:root {
    --auth-bg-start: #0b1220;
    --auth-bg-end: #0f172a;
    --auth-card-bg: rgba(15, 23, 42, 0.75);
    --auth-card-border: rgba(148, 163, 184, 0.28);
    --auth-text-main: #e2e8f0;
    --auth-text-muted: #94a3b8;
    --auth-accent: #22d3ee;
}

body.admin-auth-shell {
    min-height: 100vh;
    margin: 0;
    color: var(--auth-text-main);
    background:
        radial-gradient(circle at 15% 20%, #1e3a8a 0%, transparent 35%),
        radial-gradient(circle at 85% 80%, #0e7490 0%, transparent 30%),
        linear-gradient(135deg, var(--auth-bg-start), var(--auth-bg-end));
    font-family: 'Inter', sans-serif;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 18px;
}

.auth-card {
    width: 100%;
    max-width: 420px;
    background: var(--auth-card-bg);
    border: 1px solid var(--auth-card-border);
    border-radius: 16px;
    box-shadow: 0 20px 45px rgba(2, 8, 23, 0.6);
    backdrop-filter: blur(8px);
}

.auth-title {
    font-weight: 700;
    letter-spacing: 0.04em;
    margin-bottom: 4px;
}

.auth-logo {
    width: 74px;
    height: 74px;
    object-fit: contain;
    filter: drop-shadow(0 6px 16px rgba(14, 165, 233, 0.45));
    margin-bottom: 12px;
}

.auth-subtitle {
    color: var(--auth-text-muted);
    font-size: 0.86rem;
    margin-bottom: 0;
}

.admin-auth-shell .form-label {
    color: var(--auth-text-muted);
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    margin-bottom: 6px;
}

.admin-auth-shell .form-control,
.admin-auth-shell .input-group-text {
    background: rgba(15, 23, 42, 0.68);
    border-color: rgba(148, 163, 184, 0.35);
    color: var(--auth-text-main);
}

.admin-auth-shell .form-control::placeholder {
    color: rgba(148, 163, 184, 0.75);
}

.admin-auth-shell .form-control:focus {
    background: rgba(15, 23, 42, 0.8);
    border-color: var(--auth-accent);
    box-shadow: 0 0 0 0.18rem rgba(34, 211, 238, 0.22);
    color: var(--auth-text-main);
}

.admin-auth-shell .input-group-text {
    border-right: 0;
}

.admin-auth-shell .input-group .form-control {
    border-left: 0;
}

.btn-login {
    background: linear-gradient(135deg, #0891b2, #2563eb);
    border: 0;
    color: #fff;
    font-weight: 700;
    letter-spacing: 0.02em;
}

.btn-login:hover {
    color: #fff;
    filter: brightness(1.08);
}

.auth-back {
    color: var(--auth-text-muted);
    text-decoration: none;
    font-size: 0.86rem;
}

.auth-back:hover {
    color: var(--auth-text-main);
}