/* ============================================
   LinguaCook - 英语学习网站
   Clean, modern static site for ICP 备案
   ============================================ */

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #dbeafe;
  --text: #1e293b;
  --text-light: #64748b;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --border: #e2e8f0;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.08);
  --max-width: 960px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial,
    "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
}

/* ---- Navigation ---- */
.navbar {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

.navbar .container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.navbar .logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.navbar .logo span {
  font-size: 1.5rem;
}

.navbar nav a {
  color: var(--text-light);
  text-decoration: none;
  margin-left: 1.5rem;
  font-size: 0.95rem;
  transition: color 0.2s;
}

.navbar nav a:hover,
.navbar nav a.active {
  color: var(--primary);
}

/* ---- Hero Section ---- */
.hero {
  background: linear-gradient(135deg, #1e3a8a 0%, #2563eb 50%, #3b82f6 100%);
  color: #fff;
  padding: 5rem 1.5rem;
  text-align: center;
}

.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.hero p {
  font-size: 1.15rem;
  opacity: 0.9;
  max-width: 640px;
  margin: 0 auto 2rem;
}

.hero .btn {
  display: inline-block;
  background: #fff;
  color: var(--primary);
  padding: 0.75rem 2rem;
  border-radius: var(--radius);
  text-decoration: none;
  font-weight: 600;
  transition: transform 0.2s, box-shadow 0.2s;
}

.hero .btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

/* ---- Main Content ---- */
.main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 3rem 1.5rem;
}

.main h2 {
  font-size: 1.75rem;
  margin-bottom: 1.5rem;
  color: var(--text);
}

.main h3 {
  font-size: 1.35rem;
  margin: 2rem 0 1rem;
  color: var(--text);
}

.main p {
  margin-bottom: 1rem;
  color: var(--text);
}

.main ul,
.main ol {
  margin: 1rem 0 1.5rem 1.5rem;
}

.main li {
  margin-bottom: 0.5rem;
}

/* ---- Card Grid ---- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform 0.2s, box-shadow 0.2s;
  text-decoration: none;
  color: inherit;
  display: block;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.card img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.card .card-body {
  padding: 1.25rem;
}

.card .card-body h3 {
  font-size: 1.1rem;
  margin: 0 0 0.5rem;
  color: var(--text);
}

.card .card-body p {
  font-size: 0.9rem;
  color: var(--text-light);
  margin: 0;
}

.card .tag {
  display: inline-block;
  background: var(--primary-light);
  color: var(--primary);
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  font-size: 0.8rem;
  margin-top: 0.75rem;
}

/* ---- Features ---- */
.features {
  background: var(--bg-alt);
  padding: 3rem 1.5rem;
}

.features .container {
  max-width: var(--max-width);
  margin: 0 auto;
}

.features h2 {
  text-align: center;
  font-size: 1.75rem;
  margin-bottom: 2rem;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 2rem;
}

.feature-item {
  text-align: center;
  padding: 1.5rem;
}

.feature-item .icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.feature-item h3 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}

.feature-item p {
  font-size: 0.9rem;
  color: var(--text-light);
}

/* ---- Article Page ---- */
.article-header {
  text-align: center;
  padding: 3rem 1.5rem 1rem;
  max-width: var(--max-width);
  margin: 0 auto;
}

.article-header h1 {
  font-size: 2rem;
  margin-bottom: 0.75rem;
  font-weight: 700;
}

.article-header .meta {
  color: var(--text-light);
  font-size: 0.9rem;
}

.article-cover {
  max-width: var(--max-width);
  margin: 1.5rem auto;
  padding: 0 1.5rem;
}

.article-cover img {
  width: 100%;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  max-height: 480px;
  object-fit: cover;
}

.article-content {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
  font-size: 1.05rem;
}

.article-content p {
  margin-bottom: 1.25rem;
  line-height: 1.85;
}

.article-content blockquote {
  border-left: 4px solid var(--primary);
  padding: 1rem 1.5rem;
  margin: 1.5rem 0;
  background: var(--bg-alt);
  border-radius: 0 var(--radius) var(--radius) 0;
  font-style: italic;
  color: var(--text-light);
}

.article-content h2 {
  font-size: 1.5rem;
  margin: 2.5rem 0 1rem;
}

.article-content h3 {
  font-size: 1.25rem;
  margin: 2rem 0 0.75rem;
}

.article-content img {
  width: 100%;
  border-radius: var(--radius);
  margin: 1.5rem 0;
}

/* ---- Page Header (non-hero) ---- */
.page-header {
  background: linear-gradient(135deg, #1e3a8a, #2563eb);
  color: #fff;
  padding: 3rem 1.5rem;
  text-align: center;
}

.page-header h1 {
  font-size: 2rem;
  font-weight: 700;
}

.page-header p {
  opacity: 0.85;
  margin-top: 0.5rem;
}

/* ---- Privacy / Legal ---- */
.legal-content {
  max-width: 720px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
}

.legal-content h2 {
  font-size: 1.35rem;
  margin: 2rem 0 0.75rem;
  color: var(--text);
}

.legal-content p,
.legal-content li {
  font-size: 0.95rem;
  color: var(--text);
  line-height: 1.8;
}

/* ---- Footer ---- */
.footer {
  background: #0f172a;
  color: #cbd5e1;
  padding: 2.5rem 1.5rem;
  text-align: center;
  font-size: 0.85rem;
}

.footer a {
  color: #93c5fd;
  text-decoration: none;
}

.footer a:hover {
  text-decoration: underline;
}

.footer .links {
  margin-bottom: 1rem;
}

.footer .links a {
  margin: 0 0.75rem;
}

.footer .beian {
  margin-top: 0.75rem;
  font-size: 0.8rem;
  color: #94a3b8;
}

.footer .beian a {
  color: #94a3b8;
}

/* ---- Responsive ---- */
@media (max-width: 640px) {
  .hero h1 {
    font-size: 1.75rem;
  }

  .hero p {
    font-size: 1rem;
  }

  .navbar .container {
    flex-direction: column;
    height: auto;
    padding: 0.75rem 1rem;
    gap: 0.5rem;
  }

  .navbar nav a {
    margin-left: 0.75rem;
    font-size: 0.85rem;
  }

  .card-grid {
    grid-template-columns: 1fr;
  }

  .article-header h1 {
    font-size: 1.5rem;
  }
}

.logo-img {
    border: #1d4ed8;
    border-width: 2px;
    border-style: solid;
    border-radius: 5px;
}