/* SNU Style Course Page CSS */

:root {
  --snu-blue: #0033A0;
  --snu-blue-dark: #002266;
  --snu-blue-light: #E8F0FE;
  --text-dark: #333333;
  --text-light: #666666;
  --bg-white: #ffffff;
  --bg-light: #f8f9fa;
  --border-color: #e0e0e0;
}

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

body {
  font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  line-height: 1.6;
  color: var(--text-dark);
  background-color: var(--bg-white);
}

/* Header & Navigation */
header {
  background-color: var(--snu-blue);
  color: white;
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: white;
  text-decoration: none;
}

.logo:hover {
  opacity: 0.9;
}

nav ul {
  display: flex;
  list-style: none;
  gap: 2rem;
}

nav a {
  color: white;
  text-decoration: none;
  font-weight: 500;
  padding: 0.5rem 0;
  border-bottom: 2px solid transparent;
  transition: border-color 0.2s;
}

nav a:hover,
nav a.active {
  border-bottom-color: white;
}

/* Hero Section */
.hero {
  background: linear-gradient(135deg, var(--snu-blue) 0%, var(--snu-blue-dark) 100%);
  color: white;
  padding: 4rem 2rem;
  text-align: center;
}

.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  font-weight: 700;
}

.hero .subtitle {
  font-size: 1.25rem;
  opacity: 0.9;
  margin-bottom: 0.5rem;
}

.hero .course-code {
  font-size: 1rem;
  opacity: 0.8;
}

/* Main Content */
main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
}

section {
  margin-bottom: 3rem;
}

h2 {
  color: var(--snu-blue);
  font-size: 1.75rem;
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 3px solid var(--snu-blue);
}

h3 {
  color: var(--text-dark);
  font-size: 1.25rem;
  margin-bottom: 1rem;
  margin-top: 1.5rem;
}

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

/* Cards */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.card {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.5rem;
  transition: box-shadow 0.2s, transform 0.2s;
}

.card:hover {
  box-shadow: 0 4px 12px rgba(0,51,160,0.15);
  transform: translateY(-2px);
}

.card h3 {
  color: var(--snu-blue);
  margin-top: 0;
  margin-bottom: 0.75rem;
}

.card p {
  color: var(--text-light);
  font-size: 0.95rem;
}

.card a {
  display: inline-block;
  margin-top: 1rem;
  color: var(--snu-blue);
  text-decoration: none;
  font-weight: 500;
}

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

/* Info Box */
.info-box {
  background: var(--snu-blue-light);
  border-left: 4px solid var(--snu-blue);
  padding: 1.5rem;
  border-radius: 0 8px 8px 0;
  margin: 1.5rem 0;
}

.info-box h3 {
  color: var(--snu-blue);
  margin-top: 0;
}

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.95rem;
}

thead {
  background-color: var(--snu-blue);
  color: white;
}

th {
  padding: 1rem;
  text-align: left;
  font-weight: 600;
}

td {
  padding: 1rem;
  border-bottom: 1px solid var(--border-color);
  vertical-align: top;
}

tbody tr:hover {
  background-color: var(--snu-blue-light);
}

tbody tr:nth-child(even) {
  background-color: var(--bg-light);
}

tbody tr:nth-child(even):hover {
  background-color: var(--snu-blue-light);
}

/* Lists */
ul, ol {
  margin: 1rem 0;
  padding-left: 1.5rem;
}

li {
  margin-bottom: 0.5rem;
}

/* Links */
a {
  color: var(--snu-blue);
}

a:hover {
  text-decoration: underline;
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  background-color: var(--snu-blue);
  color: white;
  text-decoration: none;
  border-radius: 4px;
  font-weight: 500;
  transition: background-color 0.2s;
}

.btn:hover {
  background-color: var(--snu-blue-dark);
  text-decoration: none;
}

.btn-outline {
  background-color: transparent;
  border: 2px solid var(--snu-blue);
  color: var(--snu-blue);
}

.btn-outline:hover {
  background-color: var(--snu-blue);
  color: white;
}

/* Instructor Section */
.instructors {
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
}

.instructor {
  flex: 1;
  min-width: 250px;
}

.instructor h4 {
  color: var(--snu-blue);
  margin-bottom: 0.5rem;
}

.instructor p {
  color: var(--text-light);
  font-size: 0.95rem;
  margin-bottom: 0.25rem;
}

/* Announcements */
.announcement {
  background: var(--bg-light);
  border-radius: 8px;
  padding: 1rem 1.5rem;
  margin-bottom: 1rem;
}

.announcement-date {
  color: var(--snu-blue);
  font-weight: 600;
  font-size: 0.9rem;
}

.announcement-content {
  margin-top: 0.5rem;
}

/* Assignment Card */
.assignment-card {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.assignment-card h3 {
  color: var(--snu-blue);
  margin-top: 0;
}

.assignment-meta {
  display: flex;
  gap: 1.5rem;
  margin: 1rem 0;
  font-size: 0.9rem;
  color: var(--text-light);
}

.assignment-meta span {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Footer */
footer {
  background-color: var(--text-dark);
  color: white;
  padding: 2rem;
  text-align: center;
  margin-top: 4rem;
}

footer p {
  color: rgba(255,255,255,0.8);
  font-size: 0.9rem;
}

footer a {
  color: white;
}

/* Responsive */
@media (max-width: 768px) {
  .header-container {
    flex-direction: column;
    gap: 1rem;
  }

  nav ul {
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

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

  main {
    padding: 1rem;
  }

  table {
    font-size: 0.85rem;
  }

  th, td {
    padding: 0.75rem 0.5rem;
  }

  .instructors {
    flex-direction: column;
  }
}

/* Week highlight for current week */
.current-week {
  background-color: var(--snu-blue-light) !important;
  border-left: 4px solid var(--snu-blue);
}

/* Badge */
.badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  background-color: var(--snu-blue);
  color: white;
  font-size: 0.8rem;
  border-radius: 12px;
  font-weight: 500;
}

.badge-outline {
  background-color: transparent;
  border: 1px solid var(--snu-blue);
  color: var(--snu-blue);
}

/* Resource list */
.resource-list {
  list-style: none;
  padding: 0;
}

.resource-list li {
  padding: 1rem;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 1rem;
}

.resource-list li:last-child {
  border-bottom: none;
}

.resource-icon {
  width: 40px;
  height: 40px;
  background-color: var(--snu-blue-light);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--snu-blue);
  font-weight: bold;
}