:root {
    --bg-primary:   #0d1117;
    --bg-secondary: #161b22;
    --bg-tertiary:  #21262d;
    --border:       #30363d;
    --text-primary: #e6edf3;
    --text-muted:   #8b949e;
    --green:  #3fb950;
    --yellow: #d29922;
    --red:    #f85149;
    --blue:   #58a6ff;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    min-height: 100vh;
    font-size: 14px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 28px 16px;
}

/* ── 헤더 ── */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border);
}

header h1 {
    font-size: 1.4rem;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.refresh-info {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 4px;
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* ── 메트릭 카드 ── */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 12px;
    margin-bottom: 20px;
}

.card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 18px 12px 14px;
    text-align: center;
    transition: border-color 0.2s;
}

.card:hover {
    border-color: #484f58;
}

.card-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 10px;
}

.card-value {
    font-size: 2rem;
    font-weight: 700;
    line-height: 1;
    margin-bottom: 4px;
    color: var(--text-primary);
    transition: color 0.3s;
}

.card-value.small {
    font-size: 1.1rem;
    font-weight: 600;
    word-break: break-all;
}

.card-unit {
    font-size: 0.7rem;
    color: var(--text-muted);
}

.card-sub {
    font-size: 0.68rem;
    color: var(--text-muted);
    margin-top: 6px;
}

/* 게이지 바 */
.card-gauge {
    width: 100%;
    height: 4px;
    margin-top: 10px;
    background: var(--bg-tertiary);
    border-radius: 2px;
    overflow: hidden;
}

.card-gauge-fill {
    height: 100%;
    width: 0%;
    border-radius: 2px;
    background: var(--green);
    transition: width 0.3s ease, background-color 0.3s ease;
}

.card-gauge-fill.warn   { background: var(--yellow); }
.card-gauge-fill.danger { background: var(--red); }

/* 상태 색상 */
.good   { color: var(--green)  !important; }
.warn   { color: var(--yellow) !important; }
.danger { color: var(--red)    !important; }

/* ── 차트 ── */
.charts-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 20px;
}

.chart-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 16px;
}

.chart-card h2 {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-muted);
    margin-bottom: 12px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.chart-wrapper {
    position: relative;
    height: 180px;
}

/* ── 시스템 로그 ── */
.log-section {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
}

.log-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 16px;
    cursor: pointer;
    user-select: none;
    border-bottom: 1px solid var(--border);
}

.log-header:hover {
    background: var(--bg-tertiary);
}

.log-header h2 {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

#log-toggle {
    color: var(--text-muted);
    font-size: 0.75rem;
    transition: transform 0.2s;
    display: inline-block;
}

#log-toggle.collapsed {
    transform: rotate(-90deg);
}

#log-content {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.78rem;
}

thead th {
    background: var(--bg-tertiary);
    color: var(--text-muted);
    padding: 8px 14px;
    text-align: left;
    font-weight: 500;
    border-bottom: 1px solid var(--border);
    white-space: nowrap;
}

tbody td {
    padding: 6px 14px;
    border-bottom: 1px solid var(--border);
    color: var(--text-primary);
}

tbody tr:last-child td {
    border-bottom: none;
}

tbody tr:hover td {
    background: var(--bg-tertiary);
}

td.loading {
    text-align: center;
    color: var(--text-muted);
    padding: 16px;
}

/* ── 반응형 ── */
@media (max-width: 900px) {
    .cards-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 600px) {
    header {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }
    .refresh-info {
        align-items: flex-start;
    }
    .cards-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .charts-grid {
        grid-template-columns: 1fr;
    }
}