:root {
    --navy: #172b4d;
    --blue: #2864c5;
    --blue-light: #edf4ff;
    --background: #f5f7fb;
    --white: #ffffff;
    --text: #263449;
    --muted: #78869a;
    --border: #e4e9f0;
    --success: #198754;
    --warning: #d69b24;
    --radius: 12px;
}

* {
    box-sizing: border-box;
}

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

.sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    width: 245px;
    padding: 26px 18px;
    background: var(--navy);
    color: white;
}

.brand {
    font-size: 21px;
    font-weight: 750;
    margin-bottom: 40px;
}

.sidebar a {
    display: block;
    padding: 13px;
    margin: 5px 0;
    border-radius: 8px;
    color: #dce6f5;
    text-decoration: none;
}

.sidebar a:hover,
.sidebar a.active {
    background: #29466d;
    color: white;
}

.main {
    margin-left: 245px;
    padding: 35px;
}

.topbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 28px;
}

h1 {
    font-size: 27px;
    margin: 0;
}

.grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 18px;
}

.card {
    background: white;
    padding: 23px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
}

.stat {
    font-size: 30px;
    font-weight: 700;
    margin-top: 12px;
}

.muted {
    color: var(--muted);
    font-size: 13px;
}

.btn {
    display: inline-block;
    border: 0;
    border-radius: 8px;
    padding: 11px 17px;
    background: var(--blue);
    color: white;
    text-decoration: none;
    cursor: pointer;
}

.btn:hover {
    background: var(--navy);
}

input, select, textarea {
    width: 100%;
    padding: 11px;
    border: 1px solid var(--border);
    border-radius: 7px;
    margin: 7px 0 15px;
    font: inherit;
}

table {
    width: 100%;
    border-collapse: collapse;
    background: white;
}

th, td {
    padding: 14px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

th {
    color: var(--muted);
    font-size: 12px;
    text-transform: uppercase;
}

@media(max-width: 850px) {
    .sidebar {
        position: static;
        width: 100%;
    }
    .main {
        margin-left: 0;
        padding: 18px;
    }
    .grid {
        grid-template-columns: repeat(2, 1fr);
    }
}