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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

header {
    background: white;
    padding: 30px;
    border-radius: 20px;
    text-align: center;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    margin-bottom: 30px;
}

header h1 {
    color: #0891b2;
    font-size: 2.5em;
    margin-bottom: 10px;
}

.yugel-brand {
    color: #0891b2;
    font-size: 0.9em;
    margin-top: 10px;
    font-weight: 600;
}

.subtitle {
    color: #666;
    font-size: 1.1em;
}

.form-section {
    background: white;
    padding: 30px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.input-group {
    margin-bottom: 20px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    color: #333;
    font-weight: 600;
    font-size: 1em;
}

.input-group input,
.input-group select {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 1em;
    transition: all 0.3s ease;
}

.input-group input:focus,
.input-group select:focus {
    outline: none;
    border-color: #0891b2;
    box-shadow: 0 0 0 3px rgba(8, 145, 178, 0.1);
}

.kurs-form {
    background: #f8f9ff;
    padding: 25px;
    border-radius: 15px;
    margin: 25px 0;
}

.kurs-form h2 {
    color: #0891b2;
    margin-bottom: 20px;
    font-size: 1.5em;
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 20px;
}

.btn {
    padding: 15px 30px;
    border: none;
    border-radius: 10px;
    font-size: 1.1em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin: 5px;
}

.btn-primary {
    background: linear-gradient(135deg, #0891b2 0%, #06b6d4 100%);
    color: white;
    width: 100%;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(8, 145, 178, 0.4);
}

.btn-success {
    background: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
    color: white;
}

.btn-success:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(56, 239, 125, 0.4);
}

.btn-success:disabled {
    background: #ccc;
    cursor: not-allowed;
    transform: none;
}

.btn-danger {
    background: linear-gradient(135deg, #eb3349 0%, #f45c43 100%);
    color: white;
}

.btn-danger:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(235, 51, 73, 0.4);
}

.kurslar-listesi {
    margin: 25px 0;
}

.kurslar-listesi h2 {
    color: #0891b2;
    margin-bottom: 20px;
    font-size: 1.5em;
}

#kurslarContainer {
    display: grid;
    gap: 15px;
}

.kurs-card {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    padding: 20px;
    border-radius: 15px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    align-items: center;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    position: relative;
}

.kurs-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.kurs-info {
    display: flex;
    flex-direction: column;
}

.kurs-label {
    font-size: 0.85em;
    color: #666;
    margin-bottom: 3px;
}

.kurs-value {
    font-weight: 600;
    color: #333;
    font-size: 1em;
}

.btn-delete {
    background: #ff4757;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-delete:hover {
    background: #ff3838;
    transform: scale(1.05);
}

.actions {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 25px;
}

.empty-state {
    text-align: center;
    padding: 40px;
    color: #999;
    font-size: 1.1em;
}

@media (max-width: 768px) {
    header h1 {
        font-size: 1.8em;
    }
    
    .form-grid {
        grid-template-columns: 1fr;
    }
    
    .kurs-card {
        grid-template-columns: 1fr;
    }
    
    .actions {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
}

/* Auth Pages */
.auth-container {
    max-width: 450px;
    margin: 50px auto;
    background: white;
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.auth-header {
    text-align: center;
    margin-bottom: 30px;
}

.auth-header h1 {
    color: #0891b2;
    font-size: 2em;
    margin-bottom: 10px;
}

.auth-header .yugel-logo {
    font-size: 1.2em;
    color: #0891b2;
    font-weight: 700;
    margin-bottom: 5px;
}

.auth-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.auth-link {
    text-align: center;
    margin-top: 20px;
    color: #666;
}

.auth-link a {
    color: #0891b2;
    text-decoration: none;
    font-weight: 600;
}

.auth-link a:hover {
    text-decoration: underline;
}

.logout-btn {
    background: #ef4444;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    margin-left: 15px;
}

.logout-btn:hover {
    background: #dc2626;
}

.user-info {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: #f0f9ff;
    padding: 15px 20px;
    border-radius: 10px;
    margin-bottom: 20px;
}

.user-name {
    color: #0891b2;
    font-weight: 600;
    font-size: 1.1em;
}

/* Payment Page */
.payment-container {
    max-width: 600px;
    margin: 50px auto;
}

.payment-box {
    background: white;
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.payment-header {
    text-align: center;
    margin-bottom: 30px;
}

.payment-header h1 {
    color: #0891b2;
    font-size: 2em;
    margin-bottom: 10px;
}

.price-tag {
    font-size: 3em;
    color: #0891b2;
    font-weight: 700;
    text-align: center;
    margin: 20px 0;
}

.demo-warning {
    background: #fef3c7;
    border: 2px solid #f59e0b;
    padding: 20px;
    border-radius: 10px;
    margin: 20px 0;
    text-align: center;
}

.demo-warning strong {
    color: #dc2626;
    font-size: 1.1em;
}

.sample-card {
    background: #f0f9ff;
    padding: 20px;
    border-radius: 10px;
    margin: 20px 0;
    border: 2px dashed #0891b2;
}

.sample-card h3 {
    color: #0891b2;
    margin-bottom: 15px;
    text-align: center;
}

.card-info {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
    margin-top: 10px;
}

.card-info-item {
    background: white;
    padding: 10px;
    border-radius: 5px;
    text-align: center;
}

.card-info-label {
    font-size: 0.85em;
    color: #666;
    margin-bottom: 5px;
}

.card-info-value {
    font-weight: 700;
    color: #0891b2;
    font-size: 1.1em;
    cursor: pointer;
}

.card-info-value:hover {
    color: #06b6d4;
}

.copy-btn {
    background: #0891b2;
    color: white;
    border: none;
    padding: 8px 15px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.9em;
    margin-top: 10px;
}

.copy-btn:hover {
    background: #06b6d4;
}

.payment-form {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-top: 20px;
}

.card-row {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 15px;
}

.features-list {
    background: #f0f9ff;
    padding: 20px;
    border-radius: 10px;
    margin: 20px 0;
}

.features-list h3 {
    color: #0891b2;
    margin-bottom: 15px;
}

.features-list ul {
    list-style: none;
    padding: 0;
}

.features-list li {
    padding: 8px 0;
    color: #333;
}

.features-list li:before {
    content: "✓ ";
    color: #10b981;
    font-weight: bold;
    margin-right: 8px;
}