:root {
    --color-primary: #4f6df5;
    --color-primary-dark: #3d59d6;
    --color-primary-light: #eaeeff;
    --color-success: #16a34a;
    --color-success-light: #e7f7ed;
    --color-warning: #d97706;
    --color-warning-light: #fef3c7;
    --color-danger: #dc2626;
    --color-danger-light: #fde8e8;
    --color-info: #0891b2;
    --color-info-light: #e1f6fa;
    --color-neutral: #64748b;
    --color-neutral-light: #eef1f5;

    --surface: #ffffff;
    --bg: #f3f5fa;
    --text: #1e293b;
    --text-muted: #6b7686;
    --border: #e4e8f0;

    --sidebar-bg: #171d2e;
    --sidebar-bg-active: #4f6df5;
    --sidebar-hover: rgba(255, 255, 255, 0.06);
    --sidebar-text: #aab2c5;
    --sidebar-text-active: #ffffff;

    --radius-sm: 6px;
    --radius: 10px;
    --radius-lg: 16px;

    --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
    --shadow: 0 4px 16px rgba(15, 23, 42, 0.08);
    --shadow-lg: 0 12px 32px rgba(15, 23, 42, 0.14);

    --sidebar-width: 250px;
    --topbar-height: 56px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    -webkit-font-smoothing: antialiased;
}

a {
    color: inherit;
}

h1, h2, h3 {
    color: var(--text);
    letter-spacing: -0.01em;
}

/* ---------- App shell ---------- */
.app-shell {
    display: flex;
    min-height: 100vh;
}

.main-area {
    flex: 1;
    min-width: 0;
    margin-left: var(--sidebar-width);
    display: flex;
    flex-direction: column;
}

/* ---------- Sidebar ---------- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: var(--sidebar-width);
    height: 100vh;
    background: var(--sidebar-bg);
    color: var(--sidebar-text);
    display: flex;
    flex-direction: column;
    z-index: 200;
    box-shadow: var(--shadow-lg);
}

.navbar-brand {
    padding: 1.3rem 1.4rem;
    font-size: 1.05rem;
    font-weight: 700;
    color: #fff;
    display: flex;
    align-items: center;
    gap: 0.6rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    white-space: nowrap;
}

.navbar-brand::before {
    content: '🚐';
    font-size: 1.3rem;
}

.nav-toggle {
    display: none;
    position: fixed;
    top: 0.55rem;
    left: 1rem;
    z-index: 260;
    background: var(--surface);
    border: 1px solid var(--border);
    color: var(--text);
    font-size: 1.2rem;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    line-height: 1;
    box-shadow: var(--shadow-sm);
}

.navbar-menu {
    flex: 1;
    overflow-y: auto;
    list-style: none;
    padding: 0.85rem 0.75rem;
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
}

.navbar-menu li {
    list-style: none;
}

.navbar-menu a {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--sidebar-text);
    text-decoration: none;
    cursor: pointer;
    padding: 0.62rem 0.85rem;
    border-radius: var(--radius-sm);
    font-size: 0.92rem;
    font-weight: 500;
    transition: background-color 0.15s ease, color 0.15s ease;
}

.navbar-menu a .nav-icon {
    font-size: 1.05rem;
    width: 1.3rem;
    text-align: center;
    flex-shrink: 0;
}

.navbar-menu a:hover {
    background-color: var(--sidebar-hover);
    color: #fff;
}

.navbar-menu a.active {
    background-color: var(--sidebar-bg-active);
    color: #fff;
    box-shadow: var(--shadow);
}

.navbar-menu .nav-divider {
    height: 1px;
    background: rgba(255, 255, 255, 0.08);
    margin: 0.6rem 0.4rem;
}

.navbar-menu .nav-logout a {
    color: #f3a5a5;
}

.navbar-menu .nav-logout a:hover {
    background-color: rgba(220, 38, 38, 0.15);
    color: #ffb4b4;
}

.nav-backdrop {
    display: none;
}

/* ---------- Topbar (mobile) ---------- */
.topbar {
    display: none;
}

/* ---------- Content ---------- */
.content {
    padding: 2rem 2.25rem;
    flex: 1;
    width: 100%;
}

.content h1 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.35rem;
}

.content > .page > p:first-of-type {
    color: var(--text-muted);
    margin-bottom: 1rem;
    font-size: 0.92rem;
}

.page {
    display: none;
}

.page.active {
    display: block;
    animation: fadeIn 0.2s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(4px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ---------- Dashboard Stats ---------- */
.stats-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.25rem;
    margin-top: 1.5rem;
}

.stat-card {
    background: var(--surface);
    padding: 1.5rem 1.6rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
}

.stat-card h3 {
    color: var(--text-muted);
    margin-bottom: 0.6rem;
    font-size: 0.78rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.stat-card p {
    font-size: 1.9rem;
    font-weight: 700;
    color: var(--text);
}

.status-loading { color: var(--color-warning); }
.status-healthy { color: var(--color-success); }
.status-unhealthy { color: var(--color-danger); }

/* ---------- Login ---------- */
#login.page {
    display: none;
}

#login.page.active {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: calc(100vh - 4rem);
}

.login-container {
    max-width: 380px;
    width: 100%;
    margin: 0 auto;
    background: var(--surface);
    padding: 2.25rem 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border);
}

.login-container h1 {
    margin-bottom: 1.5rem;
    text-align: center;
}

.form-group {
    margin-bottom: 1.1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.4rem;
    color: var(--text);
    font-weight: 600;
    font-size: 0.87rem;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 0.65rem 0.8rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    background: var(--surface);
    color: var(--text);
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(79, 109, 245, 0.15);
}

#loginMessage {
    margin-top: 1rem;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-sm);
    display: none;
    font-size: 0.88rem;
}

#loginMessage.error {
    background-color: var(--color-danger-light);
    color: var(--color-danger);
    display: block;
}

#loginMessage.success {
    background-color: var(--color-success-light);
    color: var(--color-success);
    display: block;
}

/* ---------- Buttons ---------- */
.btn {
    background-color: var(--color-primary);
    color: white;
    border: none;
    padding: 0.65rem 1.2rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    transition: background-color 0.15s ease, transform 0.05s ease, box-shadow 0.15s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    text-decoration: none;
    margin: 0.15rem 0.35rem 0.15rem 0;
    box-shadow: var(--shadow-sm);
}

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

.btn:active {
    transform: translateY(1px);
}

.btn-secondary {
    background-color: var(--surface);
    color: var(--text);
    border: 1px solid var(--border);
    box-shadow: none;
}

.btn-secondary:hover {
    background-color: var(--color-neutral-light);
}

.btn-success {
    background-color: var(--color-success);
}

.btn-success:hover {
    background-color: #128038;
}

.btn-danger {
    background-color: var(--color-danger);
}

.btn-danger:hover {
    background-color: #b91c1c;
}

.btn-sm {
    padding: 0.4rem 0.75rem;
    font-size: 0.8rem;
    border-radius: var(--radius-sm);
}

/* ---------- Page action bar ---------- */
.content > .page > .btn:not(.modal .btn) {
    margin-bottom: 0.5rem;
}

/* ---------- Tables ---------- */
.table-container {
    background: var(--surface);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
    margin-top: 1.25rem;
    padding: 0;
    overflow-x: auto;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.1rem;
    margin-top: 1rem;
}

.card {
    background: var(--surface);
    padding: 1.3rem 1.4rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
}

.card h3 {
    margin-bottom: 0.6rem;
    font-size: 1rem;
}

.card p {
    margin-bottom: 1rem;
    color: var(--text-muted);
    font-size: 0.9rem;
}

table {
    width: 100%;
    border-collapse: collapse;
    min-width: 560px;
}

table thead {
    background-color: var(--bg);
}

table th {
    padding: 0.85rem 1.1rem;
    text-align: left;
    font-weight: 600;
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--text-muted);
    border-bottom: 1px solid var(--border);
}

table td {
    padding: 0.9rem 1.1rem;
    border-bottom: 1px solid var(--border);
    font-size: 0.9rem;
}

table tbody tr {
    transition: background-color 0.1s ease;
}

table tbody tr:hover {
    background-color: var(--bg);
}

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

/* ---------- Status badges ---------- */
.status-badge, .badge {
    display: inline-block;
    padding: 0.28rem 0.7rem;
    border-radius: 999px;
    font-size: 0.74rem;
    font-weight: 700;
    text-transform: capitalize;
    letter-spacing: 0.02em;
    background: var(--color-neutral-light);
    color: var(--color-neutral);
    white-space: nowrap;
}

.status-badge.badge-success, .badge.badge-success { background: var(--color-success-light); color: var(--color-success); }
.status-badge.badge-warning, .badge.badge-warning { background: var(--color-warning-light); color: var(--color-warning); }
.status-badge.badge-danger, .badge.badge-danger { background: var(--color-danger-light); color: var(--color-danger); }
.status-badge.badge-info, .badge.badge-info { background: var(--color-info-light); color: var(--color-info); }
.status-badge.badge-neutral, .badge.badge-neutral { background: var(--color-neutral-light); color: var(--color-neutral); }

/* ---------- Responsive ---------- */
@media (max-width: 880px) {
    .main-area {
        margin-left: 0;
    }

    .navbar {
        transform: translateX(-100%);
        transition: transform 0.25s ease;
        width: min(280px, 84vw);
    }

    .navbar-menu {
        display: flex !important;
    }

    .navbar.open {
        transform: translateX(0);
    }

    .nav-toggle {
        display: flex;
        align-items: center;
        justify-content: center;
    }

    body:has(.navbar.open) .nav-backdrop {
        display: block;
        position: fixed;
        inset: 0;
        background: rgba(15, 23, 42, 0.45);
        z-index: 190;
    }

    .content {
        padding: 4.5rem 1.1rem 1.5rem;
    }

    .stats-container {
        grid-template-columns: 1fr 1fr;
    }

    table {
        font-size: 0.85rem;
    }

    table th, table td {
        padding: 0.6rem 0.75rem;
    }
}

@media (max-width: 520px) {
    .stats-container {
        grid-template-columns: 1fr;
    }

    .login-container {
        padding: 1.75rem 1.4rem;
        margin: 0 1rem;
    }
}

/* ---------- Modal Styles ---------- */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(15, 23, 42, 0.5);
}

.modal-content {
    background-color: var(--surface);
    margin: 6% auto;
    padding: 2rem;
    width: 90%;
    max-width: 500px;
    border-radius: var(--radius-lg);
    position: relative;
    box-shadow: var(--shadow-lg);
}

.modal-content h2 {
    margin-bottom: 1.25rem;
    font-size: 1.2rem;
}

.close-btn {
    color: var(--text-muted);
    position: absolute;
    top: 1rem;
    right: 1.25rem;
    font-size: 26px;
    font-weight: bold;
    cursor: pointer;
    line-height: 1;
}

.close-btn:hover,
.close-btn:focus {
    color: var(--text);
}

@media (max-width: 768px) {
    .modal-content {
        width: 92%;
        margin: 12% auto;
        padding: 1.4rem;
        max-height: 80vh;
        overflow-y: auto;
    }
}