:root {
    --app-bg-start: #e6eef9;
    --app-bg-end: #f7f9fd;
    --app-surface: #ffffff;
    --app-border: #dbe3ef;
    --app-text: #172033;
    --app-muted: #5d6b83;
    --app-brand: #0d6efd;
    --app-brand-dark: #0b5ed7;
    --app-shadow: 0 12px 30px rgba(23, 32, 51, 0.08);
}

body {
    background: radial-gradient(circle at 12% -6%, #d6e6ff 0, transparent 35%),
        linear-gradient(160deg, var(--app-bg-start), var(--app-bg-end));
    color: var(--app-text);
    min-height: 100vh;
}

.app-nav {
    background: rgba(255, 255, 255, 0.86);
    border-bottom: 1px solid var(--app-border);
    backdrop-filter: blur(8px);
}

.app-main {
    padding-top: 2rem;
    padding-bottom: 3rem;
}

.surface-card {
    background: var(--app-surface);
    border: 1px solid var(--app-border);
    border-radius: 1rem;
    box-shadow: var(--app-shadow);
}

.hero-title {
    letter-spacing: 0.01em;
}

.hero-subtitle {
    color: var(--app-muted);
}

.quick-link-card {
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.quick-link-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 16px 35px rgba(23, 32, 51, 0.12);
}

.metric-value {
    font-size: clamp(1.8rem, 2.2vw, 2.5rem);
    font-weight: 700;
}

.metric-good {
    color: #198754;
}

.metric-warn {
    color: #fd7e14;
}

.metric-hot {
    color: #dc3545;
}

.card-title-muted {
    color: var(--app-muted);
    font-size: 0.95rem;
}

.table thead th {
    white-space: nowrap;
}

.auth-panel {
    max-width: 460px;
    margin: 0 auto;
}

.dashboard-refresh {
    color: var(--app-muted);
    font-size: 0.92rem;
}

.section-gap {
    margin-top: 1.25rem;
}

.video-frame {
    border-radius: 0.75rem;
    overflow: hidden;
}