html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    overflow: hidden; /* Ngăn scroll */
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

/* Background full màn hình */
body {
    background: linear-gradient(to right, #00c6ff, #0072ff);
}

/* Canh giữa form */
.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

/* Hộp login */
.login-box {
    background: white;
    padding: 40px 30px;
    border-radius: 10px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
    width: 350px;
    text-align: center;
}

    .login-box h2 {
        margin-bottom: 30px;
        color: #333;
    }

.input-group {
    position: relative;
    margin-bottom: 20px;
}

    .input-group i {
        position: absolute;
        top: 50%;
        left: 12px;
        transform: translateY(-50%);
        color: #aaa;
        font-size: 16px;
    }

    .input-group input {
        width: 100%;
        padding: 10px 12px 10px 40px;
        font-size: 15px;
        height: 40px;
        border: 1px solid #ccc;
        border-radius: 6px;
        outline: none;
        box-sizing: border-box;
        transition: border-color 0.3s;
    }

.login-btn {
    width: 100%;
    height: 45px;
    border: none;
    border-radius: 8px;
    background: linear-gradient(135deg, #007bff, #0056d6);
    color: white;
    font-size: 16px;
    font-weight: 600;
    letter-spacing: 0.3px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px; /* khoảng cách icon – text */
    box-shadow: 0 4px 12px rgba(0, 86, 214, 0.3);
    cursor: pointer;
    transition: all 0.25s ease-in-out;
}

    .login-btn i {
        font-size: 17px;
    }

    .login-btn:hover {
        background: linear-gradient(135deg, #0066db, #004bb3);
        box-shadow: 0 6px 16px rgba(0, 86, 214, 0.45);
        transform: translateY(-1px);
    }

    .login-btn:active {
        transform: translateY(1px);
        box-shadow: 0 3px 8px rgba(0, 86, 214, 0.3);
    }

.input-group input {
    width: 100%;
    padding: 10px 12px 10px 40px;
    font-size: 15px;
    height: 40px;
    border: 1px solid #ccc;
    border-radius: 6px;
    outline: none;
    background: #fff; /* <<< đảm bảo nền trắng */
    color: #333; /* <<< chữ đậm rõ */
    box-sizing: border-box;
    transition: border-color 0.3s, box-shadow 0.2s;
}

.input-group input:focus {
    border-color: #0072ff;
    background-color: #fff8d6; /* vàng nhạt */
    box-shadow: 0 0 4px rgba(0, 114, 255, 0.35);
    transition: 0.25s ease;
}