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

:root {
    --spacing-unit: 8px;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;

    --color-primary: #0066FF;
    --color-primary-light: #E6F0FF;
    --color-primary-dark: #0052CC;

    --color-bg: #F5F7FA;
    --color-surface: #FFFFFF;
    --color-border: #E4E7EB;

    --color-text-primary: #1A1D1F;
    --color-text-secondary: #6F767E;
    --color-text-tertiary: #9A9FA5;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.12);
}

body {
    background: var(--color-bg);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    color: var(--color-text-primary);
    line-height: 1.5;
}

.app-container {
    min-height: 100vh;
    padding: calc(var(--spacing-unit) * 3) calc(var(--spacing-unit) * 2);
}

.content-wrapper {
    max-width: 800px;
    margin: 0 auto;
}

/* Header */
.page-header {
    text-align: center;
    margin-bottom: calc(var(--spacing-unit) * 4);
}

.page-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-text-primary);
    margin: 0;
}

/* Direction Selector */
.direction-selector {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: calc(var(--spacing-unit) * 2);
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.direction-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: calc(var(--spacing-unit));
    padding: calc(var(--spacing-unit) * 2);
    background: var(--color-surface);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    text-decoration: none;
    color: var(--color-text-secondary);
    font-weight: 600;
    transition: all 0.2s;
    box-shadow: var(--shadow-sm);
}

.direction-btn:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

.direction-icon {
    font-size: 1.5rem;
}

/* Date Selector */
.date-selector {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
    gap: calc(var(--spacing-unit));
    margin-bottom: calc(var(--spacing-unit) * 3);
    padding: calc(var(--spacing-unit));
    background: var(--color-surface);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.date-btn {
    padding: calc(var(--spacing-unit)) calc(var(--spacing-unit) * 2);
    background: transparent;
    border: 2px solid transparent;
    border-radius: var(--radius-sm);
    text-decoration: none;
    color: var(--color-text-secondary);
    font-weight: 500;
    font-size: 0.875rem;
    text-align: center;
    transition: all 0.2s;
}

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

.date-btn.active {
    background: var(--color-primary-light);
    border-color: var(--color-primary);
    color: var(--color-primary);
}

/* Filters */
.filters-card {
    background: var(--color-surface);
    padding: calc(var(--spacing-unit) * 3);
    border-radius: var(--radius-md);
    margin-bottom: calc(var(--spacing-unit) * 3);
    box-shadow: var(--shadow-sm);
}

.filter-row-inline {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: calc(var(--spacing-unit) * 3);
}

.filter-label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-text-primary);
}

.filter-dropdown-btn {
    width: 100%;
    padding: calc(var(--spacing-unit) * 1.5);
    background: var(--color-surface);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text-primary);
    font-weight: 500;
    text-align: left;
    transition: all 0.2s;
}

.filter-dropdown-btn:hover {
    border-color: var(--color-primary);
}

.toggle-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: calc(var(--spacing-unit));
    padding: calc(var(--spacing-unit) * 1.5);
    background: var(--color-surface);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    font-weight: 500;
    transition: all 0.2s;
    cursor: pointer;
}

.toggle-btn:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

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

.station-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: calc(var(--spacing-unit));
}

.station-btn {
    padding: calc(var(--spacing-unit)) calc(var(--spacing-unit) * 2);
    background: var(--color-surface);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    font-weight: 500;
    font-size: 0.875rem;
    transition: all 0.2s;
    cursor: pointer;
}

.station-btn:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    background: var(--color-primary-light);
}

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

/* Train Card */
.train-list {
    display: flex;
    flex-direction: column;
    gap: calc(var(--spacing-unit) * 2);
}

.train-card {
    background: var(--color-surface);
    padding: calc(var(--spacing-unit) * 2);
    border-radius: var(--radius-md);
    border: 2px solid var(--color-border);
    box-shadow: var(--shadow-sm);
    transition: all 0.2s;
    cursor: pointer;
}

.train-card:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.train-card.past {
    opacity: 0.5;
}

.train-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.train-number {
    display: flex;
    align-items: baseline;
    gap: calc(var(--spacing-unit));
}

.train-number .label {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    font-weight: 500;
}

.train-number .value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text-primary);
}

.share-btn {
    padding: calc(var(--spacing-unit)) calc(var(--spacing-unit) * 2);
    background: var(--color-surface);
    border: 2px solid var(--color-primary);
    border-radius: var(--radius-sm);
    color: var(--color-primary);
    font-weight: 600;
    transition: all 0.2s;
    cursor: pointer;
}

.share-btn:hover {
    background: var(--color-primary);
    color: white;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.train-times {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: calc(var(--spacing-unit) * 2);
    align-items: center;
}

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

.time-label {
    font-size: 0.75rem;
    color: var(--color-text-tertiary);
    font-weight: 500;
    margin-bottom: calc(var(--spacing-unit) / 2);
}

.time-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-text-primary);
    font-variant-numeric: tabular-nums;
}

.time-separator {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: calc(var(--spacing-unit));
}

.duration-badge {
    display: flex;
    align-items: center;
    gap: calc(var(--spacing-unit) / 2);
    padding: calc(var(--spacing-unit) / 2) calc(var(--spacing-unit));
    background: var(--color-primary-light);
    border-radius: calc(var(--radius-sm) / 2);
    color: var(--color-primary);
    font-size: 0.875rem;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
}

.arrow {
    font-size: 1.5rem;
    color: var(--color-text-tertiary);
}

/* Timeline */
.stops-section {
    display: none;
    margin-top: calc(var(--spacing-unit) * 2);
    padding-top: calc(var(--spacing-unit) * 2);
    border-top: 2px solid var(--color-border);
}

.train-timeline {
    display: flex;
    gap: calc(var(--spacing-unit) * 3);
    overflow-x: auto;
    padding: calc(var(--spacing-unit) * 2) 0;
    scrollbar-width: thin;
    scrollbar-color: var(--color-border) transparent;
}

.train-timeline::-webkit-scrollbar {
    height: 4px;
}

.train-timeline::-webkit-scrollbar-track {
    background: transparent;
}

.train-timeline::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 2px;
}

.timeline-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    min-width: 80px;
    position: relative;
}

.station-dot {
    width: 16px;
    height: 16px;
    background: var(--color-primary);
    border-radius: 50%;
    margin-bottom: calc(var(--spacing-unit));
    box-shadow: 0 0 0 4px var(--color-primary-light);
}

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

.station-name {
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: calc(var(--spacing-unit) / 2);
    font-size: 0.875rem;
}

.station-time {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    font-weight: 500;
    font-variant-numeric: tabular-nums;
}

.timeline-line {
    position: absolute;
    top: 8px;
    right: calc(-1 * var(--spacing-unit) * 1.5);
    width: calc(var(--spacing-unit) * 3);
    height: 3px;
    background: var(--color-primary);
}

.scroll-hint {
    text-align: center;
    gap: calc(var(--spacing-unit));
    margin-top: calc(var(--spacing-unit) * 2);
}

.share-actions .btn {
    flex: 1;
    border-radius: var(--radius-sm);
    padding: calc(var(--spacing-unit) * 1.5);
    font-weight: 600;
}

.filter-row-horizontal {
    display: flex;
    gap: calc(var(--spacing-unit) * 2);
    margin-bottom: calc(var(--spacing-unit) * 3);
}

.flex-grow-1 {
    flex: 1;
}

/* Mobile Optimization */
@media (max-width: 768px) {
    .app-container {
        padding: var(--spacing-unit);
    }

    .page-header {
        margin-bottom: calc(var(--spacing-unit) * 2);
    }

    .page-title {
        font-size: 1.5rem;
    }

    .direction-selector {
        gap: var(--spacing-unit);
        margin-bottom: var(--spacing-unit);
    }

    .direction-btn {
        padding: var(--spacing-unit);
    }

    .date-selector {
        display: flex;
        gap: 2px;
        margin-bottom: calc(var(--spacing-unit) * 1.5);
        padding: 4px;
        overflow-x: hidden;
    }

    .date-btn {
        flex: 1;
        min-width: 0;
        padding: 6px 0;
        font-size: 0.75rem;
        text-align: center;
        white-space: nowrap;
    }

    .filters-card {
        padding: calc(var(--spacing-unit) * 1.5);
        margin-bottom: calc(var(--spacing-unit) * 2);
    }

    .filter-row-horizontal {
        margin-bottom: calc(var(--spacing-unit) * 1.5);
        gap: var(--spacing-unit);
    }

    .filter-dropdown-btn,
    .toggle-btn {
        padding: var(--spacing-unit);
    }

    .station-grid {
        grid-template-columns: repeat(6, 1fr);
        gap: 4px;
    }

    .station-btn {
        padding: 6px 2px;
        font-size: 0.75rem;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .time-value {
        font-size: 1.5rem;
    }

    .train-number .value {
        font-size: 1.25rem;
    }

    .train-card {
        padding: var(--spacing-unit);
    }

    .train-header {
        margin-bottom: var(--spacing-unit);
    }

    .train-times {
        gap: var(--spacing-unit);
    }
}