:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #0f766e;
    --accent: #db2777;
    --success: #16a34a;
    --warning: #d97706;
    --danger: #dc2626;
    --background: #eef2f7;
    --surface: #ffffff;
    --surface-muted: #f8fafc;
    --text-primary: #172033;
    --text-secondary: #64748b;
    --border: #dbe3ee;
    --border-strong: #cbd5e1;
    --shadow-sm: 0 1px 2px rgb(15 23 42 / 0.06);
    --shadow: 0 8px 20px rgb(15 23 42 / 0.08);
    --radius: 8px;
    --radius-sm: 6px;
    --transition: 160ms ease;
}

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

body {
    min-height: 100vh;
    padding: 24px;
    background: var(--background);
    color: var(--text-primary);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    font-size: 15px;
    line-height: 1.6;
}

button,
input {
    font: inherit;
}

.container {
    width: min(1180px, 100%);
    margin: 0 auto;
}

.page-header {
    padding: 4px 0 20px;
}

h1 {
    color: var(--text-primary);
    font-size: 2rem;
    font-weight: 760;
}

.app-main {
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.card {
    padding: 22px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
}

.card-header {
    display: flex;
    gap: 14px;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 18px;
    padding-bottom: 14px;
    border-bottom: 1px solid var(--border);
}

.card-title {
    color: var(--text-primary);
    font-size: 1.25rem;
    font-weight: 720;
}

.clear-data-container {
    display: flex;
    justify-content: flex-end;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 40px;
    padding: 9px 16px;
    border: 1px solid transparent;
    border-radius: var(--radius-sm);
    background: var(--primary);
    color: #ffffff;
    cursor: pointer;
    font-weight: 650;
    line-height: 1.2;
    text-align: center;
    transition: background var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.btn:hover {
    background: var(--primary-dark);
}

.btn:focus-visible,
input:focus-visible,
.time-slider-handle:focus-visible {
    outline: 3px solid rgb(37 99 235 / 0.24);
    outline-offset: 2px;
}

.btn-sm {
    min-height: 34px;
    padding: 7px 12px;
    font-size: 0.9rem;
}

.btn-warning {
    background: var(--warning);
}

.btn-warning:hover {
    background: #b45309;
}

.btn-danger {
    background: var(--danger);
}

.btn-danger:hover {
    background: #b91c1c;
}

.btn-clear {
    background: #475569;
}

.btn-clear:hover {
    background: #334155;
}

.hidden {
    display: none !important;
}

.form-panel {
    padding: 18px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface-muted);
}

.form-group {
    margin-bottom: 16px;
}

.form-group:last-child {
    margin-bottom: 0;
}

label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-primary);
    font-size: 0.95rem;
    font-weight: 650;
}

input {
    width: 100%;
    padding: 11px 12px;
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-sm);
    background: var(--surface);
    color: var(--text-primary);
    transition: border-color var(--transition), box-shadow var(--transition);
}

input:focus {
    border-color: var(--primary);
    outline: none;
    box-shadow: 0 0 0 3px rgb(37 99 235 / 0.12);
}

.time-range-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 16px;
}

.granularity-input {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    align-items: center;
}

.granularity-input input {
    width: 120px;
}

.granularity-input span,
.empty-inline {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.empty-inline {
    width: 100%;
    font-style: italic;
}

.time-slider-container {
    margin-top: 14px;
}

.time-slider {
    position: relative;
    width: 100%;
    height: 36px;
    margin: 14px 0 10px;
    border-radius: 999px;
    background: #e2e8f0;
    box-shadow: inset 0 1px 2px rgb(15 23 42 / 0.08);
    cursor: pointer;
}

.time-slider-track {
    position: absolute;
    height: 100%;
    border-radius: 999px;
    background: var(--secondary);
    box-shadow: inset 0 0 0 1px rgb(255 255 255 / 0.25);
}

.time-slider-handle {
    position: absolute;
    top: 3px;
    z-index: 2;
    width: 16px;
    height: 30px;
    border: 2px solid var(--primary);
    border-radius: var(--radius-sm);
    background: #ffffff;
    box-shadow: var(--shadow-sm);
    cursor: grab;
    touch-action: none;
}

.time-slider-handle:hover {
    border-color: var(--primary-dark);
}

.time-slider-handle:active {
    cursor: grabbing;
}

.time-display {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 650;
}

.item-list,
.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 14px;
}

.item-card {
    position: relative;
    overflow: hidden;
    padding: 16px;
    border: 1px solid var(--border);
    border-left: 4px solid var(--item-color, var(--primary));
    border-radius: var(--radius);
    background: #ffffff;
    box-shadow: var(--shadow-sm);
    transition: border-color var(--transition), box-shadow var(--transition);
}

.item-card:hover,
.item-card.highlighted {
    border-color: var(--item-color, var(--primary));
    box-shadow: var(--shadow);
}

.item-header {
    display: flex;
    gap: 12px;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 12px;
}

.item-name {
    min-width: 0;
    overflow-wrap: anywhere;
    color: var(--text-primary);
    font-size: 1.05rem;
    font-weight: 720;
}

.item-cost {
    flex: 0 0 auto;
    color: var(--item-color, var(--primary));
    font-size: 1.05rem;
    font-weight: 760;
    white-space: nowrap;
}

.mini-time-track {
    position: relative;
    height: 8px;
    margin: 8px 0;
    overflow: hidden;
    border-radius: 999px;
    background: #e2e8f0;
}

.mini-time-bar {
    position: absolute;
    height: 100%;
    border-radius: 999px;
}

.mini-time-labels {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-size: 0.78rem;
}

.item-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 14px;
}

.expense-tags,
.person-expenses {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.expense-tags {
    margin-top: 12px;
}

.expense-tag {
    max-width: 100%;
    padding: 4px 10px;
    overflow-wrap: anywhere;
    border-radius: 999px;
    color: #ffffff;
    font-size: 0.82rem;
    font-weight: 650;
}

.muted-tag {
    background: #94a3b8 !important;
}

.expense-checkbox {
    display: inline-flex;
    max-width: 100%;
    align-items: center;
    gap: 7px;
    padding: 7px 10px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: #ffffff;
    font-size: 0.9rem;
}

.expense-checkbox:hover {
    border-color: var(--primary);
}

.expense-checkbox input {
    width: 16px;
    height: 16px;
    flex: 0 0 auto;
    cursor: pointer;
}

.expense-checkbox label {
    min-width: 0;
    margin: 0;
    overflow-wrap: anywhere;
    cursor: pointer;
    font-weight: 600;
}

.person-result {
    overflow: hidden;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: #ffffff;
    box-shadow: var(--shadow-sm);
    transition: border-color var(--transition), box-shadow var(--transition);
}

.person-result:hover,
.person-result.highlighted {
    border-color: var(--primary);
    box-shadow: var(--shadow);
}

.person-result-header {
    padding: 16px;
    background: var(--text-primary);
    color: #ffffff;
    text-align: center;
}

.person-name {
    margin-bottom: 6px;
    overflow-wrap: anywhere;
    font-size: 1.08rem;
    font-weight: 720;
}

.person-total-amount {
    font-size: 1.7rem;
    font-weight: 780;
}

.person-result-breakdown {
    display: flex;
    height: 8px;
    background: #e2e8f0;
}

.breakdown-segment {
    min-width: 2px;
}

.person-result-details {
    padding: 14px 16px;
}

.detail-item {
    display: flex;
    gap: 12px;
    align-items: center;
    justify-content: space-between;
    padding: 8px 0;
    border-bottom: 1px solid var(--border);
}

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

.detail-name {
    display: flex;
    min-width: 0;
    align-items: center;
    gap: 8px;
    overflow-wrap: anywhere;
    font-size: 0.92rem;
}

.detail-color {
    width: 12px;
    height: 12px;
    flex: 0 0 auto;
    border-radius: 3px;
}

.detail-amount {
    flex: 0 0 auto;
    font-size: 0.95rem;
    font-weight: 720;
    white-space: nowrap;
}

.empty-state {
    grid-column: 1 / -1;
    padding: 32px 20px;
    border: 1px dashed var(--border-strong);
    border-radius: var(--radius);
    color: var(--text-secondary);
    background: var(--surface-muted);
    font-style: italic;
    text-align: center;
}

footer {
    padding: 18px 0 4px;
    color: var(--text-secondary);
    font-size: 0.9rem;
    text-align: center;
}

@media (max-width: 768px) {
    body {
        padding: 14px;
    }

    h1 {
        font-size: 1.55rem;
    }

    .page-header {
        padding-bottom: 14px;
    }

    .card {
        padding: 16px;
    }

    .card-header {
        align-items: stretch;
        flex-direction: column;
    }

    .clear-data-container {
        justify-content: stretch;
    }

    .clear-data-container .btn,
    .card-header .btn {
        width: 100%;
    }

    .item-list,
    .results-grid {
        grid-template-columns: 1fr;
    }

    .item-header,
    .detail-item {
        align-items: flex-start;
        flex-direction: column;
    }

    .item-cost,
    .detail-amount {
        white-space: normal;
    }
}