:root {
    color-scheme: light dark;
    --bg: #f5f7fb;
    --panel: #ffffff;
    --panel-soft: #f8faff;
    --text: #13213a;
    --muted: #68758a;
    --border: #dce3ee;
    --brand: #0b1f4d;
    --brand-2: #1e4e9a;
    --success: #137a4c;
    --danger: #b42318;
    --warning-bg: #fff8e7;
    --warning-border: #e8c76d;
    --shadow: 0 14px 40px rgba(21, 43, 85, 0.08);
    --radius: 18px;
}

* {
    box-sizing: border-box;
}

html {
    background: var(--bg);
}

body {
    margin: 0;
    min-height: 100vh;
    background: var(--bg);
    color: var(--text);
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    -webkit-font-smoothing: antialiased;
}

button,
input {
    font: inherit;
}

button {
    touch-action: manipulation;
}

.app-shell {
    width: min(1180px, calc(100% - 28px));
    margin: 0 auto;
    padding: max(24px, env(safe-area-inset-top)) 0 max(40px, env(safe-area-inset-bottom));
}

.hero {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 24px;
    padding: 18px 4px 26px;
}

.eyebrow,
.section-kicker {
    margin: 0 0 6px;
    color: var(--brand-2);
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

h1,
h2,
p {
    margin-top: 0;
}

h1 {
    margin-bottom: 10px;
    font-size: clamp(2rem, 5vw, 3.4rem);
    line-height: 1;
    letter-spacing: -0.04em;
}

h2 {
    margin-bottom: 0;
    font-size: clamp(1.25rem, 3vw, 1.6rem);
    letter-spacing: -0.02em;
}

.intro {
    max-width: 760px;
    margin-bottom: 0;
    color: var(--muted);
    font-size: 1.02rem;
    line-height: 1.6;
}

.live-pill,
.sensor-status,
.counter {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    white-space: nowrap;
    border-radius: 999px;
    font-weight: 700;
}

.live-pill {
    padding: 10px 14px;
    background: var(--panel);
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.live-pill .dot {
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: #98a2b3;
}

.live-pill.is-running .dot {
    background: var(--success);
    box-shadow: 0 0 0 5px rgba(19, 122, 76, 0.12);
}

.panel {
    margin-bottom: 18px;
    padding: 22px;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.section-heading {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 18px;
}

.diagnostic-grid,
.sensor-grid,
.metric-grid,
.storage-stats {
    display: grid;
    gap: 12px;
}

.diagnostic-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.diagnostic-card {
    padding: 16px;
    border: 1px solid var(--border);
    border-radius: 14px;
    background: var(--panel-soft);
}

.diagnostic-card strong,
.diagnostic-card small,
.diagnostic-label {
    display: block;
}

.diagnostic-label {
    margin-bottom: 8px;
    color: var(--muted);
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.diagnostic-card strong {
    margin-bottom: 4px;
    font-size: 1.15rem;
}

.diagnostic-card small {
    color: var(--muted);
    line-height: 1.4;
}

.status-good {
    color: var(--success);
}

.status-bad {
    color: var(--danger);
}

.browser-note {
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--border);
    color: var(--muted);
    font-size: 0.78rem;
    overflow-wrap: anywhere;
}

.field {
    display: grid;
    gap: 7px;
    width: min(500px, 100%);
}

.field span {
    font-size: 0.9rem;
    font-weight: 700;
}

.field input {
    width: 100%;
    min-height: 46px;
    padding: 10px 12px;
    color: var(--text);
    background: var(--panel-soft);
    border: 1px solid var(--border);
    border-radius: 12px;
    outline: none;
}

.field input:focus {
    border-color: var(--brand-2);
    box-shadow: 0 0 0 3px rgba(30, 78, 154, 0.12);
}

.button-row {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 10px;
    margin-top: 14px;
}

.measurement-row {
    padding-top: 14px;
    border-top: 1px solid var(--border);
}

.button {
    min-height: 44px;
    padding: 10px 15px;
    border: 1px solid transparent;
    border-radius: 12px;
    cursor: pointer;
    font-weight: 750;
    transition: transform 120ms ease, opacity 120ms ease, border-color 120ms ease;
}

.button:active:not(:disabled) {
    transform: translateY(1px);
}

.button:disabled {
    cursor: not-allowed;
    opacity: 0.45;
}

.button-primary {
    color: #fff;
    background: var(--brand);
}

.button-success {
    color: #fff;
    background: var(--success);
}

.button-danger {
    color: #fff;
    background: var(--danger);
}

.button-secondary {
    color: var(--text);
    background: var(--panel-soft);
    border-color: var(--border);
}

.button-ghost {
    color: var(--muted);
    background: transparent;
    border-color: transparent;
}

.button-small {
    min-height: 36px;
    padding: 7px 10px;
    font-size: 0.82rem;
}

.session-status {
    color: var(--muted);
    font-size: 0.9rem;
}

.info-box {
    margin-top: 16px;
    padding: 14px 16px;
    background: var(--warning-bg);
    border: 1px solid var(--warning-border);
    border-radius: 12px;
    line-height: 1.5;
}

.counter {
    padding: 8px 12px;
    background: var(--panel-soft);
    border: 1px solid var(--border);
    color: var(--muted);
}

.empty-state {
    display: grid;
    gap: 6px;
    padding: 30px 18px;
    text-align: center;
    border: 1px dashed var(--border);
    border-radius: 14px;
    color: var(--muted);
}

.empty-state strong {
    color: var(--text);
}

.sensor-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.sensor-card {
    min-width: 0;
    padding: 16px;
    border: 1px solid var(--border);
    border-radius: 16px;
    background: var(--panel-soft);
}

.sensor-card-head {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 12px;
}

.sensor-name {
    display: block;
    font-weight: 800;
    overflow-wrap: anywhere;
}

.sensor-id {
    display: block;
    margin-top: 3px;
    color: var(--muted);
}

.sensor-status {
    padding: 5px 9px;
    font-size: 0.75rem;
}

.sensor-status.is-connected {
    color: var(--success);
    background: rgba(19, 122, 76, 0.1);
}

.sensor-status.is-disconnected {
    color: var(--danger);
    background: rgba(180, 35, 24, 0.09);
}

.heart-rate-block {
    display: flex;
    align-items: baseline;
    justify-content: center;
    gap: 7px;
    margin: 24px 0;
}

.heart-rate-block strong {
    font-size: clamp(3.4rem, 8vw, 5.4rem);
    line-height: 0.9;
    letter-spacing: -0.06em;
}

.heart-rate-block span {
    color: var(--muted);
    font-weight: 700;
}

.metric-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.metric-grid div,
.storage-stats div {
    padding: 10px;
    border: 1px solid var(--border);
    border-radius: 10px;
    background: var(--panel);
}

.metric-grid span,
.metric-grid strong,
.storage-stats span,
.storage-stats strong {
    display: block;
}

.metric-grid span,
.storage-stats span {
    margin-bottom: 4px;
    color: var(--muted);
    font-size: 0.75rem;
}

.metric-grid strong {
    font-size: 0.95rem;
}

.sensor-meta {
    display: flex;
    justify-content: space-between;
    gap: 10px;
    margin-top: 12px;
    color: var(--muted);
    font-size: 0.76rem;
}

.sensor-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 14px;
}

.storage-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    margin-bottom: 16px;
}

.storage-stats strong {
    overflow-wrap: anywhere;
}

.table-wrap {
    overflow-x: auto;
    border: 1px solid var(--border);
    border-radius: 12px;
}

table {
    width: 100%;
    border-collapse: collapse;
    min-width: 660px;
}

th,
td {
    padding: 11px 12px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

th {
    background: var(--panel-soft);
    color: var(--muted);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

tr:last-child td {
    border-bottom: 0;
}

.muted-cell {
    color: var(--muted);
    text-align: center;
}

.event-log {
    min-height: 180px;
    max-height: 320px;
    margin: 0;
    padding: 14px;
    overflow: auto;
    white-space: pre-wrap;
    overflow-wrap: anywhere;
    color: #dbeafe;
    background: #0a1020;
    border-radius: 12px;
    font: 0.8rem/1.55 ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

@media (max-width: 920px) {
    .sensor-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 720px) {
    .app-shell {
        width: min(100% - 18px, 1180px);
    }

    .hero,
    .section-heading {
        align-items: stretch;
        flex-direction: column;
    }

    .live-pill,
    .counter {
        width: fit-content;
    }

    .diagnostic-grid,
    .sensor-grid,
    .storage-stats {
        grid-template-columns: 1fr;
    }

    .panel {
        padding: 16px;
        border-radius: 15px;
    }

    .button-row .button {
        flex: 1 1 180px;
    }

    .sensor-meta {
        flex-direction: column;
    }
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #0c111d;
        --panel: #121a29;
        --panel-soft: #172132;
        --text: #edf2fb;
        --muted: #a4b0c4;
        --border: #28364b;
        --brand: #3569bd;
        --brand-2: #7db2ff;
        --success: #5fd19b;
        --danger: #ff8a82;
        --warning-bg: #2a2313;
        --warning-border: #6b5923;
        --shadow: 0 14px 40px rgba(0, 0, 0, 0.2);
    }

    .button-primary,
    .button-success,
    .button-danger {
        color: #fff;
    }
}