:root {
    --bg: #07131a;
    --panel: #10222c;
    --chart: #081218;
    --chart-plot: #03080c;
    --ink: #e8f4f2;
    --muted: #8aa4ad;
    --fresh: #3ddc97;
    --stale: #f4c95d;
    --bad: #ff6b6b;
    --range-green: #3ddc97;
    --range-yellow: #f4c95d;
    --range-orange: #f08c32;
    --range-dark-red: #b71c1c;
    --line: #1d3a46;
}

* {
    box-sizing: border-box;
}

html, body {
    margin: 0;
    min-height: 100%;
    background: radial-gradient(circle at top, #123040, var(--bg) 55%);
    color: var(--ink);
    font-family: "Segoe UI", system-ui, sans-serif;
}

.shell {
    max-width: 960px;
    margin: 0 auto;
    padding: 1.5rem 1.25rem 2.5rem;
}

.top h1 {
    margin: 0;
    font-size: 1.1rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.muted {
    color: var(--muted);
    margin: 0.25rem 0 0;
}

.banner {
    margin: 1rem 0 0;
    padding: 0.85rem 1rem;
    border-radius: 12px;
    font-weight: 700;
    letter-spacing: 0.04em;
}

.banner.stale {
    background: #3d3212;
    color: var(--stale);
}

.banner.disconnected,
.banner.missing {
    background: #3a1518;
    color: var(--bad);
}

.hidden {
    display: none;
}

.current {
    margin: 2rem 0 1.5rem;
    text-align: center;
}

.value {
    margin: 0;
    font-size: clamp(5rem, 18vw, 8rem);
    line-height: 0.9;
    font-weight: 800;
}

.unit {
    margin: 0.4rem 0 0;
    color: var(--muted);
    letter-spacing: 0.18em;
}

.arrow {
    margin: 1rem 0 0;
    font-size: 3rem;
    min-height: 3rem;
}

.trend, .age {
    margin: 0.35rem 0 0;
    color: var(--muted);
}

.ranges {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
    margin-bottom: 1rem;
}

.ranges button {
    background: var(--panel);
    color: var(--ink);
    border: 1px solid var(--line);
    border-radius: 999px;
    padding: 0.5rem 1rem;
    cursor: pointer;
}

.ranges button.active {
    background: #1a6b62;
    border-color: #2b9d90;
}

.chart-wrap {
    background: var(--chart);
    border: 1px solid #0d1c24;
    border-radius: 18px;
    padding: 0.85rem 1rem 0.7rem;
}

.chart-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    gap: 1rem;
    margin: 0 0.15rem 0.35rem;
    min-height: 1.4rem;
}

.chart-window,
.chart-stats,
.chart-hint {
    margin: 0;
    color: var(--muted);
    font-size: 0.82rem;
}

.chart-stats {
    text-align: right;
    letter-spacing: 0.02em;
}

.chart-stats strong {
    color: var(--ink);
    font-weight: 650;
}

.chart-main {
    position: relative;
    height: min(420px, 52vh);
    cursor: crosshair;
    touch-action: none;
    background: var(--chart-plot);
    border-radius: 12px;
}

.chart-overview-wrap {
    height: 84px;
    margin-top: 0.35rem;
    cursor: ew-resize;
    touch-action: none;
    background: var(--chart-plot);
    border-radius: 10px;
}

.chart-main canvas,
.chart-overview-wrap canvas {
    display: block;
    width: 100%;
    height: 100%;
}

.chart-hint {
    margin-top: 0.45rem;
    text-align: center;
    font-size: 0.75rem;
}

.chart-tooltip {
    position: absolute;
    pointer-events: none;
    z-index: 4;
    min-width: 9.5rem;
    padding: 0.55rem 0.7rem 0.6rem;
    border-radius: 12px;
    background: #0b1c24;
    border: 1px solid #2b9d90;
    box-shadow: 0 10px 28px rgba(0, 0, 0, 0.4);
    transform: translate(-50%, calc(-100% - 14px));
}

.chart-tooltip .t-time {
    margin: 0;
    color: var(--muted);
    font-size: 0.78rem;
}

.chart-tooltip .t-value {
    margin: 0.15rem 0 0;
    font-size: 1.45rem;
    font-weight: 800;
    line-height: 1.1;
    color: var(--fresh);
}

.chart-tooltip .t-trend {
    margin: 0.2rem 0 0;
    color: var(--ink);
    font-size: 0.85rem;
}

@media (max-width: 640px) {
    .chart-toolbar {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.2rem;
    }

    .chart-stats {
        text-align: left;
    }

    .chart-main {
        height: 280px;
    }
}

body.fresh .value { color: var(--fresh); }
body.stale .value { color: var(--stale); }
body.disconnected .value,
body.missing .value { color: var(--bad); }