:root {
    --bg-dark: #151521;
    --bg-card: #1e1e2d;
    --primary: #5636f3;
    --primary-hover: #4e30e0;
    --text-main: #b7b7b7;
    --text-bright: #ffffff;
    --border-color: #323248;
}

body {
    background-color: var(--bg-dark);
    /* Subtle background grid or gradient */
    background-image: radial-gradient(circle at 10% 20%, rgba(86, 54, 243, 0.05) 0%, transparent 40%),
                      radial-gradient(circle at 90% 80%, rgba(11, 183, 131, 0.05) 0%, transparent 40%);
    color: var(--text-main);
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    background-attachment: fixed;
}

.auth-card {
    background-color: var(--bg-card);
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    width: 100%;
    /* Max width controlled by parent column usually, or settable here */
    padding: 2.5rem;
    border: 1px solid rgba(255,255,255,0.03);
    position: relative;
    overflow: hidden;
    /* Glass feel */
    backdrop-filter: blur(10px);
}

/* Auth Card Header Decoration */
.auth-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), #8950fc);
}

.brand-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-bright);
    text-align: center;
    margin-bottom: 2rem;
    display: block;
    text-decoration: none;
    transition: transform 0.3s ease;
}

.brand-logo:hover {
    transform: translateY(-2px);
}

.auth-title {
    text-align: center;
    margin-bottom: 1.5rem;
    color: var(--text-bright);
    font-weight: 600;
}

.form-label {
    color: #7e8299;
    font-weight: 500;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.form-control, .form-select {
    background-color: #1b1b29; /* Slightly darker than card */
    border: 1px solid var(--border-color);
    color: var(--text-bright);
    padding: 0.85rem 1rem;
    font-weight: 500;
    border-radius: 0.55rem;
    height: auto;
    transition: all 0.2s ease;
}

.form-control:focus, .form-select:focus {
    background-color: #1b1b29;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(86, 54, 243, 0.1);
    color: var(--text-bright);
}

.input-group-text {
    background-color: #2b2b40;
    border-color: var(--border-color);
    color: #5d5f77;
}

.btn-primary {
    background-color: var(--primary);
    border-color: var(--primary);
    color: #ffffff;
    padding: 0.85rem 1.5rem;
    font-weight: 600;
    border-radius: 0.55rem;
    transition: all 0.2s ease;
    width: 100%;
    box-shadow: 0 4px 12px rgba(86, 54, 243, 0.2);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    border-color: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 6px 15px rgba(86, 54, 243, 0.3);
}

.auth-footer {
    text-align: center;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255,255,255,0.05);
    font-size: 0.9rem;
    color: #6c757d;
}

.auth-footer a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s ease;
}

.auth-footer a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* Radio Button Group Styling */
.btn-outline-primary {
    color: #7e8299;
    border-color: var(--border-color);
    background-color: transparent;
}
.btn-outline-primary:hover {
    background-color: rgba(86, 54, 243, 0.1);
    border-color: var(--primary);
    color: var(--primary);
}
.btn-check:checked + .btn-outline-primary {
    background-color: var(--primary);
    border-color: var(--primary);
    color: white;
}