body, html {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Canvas nằm dưới cùng, không cản trở click chuột vào form */
#glCanvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: 0;
    pointer-events: none;
}

/* Form đăng nhập - Kính mờ */
.login-card {
    background: rgba(255, 255, 255, 0.75);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.5);
    border-radius: 16px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.05);
    padding: 40px 35px;
    width: 100%;
    max-width: 420px;
    z-index: 1;
    position: relative;
}

/* Chi tiết UI */
.logo-icon {
    background: #000;
    color: #fff;
    width: 36px;
    height: 36px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px auto;
}

.form-group label {
    font-size: 0.75rem;
    font-weight: 700;
    color: #6c757d;
    text-transform: uppercase;
    margin-bottom: 0.5rem;
}

.form-control {
    border-radius: 8px;
    padding: 12px 15px;
    border: 1px solid #e2e8f0;
    font-size: 0.95rem;
    background: rgba(255,255,255,0.9);
}

    .form-control:focus {
        box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.15);
        border-color: #80bdff;
        outline: none;
    }

.btn-primary {
    background-color: #000;
    border-color: #000;
    border-radius: 8px;
    padding: 12px;
    font-weight: 500;
}

    .btn-primary:hover {
        background-color: #222;
        box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    }

.btn-outline-google {
    border: 1px solid #e2e8f0;
    background: #fff;
    border-radius: 8px;
    padding: 10px;
    font-weight: 500;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

    .btn-outline-google:hover {
        background: #f8f9fa;
    }

.divider {
    display: flex;
    align-items: center;
    margin: 25px 0;
}

    .divider::before, .divider::after {
        content: '';
        flex: 1;
        border-bottom: 1px solid #e2e8f0;
    }

    .divider span {
        padding: 0 15px;
        color: #adb5bd;
        font-size: 0.85rem;
    }

.text-link {
    font-size: 0.8rem;
    font-weight: 600;
    text-decoration: none;
    color: #4f46e5;
}