/* ============================================
   RESET & BASE
   ============================================ */

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

:root {
  --primary-color: #0077b6;
  --secondary-color: #2ca58d;
  --text-primary: #1a1a1a;
  --text-secondary: #666666;
  --text-light: #999999;
  --background: #ffffff;
  --border-color: #e5e5e5;
  --hover-color: #f8f9fa;

  --font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    sans-serif;
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 3rem;
  --spacing-xl: 4rem;
  --spacing-2xl: 6rem;

  --container-max-width: 1200px;
  --content-max-width: 700px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-primary);
  background-color: var(--background);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */

h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: var(--spacing-sm);
}

h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 700;
}

h2 {
  font-size: clamp(2rem, 4vw, 3rem);
}

h3 {
  font-size: 1.5rem;
}

a {
  text-decoration: none;
  color: inherit;
  transition: color 0.3s ease;
}

p {
  margin-bottom: var(--spacing-sm);
}

/* ============================================
   UTILITIES
   ============================================ */

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

.gradient-text {
  background: linear-gradient(
    135deg,
    var(--primary-color),
    var(--secondary-color)
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.btn {
  display: inline-block;
  padding: 0.875rem 2rem;
  font-size: 1rem;
  font-weight: 500;
  border: none;
  border-radius: 50px;
  cursor: pointer;
  transition: all 0.3s ease;
  text-align: center;
  font-family: var(--font-family);
}

.btn-primary {
  background: var(--primary-color);
  color: white;
}

.btn-primary:hover {
  background: #005f94;
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(0, 119, 182, 0.2);
}

.btn-secondary {
  background: transparent;
  color: var(--text-primary);
  border: 2px solid var(--border-color);
}

.btn-secondary:hover {
  background: var(--hover-color);
  border-color: var(--primary-color);
  color: var(--primary-color);
}

/* ============================================
   HEADER
   ============================================ */

.header {
  position: sticky;
  top: 0;
  background: var(--background);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  backdrop-filter: blur(10px);
  background: rgba(255, 255, 255, 0.95);
}

.nav-wrapper {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) 0;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-weight: 600;
  font-size: 1.125rem;
}

.logo svg {
  stroke: var(--primary-color);
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: var(--spacing-md);
}

.nav-menu a {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  transition: color 0.3s ease;
}

.nav-menu a:hover {
  color: var(--text-primary);
}

.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.mobile-menu-toggle span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  transition: all 0.3s ease;
}

/* ============================================
   HERO SECTION
   ============================================ */

.hero {
  padding: var(--spacing-2xl) 0;
  text-align: center;
}

.hero-content {
  max-width: var(--content-max-width);
  margin: 0 auto;
}

.hero-title {
  margin-bottom: var(--spacing-md);
}

.hero-subtitle {
  font-size: 1.5rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-sm);
  font-weight: 300;
}

.hero-description {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
  line-height: 1.8;
}

.hero-cta {
  display: flex;
  gap: var(--spacing-sm);
  justify-content: center;
  flex-wrap: wrap;
}

/* ============================================
   FEATURES SECTION
   ============================================ */

.features {
  padding: var(--spacing-2xl) 0;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-lg);
}

.feature-card {
  padding: var(--spacing-lg);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  text-align: center;
  transition: all 0.3s ease;
}

.feature-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.05);
}

.feature-icon {
  margin-bottom: var(--spacing-sm);
  display: flex;
  justify-content: center;
}

.feature-card h3 {
  margin-bottom: var(--spacing-xs);
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

/* ============================================
   ARTICLES SECTION
   ============================================ */

.articles {
  padding: var(--spacing-2xl) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
  max-width: var(--content-max-width);
  margin-left: auto;
  margin-right: auto;
}

.section-title {
  margin-bottom: var(--spacing-xs);
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: var(--spacing-lg);
}

.article-card {
  background: var(--background);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  overflow: hidden;
  transition: all 0.3s ease;
}

.article-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.05);
}

.article-image {
  height: 200px;
  background: linear-gradient(135deg, #f5f7fa 0%, #e9ecef 100%);
  position: relative;
}

.placeholder-image {
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, #e3f2fd 0%, #bbdefb 100%);
  opacity: 0.7;
}

.article-content {
  padding: var(--spacing-md);
}

.article-meta {
  display: flex;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
}

.article-date,
.article-category {
  font-size: 0.8125rem;
  color: var(--text-light);
  font-weight: 500;
}

.article-category {
  color: var(--primary-color);
}

.article-title {
  margin-bottom: var(--spacing-xs);
  font-size: 1.25rem;
}

.article-excerpt {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  line-height: 1.6;
  margin-bottom: var(--spacing-sm);
}

.article-link {
  color: var(--primary-color);
  font-weight: 500;
  font-size: 0.9375rem;
  display: inline-flex;
  align-items: center;
  transition: all 0.3s ease;
}

.article-link:hover {
  gap: 8px;
}

/* ============================================
   ABOUT SECTION
   ============================================ */

.about {
  padding: var(--spacing-2xl) 0;
  background: var(--hover-color);
}

.about-content {
  max-width: var(--content-max-width);
  margin: 0 auto;
}

.about-description {
  font-size: 1.0625rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: var(--spacing-md);
}

.about-stats {
  display: flex;
  gap: var(--spacing-xl);
  margin-top: var(--spacing-lg);
  flex-wrap: wrap;
}

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

.stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  background: linear-gradient(
    135deg,
    var(--primary-color),
    var(--secondary-color)
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}

.stat-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: var(--spacing-xs);
}

/* ============================================
   NEWSLETTER SECTION
   ============================================ */

.newsletter {
  padding: var(--spacing-2xl) 0;
  text-align: center;
}

.newsletter-content {
  max-width: 600px;
  margin: 0 auto;
}

.newsletter-title {
  margin-bottom: var(--spacing-sm);
}

.newsletter-subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
}

.newsletter-form {
  display: flex;
  gap: var(--spacing-xs);
  max-width: 500px;
  margin: 0 auto var(--spacing-sm);
}

.newsletter-form input {
  flex: 1;
  padding: 0.875rem 1.5rem;
  font-size: 1rem;
  border: 2px solid var(--border-color);
  border-radius: 50px;
  outline: none;
  transition: all 0.3s ease;
  font-family: var(--font-family);
}

.newsletter-form input:focus {
  border-color: var(--primary-color);
}

.newsletter-disclaimer {
  font-size: 0.8125rem;
  color: var(--text-light);
}

/* ============================================
   FOOTER
   ============================================ */

.footer {
  padding: var(--spacing-xl) 0 var(--spacing-md);
  border-top: 1px solid var(--border-color);
  margin-top: var(--spacing-2xl);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-lg);
}

.footer-section h4 {
  font-size: 1rem;
  margin-bottom: var(--spacing-sm);
}

.footer-description {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: var(--spacing-xs);
}

.footer-links a {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  transition: color 0.3s ease;
}

.footer-links a:hover {
  color: var(--primary-color);
}

.social-links {
  display: flex;
  gap: var(--spacing-sm);
}

.social-links a {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border-color);
  border-radius: 50%;
  color: var(--text-secondary);
  transition: all 0.3s ease;
}

.social-links a:hover {
  color: var(--primary-color);
  border-color: var(--primary-color);
  transform: translateY(-2px);
}

.footer-bottom {
  text-align: center;
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--border-color);
  font-size: 0.875rem;
  color: var(--text-light);
}

/* ============================================
   RESPONSIVE
   ============================================ */

@media (max-width: 768px) {
  .container {
    padding: 0 var(--spacing-sm);
  }

  .hero {
    padding: var(--spacing-xl) 0;
  }

  .hero-subtitle {
    font-size: 1.25rem;
  }

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

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

  .hero-cta .btn {
    width: 100%;
  }

  .features,
  .articles,
  .about,
  .newsletter {
    padding: var(--spacing-xl) 0;
  }

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

  .mobile-menu-toggle {
    display: flex;
  }

  .nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--background);
    flex-direction: column;
    padding: var(--spacing-md);
    border-top: 1px solid var(--border-color);
  }

  .nav-menu.active {
    display: flex;
  }

  .newsletter-form {
    flex-direction: column;
  }

  .newsletter-form input,
  .newsletter-form button {
    width: 100%;
  }

  .about-stats {
    justify-content: center;
  }

  .footer-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .footer-section:first-child {
    text-align: center;
  }

  .social-links {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  :root {
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
  }

  .article-card {
    margin: 0;
  }

  .stat-item {
    flex: 1;
    text-align: center;
  }
}