:root {
    --bg: #f5f7fb;
    --card: #ffffff;
    --text: #1f2937;
    --muted: #6b7280;
    --border: #d1d5db;
    --accent: #2563eb;
    --accent-dark: #1d4ed8;
    --fresh: #15803d;
    --late: #b45309;
    --stale: #92400e;
    --offline: #b91c1c;
    --shadow: 0 4px 14px rgba(15, 23, 42, 0.06);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
}

.topbar {
    background: var(--card);
    border-bottom: 1px solid var(--border);
    padding: 16px 24px;
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    gap: 16px;
    flex-wrap: wrap;
}

.topbar h1 {
    margin: 0 0 6px 0;
    font-size: 24px;
}

.subtle {
    color: var(--muted);
    margin: 0;
    font-size: 14px;
}

.topbar nav a {
    margin-right: 16px;
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
}

.page {
    padding: 24px;
}

.summary-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 16px;
    margin-bottom: 16px;
}

.two-column {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 16px;
    margin-bottom: 16px;
    box-shadow: var(--shadow);
}

.stat-card h2,
.card h2,
.card h3 {
    margin-top: 0;
}

.big {
    font-size: 32px;
    font-weight: 700;
    margin: 0;
}

.section-title-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.node-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 16px;
}

.node-card {
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 14px;
    background: #fbfdff;
}

.node-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 12px;
}

.node-card-header h3 {
    margin: 0;
}

.level-row {
    display: flex;
    gap: 12px;
    align-items: center;
    margin-bottom: 12px;
}

.barrel-container {
    width: 64px;
    height: 96px;
    position: relative;
    padding: 2px;
}

.barrel-shape {
    width: 100%;
    height: 100%;
    background: #cbd5e1; /* Slighly darker grey for empty state */
    border-radius: 12px 12px 16px 16px; /* More rounded bottom for barrel feel */
    position: relative;
    overflow: hidden;
    border: 3px solid #334155;
    box-shadow: inset 0 0 10px rgba(0,0,0,0.1);
}

.barrel-fill {
    width: 100%;
    background: linear-gradient(180deg, #3b82f6, #1d4ed8);
    position: absolute;
    bottom: 0;
    left: 0;
    transition: height 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: inset 0 2px 4px rgba(255,255,255,0.3);
}

.barrel-outline {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    /* More pronounced barrel ribs and a side reflection/shine */
    background: 
        linear-gradient(to right, rgba(255,255,255,0.2) 0%, transparent 20%, transparent 80%, rgba(0,0,0,0.1) 100%),
        linear-gradient(to bottom, 
            transparent 15%, rgba(0,0,0,0.2) 15%, rgba(0,0,0,0.2) 18%, transparent 18%,
            transparent 35%, rgba(0,0,0,0.2) 35%, rgba(0,0,0,0.2) 38%, transparent 38%,
            transparent 55%, rgba(0,0,0,0.2) 55%, rgba(0,0,0,0.2) 58%, transparent 58%,
            transparent 75%, rgba(0,0,0,0.2) 75%, rgba(0,0,0,0.2) 78%, transparent 78%);
    pointer-events: none;
}

.level-value {
    font-weight: 700;
    font-size: 24px;
    color: var(--accent);
}

.node-meta-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px 12px;
    font-size: 14px;
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
}

th,
td {
    border: 1px solid var(--border);
    padding: 8px;
    text-align: left;
    vertical-align: top;
}

th {
    background: #eef2ff;
}

.badge {
    display: inline-block;
    padding: 4px 8px;
    border-radius: 999px;
    color: white;
    font-size: 12px;
    font-weight: 700;
}

.badge.fresh {
    background: var(--fresh);
}

.badge.late {
    background: var(--late);
}

.badge.stale {
    background: var(--stale);
}

.badge.offline {
    background: var(--offline);
}

.config-form {
    display: block;
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 12px;
    margin-bottom: 16px;
}

label {
    display: flex;
    flex-direction: column;
    gap: 6px;
    font-size: 14px;
    font-weight: 600;
}

input,
select,
button {
    font: inherit;
}

input,
select {
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: white;
}

.btn-primary {
    background: var(--accent);
    color: white;
    border: 0;
    padding: 10px 16px;
    border-radius: 8px;
    font-weight: 700;
    cursor: pointer;
}

.btn-primary:hover {
    background: var(--accent-dark);
}

.json-cell {
    display: inline-block;
    max-width: 420px;
    white-space: pre-wrap;
    word-break: break-word;
    font-size: 12px;
}

.kv-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 10px;
    margin: 10px 0 16px 0;
}

.table-scroll {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.btn-secondary {
    background: #4b5563;
    color: #fff;
    border: 0;
    padding: 8px 12px;
    border-radius: 8px;
    font-weight: 700;
    cursor: pointer;
    white-space: nowrap;
}

.btn-secondary:hover {
    background: #374151;
}

@media (min-width: 900px) {
    .kv-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 700px) {
    .topbar {
        align-items: flex-start;
    }

    .topbar nav a {
        display: inline-block;
        margin: 0 10px 8px 0;
    }

    table, thead, tbody, th, td, tr {
        font-size: 13px;
    }

    .json-cell {
        max-width: 90vw;
    }

    .page {
        padding: 12px;
    }

    .card {
        padding: 12px;
    }

    .node-meta-grid {
        grid-template-columns: 1fr;
        font-size: 13px;
    }

    .level-row {
        flex-direction: column;
        align-items: center;
        gap: 16px;
    }

    .barrel-container {
        width: 80px;
        height: 120px;
    }

    .level-value {
        font-size: 32px;
    }

    h2 {
        font-size: 20px;
    }

    h3 {
        font-size: 18px;
    }
}

.action-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-items: center;
}

.chart-wrap {
    position: relative;
    width: 100%;
    height: 420px;
}