:root {
    color-scheme: light;
    --navy: #14213d;
    --blue: #2563eb;
    --blue-dark: #1d4ed8;
    --blue-light: #eff6ff;
    --slate-900: #172033;
    --slate-700: #475569;
    --slate-500: #64748b;
    --slate-300: #cbd5e1;
    --slate-200: #e2e8f0;
    --slate-100: #f1f5f9;
    --white: #ffffff;
    --danger: #b42318;
}

* {
    box-sizing: border-box;
}

html,
body {
    height: 100%;
    margin: 0;
}

body {
    min-width: 320px;
    background: var(--slate-100);
    color: var(--slate-900);
    font-family:
        Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont,
        "Segoe UI", sans-serif;
}

button,
input {
    font: inherit;
}

.site-header {
    display: flex;
    height: 72px;
    align-items: center;
    padding: 0 28px;
    border-bottom: 1px solid var(--slate-200);
    background: var(--white);
}

.brand {
    display: inline-flex;
    align-items: center;
    color: inherit;
    gap: 12px;
    text-decoration: none;
}

.brand-mark {
    display: grid;
    width: 40px;
    height: 40px;
    place-items: center;
    border-radius: 12px;
    background: var(--navy);
    color: var(--white);
    font-size: 0.75rem;
    font-weight: 800;
    letter-spacing: 0.05em;
}

.brand strong,
.brand small {
    display: block;
}

.brand strong {
    font-size: 1.05rem;
    line-height: 1.2;
}

.brand small {
    margin-top: 2px;
    color: var(--slate-500);
    font-size: 0.75rem;
}

.app-shell {
    display: grid;
    min-height: calc(100vh - 72px);
    grid-template-columns: minmax(300px, 360px) 1fr;
}

.control-panel {
    z-index: 2;
    padding: 34px 30px;
    border-right: 1px solid var(--slate-200);
    background: var(--white);
    box-shadow: 8px 0 24px rgb(15 23 42 / 6%);
}

.panel-heading {
    padding-bottom: 28px;
    border-bottom: 1px solid var(--slate-200);
}

.eyebrow {
    margin: 0 0 8px;
    color: var(--blue);
    font-size: 0.72rem;
    font-weight: 800;
    letter-spacing: 0.11em;
    text-transform: uppercase;
}

.panel-heading h1 {
    margin: 0;
    font-size: clamp(1.7rem, 3vw, 2.1rem);
    letter-spacing: -0.035em;
    line-height: 1.1;
}

.panel-heading p:last-child {
    margin: 14px 0 0;
    color: var(--slate-500);
    font-size: 0.9rem;
    line-height: 1.55;
}

.field-group {
    margin-top: 26px;
}

.field-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 0.86rem;
    font-weight: 700;
}

.field-group input {
    width: 100%;
    height: 46px;
    padding: 0 12px;
    border: 1px solid var(--slate-300);
    border-radius: 10px;
    background: var(--white);
    color: var(--slate-900);
    outline: none;
}

.field-group input:focus {
    border-color: var(--blue);
    box-shadow: 0 0 0 3px rgb(37 99 235 / 14%);
}

.field-group input:disabled {
    background: var(--slate-100);
    color: var(--slate-500);
    cursor: not-allowed;
}

.field-group small {
    display: block;
    margin-top: 7px;
    color: var(--slate-500);
    font-size: 0.75rem;
}

.selection-summary {
    display: grid;
    margin-top: 24px;
    overflow: hidden;
    border: 1px solid var(--slate-200);
    border-radius: 12px;
    grid-template-columns: 1fr 1fr;
}

.selection-summary div {
    padding: 14px;
}

.selection-summary div + div {
    border-left: 1px solid var(--slate-200);
}

.selection-summary span,
.selection-summary strong {
    display: block;
}

.selection-summary span {
    color: var(--slate-500);
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.selection-summary strong {
    margin-top: 5px;
    font-size: 0.84rem;
}

.instruction-card {
    display: flex;
    margin-top: 22px;
    padding: 15px;
    border-radius: 12px;
    background: var(--blue-light);
    gap: 12px;
}

.step-number {
    display: grid;
    width: 27px;
    height: 27px;
    flex: 0 0 auto;
    place-items: center;
    border-radius: 50%;
    background: var(--blue);
    color: var(--white);
    font-size: 0.75rem;
    font-weight: 800;
}

.instruction-card strong {
    font-size: 0.83rem;
}

.instruction-card p {
    margin: 3px 0 0;
    color: var(--slate-700);
    font-size: 0.76rem;
    line-height: 1.4;
}

.panel-actions {
    display: grid;
    margin-top: 24px;
    gap: 10px;
}

#start-optimization,
.secondary-button {
    width: 100%;
    height: 48px;
    border: 0;
    border-radius: 11px;
    cursor: pointer;
    font-weight: 750;
    transition:
        background 150ms ease,
        border-color 150ms ease,
        color 150ms ease,
        transform 150ms ease;
}

#start-optimization {
    background: var(--blue);
    color: var(--white);
}

#start-optimization:not(:disabled):hover {
    background: var(--blue-dark);
    transform: translateY(-1px);
}

#start-optimization:disabled {
    background: var(--slate-200);
    color: var(--slate-500);
    cursor: not-allowed;
}

.secondary-button {
    border: 1px solid var(--slate-300);
    background: var(--white);
    color: var(--slate-700);
}

.secondary-button:not(:disabled):hover {
    border-color: var(--slate-500);
    color: var(--slate-900);
}

.secondary-button:disabled {
    border-color: var(--slate-200);
    color: var(--slate-300);
    cursor: not-allowed;
}

.app-status {
    min-height: 34px;
    margin: 12px 4px 0;
    color: var(--slate-500);
    font-size: 0.76rem;
    line-height: 1.45;
    text-align: center;
}

.app-status[data-state="success"] {
    color: #067647;
}

.app-status[data-state="warning"] {
    color: #b54708;
}

.app-status[data-state="error"] {
    color: var(--danger);
}

.route-summary {
    margin-top: 22px;
    padding-top: 20px;
    border-top: 1px solid var(--slate-200);
}

.route-summary[hidden] {
    display: none;
}

.route-summary-heading {
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    gap: 12px;
}

.route-summary-heading h2 {
    margin: 0;
    font-size: 1rem;
}

.route-summary-heading > strong {
    color: var(--navy);
    font-size: 0.9rem;
}

.route-list {
    display: grid;
    margin-top: 14px;
    gap: 8px;
}

.route-item {
    display: grid;
    align-items: center;
    padding: 10px 11px;
    border: 1px solid var(--slate-200);
    border-radius: 10px;
    cursor: pointer;
    grid-template-columns: auto auto 1fr auto;
    gap: 9px;
}

.route-checkbox {
    width: 15px;
    height: 15px;
    margin: 0;
    cursor: pointer;
}

.route-checkbox:disabled {
    cursor: not-allowed;
}

.route-swatch {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}

.route-item strong {
    font-size: 0.78rem;
}

.route-item span {
    color: var(--slate-500);
    font-size: 0.72rem;
}

.longest-route {
    margin: 10px 2px 0;
    color: var(--slate-500);
    font-size: 0.72rem;
}

.map-region {
    position: relative;
    min-height: 560px;
    background: #dce6ed;
}

#map {
    width: 100%;
    height: 100%;
    min-height: inherit;
}

.map-message {
    position: absolute;
    top: 50%;
    left: 50%;
    display: flex;
    min-width: 220px;
    align-items: center;
    justify-content: center;
    padding: 18px 22px;
    border: 1px solid rgb(255 255 255 / 70%);
    border-radius: 14px;
    background: rgb(255 255 255 / 94%);
    box-shadow: 0 12px 35px rgb(15 23 42 / 16%);
    color: var(--slate-500);
    flex-direction: column;
    font-size: 0.78rem;
    gap: 5px;
    text-align: center;
    transform: translate(-50%, -50%);
}

.map-message strong {
    color: var(--slate-900);
    font-size: 0.9rem;
}

.map-message[hidden] {
    display: none;
}

.spinner {
    width: 26px;
    height: 26px;
    margin-bottom: 4px;
    border: 3px solid var(--slate-200);
    border-top-color: var(--blue);
    border-radius: 50%;
    animation: spin 700ms linear infinite;
}

.map-error {
    border-color: #fecaca;
    color: var(--danger);
}

.map-error strong {
    color: var(--danger);
}

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

@media (max-width: 760px) {
    .site-header {
        height: 64px;
        padding: 0 18px;
    }

    .app-shell {
        grid-template-columns: 1fr;
    }

    .control-panel {
        padding: 24px 20px;
        border-right: 0;
        border-bottom: 1px solid var(--slate-200);
    }

    .panel-heading {
        padding-bottom: 20px;
    }

    .map-region,
    #map {
        min-height: 58vh;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
        transition: none !important;
    }

    .spinner {
        animation-duration: 1.5s;
    }
}