:root {
    --bg-deep: #081820;
    --bg-panel: #0f2530;
    --bg-panel-raised: #14303d;
    --grid-line: #1d3a45;
    --text-primary: #eaf3f2;
    --text-muted: #7fa3ac;
    --accent-flow: #35c4c9;
    --accent-flow-dim: rgba(53, 196, 201, 0.15);
    --accent-alert: #f0a857;
    --accent-danger: #e07a5f;
    --font-display: 'Space Grotesk', sans-serif;
    --font-body: 'Inter', sans-serif;
    --font-mono: 'IBM Plex Mono', monospace;
    --radius: 10px;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    background: var(--bg-deep);
    color: var(--text-primary);
    font-family: var(--font-body);
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--accent-flow);
}

/* ---------- Header ---------- */
header {
    padding: 28px clamp(16px, 4vw, 48px) 0;
    border-bottom: 1px solid var(--grid-line);
    background: linear-gradient(180deg, var(--bg-panel) 0%, var(--bg-deep) 100%);
}

.eyebrow {
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--accent-flow);
    margin: 0 0 6px;
}

h1 {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: clamp(22px, 3vw, 30px);
    margin: 0 0 20px;
    letter-spacing: -0.01em;
}

/* Signature element: animated flow line */
.flow-line {
    height: 2px;
    width: 100%;
    background-image: repeating-linear-gradient(90deg,
            var(--accent-flow) 0px, var(--accent-flow) 10px,
            transparent 10px, transparent 22px);
    background-size: 200% 100%;
    animation: flow 3.2s linear infinite;
    opacity: 0.6;
}

@keyframes flow {
    to {
        background-position: -200% 0;
    }
}

@media (prefers-reduced-motion: reduce) {
    .flow-line {
        animation: none;
    }
}

/* ---------- Controls ---------- */
.controls {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    align-items: flex-end;
    padding: 20px clamp(16px, 4vw, 48px);
    background: var(--bg-panel);
    border-bottom: 1px solid var(--grid-line);
}

.field {
    display: flex;
    flex-direction: column;
    gap: 6px;
    min-width: 150px;
}

.field.grow {
    flex: 1;
    min-width: 220px;
}

label {
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--text-muted);
}

select,
input[type="datetime-local"],
input[type="text"],
input[type="password"] {
    background: var(--bg-panel-raised);
    border: 1px solid var(--grid-line);
    border-radius: var(--radius);
    color: var(--text-primary);
    padding: 9px 10px;
    font-family: var(--font-body);
    font-size: 14px;
    outline: none;
}

select:focus,
input:focus {
    border-color: var(--accent-flow);
    box-shadow: 0 0 0 3px var(--accent-flow-dim);
}

.presets {
    display: flex;
    gap: 6px;
}

button {
    font-family: var(--font-body);
    font-weight: 600;
    font-size: 13px;
    border-radius: var(--radius);
    border: 1px solid var(--grid-line);
    background: var(--bg-panel-raised);
    color: var(--text-primary);
    padding: 9px 14px;
    cursor: pointer;
    transition: border-color 0.15s ease, background 0.15s ease;
}

button:hover {
    border-color: var(--accent-flow);
}

button:focus-visible {
    outline: 2px solid var(--accent-flow);
    outline-offset: 2px;
}

button.preset-active {
    background: var(--accent-flow-dim);
    border-color: var(--accent-flow);
    color: var(--accent-flow);
}

button.primary {
    background: var(--accent-flow);
    color: var(--bg-deep);
    border-color: var(--accent-flow);
}

button.primary:hover {
    filter: brightness(1.08);
}

details.settings {
    margin-left: auto;
    font-family: var(--font-mono);
    font-size: 12px;
}

details.settings summary {
    cursor: pointer;
    color: var(--text-muted);
    list-style: none;
}

details.settings summary::-webkit-details-marker {
    display: none;
}

details.settings summary:before {
    content: '⚙ ';
}

.settings-panel {
    position: absolute;
    right: clamp(16px, 4vw, 48px);
    margin-top: 10px;
    background: var(--bg-panel-raised);
    border: 1px solid var(--grid-line);
    border-radius: var(--radius);
    padding: 14px;
    display: flex;
    flex-direction: column;
    gap: 10px;
    width: 260px;
    z-index: 10;
}

/* ---------- Layout ---------- */
main {
    padding: 24px clamp(16px, 4vw, 48px) 48px;
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 20px;
}

@media (max-width: 860px) {
    main {
        grid-template-columns: 1fr;
    }
}

.panel {
    background: var(--bg-panel);
    border: 1px solid var(--grid-line);
    border-radius: var(--radius);
    padding: 18px;
}

.panel h2 {
    font-family: var(--font-display);
    font-size: 15px;
    font-weight: 600;
    margin: 0 0 14px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.panel h2 .count {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    font-weight: 400;
}

/* Tank list */
.tank-row {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 8px;
    border-radius: 8px;
    cursor: pointer;
    border: 1px solid transparent;
}

.tank-row:hover {
    background: var(--bg-panel-raised);
}

.tank-row.selected {
    background: var(--accent-flow-dim);
    border-color: var(--accent-flow);
}

.tank-gauge {
    width: 10px;
    height: 28px;
    border-radius: 4px;
    background: var(--bg-panel-raised);
    border: 1px solid var(--grid-line);
    position: relative;
    overflow: hidden;
    flex-shrink: 0;
}

.tank-gauge .fill {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--accent-flow);
}

.tank-meta {
    display: flex;
    flex-direction: column;
    gap: 2px;
    min-width: 0;
}

.tank-name {
    font-size: 13px;
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.tank-id {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
}

.empty-state {
    color: var(--text-muted);
    font-size: 13px;
    padding: 18px 6px;
    line-height: 1.5;
}

/* Charts column */
.charts-col {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.stat-pills {
    display: flex;
    gap: 10px;
    margin-bottom: 14px;
    flex-wrap: wrap;
}

.pill {
    font-family: var(--font-mono);
    font-size: 12px;
    background: var(--bg-panel-raised);
    border: 1px solid var(--grid-line);
    border-radius: 999px;
    padding: 5px 12px;
    color: var(--text-muted);
}

.pill strong {
    color: var(--text-primary);
    font-weight: 600;
}

canvas {
    max-height: 260px;
}

.status-bar {
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-muted);
    padding: 10px clamp(16px, 4vw, 48px);
    border-top: 1px solid var(--grid-line);
}

.status-bar.error {
    color: var(--accent-danger);
}