:root {
    --color-bg: #f5f7fb;
    --color-surface: #ffffff;
    --color-muted: #6b7280;
    --color-border: #e6e9ef;

    --color-primary: #2563eb; /* blue */
    --color-primary-600: #1d4ed8;
    --color-primary-bg: rgba(37, 99, 235, 0.06);
    --color-primary-border: rgba(37, 99, 235, 0.12);

    /* Semantic color tokens */
    --color-success: #10b981; /* green-500 */
    --color-success-600: #059669; /* green-600 */
    --color-success-bg: rgba(16, 185, 129, 0.06);
    --color-success-border: rgba(5, 150, 105, 0.12);

    --color-warning: #f59e0b; /* amber-500 */
    --color-warning-600: #d97706; /* amber-600 */
    --color-warning-bg: rgba(245, 158, 11, 0.06);
    --color-warning-border: rgba(217, 119, 6, 0.12);

    --color-danger: #ef4444; /* red-500 */
    --color-danger-600: #dc2626; /* red-600 */
    --color-danger-bg: rgba(239, 68, 68, 0.06);
    --color-danger-border: rgba(220, 38, 38, 0.12);

    --shadow-sm: 0 1px 2px rgba(16, 24, 40, 0.05);
    --shadow-md: 0 6px 18px rgba(16, 24, 40, 0.08);

    --radius: 10px;
    --gap: 1rem;
    --container-pad: 1.25rem;
}

* {
    box-sizing: border-box;
}

html, body {
    height: 100%;
}

body {
    display: flex;
    height: 100vh;
    overflow: hidden;
    margin: 0;
    font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
    background: var(--color-bg);
    color: #0f172a;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    line-height: 1.4;
}

main {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow-y: scroll;
}

/* Sidebar */

.sidebar {
    width: 280px;
    display: flex;
    flex-direction: column;
    position: relative;
    z-index: 100;
    border-right: 1px solid var(--color-border);
    box-shadow: var(--shadow-sm);
    background: var(--color-surface);
}

.sidebar-header {
    padding: 0 var(--container-pad);
    border-bottom: 1px solid var(--color-border);
}

.sidebar-menu {
    list-style: none;
    padding: 20px 0;
    margin: 0;
    flex: 1;
    overflow-y: auto;
}

.sidebar-menu .sidebar-item {
    margin: 4px 12px;
}

a.sidebar-link {
    display: flex;
    align-items: center;
    padding: 12px 16px;
}

a.sidebar-link .sidebar-icon {
    width: 24px;
    text-align: center;
}

.sidebar-footer {
    padding: 16px;
    border-top: 1px solid var(--color-border);
}

/* Layout helpers */
.container {
    padding: var(--container-pad);
}

.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--gap);
    padding: 0.75rem var(--container-pad);
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-sm);
}

.site-title {
    font-size: 1.25rem;
    font-weight: 600;
}

.site-title a {
    color: inherit;
    text-decoration: none;
}

.nav-actions {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.65rem 0.75rem;
    border-radius: 8px;
    border: 1px solid transparent;
    text-decoration: none;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.95rem;
}

/* Normalize appearance for anchors and native buttons so sizes match */
a.btn, button.btn, input[type="submit"].btn {
    -webkit-appearance: none;
    appearance: none;
    font-family: inherit;
    line-height: 1.4;
    vertical-align: middle;
    box-sizing: border-box;
}

.btn:focus {
    outline: 2px solid rgba(37, 99, 235, 0.25);
    outline-offset: 2px;
}

.btn-primary {
    background: linear-gradient(180deg, var(--color-primary), var(--color-primary-600));
    color: white;
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
    background: linear-gradient(180deg, var(--color-primary-600), var(--color-primary));
}

.btn-danger {
    background: linear-gradient(180deg, var(--color-danger), var(--color-danger-600));
    color: white;
}

.btn-danger:hover {
    background: linear-gradient(180deg, var(--color-danger-600), var(--color-danger));
}

.btn-ghost {
    background: transparent;
    color: var(--color-muted);
    border-color: var(--color-border);
}

.btn-ghost:hover {
    border-color: var(--color-primary-600);
    color: var(--color-primary);
}

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

.form-label {
    display: block;
    margin-top: 0.75rem;
    margin-bottom: 0.25rem;
    font-weight: 600;
    color: var(--color-muted);
    font-size: 0.95rem;
}

.form-control {
    width: 100%;
    padding: 0.65rem 0.75rem;
    border-radius: 8px;
    border: 1px solid var(--color-border);
    background: transparent;
    font-size: 1rem;
}

.form-control:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.08);
    border-color: var(--color-primary-600);
}

.alert {
    padding: 0.6rem 0.75rem;
    border-radius: 8px;
    margin-bottom: 0.75rem;
    border: 1px solid transparent;
    font-weight: 600;
}

.flash {
    padding: 0.7em 1.2em;
    border-radius: var(--radius);
    margin: var(--container-pad) var(--container-pad) 0 var(--container-pad);
}

.flash-info {
    background: var(--color-primary-bg);
    color: var(--color-primary-600);
    border-color: var(--color-primary-border);
}

.alert-danger, .flash-error {
    background: var(--color-danger-bg);
    color: var(--color-danger-600);
    border-color: var(--color-danger-border);
}

.alert-success, .flash-success {
    background: var(--color-success-bg);
    color: var(--color-success-600);
    border-color: var(--color-success-border);
}

.alert-warning, .flash-warning {
    background: var(--color-warning-bg);
    color: var(--color-warning-600);
    border-color: var(--color-warning-border);
}

.card {
    background: var(--color-surface);
    padding: 1rem;
    border-radius: var(--radius);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-sm);
    overflow: auto;
}

.card h2 {
    margin: 0 0 0.5rem 0;
    font-size: 1rem;
}

.card h3 {
    margin: 0 0 0.5rem 0;
    font-size: 0.95rem;
    color: var(--color-muted);
}

.card .value {
    font-size: 1.5rem;
    font-weight: 700;
}

.panel-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.list-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.6rem;
    border-radius: 8px;
    background: linear-gradient(180deg, rgba(0, 0, 0, 0.01), rgba(0, 0, 0, 0.01));
    border: 1px solid var(--color-border);
}

.list-item small {
    color: var(--color-muted);
}

/* Footer tiny */
.footer-note {
    margin-top: 0.75rem;
    font-size: 0.85rem;
    color: var(--color-muted);
}