 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  border-radius: 0 !important;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  background-color: var(--bg-paper);
}

body {
  font-family: var(--font-body);
  color: var(--text-ink);
  background-color: var(--bg-paper);
  background-image: 
    linear-gradient(to right, var(--grid-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid-line) 1px, transparent 1px);
  background-size: var(--grid-size) var(--grid-size);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  position: relative;
}

/* 技术制图顶底刻度指示 */
.blueprint-edge-marker {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background-color: var(--accent-orange);
  z-index: 1000;
}

/* 版心容器 */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 标头技术编号与标签系统 */
.tech-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-ink);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 3px 8px;
  background: transparent;
  border: 1px solid var(--border-dark);
  margin-bottom: 12px;
}

.tech-label .code-accent {
  color: var(--accent-orange);
  font-weight: 700;
}

.fig-badge {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent-orange);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  display: block;
  margin-bottom: 6px;
}

/* 标题样式 */
h1, h2, h3, h4 {
  font-family: var(--font-heading);
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.15;
  color: var(--text-ink);
}

h1 {
  font-size: clamp(2.4rem, 5.5vw, 4.4rem);
  text-transform: uppercase;
  margin-bottom: 20px;
}

h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  margin-bottom: 12px;
}

h3 {
  font-size: 1.35rem;
  margin-bottom: 8px;
}

p {
  color: rgba(23, 21, 15, 0.88);
  font-size: 1.05rem;
}

/* 按钮规范 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 14px 28px;
  border: 2px solid var(--border-dark);
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.15s ease, color 0.15s ease, border-color 0.15s ease;
  line-height: 1;
}

.btn-primary {
  background-color: var(--accent-orange);
  color: var(--text-ink);
  border-color: var(--border-dark);
}

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

.btn-secondary {
  background-color: transparent;
  color: var(--text-ink);
  border-color: var(--border-dark);
}

.btn-secondary:hover {
  background-color: var(--accent-orange);
  color: var(--text-ink);
}

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
}

/* 顶部导航 Header */
.site-header {
  border-bottom: 2px solid var(--border-dark);
  background: var(--bg-paper);
  position: sticky;
  top: 0;
  z-index: 999;
}

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

/* Logo 规范: 2.5px 黑色描边正方形，内含一个实心橙色四分之一圆光圈 */
.brand-logo-link {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text-ink);
}

.logo-graphic {
  width: 32px;
  height: 32px;
  border: 2.5px solid var(--border-dark);
  background-color: var(--bg-paper);
  position: relative;
  overflow: hidden;
  display: block;
}

.logo-graphic::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: var(--accent-orange);
  clip-path: circle(100% at 0% 0%);
}

.brand-wordmark {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  text-transform: uppercase;
}

.brand-wordmark span {
  color: var(--accent-orange);
}

/* 导航链接 */
.site-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-link {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-ink);
  text-decoration: none;
  text-transform: uppercase;
  padding: 6px 0;
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background-color: var(--accent-orange);
  transition: width 0.2s ease;
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

.nav-btn {
  padding: 10px 18px;
  font-size: 0.82rem;
}

/* 章节通用样式 */
.section {
  padding: 96px 0;
  border-bottom: 2px solid var(--border-dark);
  position: relative;
}

.section-header {
  margin-bottom: 56px;
  border-left: 4px solid var(--accent-orange);
  padding-left: 20px;
}

.section-desc {
  max-width: 680px;
  margin-top: 10px;
  color: rgba(23, 21, 15, 0.75);
}

/* 主视觉区 (Hero) */
.hero-section {
  padding: 88px 0 96px 0;
  border-bottom: 2px solid var(--border-dark);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.95fr;
  gap: 48px;
  align-items: center;
}

.hero-content {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.hero-subtitle {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--accent-orange);
  margin-bottom: 12px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.hero-intro {
  font-size: 1.15rem;
  line-height: 1.7;
  margin-bottom: 32px;
  color: rgba(23, 21, 15, 0.9);
}

.hero-specs-board {
  border: 2px solid var(--border-dark);
  background: var(--bg-paper);
  padding: 24px;
}

.specs-header {
  display: flex;
  justify-content: space-between;
  border-bottom: 1px solid var(--border-dark);
  padding-bottom: 12px;
  margin-bottom: 16px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
}

.specs-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.spec-item {
  border: 1px solid var(--border-light);
  padding: 12px;
  background: rgba(255, 255, 255, 0.5);
}

.spec-title {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  color: rgba(23, 21, 15, 0.6);
  margin-bottom: 4px;
}

.spec-val {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-ink);
}

.spec-val span {
  color: var(--accent-orange);
}

/* 核心特性 3个图文卡片 (Feature Cards) */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  border: 2px solid var(--border-dark);
  background: var(--bg-paper);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.feature-card:hover {
  border-color: var(--accent-orange);
}

.feature-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 12px;
  margin-bottom: 20px;
}

.feature-icon-box {
  width: 48px;
  height: 48px;
  border: 1.5px solid var(--border-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  background: rgba(255, 255, 255, 0.6);
}

.feature-card h3 {
  margin-bottom: 12px;
  font-size: 1.3rem;
}

.feature-card p {
  font-size: 0.95rem;
  color: rgba(23, 21, 15, 0.85);
  line-height: 1.65;
}

/* 流媒体与 AI 支持图卡 */
.media-ai-container {
  border: 2px solid var(--border-dark);
  background: var(--bg-paper);
}

.media-ai-tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border-bottom: 2px solid var(--border-dark);
}

.media-ai-column {
  padding: 36px 32px;
}

.media-ai-column:first-child {
  border-right: 2px solid var(--border-dark);
}

.media-ai-column h3 {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  font-size: 1.35rem;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

.tag-pill {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  border: 1px solid var(--border-dark);
  padding: 6px 12px;
  background: rgba(255, 255, 255, 0.7);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.tag-pill .dot {
  width: 6px;
  height: 6px;
  background-color: var(--accent-orange);
  display: inline-block;
}

/* 价格对比表 (Pricing) */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.pricing-card {
  border: 2px solid var(--border-dark);
  background: var(--bg-paper);
  padding: 28px 20px;
  display: flex;
  flex-direction: column;
  position: relative;
}

.pricing-card.featured {
  border: 2px solid var(--accent-orange);
  background: #FFFDF9;
}

.pricing-featured-tag {
  position: absolute;
  top: -14px;
  right: 16px;
  background: var(--accent-orange);
  color: var(--text-ink);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  padding: 3px 8px;
  border: 1px solid var(--border-dark);
}

.pricing-name {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  margin-bottom: 8px;
}

.pricing-price-wrap {
  margin: 16px 0;
  padding: 12px 0;
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.pricing-price {
  font-family: var(--font-mono);
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--text-ink);
}

.pricing-price span {
  font-size: 0.85rem;
  font-weight: 500;
  color: rgba(23, 21, 15, 0.65);
}

.pricing-list {
  list-style: none;
  margin-bottom: 24px;
  flex-grow: 1;
}

.pricing-list li {
  font-size: 0.9rem;
  padding: 6px 0;
  border-bottom: 1px dashed rgba(23, 21, 15, 0.15);
  display: flex;
  align-items: center;
  gap: 8px;
}

.pricing-list li::before {
  content: '+';
  color: var(--accent-orange);
  font-weight: 700;
  font-family: var(--font-mono);
}

/* 常见问题解答 (FAQ) */
.faq-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.faq-item {
  border: 2px solid var(--border-dark);
  background: var(--bg-paper);
  padding: 24px;
}

.faq-item h3 {
  font-size: 1.15rem;
  margin-bottom: 12px;
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.faq-item h3 .q-num {
  font-family: var(--font-mono);
  color: var(--accent-orange);
  font-weight: 700;
}

.faq-item p {
  font-size: 0.95rem;
  color: rgba(23, 21, 15, 0.85);
  line-height: 1.6;
}

/* 用户评价 (Reviews) */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  border: 2px solid var(--border-dark);
  background: var(--bg-paper);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.review-rating {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--accent-orange);
  margin-bottom: 12px;
  font-weight: 700;
}

.review-content {
  font-size: 0.95rem;
  line-height: 1.65;
  margin-bottom: 20px;
}

.review-author {
  border-top: 1px solid var(--border-light);
  padding-top: 12px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.author-name {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.95rem;
}

.author-title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: rgba(23, 21, 15, 0.6);
  text-transform: uppercase;
}

/* 页脚规范：页脚只保留这四个标题，内容打开新的页面展示 */
.site-footer {
  border-top: 2px solid var(--border-dark);
  background: var(--bg-paper);
  padding: 48px 0 36px 0;
}

.footer-nav-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  border-bottom: 2px solid var(--border-dark);
  padding-bottom: 36px;
  margin-bottom: 28px;
}

.footer-nav-col h4 {
  font-family: var(--font-mono);
  font-size: 1rem;
  text-transform: uppercase;
  margin-bottom: 16px;
  letter-spacing: 0.05em;
}

.footer-nav-col h4 a {
  color: var(--text-ink);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1.5px solid var(--border-dark);
  background: rgba(255, 255, 255, 0.4);
  transition: all 0.15s ease;
}

.footer-nav-col h4 a:hover {
  background: var(--accent-orange);
  border-color: var(--border-dark);
}

.footer-nav-col p {
  font-size: 0.85rem;
  color: rgba(23, 21, 15, 0.65);
  line-height: 1.5;
}

.footer-bottom-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: rgba(23, 21, 15, 0.6);
}

/* 文章列表与文章页专项样式 */
.article-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.article-card {
  border: 2px solid var(--border-dark);
  background: var(--bg-paper);
  padding: 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: border-color 0.2s ease;
}

.article-card:hover {
  border-color: var(--accent-orange);
}

.article-card-header {
  margin-bottom: 16px;
}

.article-meta {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--accent-orange);
  margin-bottom: 8px;
  text-transform: uppercase;
}

.article-card-title {
  font-size: 1.25rem;
  line-height: 1.35;
  margin-bottom: 12px;
}

.article-card-title a {
  color: var(--text-ink);
  text-decoration: none;
}

.article-card-title a:hover {
  color: var(--accent-orange);
}

.article-excerpt {
  font-size: 0.95rem;
  color: rgba(23, 21, 15, 0.8);
  margin-bottom: 20px;
}

.article-body-wrapper {
  max-width: 860px;
  margin: 0 auto;
  background: var(--bg-paper);
  border: 2px solid var(--border-dark);
  padding: 48px;
}

.article-body-wrapper h1 {
  font-size: 2.2rem;
  margin-bottom: 16px;
}

.article-body-wrapper h2 {
  font-size: 1.5rem;
  margin: 32px 0 16px 0;
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 8px;
}

.article-body-wrapper h3 {
  font-size: 1.2rem;
  margin: 24px 0 12px 0;
}

.article-body-wrapper p {
  margin-bottom: 18px;
  line-height: 1.8;
}

.article-body-wrapper ul, .article-body-wrapper ol {
  margin-bottom: 20px;
  padding-left: 24px;
}

.article-body-wrapper li {
  margin-bottom: 8px;
}

.article-body-wrapper a {
  color: var(--text-ink);
  text-decoration: underline;
  text-decoration-color: var(--accent-orange);
  text-underline-offset: 4px;
  font-weight: 600;
}

.article-body-wrapper a:hover {
  color: var(--accent-orange);
}

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

@media (max-width: 768px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }
  .header-inner {
    height: auto;
    padding: 16px 0;
    flex-direction: column;
    gap: 16px;
  }
  .site-nav {
    flex-wrap: wrap;
    justify-content: center;
    gap: 14px;
  }
  .pricing-grid {
    grid-template-columns: 1fr;
  }
  .media-ai-tabs {
    grid-template-columns: 1fr;
  }
  .media-ai-column:first-child {
    border-right: none;
    border-bottom: 2px solid var(--border-dark);
  }
  .faq-grid {
    grid-template-columns: 1fr;
  }
  .reviews-grid {
    grid-template-columns: 1fr;
  }
  .footer-nav-grid {
    grid-template-columns: 1fr;
  }
  .article-grid {
    grid-template-columns: 1fr;
  }
  .article-body-wrapper {
    padding: 24px 16px;
  }
  .footer-bottom-info {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }
  .btn {
    width: 100%;
    padding: 16px 20px;
  }
  .btn-group {
    width: 100%;
    flex-direction: column;
  }
}