* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: 'Segoe UI', Arial, sans-serif; background: #f7f8fc; color: #2b2d42; }
.container { max-width: 1100px; margin: 0 auto; padding: 0 20px; }
a { text-decoration: none; color: #4361ee; }

.navbar { background: #fff; box-shadow: 0 2px 8px rgba(0,0,0,0.05); padding: 16px 0; margin-bottom: 20px; }
.navbar-inner { display: flex; justify-content: space-between; align-items: center; }
.logo { font-size: 22px; font-weight: 700; color: #4361ee; }
.admin-nav a { margin-left: 16px; color: #2b2d42; font-weight: 500; }

.hero { background: linear-gradient(135deg, #4361ee, #3a0ca3); color: #fff; padding: 60px 0; text-align: center; }
.hero h1 { font-size: 32px; margin-bottom: 12px; }
.hero p { font-size: 16px; opacity: 0.9; }

.courses { padding: 50px 0; }
.courses h2 { margin-bottom: 24px; }
.course-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 24px; }
.course-card { background: #fff; border-radius: 10px; overflow: hidden; box-shadow: 0 2px 10px rgba(0,0,0,0.06); transition: transform 0.2s; }
.course-card:hover { transform: translateY(-4px); }
.course-card img { width: 100%; height: 160px; object-fit: cover; background: #e9ecef; }
.course-card-body { padding: 16px; }
.course-card-body h3 { font-size: 18px; margin-bottom: 8px; }
.course-desc { color: #666; font-size: 14px; margin-bottom: 10px; }

.price-row { display: flex; align-items: center; gap: 10px; margin: 8px 0; }
.old-price { text-decoration: line-through; color: #999; font-size: 14px; }
.final-price { font-size: 20px; font-weight: 700; color: #2b2d42; }
.final-price-big { font-size: 28px; font-weight: 700; margin: 8px 0; }
.discount-badge { background: #e63946; color: #fff; font-size: 12px; padding: 2px 8px; border-radius: 12px; }
.validity { color: #4361ee; font-size: 13px; font-weight: 600; margin-bottom: 10px; }

.btn-enroll { display: inline-block; background: #4361ee; color: #fff; padding: 10px 20px; border-radius: 6px; border: none; cursor: pointer; font-size: 15px; font-weight: 600; }
.btn-enroll:hover { background: #3a0ca3; }
.full-width { width: 100%; text-align: center; }

.course-detail { padding: 40px 0; }
.course-detail-grid { display: grid; grid-template-columns: 2fr 1fr; gap: 30px; }
.detail-thumb { width: 100%; border-radius: 10px; margin-bottom: 16px; }
.enroll-box { background: #fff; padding: 24px; border-radius: 10px; box-shadow: 0 2px 10px rgba(0,0,0,0.06); height: fit-content; }

.enroll-form label, .auth-wrap label, .admin-form label { display: block; margin: 12px 0 6px; font-weight: 600; font-size: 14px; }
.enroll-form input, .auth-wrap input, .admin-form input, .admin-form select, .admin-form textarea {
    width: 100%; padding: 10px; border: 1px solid #ddd; border-radius: 6px; font-size: 14px;
}

.auth-wrap { max-width: 400px; margin: 60px auto; background: #fff; padding: 30px; border-radius: 10px; box-shadow: 0 2px 10px rgba(0,0,0,0.06); }
.error-msg { background: #ffe5e5; color: #e63946; padding: 10px; border-radius: 6px; margin-bottom: 12px; font-size: 14px; }

.checkout-wrap { max-width: 450px; margin: 80px auto; background: #fff; padding: 30px; border-radius: 10px; box-shadow: 0 2px 10px rgba(0,0,0,0.06); text-align: center; }
.success-box h2 { color: #2a9d8f; margin-bottom: 12px; }

.footer { background: #2b2d42; color: #fff; text-align: center; padding: 20px 0; margin-top: 60px; }

.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 20px; margin-top: 20px; }
.stat-card { background: #fff; padding: 24px; border-radius: 10px; text-align: center; box-shadow: 0 2px 10px rgba(0,0,0,0.06); }
.stat-card h3 { font-size: 28px; color: #4361ee; }

.flex-between { display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px; }
.admin-table { width: 100%; border-collapse: collapse; background: #fff; border-radius: 10px; overflow: hidden; }
.admin-table th, .admin-table td { padding: 12px 16px; text-align: left; border-bottom: 1px solid #eee; font-size: 14px; }
.admin-table th { background: #f4f6ff; }

.badge-active { background: #d1f7e6; color: #2a9d8f; padding: 3px 10px; border-radius: 10px; font-size: 12px; }
.badge-expired { background: #ffe5e5; color: #e63946; padding: 3px 10px; border-radius: 10px; font-size: 12px; }

.admin-form { background: #fff; padding: 24px; border-radius: 10px; max-width: 600px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

@media (max-width: 768px) {
    .course-detail-grid { grid-template-columns: 1fr; }
}