:root {
    --bg: #f5f7fb;
    --panel: #ffffff;
    --text: #1d2433;
    --muted: #6d7585;
    --line: #d9deea;
    --accent: #304ffe;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
}

.site-header,
.site-footer {
    padding: 16px 24px;
    background: var(--panel);
    border-bottom: 1px solid var(--line);
}

.site-footer {
    border-top: 1px solid var(--line);
    border-bottom: 0;
}

.site-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.site-header nav a,
.site-sidebar a {
    color: var(--accent);
    text-decoration: none;
    margin-right: 12px;
}

.layout-shell {
    display: grid;
    grid-template-columns: 260px 1fr;
    min-height: calc(100vh - 120px);
}

.site-sidebar {
    padding: 24px 18px;
    background: var(--panel);
    border-right: 1px solid var(--line);
}

.layout-content {
    padding: 24px;
}

section,
form {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 24px;
}

input,
button,
select {
    width: 100%;
    padding: 10px 12px;
    margin-top: 6px;
    margin-bottom: 14px;
}

button {
    cursor: pointer;
}

.nav-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.nav-group {
    margin-top: 18px;
    margin-bottom: 8px;
    font-size: 12px;
    font-weight: bold;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--muted);
}

.nav-item {
    margin: 0 0 8px 0;
}

.nav-subitem {
    padding-left: 10px;
}

.nav-link {
    display: block;
    padding: 6px 8px;
    border-radius: 8px;
    margin-right: 0 !important;
}

.nav-link:hover {
    background: #eef2ff;
}