/* CSS Variables for consistent theming */
:root {
    --primary-color: #7868E6;
    --secondary-color: #B8B5FF;
    --background-color: #EDEEF7;
    --accent-color: #E4FBFF;
    --error-color: #FFB4B4;
    --text-dark: #2c3e50;
    --text-light: #ffffff;
    --border-radius: 12px;
    --box-shadow: 0 4px 20px rgba(120, 104, 230, 0.15);
    --transition: all 0.3s ease;
    --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

/* Paper Texture Background */
body {
    background-color: var(--background-color);
    background-image: 
        radial-gradient(circle at 20% 50%, rgba(120, 104, 230, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(184, 181, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 80%, rgba(228, 251, 255, 0.2) 0%, transparent 50%);
    background-attachment: fixed;
    font-family: var(--font-family);
    margin: 0;
    padding: 0;
    min-height: 100vh;
    color: var(--text-dark);
    line-height: 1.6;
}

/* Reset and Base Styles */
* {
    box-sizing: border-box;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    text-align: center;
    margin-bottom: 40px;
    padding: 30px 0;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--border-radius);
    color: var(--text-light);
    box-shadow: var(--box-shadow);
}

.header h1 {
    margin: 0 0 10px 0;
    font-size: 2.5rem;
    font-weight: 700;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.header p {
    margin: 0;
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 30px;
}

/* Card Component */
.card {
    background: var(--text-light);
    border-radius: var(--border-radius);
    padding: 30px;
    box-shadow: var(--box-shadow);
    border: 1px solid rgba(120, 104, 230, 0.1);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(120, 104, 230, 0.2);
}

.card h2 {
    margin: 0 0 25px 0;
    color: var(--primary-color);
    font-size: 1.8rem;
    font-weight: 600;
}

/* Form Styles */
.return-form {
    display: grid;
    gap: 25px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-weight: 600;
    color: var(--text-dark);
    font-size: 1rem;
}

.form-group input,
.form-group select {
    padding: 12px 16px;
    border: 2px solid #e0e0e0;
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
    background: var(--text-light);
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(120, 104, 230, 0.1);
}

.form-group input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    height: 8px;
    background: linear-gradient(90deg, var(--secondary-color), var(--primary-color));
    border-radius: 4px;
    outline: none;
    padding: 0;
}

.form-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(120, 104, 230, 0.3);
}

.form-group input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 8px rgba(120, 104, 230, 0.3);
}

.range-value {
    font-weight: 600;
    color: var(--primary-color);
    text-align: center;
    font-size: 1.1rem;
}

.error-message {
    color: var(--error-color);
    font-size: 0.9rem;
    font-weight: 500;
    display: none;
}

.error-message.show {
    display: block;
}

/* Buttons */
.btn-primary,
.btn-secondary {
    padding: 14px 28px;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--text-light);
    box-shadow: var(--box-shadow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(120, 104, 230, 0.4);
}

.btn-secondary {
    background: var(--text-light);
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: var(--text-light);
}

.btn-primary:disabled,
.btn-secondary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

/* Timeline Controls */
.timeline-controls {
    display: flex;
    gap: 15px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

/* Timeline Styles */
.timeline-container {
    position: relative;
    padding: 20px 0;
}

.timeline-item {
    display: flex;
    align-items: center;
    margin-bottom: 30px;
    position: relative;
    padding-left: 50px;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 0;
    bottom: -30px;
    width: 2px;
    background: linear-gradient(180deg, var(--primary-color), var(--secondary-color));
}

.timeline-item:last-child::before {
    bottom: 50%;
}

.timeline-marker {
    position: absolute;
    left: 10px;
    top: 10px;
    width: 20px;
    height: 20px;
    background: var(--primary-color);
    border-radius: 50%;
    border: 4px solid var(--text-light);
    box-shadow: 0 2px 8px rgba(120, 104, 230, 0.3);
    z-index: 2;
}

.timeline-content {
    flex: 1;
    background: var(--accent-color);
    padding: 20px;
    border-radius: var(--border-radius);
    border-left: 4px solid var(--primary-color);
    transition: var(--transition);
}

.timeline-content:hover {
    transform: translateX(5px);
    box-shadow: 0 4px 15px rgba(120, 104, 230, 0.2);
}

.timeline-week {
    font-weight: 700;
    color: var(--primary-color);
    font-size: 1.2rem;
    margin-bottom: 8px;
}

.timeline-date {
    color: var(--text-dark);
    font-weight: 600;
    margin-bottom: 8px;
}

.timeline-hours {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 12px;
}

.timeline-activities {
    list-style: none;
    padding: 0;
    margin: 0;
}

.timeline-activities li {
    padding: 4px 0;
    color: var(--text-dark);
    position: relative;
    padding-left: 20px;
}

.timeline-activities li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* Checklist Styles */
.checklist-container {
    display: grid;
    gap: 20px;
}

.checklist-category {
    background: var(--accent-color);
    padding: 20px;
    border-radius: var(--border-radius);
    border-left: 4px solid var(--primary-color);
}

.checklist-category h3 {
    margin: 0 0 15px 0;
    color: var(--primary-color);
    font-size: 1.3rem;
}

.checklist-items {
    list-style: none;
    padding: 0;
    margin: 0;
}

.checklist-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 0;
    border-bottom: 1px solid rgba(120, 104, 230, 0.1);
}

.checklist-item:last-child {
    border-bottom: none;
}

.checklist-item input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--primary-color);
}

.checklist-item label {
    flex: 1;
    cursor: pointer;
    font-weight: 500;
}

.checklist-item.completed label {
    text-decoration: line-through;
    opacity: 0.7;
}

/* Saved Schedules */
.saved-schedules-container {
    display: grid;
    gap: 20px;
}

.saved-schedule {
    background: var(--accent-color);
    padding: 20px;
    border-radius: var(--border-radius);
    border-left: 4px solid var(--primary-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.saved-schedule-info h4 {
    margin: 0 0 8px 0;
    color: var(--primary-color);
    font-size: 1.2rem;
}

.saved-schedule-info p {
    margin: 0;
    color: var(--text-dark);
    font-size: 0.9rem;
}

.saved-schedule-actions {
    display: flex;
    gap: 10px;
}

.btn-small {
    padding: 8px 16px;
    font-size: 0.9rem;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
}

.btn-load {
    background: var(--primary-color);
    color: var(--text-light);
}

.btn-delete {
    background: var(--error-color);
    color: var(--text-dark);
}

.btn-small:hover {
    transform: translateY(-1px);
}

.no-schedules {
    text-align: center;
    color: var(--text-dark);
    opacity: 0.7;
    font-style: italic;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(237, 238, 247, 0.9);
    display: none;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    z-index: 1000;
}

.loading-overlay.show {
    display: flex;
}

.loading-spinner {
    width: 50px;
    height: 50px;
    border: 4px solid var(--secondary-color);
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 20px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 1001;
}

.modal.show {
    display: flex;
}

.modal-content {
    background: var(--text-light);
    padding: 30px;
    border-radius: var(--border-radius);
    max-width: 400px;
    width: 90%;
    text-align: center;
    box-shadow: var(--box-shadow);
}

.modal-content h3 {
    margin: 0 0 15px 0;
    color: var(--primary-color);
    font-size: 1.5rem;
}

.modal-content p {
    margin: 0 0 25px 0;
    color: var(--text-dark);
    line-height: 1.6;
}

.modal-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
}

/* Footer */
.footer {
    margin-top: 50px;
    padding: 30px 0;
    text-align: center;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--text-light);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

.footer p {
    margin: 0;
    font-size: 1rem;
    opacity: 0.9;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    .header h1 {
        font-size: 2rem;
    }
    
    .header p {
        font-size: 1rem;
    }
    
    .card {
        padding: 20px;
    }
    
    .timeline-controls {
        flex-direction: column;
    }
    
    .timeline-item {
        padding-left: 40px;
    }
    
    .timeline-marker {
        left: 5px;
        width: 16px;
        height: 16px;
    }
    
    .timeline-item::before {
        left: 12px;
    }
    
    .saved-schedule {
        flex-direction: column;
        gap: 15px;
        align-items: flex-start;
    }
    
    .saved-schedule-actions {
        align-self: stretch;
        justify-content: space-between;
    }
    
    .modal-buttons {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 1.8rem;
    }
    
    .card {
        padding: 15px;
    }
    
    .btn-primary,
    .btn-secondary {
        padding: 12px 20px;
        font-size: 0.9rem;
    }
    
    .timeline-content {
        padding: 15px;
    }
    
    .checklist-category {
        padding: 15px;
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --primary-color: #5a4bb8;
        --secondary-color: #8a87d4;
        --text-dark: #000000;
    }
    
    .card {
        border: 2px solid var(--primary-color);
    }
    
    .form-group input,
    .form-group select {
        border: 2px solid var(--text-dark);
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Print styles */
@media print {
    .timeline-controls,
    .btn-primary,
    .btn-secondary,
    .footer {
        display: none;
    }
    
    .card {
        box-shadow: none;
        border: 1px solid #ccc;
    }
    
    .timeline-item {
        break-inside: avoid;
    }
}