@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background-color: #f8fafc;
  color: #0f172a;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  min-height: 100vh;
  padding: 0 16px;
}

/* Card Container Top Positioned */
.card {
  background: #ffffff;
  padding: 32px;
  border-radius: 12px;
  border: 1px solid #e2e8f0;
  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.05);
  width: 100%;
  max-width: 420px;
  margin-top: 50px;
  margin-bottom: 50px;
}

.card-wide {
  max-width: 750px;
}

h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: #0f172a;
  margin-bottom: 20px;
  letter-spacing: -0.02em;
}

h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: #334155;
  margin-bottom: 12px;
}

/* Form Inputs */
.input-field {
  width: 100%;
  padding: 12px 16px;
  margin-bottom: 12px;
  border: 1px solid #cbd5e1;
  border-radius: 8px;
  font-size: 0.95rem;
  color: #0f172a;
  outline: none;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.input-field:focus {
  border-color: #2563eb;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

/* Reusable Buttons */
.btn-group {
  display: flex;
  gap: 10px;
  margin-top: 8px;
}

.btn {
  display: inline-block;
  width: 100%;
  padding: 12px 16px;
  border: none;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.15s ease, transform 0.1s ease;
  text-align: center;
  text-decoration: none;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background-color: #2563eb;
  color: #ffffff;
}

.btn-primary:hover {
  background-color: #1d4ed8;
}

.btn-secondary {
  background-color: #f1f5f9;
  color: #334155;
  border: 1px solid #e2e8f0;
}

.btn-secondary:hover {
  background-color: #e2e8f0;
}

.btn-link {
  background: none;
  border: none;
  color: #64748b;
  font-size: 0.875rem;
  font-weight: 500;
  margin-top: 14px;
  width: 100%;
  cursor: pointer;
  text-decoration: underline;
}

.btn-link:hover {
  color: #0f172a;
}

.btn-danger {
  background-color: #ef4444;
  color: #ffffff;
  margin-top: 20px;
}

.btn-danger:hover {
  background-color: #dc2626;
}

/* User Badge & Dynamic Course Container */
.user-badge {
  font-size: 0.9rem;
  color: #64748b;
  background: #f1f5f9;
  padding: 8px 12px;
  border-radius: 6px;
  margin-bottom: 24px;
  display: inline-block;
  font-weight: 500;
}

.courses-box {
  background: #f8fafc;
  padding: 20px;
  border-radius: 12px;
  border: 1px solid #e2e8f0;
}

.course-list {
  list-style-type: none;
}

.course-item {
  background: #ffffff;
  border: 1px solid #e2e8f0;
  border-radius: 8px;
  margin-bottom: 10px;
  transition: transform 0.15s ease, border-color 0.15s ease;
}

.course-item:hover {
  transform: translateY(-2px);
  border-color: #cbd5e1;
}

.course-link {
  display: block;
  padding: 14px 16px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  color: #2563eb;
}

.nav-back { display: inline-block; width: auto; margin-bottom: 20px; }
.lesson-display { margin-top: 20px; }
.lesson-body { line-height: 1.6; color: #334155; margin-top: 15px; }
.text-muted { color: #64748b; }

.video-container {
  position: relative;
  padding-bottom: 56.25%;
  height: 0;
  overflow: hidden;
  margin-bottom: 20px;
  border-radius: 8px;
}

.video-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}