/* Course Listing and Topic Page Styles */

.course-header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 40px 30px;
  text-align: center;
}

.course-header h1 {
  font-size: 2.5em;
  margin-bottom: 15px;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.course-header p {
  font-size: 1.2em;
  opacity: 0.95;
}

.course-content {
  padding: 40px 30px;
  max-width: 1000px;
  margin: 0 auto;
}

.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 25px;
  margin-top: 30px;
}

.topic-card {
  background: white;
  border-radius: 12px;
  padding: 25px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  transition: all 0.3s ease;
  border: 2px solid transparent;
  cursor: pointer;
}

.topic-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
  border-color: #667eea;
}

.topic-card h3 {
  color: #667eea;
  font-size: 1.5em;
  margin-bottom: 15px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.topic-card p {
  color: #666;
  line-height: 1.6;
  margin-bottom: 15px;
}

.topic-card .topic-link {
  display: inline-block;
  color: #f5576c;
  text-decoration: none;
  font-weight: 600;
  transition: color 0.2s;
}

.topic-card .topic-link:hover {
  color: #764ba2;
}

/* Topic Page Styles */
.topic-page {
  padding: 40px 30px;
  max-width: 900px;
  margin: 0 auto;
}

.topic-page h1 {
  color: #667eea;
  font-size: 2.5em;
  margin-bottom: 20px;
  border-bottom: 4px solid #667eea;
  padding-bottom: 15px;
}

.topic-page h2 {
  color: #764ba2;
  font-size: 1.8em;
  margin-top: 40px;
  margin-bottom: 20px;
}

.topic-page h3 {
  color: #667eea;
  font-size: 1.4em;
  margin-top: 30px;
  margin-bottom: 15px;
}

.topic-page p {
  line-height: 1.8;
  margin-bottom: 20px;
  color: #444;
}

.topic-page ul,
.topic-page ol {
  margin: 20px 0;
  padding-left: 30px;
}

.topic-page li {
  margin: 10px 0;
  line-height: 1.6;
}

.topic-intro {
  background: linear-gradient(135deg, #f093fb15 0%, #f5576c15 100%);
  padding: 25px;
  border-radius: 12px;
  margin-bottom: 30px;
  border-left: 5px solid #f5576c;
}

.code-example {
  background: #f8f9fa;
  border-radius: 8px;
  padding: 20px;
  margin: 20px 0;
  border-left: 4px solid #667eea;
  overflow-x: auto;
}

.code-example h4 {
  color: #667eea;
  margin-bottom: 15px;
  font-size: 1.1em;
}

.code-example pre {
  background: #282c34;
  color: #abb2bf;
  padding: 20px;
  border-radius: 6px;
  overflow-x: auto;
  font-family: "Courier New", Courier, monospace;
  font-size: 0.95em;
  line-height: 1.5;
}

.code-example code {
  font-family: "Courier New", Courier, monospace;
}

.key-concepts {
  background: #fff9e6;
  padding: 25px;
  border-radius: 12px;
  margin: 30px 0;
  border-left: 5px solid #ffc107;
}

.key-concepts h3 {
  color: #f57c00;
  margin-top: 0;
}

.helpful-links {
  background: #e3f2fd;
  padding: 25px;
  border-radius: 12px;
  margin: 30px 0;
  border-left: 5px solid #2196f3;
}

.helpful-links h3 {
  color: #1976d2;
  margin-top: 0;
}

.helpful-links ul {
  margin: 15px 0;
  padding-left: 20px;
}

.helpful-links a {
  color: #1976d2;
  text-decoration: none;
  transition: color 0.2s;
}

.helpful-links a:hover {
  color: #0d47a1;
  text-decoration: underline;
}

.back-to-course {
  display: inline-block;
  margin: 30px 0;
  padding: 12px 25px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  text-decoration: none;
  border-radius: 8px;
  font-weight: 600;
  transition: all 0.3s;
}

.back-to-course:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
}

/* Badge for difficulty level */
.difficulty-badge {
  display: inline-block;
  padding: 5px 15px;
  border-radius: 20px;
  font-size: 0.85em;
  font-weight: 600;
  margin-left: 10px;
}

.difficulty-badge.beginner {
  background: #4caf50;
  color: white;
}

.difficulty-badge.intermediate {
  background: #ff9800;
  color: white;
}

/* Grades Page */
.grades-board {
  background: white;
  border-radius: 12px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  padding: 20px;
  margin-top: 20px;
}

.grades-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.grades-toolbar h2 {
  margin: 0;
}

.grades-table-wrap {
  overflow-x: auto;
}

.grades-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 760px;
}

.grades-table th,
.grades-table td {
  border-bottom: 1px solid #e6e8ef;
  text-align: left;
  padding: 12px;
  vertical-align: middle;
}

.grades-table th {
  background: #f8f9fa;
  color: #3b4583;
  font-weight: 700;
}

.type-badge,
.status-badge {
  display: inline-block;
  border-radius: 999px;
  padding: 4px 10px;
  font-size: 0.85em;
  font-weight: 700;
}

.type-badge.assignment {
  background: #e6f4ea;
  color: #1b5e20;
}

.type-badge.quiz {
  background: #e3f2fd;
  color: #0d47a1;
}

.type-badge.log {
  background: #fbe3d3;
  color: #c4680c;
}

.status-badge.graded {
  background: #ede7f6;
  color: #4527a0;
}

.status-badge.submitted {
  background: #fff4e5;
  color: #9c4a00;
}

.status-badge.assigned {
  background: #eceff1;
  color: #37474f;
}

.feedback-button {
  display: inline-block;
  text-decoration: none;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border-radius: 8px;
  padding: 8px 12px;
  font-weight: 600;
  font-size: 0.9em;
}

.feedback-button:hover {
  filter: brightness(1.05);
}

.feedback-pending {
  color: #6c757d;
  font-size: 0.9em;
}

/* Responsive */
@media (max-width: 768px) {
  .topic-grid {
    grid-template-columns: 1fr;
  }

  .course-header h1 {
    font-size: 1.8em;
  }

  .topic-page h1 {
    font-size: 2em;
  }

  .topic-page h2 {
    font-size: 1.5em;
  }

  .code-example pre {
    font-size: 0.85em;
  }

  .grades-table {
    min-width: 640px;
  }
}