:root {
    --bg: #faf9f8;
    --card-bg: #ffffff;
    --border: #e1dfdd;
    --text: #201f1e;
    --text-muted: #605e5c;
    --accent: #0078d4;
    --danger: #d13438;
    --ok: #107c10;
    --shadow: 0 1.6px 3.6px rgba(0, 0, 0, .09), 0 .3px .9px rgba(0, 0, 0, .07);
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #1b1a19;
        --card-bg: #252423;
        --border: #3b3a39;
        --text: #f3f2f1;
        --text-muted: #a19f9d;
        --accent: #4aa3e8;
        --danger: #f1707b;
        --ok: #5ec75e;
        --shadow: none;
    }
}

* { box-sizing: border-box; }

body {
    margin: 0;
    padding: 20px 24px 40px;
    background: var(--bg);
    color: var(--text);
    font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
    font-size: 14px;
}

.app-header {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    align-items: flex-end;
    justify-content: space-between;
    margin-bottom: 16px;
}

h1 {
    margin: 0;
    font-size: 20px;
    font-weight: 600;
}

.subtitle {
    margin: 4px 0 0;
    color: var(--text-muted);
}

.toolbar {
    display: flex;
    gap: 8px;
    align-items: center;
}

.range-picker {
    display: flex;
    border: 1px solid var(--border);
    border-radius: 4px;
    overflow: hidden;
    background: var(--card-bg);
}

.range-picker button {
    border: 0;
    border-right: 1px solid var(--border);
    background: transparent;
    color: var(--text);
    padding: 7px 13px;
    font: inherit;
    cursor: pointer;
}

.range-picker button:last-child { border-right: 0; }
.range-picker button:hover { background: rgba(127, 127, 127, .12); }

.range-picker button.selected {
    background: var(--accent);
    color: #fff;
}

.icon-button {
    border: 1px solid var(--border);
    background: var(--card-bg);
    color: var(--text);
    border-radius: 4px;
    width: 34px;
    height: 34px;
    font-size: 16px;
    cursor: pointer;
}

.icon-button:hover { background: rgba(127, 127, 127, .12); }

.custom-range {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    align-items: center;
    padding: 12px 14px;
    margin-bottom: 16px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 4px;
}

.custom-range label {
    display: flex;
    gap: 6px;
    align-items: center;
    color: var(--text-muted);
}

.custom-range input {
    font: inherit;
    padding: 5px 7px;
    border: 1px solid var(--border);
    border-radius: 3px;
    background: var(--bg);
    color: var(--text);
    color-scheme: light dark;
}

.custom-range button {
    font: inherit;
    padding: 6px 14px;
    border: 0;
    border-radius: 3px;
    background: var(--accent);
    color: #fff;
    cursor: pointer;
}

.charts-area { position: relative; }

.charts {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

/* Cards stay on screen while a reload runs, dimmed, so the page never flashes empty and the
   layout does not jump when the new ones land. */
.charts-area.busy .charts {
    opacity: .4;
    pointer-events: none;
    transition: opacity .15s ease;
}

/* Fixed rather than centred in the container: a year of data is taller than the viewport, and
   an overlay centred on the container would sit somewhere off screen. */
.loading-overlay {
    position: fixed;
    top: 14px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 20;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 16px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 999px;
    box-shadow: var(--shadow);
    color: var(--text-muted);
    font-size: 13px;
}

.spinner {
    width: 14px;
    height: 14px;
    border: 2px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin .7s linear infinite;
}

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

@media (prefers-reduced-motion: reduce) {
    .spinner { animation-duration: 2.4s; }
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 4px;
    box-shadow: var(--shadow);
    padding: 14px 16px 8px;
}

.card-header {
    display: flex;
    flex-wrap: wrap;
    gap: 8px 20px;
    align-items: baseline;
    justify-content: space-between;
    margin-bottom: 6px;
}

.card-header h2 {
    margin: 0;
    font-size: 15px;
    font-weight: 600;
}

/* IP shown next to the friendly name, so a card is still identifiable at a glance. */
.server-address {
    margin-left: 8px;
    color: var(--text-muted);
    font-size: 12px;
    font-weight: 400;
}

.stats {
    display: flex;
    gap: 18px;
    color: var(--text-muted);
    font-size: 13px;
}

.stat strong { color: var(--text); font-weight: 600; }
.stat.bad strong { color: var(--danger); }
.stat.good strong { color: var(--ok); }

.chart-holder {
    position: relative;
    height: 260px;
}

.card.empty .chart-holder {
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    height: 120px;
}

.status, .error {
    color: var(--text-muted);
    margin-top: 16px;
}

.error { color: var(--danger); margin: 0; }

.hidden { display: none; }