/* Global Styles */
:root {
    --primary-color: #6366f1;
    --primary-light: #818cf8;
    --primary-dark: #4f46e5;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --info-color: #3b82f6;
    --bg-color: #f8fafc;
    --border-color: #e2e8f0;
    --text-color: #1e293b;
    --text-light: #64748b;
}

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

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

/* Navigation */
.navbar {
    background-color: white;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
    text-decoration: none;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-item {
    margin: 0;
}

.nav-link {
    color: var(--text-color);
    text-decoration: none;
    transition: color 0.3s;
}

.nav-link:hover {
    color: var(--primary-color);
}

.nav-link.logout {
    color: var(--error-color);
}

.nav-email {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 4rem 2rem;
    border-radius: 10px;
    margin-bottom: 3rem;
}

.hero-content {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

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

.hero p {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.auth-section {
    background: rgba(255, 255, 255, 0.1);
    padding: 2rem;
    border-radius: 8px;
    margin-top: 2rem;
}

.login-form {
    display: flex;
    gap: 1rem;
    max-width: 400px;
    margin: 0 auto;
}

.login-form .form-input {
    flex: 1;
    padding: 0.75rem;
    border: none;
    border-radius: 5px;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    text-decoration: none;
    transition: all 0.3s;
    font-weight: 500;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background-color: var(--secondary-color);
    color: white;
}

.btn-secondary:hover {
    background-color: #475569;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.1rem;
}

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
}

.btn-remove {
    background-color: transparent;
    border: none;
    color: var(--error-color);
    cursor: pointer;
    font-size: 1.2rem;
    padding: 0 0.5rem;
    margin-left: 0.5rem;
}

/* Features Section */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin: 3rem 0;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    text-align: center;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.feature-card h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
}

.feature-card p {
    color: var(--text-light);
}

/* Preferences Form */
.preferences-container {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    max-width: 700px;
    margin: 2rem auto;
}

.preferences-container h1 {
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--text-light);
    margin-bottom: 2rem;
}

fieldset {
    border: 1px solid var(--border-color);
    border-radius: 5px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

legend {
    padding: 0 0.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.field-description {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-top: 0.5rem;
    margin-bottom: 1rem;
}

.form-input {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.form-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

input[type="time"] {
    padding: 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: 5px;
}

input[type="number"] {
    padding: 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: 5px;
}

/* Course Selection */
.courses-container {
    margin-bottom: 1rem;
}

.course-input-group {
    display: flex;
    gap: 0.5rem;
}

.course-select {
    flex: 1;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 5px;
}

.courses-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1rem;
}

.course-tag {
    background: var(--primary-light);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

/* Day Checkboxes */
.days-checkboxes {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.days-checkboxes label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
}

input[type="checkbox"],
input[type="radio"] {
    cursor: pointer;
}

.checkbox-label {
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
    cursor: pointer;
}

.checkbox-label input {
    margin-top: 0.25rem;
}

/* Messages & Alerts */
.message {
    padding: 1rem;
    border-radius: 5px;
    margin-bottom: 1rem;
}

.message.success {
    background-color: #d1fae5;
    color: #065f46;
    border: 1px solid #6ee7b7;
}

.message.error {
    background-color: #fee2e2;
    color: #991b1b;
    border: 1px solid #fca5a5;
}

.alert {
    padding: 1rem;
    border-radius: 5px;
    margin-bottom: 1rem;
    border-left: 4px solid;
}

.alert-info {
    background-color: #dbeafe;
    color: #1e40af;
    border-left-color: #3b82f6;
}

.alert-warning {
    background-color: #fef3c7;
    color: #92400e;
    border-left-color: #f59e0b;
}

.alert-error {
    background-color: #fee2e2;
    color: #991b1b;
    border-left-color: #ef4444;
}

.alert-success {
    background-color: #d1fae5;
    color: #065f46;
    border-left-color: #10b981;
}

.alert-primary {
    background-color: #e0e7ff;
    color: #1e3a8a;
    border-left-color: #6366f1;
}

/* Loading */
.loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    padding: 2rem;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.hidden {
    display: none !important;
}

/* Schedules Display */
.schedules-container {
    background: white;
    padding: 2rem;
    border-radius: 8px;
}

.schedules-header {
    margin-bottom: 2rem;
}

.schedules-header h1 {
    margin-bottom: 0.5rem;
}

.schedule-count {
    color: var(--text-light);
    font-size: 1.1rem;
}

.schedules-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.schedule-card {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    transition: all 0.3s;
}

.schedule-card:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    border-color: var(--primary-color);
}

.schedule-card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.schedule-card-calendar {
    padding: 1rem;
}

.schedule-meta {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-bottom: 0.9rem;
}

.schedule-meta span {
    background: #f1f5f9;
    color: var(--text-light);
    border-radius: 999px;
    padding: 0.3rem 0.7rem;
    font-size: 0.78rem;
}

.week-calendar {
    display: grid;
    grid-template-columns: repeat(5, minmax(130px, 1fr));
    gap: 0.6rem;
    margin-bottom: 1rem;
}

.day-column {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: #fff;
    min-height: 180px;
    overflow: hidden;
}

.day-header {
    background: var(--primary-color);
    color: white;
    font-size: 0.78rem;
    font-weight: 600;
    padding: 0.4rem 0.5rem;
}

.day-content {
    padding: 0.45rem;
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.calendar-class-block {
    border: 1px solid rgba(15, 23, 42, 0.12);
    border-radius: 6px;
    padding: 0.4rem;
}

.class-code {
    font-size: 0.74rem;
    font-weight: 700;
    color: #0f172a;
}

.class-title {
    font-size: 0.72rem;
    color: #334155;
    margin: 0.15rem 0;
}

.class-time {
    font-size: 0.7rem;
    color: #475569;
}

.empty-day {
    font-size: 0.72rem;
    color: #94a3b8;
    font-style: italic;
}

.schedule-class-list {
    border-top: 1px solid var(--border-color);
    padding-top: 0.65rem;
}

.class-row {
    padding: 0.45rem 0;
    border-bottom: 1px dashed var(--border-color);
    font-size: 0.85rem;
}

.class-row:last-child {
    border-bottom: none;
}

.class-row-sub {
    color: var(--text-light);
    font-size: 0.78rem;
}

.schedule-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
}

.schedule-table th,
.schedule-table td {
    padding: 0.5rem;
    border-bottom: 1px solid var(--border-color);
    text-align: left;
}

.schedule-table th {
    background-color: var(--primary-light);
    color: white;
}

/* Payment Section */
.payment-section {
    background: linear-gradient(135deg, #e0e7ff 0%, #f0f4ff 100%);
    border: 2px solid var(--primary-color);
}

.payment-section h2 {
    color: var(--primary-dark);
    margin-bottom: 1rem;
}

.payment-info {
    background: white;
    padding: 1rem;
    border-radius: 5px;
    margin: 1rem 0;
}

.payment-info p {
    margin: 0.5rem 0;
}

.download-section {
    margin: 2rem 0;
    padding: 1.5rem;
    background: #f0fdf4;
    border: 1px dashed var(--success-color);
    border-radius: 5px;
}

.download-section h2 {
    color: var(--success-color);
    margin-bottom: 1rem;
}

/* Checkout Pages */
.checkout-success-container,
.checkout-cancel-container,
.error-container {
    max-width: 500px;
    margin: 3rem auto;
    padding: 2rem;
    background: white;
    border-radius: 8px;
    text-align: center;
}

.success-icon {
    font-size: 3rem;
    color: var(--success-color);
    margin-bottom: 1rem;
}

.checkout-success-container h1,
.checkout-cancel-container h1,
.error-container h1 {
    margin-bottom: 1rem;
}

.success-details {
    background: var(--bg-color);
    padding: 1rem;
    border-radius: 5px;
    margin: 2rem 0;
}

.button-group {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
    flex-wrap: wrap;
}

.button-group a {
    flex: 1;
    min-width: 150px;
}

/* Modal */
.modal {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    z-index: 2000;
    border-radius: 8px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    max-width: 500px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-content {
    padding: 2rem;
    position: relative;
}

.modal-close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-light);
}

.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1999;
}

/* Footer */
.footer {
    background-color: var(--text-color);
    color: white;
    text-align: center;
    padding: 2rem;
    margin-top: 3rem;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-menu {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .container {
        padding: 1rem;
    }
    
    .hero {
        padding: 2rem 1rem;
    }
    
    .hero h1 {
        font-size: 1.8rem;
    }
    
    .login-form {
        flex-direction: column;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .schedules-grid {
        grid-template-columns: 1fr;
    }

    .week-calendar {
        grid-template-columns: 1fr;
    }
}