:root {
    --primary: #2563eb;
    --bg: #f4f7fb;
    --panel: #ffffff;
    --text: #172033;
    --muted: #6b7280;
    --border: #dbe3ef;
    --danger: #dc2626;
    --success: #059669;
    --shadow: 0 14px 40px rgba(15, 23, 42, .08);
}

[data-theme="dark"] {
    --bg: #101827;
    --panel: #172033;
    --text: #eef4ff;
    --muted: #a8b3c7;
    --border: #2b3a50;
    --shadow: 0 14px 40px rgba(0, 0, 0, .25);
}

* { box-sizing: border-box; }
body {
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    background: var(--bg);
    color: var(--text);
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; }

.app-shell { display: flex; min-height: 100vh; }
.sidebar {
    width: 260px;
    background: var(--panel);
    border-right: 1px solid var(--border);
    padding: 22px;
    position: sticky;
    top: 0;
    height: 100vh;
    overflow-y: auto;
}
.brand { display: flex; align-items: center; gap: 12px; font-weight: 800; margin-bottom: 24px; }
.brand img { width: 38px; height: 38px; object-fit: contain; }
.sidebar nav { display: grid; gap: 6px; }
.sidebar a {
    padding: 11px 12px;
    border-radius: 8px;
    color: var(--muted);
    font-weight: 700;
}
.sidebar a.active, .sidebar a:hover { color: #fff; background: var(--primary); }

.main { flex: 1; padding: 24px; min-width: 0; }
.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 20px;
}
.topbar h1 { margin: 0; font-size: 28px; }
.topbar p { margin: 5px 0 0; color: var(--muted); }
.top-actions { display: flex; align-items: center; gap: 10px; }
.content { display: grid; gap: 18px; }

.panel, .stat, .install-card, .login-panel {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 8px;
    box-shadow: var(--shadow);
}
.panel { padding: 18px; overflow-x: auto; }
.panel h2 { margin: 0 0 16px; font-size: 18px; }
.stats-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; }
.stat { padding: 18px; }
.stat span { display: block; color: var(--muted); font-size: 13px; margin-bottom: 10px; }
.stat strong { font-size: 26px; }
.danger-text strong { color: var(--danger); }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }

form { margin: 0; }
label { display: grid; gap: 7px; color: var(--muted); font-size: 13px; font-weight: 700; }
input, select, textarea {
    width: 100%;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 11px 12px;
    background: var(--panel);
    color: var(--text);
    font: inherit;
}
textarea { min-height: 92px; resize: vertical; }
.grid-form { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; align-items: end; }
.grid-form .wide { grid-column: 1 / -1; }
.stack-form { display: grid; gap: 12px; }
.inline-form { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)) auto; gap: 10px; margin-bottom: 14px; }
.form-title { margin: 0 0 10px; font-size: 14px; }
.permission-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; }
.permission-grid label {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px;
    border: 1px solid var(--border);
    border-radius: 8px;
}
.permission-grid input { width: auto; }

.btn, button {
    border: 0;
    border-radius: 8px;
    padding: 11px 14px;
    font-weight: 800;
    cursor: pointer;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
    background: #e7edf7;
    color: #172033;
}
.btn.primary { background: var(--primary); color: #fff; }
.btn.ghost { background: transparent; border: 1px solid var(--border); color: var(--text); }
.btn.danger, .danger { background: var(--danger); color: #fff; }
.btn.small { padding: 7px 10px; font-size: 12px; }
.btn.full { width: 100%; }
.icon-btn {
    width: 40px;
    height: 40px;
    border-radius: 8px;
    color: var(--text);
    background: var(--panel);
    border: 1px solid var(--border);
}

table { width: 100%; border-collapse: collapse; min-width: 680px; }
th, td { padding: 12px; border-bottom: 1px solid var(--border); text-align: left; vertical-align: top; }
th { color: var(--muted); font-size: 12px; text-transform: uppercase; }
.actions { display: flex; gap: 8px; align-items: center; }
.actions form { display: inline; }
.row-danger td { background: rgba(220, 38, 38, .08); }
.badge {
    display: inline-flex;
    padding: 5px 8px;
    border-radius: 999px;
    background: #e7edf7;
    color: #172033;
    font-size: 12px;
    font-weight: 800;
}
.badge.ok { background: rgba(5, 150, 105, .14); color: var(--success); }
.badge.danger { background: rgba(220, 38, 38, .14); color: var(--danger); }
.alert { padding: 12px 14px; border-radius: 8px; background: rgba(37, 99, 235, .12); border: 1px solid var(--border); margin-bottom: 14px; }
.alert.danger { background: rgba(220, 38, 38, .12); color: var(--danger); }
.alert.success { color: var(--success); }
.reply { border: 1px solid var(--border); border-radius: 8px; padding: 12px; margin-bottom: 10px; }
.reply p { white-space: pre-wrap; }
.rack-layout { display: grid; gap: 4px; max-width: 520px; margin-bottom: 18px; }
.rack-unit {
    display: grid;
    grid-template-columns: 58px 1fr;
    align-items: center;
    min-height: 32px;
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 5px 9px;
    background: rgba(148, 163, 184, .08);
}
.rack-unit.filled { background: rgba(37, 99, 235, .13); border-color: var(--primary); }
.rack-unit span { color: var(--muted); font-size: 12px; }

.install-body, .login-body {
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding: 24px;
    background: radial-gradient(circle at top left, rgba(37, 99, 235, .20), transparent 34%), var(--bg);
}
.install-card { width: min(860px, 100%); padding: 26px; }
.login-panel { width: min(420px, 100%); padding: 26px; }
.login-panel form { display: grid; gap: 14px; }
.login-logo { width: 78px; height: 78px; object-fit: contain; margin-bottom: 12px; }

@media (max-width: 980px) {
    .app-shell { display: block; }
    .sidebar { width: 100%; height: auto; position: static; }
    .sidebar nav { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .stats-grid, .two-col { grid-template-columns: 1fr; }
    .grid-form, .inline-form, .permission-grid { grid-template-columns: 1fr; }
    .topbar { align-items: flex-start; flex-direction: column; }
}

@media (max-width: 560px) {
    .main { padding: 14px; }
    .sidebar { padding: 14px; }
    .sidebar nav { grid-template-columns: 1fr; }
    .top-actions { width: 100%; justify-content: space-between; }
    table { min-width: 560px; }
}