/* ========================================
   Shared Styles - Course Landing Pages
   ======================================== */

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: 'Inter', 'Noto Sans TC', -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  line-height: 1.3;
  font-weight: 700;
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 4vw, 2.5rem); }
h3 { font-size: clamp(1.25rem, 3vw, 1.75rem); }

p {
  font-size: 1.125rem;
  line-height: 1.75;
}

/* Container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Section */
.section {
  padding: 5rem 0;
}

/* Button Base */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 1rem 2rem;
  font-size: 1.125rem;
  font-weight: 600;
  text-decoration: none;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.3s ease;
}

.btn:hover {
  transform: translateY(-2px);
}

/* Card Base */
.card {
  background: var(--card-bg, #fff);
  border-radius: 16px;
  padding: 2rem;
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(0,0,0,0.12);
}

/* Grid */
.grid {
  display: grid;
  gap: 2rem;
}

.grid-2 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); }

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }
.mt-2 { margin-top: 1rem; }
.mt-4 { margin-top: 2rem; }

/* Responsive */
@media (max-width: 768px) {
  .section {
    padding: 3rem 0;
  }
  
  .container {
    padding: 0 1rem;
  }
  
  .btn {
    width: 100%;
    padding: 1rem 1.5rem;
  }
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

.animate-fade-in {
  animation: fadeInUp 0.6s ease forwards;
}

.animate-delay-1 { animation-delay: 0.1s; }
.animate-delay-2 { animation-delay: 0.2s; }
.animate-delay-3 { animation-delay: 0.3s; }