/* Modern MBTA Tracker Design System */
:root {
    /* Light Theme */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #e9ecef;
    --bg-card: #ffffff;
    --text-primary: #212529;
    --text-secondary: #495057;
    --text-muted: #6c757d;
    --border-color: #dee2e6;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
    
    /* MBTA Line Colors */
    --line-red: #DA020E;
    --line-blue: #003DA5;
    --line-orange: #ED8B00;
    --line-green: #00843D;
    
    /* Status Colors */
    --success: #28a745;
    --warning: #ffc107;
    --danger: #dc3545;
    --info: #17a2b8;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
}

[data-theme="dark"] {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-tertiary: #21262d;
    --bg-card: #161b22;
    --text-primary: #c9d1d9;
    --text-secondary: #8b949e;
    --text-muted: #6e7681;
    --border-color: #30363d;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.5);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.app-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-md);
    min-height: 100vh;
}

/* Header */
.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--border-color);
}

.header-content h1 {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
    letter-spacing: -0.02em;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
    font-weight: 500;
}

.theme-toggle {
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: 50%;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 1.5rem;
    transition: all 0.2s ease;
}

.theme-toggle:hover {
    background: var(--bg-tertiary);
    transform: scale(1.05);
}

/* Main Content */
.main-content {
    display: grid;
    gap: var(--spacing-lg);
}

/* Sections */
.section {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.section-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--text-primary);
}

.section-title .icon {
    font-size: 1.75rem;
}

/* Form Styles */
.trip-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form-group label {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Searchable Select */
.searchable-select {
    position: relative;
}

.searchable-select input[type="text"] {
    width: 100%;
    padding: 0.875rem 1rem;
    font-size: 1rem;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    transition: all 0.2s ease;
    font-weight: 500;
}

.searchable-select input[type="text"]:focus {
    outline: none;
    border-color: var(--line-blue);
    background: var(--bg-primary);
    box-shadow: 0 0 0 3px rgba(0, 61, 165, 0.1);
}

.dropdown-options {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    margin-top: 0.5rem;
    max-height: 400px;
    overflow-y: auto;
    z-index: 1000;
    box-shadow: var(--shadow-lg);
    display: none;
}

.searchable-select.open .dropdown-options {
    display: block;
}

.optgroup-label {
    padding: 0.75rem 1rem;
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    position: sticky;
    top: 0;
    z-index: 10;
}

.option {
    padding: 0.875rem 1rem;
    cursor: pointer;
    border-bottom: 1px solid var(--border-color);
    transition: background 0.15s ease;
    font-weight: 500;
}

.option:hover,
.option.selected {
    background: var(--bg-tertiary);
}

.option.hidden {
    display: none;
}

/* Buttons */
.btn-primary,
.btn-secondary {
    padding: 1rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
}

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

.btn-primary:hover {
    background: #002d7a;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover {
    background: var(--bg-tertiary);
    border-color: var(--text-secondary);
}

.btn-icon {
    font-size: 1.1rem;
}

/* Trip Results */
.trip-result {
    margin-top: var(--spacing-md);
}

.trip-plan-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    margin-top: var(--spacing-md);
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.trip-header {
    display: flex;
    align-items: baseline;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--border-color);
}

.trip-time {
    font-size: 4rem;
    font-weight: 800;
    line-height: 1;
    color: var(--text-primary);
}

.trip-time-unit {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-left: 0.25rem;
}

.trip-route {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-top: var(--spacing-xs);
}

.trip-meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.meta-badge {
    background: var(--bg-tertiary);
    padding: 0.5rem 1rem;
    border-radius: 100px;
    font-size: 0.9rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-primary);
}

.meta-badge .badge-icon {
    font-size: 1.1rem;
}

/* Trip Steps Timeline */
.trip-steps {
    position: relative;
    padding-left: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.trip-steps::before {
    content: '';
    position: absolute;
    left: 0.5rem;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--border-color);
}

.trip-step {
    position: relative;
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-md);
}

.step-indicator {
    position: absolute;
    left: -0.625rem;
    top: 0.5rem;
    width: 1.25rem;
    height: 1.25rem;
    border-radius: 50%;
    border: 3px solid var(--bg-card);
    z-index: 2;
}

.step-content {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
}

.step-content.transfer-step {
    background: var(--bg-tertiary);
    border: 2px solid var(--text-primary);
    border-style: dashed;
}

.step-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xs);
}

.step-station {
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--text-primary);
}

.step-time {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-secondary);
    background: var(--bg-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: 100px;
}

.step-description {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-top: var(--spacing-xs);
}

.step-line {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 100px;
    font-size: 0.85rem;
    font-weight: 700;
    color: white;
    margin-top: var(--spacing-xs);
}

.transfer-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 100px;
    font-size: 0.9rem;
    font-weight: 700;
    background: var(--bg-secondary);
    color: var(--text-primary);
    margin-top: var(--spacing-xs);
    border: 2px solid var(--text-primary);
}

/* Line Colors */
.line-red { background-color: var(--line-red); }
.line-blue { background-color: var(--line-blue); }
.line-orange { background-color: var(--line-orange); }
.line-green { background-color: var(--line-green); }
.line-transfer { background-color: var(--text-primary); }

/* Alerts */
.alert-card {
    background: #fff3cd;
    border: 2px solid #ffc107;
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
}

[data-theme="dark"] .alert-card {
    background: #3d2e00;
    border-color: #ffc107;
}

.alert-header {
    font-weight: 700;
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.alert-description {
    font-size: 0.95rem;
    line-height: 1.5;
}

/* Favorite Stations */
.add-favorite-form {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
}

.add-favorite-form .form-group {
    flex: 1;
}

.favorites-list {
    display: grid;
    gap: var(--spacing-md);
}

.favorite-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    transition: all 0.2s ease;
}

.favorite-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.favorite-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 1px solid var(--border-color);
}

.favorite-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.favorite-line {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
}

.remove-favorite-btn {
    background: transparent;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-muted);
    transition: all 0.2s ease;
    padding: 0.25rem;
    line-height: 1;
}

.remove-favorite-btn:hover {
    color: var(--danger);
    transform: scale(1.1);
}

/* Predictions */
.predictions-container {
    margin-top: var(--spacing-sm);
}

.predictions-loading {
    text-align: center;
    padding: var(--spacing-md);
    color: var(--text-muted);
    font-style: italic;
}

.predictions-empty {
    text-align: center;
    padding: var(--spacing-md);
    color: var(--text-muted);
    font-style: italic;
}

.direction-group {
    margin-bottom: var(--spacing-md);
}

.direction-header {
    font-weight: 700;
    font-size: 0.95rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.predictions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: var(--spacing-sm);
}

.prediction-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: var(--spacing-sm);
    transition: all 0.2s ease;
}

.prediction-card:hover {
    border-color: var(--line-blue);
    box-shadow: var(--shadow-sm);
}

.prediction-route {
    font-weight: 700;
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.prediction-time {
    display: flex;
    align-items: baseline;
    gap: var(--spacing-xs);
}

.minutes-away {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--line-blue);
}

.minutes-away.arriving-now {
    color: var(--success);
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.7;
    }
}

.time-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.arrival-time {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

/* Empty States */
.empty-state {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--text-muted);
}

.empty-state-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.empty-state-text {
    font-size: 1.1rem;
    font-weight: 500;
}

/* Responsive Design */
@media (max-width: 768px) {
    .app-container {
        padding: var(--spacing-sm);
    }

    .header-content h1 {
        font-size: 2rem;
    }

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

    .trip-time {
        font-size: 3rem;
    }

    .predictions-grid {
        grid-template-columns: 1fr;
    }

    .add-favorite-form {
        flex-direction: column;
    }
}

/* Utility Classes */
.hidden {
    display: none !important;
}

.text-center {
    text-align: center;
}

.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }

/* New Feature Styles */
.button-group {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.recent-searches {
    padding: var(--spacing-sm);
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.alternative-route {
    transition: all 0.2s ease;
}

.alternative-route:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.saved-trip-item {
    transition: all 0.2s ease;
}

.saved-trip-item:hover {
    box-shadow: var(--shadow-sm);
}