/* ============================================
   Smart AI Tools Review — Stylesheet
   Clean, professional, fast-loading
   ============================================ */

:root {
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-text: #1a1a2e;
  --color-text-secondary: #555;
  --color-text-muted: #888;
  --color-accent: #2563eb;
  --color-accent-dark: #1d4ed8;
  --color-accent-light: #eff6ff;
  --color-border: #e5e7eb;
  --color-code-bg: #f3f4f6;
  --color-success: #059669;
  --color-warning: #d97706;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-serif: 'Merriweather', Georgia, serif;
  --max-width: 1200px;
  --content-width: 780px;
  --radius: 12px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.1);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  color: var(--color-accent-dark);
}

img { max-width: 100%; height: auto; }

/* ---- Header ---- */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--color-text);
}

.logo:hover { color: var(--color-text); }

.logo-icon {
  font-size: 1.4rem;
}

.main-nav {
  display: flex;
  gap: 24px;
}

.main-nav a {
  color: var(--color-text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
}

.main-nav a:hover {
  color: var(--color-accent);
}

/* ---- Hero ---- */
.hero {
  background: linear-gradient(135deg, #1e3a5f 0%, #2563eb 100%);
  color: white;
  padding: 80px 0 64px;
  text-align: center;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
  line-height: 1.15;
}

.hero-subtitle {
  font-size: 1.2rem;
  opacity: 0.9;
  max-width: 640px;
  margin: 0 auto 40px;
  line-height: 1.6;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 48px;
}

.stat {
  display: flex;
  flex-direction: column;
}

.stat-number {
  font-size: 2rem;
  font-weight: 800;
}

.stat-label {
  font-size: 0.85rem;
  opacity: 0.7;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* ---- Articles Grid ---- */
.articles-section {
  padding: 64px 0;
}

.section-title {
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 32px;
  letter-spacing: -0.02em;
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 24px;
}

.article-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px;
  transition: box-shadow 0.2s, transform 0.2s;
}

.article-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.card-category {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-accent);
  margin-bottom: 12px;
}

.article-card h2 {
  font-size: 1.35rem;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 12px;
}

.article-card h2 a {
  color: var(--color-text);
}

.article-card h2 a:hover {
  color: var(--color-accent);
}

.card-description {
  color: var(--color-text-secondary);
  font-size: 0.95rem;
  margin-bottom: 16px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.card-tags {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.tag {
  background: var(--color-accent-light);
  color: var(--color-accent);
  padding: 2px 10px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 500;
}

.read-more {
  font-weight: 600;
  font-size: 0.95rem;
}

/* ---- About Section ---- */
.about-section {
  padding: 64px 0;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
}

.about-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.about-card {
  padding: 24px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  text-align: center;
}

.about-icon {
  font-size: 2rem;
  display: block;
  margin-bottom: 12px;
}

.about-card h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.about-card p {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
}

/* ---- Article Page ---- */
.article-page {
  padding: 48px 0 80px;
}

.article-page .container {
  max-width: var(--content-width);
}

.article-header {
  margin-bottom: 40px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--color-border);
}

.article-meta-top {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.category-badge {
  background: var(--color-accent);
  color: white;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.article-meta-top time {
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.article-header h1 {
  font-size: 2.4rem;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
}

.article-description {
  font-size: 1.15rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 16px;
}

.article-tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

/* ---- Article Content ---- */
.article-content {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  line-height: 1.8;
}

.article-content h2 {
  font-family: var(--font-sans);
  font-size: 1.6rem;
  font-weight: 700;
  margin-top: 48px;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
}

.article-content h3 {
  font-family: var(--font-sans);
  font-size: 1.2rem;
  font-weight: 600;
  margin-top: 32px;
  margin-bottom: 12px;
}

.article-content p {
  margin-bottom: 20px;
}

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

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

.article-content strong {
  font-weight: 700;
}

.article-content a {
  text-decoration: underline;
  text-underline-offset: 2px;
}

.article-content blockquote {
  border-left: 4px solid var(--color-accent);
  padding: 16px 24px;
  margin: 24px 0;
  background: var(--color-accent-light);
  border-radius: 0 var(--radius) var(--radius) 0;
  font-style: italic;
}

.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
  font-family: var(--font-sans);
  font-size: 0.9rem;
}

.article-content thead {
  background: var(--color-accent-light);
}

.article-content th {
  text-align: left;
  padding: 12px 16px;
  font-weight: 600;
  border-bottom: 2px solid var(--color-accent);
  color: var(--color-accent-dark);
}

.article-content td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--color-border);
}

.article-content tr:hover td {
  background: var(--color-accent-light);
}

.article-content code {
  background: var(--color-code-bg);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.9em;
}

.article-content pre {
  background: var(--color-code-bg);
  padding: 20px;
  border-radius: var(--radius);
  overflow-x: auto;
  margin: 24px 0;
}

.article-content pre code {
  background: none;
  padding: 0;
}

.article-content hr {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: 40px 0;
}

/* ---- Article Footer ---- */
.article-footer {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--color-border);
}

.share-section {
  background: var(--color-accent-light);
  padding: 24px;
  border-radius: var(--radius);
  margin-bottom: 24px;
  text-align: center;
}

.back-link {
  display: inline-block;
  font-weight: 600;
  font-size: 0.95rem;
}

/* ---- 404 ---- */
.not-found {
  text-align: center;
  padding: 120px 24px;
}

.not-found h1 {
  font-size: 6rem;
  font-weight: 800;
  color: var(--color-accent);
  line-height: 1;
}

.not-found p {
  font-size: 1.2rem;
  color: var(--color-text-secondary);
  margin: 16px 0 32px;
}

.btn {
  display: inline-block;
  background: var(--color-accent);
  color: white;
  padding: 12px 24px;
  border-radius: 8px;
  font-weight: 600;
  transition: background 0.2s;
}

.btn:hover {
  background: var(--color-accent-dark);
  color: white;
}

/* ---- Footer ---- */
.site-footer {
  background: var(--color-text);
  color: #ccc;
  padding: 48px 0 24px;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  gap: 48px;
  margin-bottom: 32px;
}

.footer-brand {
  max-width: 400px;
}

.footer-brand .logo-icon,
.footer-brand .logo-text {
  color: white;
}

.footer-brand .logo-text {
  font-weight: 700;
  font-size: 1.1rem;
  margin-left: 8px;
}

.footer-brand p {
  margin-top: 12px;
  font-size: 0.9rem;
  line-height: 1.6;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-links h4 {
  color: white;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 4px;
}

.footer-links a {
  color: #aaa;
  font-size: 0.9rem;
}

.footer-links a:hover { color: white; }

.footer-bottom {
  border-top: 1px solid #333;
  padding-top: 20px;
  font-size: 0.8rem;
  color: #888;
}

.affiliate-disclosure {
  margin-top: 8px;
  font-size: 0.75rem;
  color: #666;
}

/* ---- Responsive ---- */
@media (max-width: 768px) {
  .hero h1 { font-size: 2rem; }
  .hero-subtitle { font-size: 1rem; }
  .hero-stats { gap: 24px; }
  .stat-number { font-size: 1.4rem; }
  .hero { padding: 48px 0 40px; }

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

  .article-header h1 { font-size: 1.7rem; }
  .article-content { font-size: 1rem; }
  .article-content h2 { font-size: 1.3rem; }

  .footer-content {
    flex-direction: column;
    gap: 24px;
  }

  .article-content table {
    display: block;
    overflow-x: auto;
    white-space: nowrap;
  }
}

@media (max-width: 480px) {
  .site-header .container { padding: 0 16px; }
  .container { padding: 0 16px; }
  .article-card { padding: 20px; }
  .hero h1 { font-size: 1.6rem; }
}