body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: #f4f6f8;
    color: #222;
    overflow: hidden;
}

.app-shell {
    height: 100vh;
    display: flex;
    flex-direction: column;
}

.topbar {
    height: 60px;
    background: #1f2937;
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    position: sticky;
    top: 0;
    z-index: 1000;
    flex-shrink: 0;
}

.brand {
    font-size: 20px;
    font-weight: bold;
}

.topbar-right {
    display: flex;
    align-items: center;
    gap: 12px;
}

.main-layout {
    display: flex;
    min-height: calc(100vh - 60px);
    height: calc(100vh - 60px);
    overflow: hidden;
}

.sidebar {
    width: 240px;
    background: #111827;
    padding: 20px 0;
    overflow-y: auto;
    position: sticky;
    top: 0;
    align-self: flex-start;
    height: calc(100vh - 60px);
    flex-shrink: 0;
}

.sidebar nav a {
    display: block;
    color: #e5e7eb;
    text-decoration: none;
    padding: 12px 20px;
}

.sidebar nav a:hover {
    background: #1f2937;
}

.content {
    flex: 1;
    padding: 24px;
    overflow-y: auto;
    height: calc(100vh - 60px);
    box-sizing: border-box;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 16px;
}

.card {
    background: #fff;
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.06);
}

.card h3 {
    margin-top: 0;
    font-size: 16px;
}

.metric {
    font-size: 28px;
    font-weight: bold;
    margin-top: 8px;
}

.btn {
    display: inline-block;
    padding: 9px 14px;
    border-radius: 6px;
    text-decoration: none;
    color: #fff;
}

.btn-danger {
    background: #c62828;
}

.login-page {
    font-family: Arial, sans-serif;
    background: #eef2f7;
    margin: 0;
    padding: 0;
}

.login-box {
    width: 100%;
    max-width: 420px;
    margin: 80px auto;
    background: #fff;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 2px 16px rgba(0,0,0,0.08);
}

.login-box h2 {
    margin-top: 0;
    margin-bottom: 20px;
    text-align: center;
}

.login-box label {
    display: block;
    margin: 12px 0 6px;
    font-weight: bold;
}

.login-box input[type="email"],
.login-box input[type="password"] {
    width: 100%;
    padding: 12px;
    box-sizing: border-box;
    border: 1px solid #cfd8dc;
    border-radius: 6px;
}

.login-box button {
    width: 100%;
    margin-top: 18px;
    padding: 12px;
    background: #1976d2;
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    cursor: pointer;
}

.login-box button:hover {
    background: #1565c0;
}

.error {
    background: #ffebee;
    color: #b71c1c;
    padding: 10px;
    border-radius: 6px;
    margin-bottom: 15px;
}

.hint {
    margin-top: 15px;
    font-size: 13px;
    color: #555;
    text-align: center;
}