* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Poppins', sans-serif;
    background-color: #f0f2f5;
    color: #1c1e21;
}

/* ===== MOBILE (MẶC ĐỊNH) ===== */

main {
    min-height: calc(100vh - 150px); /* chừa chỗ cho footer */
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
}

footer {
    background-color: #ffffff;
}

.row {
    display: flex;
    flex-direction: column;      /* mobile: xếp dọc */
    justify-content: center;
    align-items: center;
    width: 100%;
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px 16px;
    /* bỏ absolute + transform để không vỡ layout trên điện thoại */
}

.col-logo,
.col-form {
    width: 100%;
    text-align: center;
}

.col-logo img {
    max-width: 260px;
    width: 100%;
}

.col-logo h2 {
    font-size: 20px;
    font-weight: 400;
    padding: 10px 10px 20px;
    line-height: 26px;
}

.col-form .form-container {
    background-color: #ffffff;
    border: none;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1),
                0 8px 16px rgba(0, 0, 0, 0.1);
    margin-bottom: 20px;
    padding: 16px;
    width: 100%;
    max-width: 400px;
}

.col-form .form-container input,
.col-form .form-container .btn-login {
    width: 100%;
    margin: 6px 0;
    height: 44px;
    vertical-align: middle;
    font-size: 15px;
}

.col-form .form-container input {
    border: 1px solid #dddfe2;
    color: #1d2129;
    padding: 0 8px;
    outline: none;
}

.col-form .form-container input:focus {
    border-color: #1877f2;
    box-shadow: 0 0 0 2px #e7f3ff;
}

.col-form .form-container .btn-login {
    background-color: #1877f2;
    border: none;
    border-radius: 6px;
    font-size: 18px;
    padding: 0 16px;
    color: #ffffff;
    font-weight: 700;
    cursor: pointer;
}

.col-form .form-container a {
    display: block;
    color: #1877f2;
    font-size: 14px;
    text-decoration: none;
    padding: 10px 0 16px;
    border-bottom: 1px solid #dadde1;
}

.col-form .form-container a:hover {
    text-decoration: underline;
}

.col-form .form-container .btn-new {
    background-color: #42b72a;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    line-height: 44px;
    padding: 0 16px;
    color: #ffffff;
    font-weight: 700;
    margin-top: 16px;
    cursor: pointer;
}

.col-form p {
    font-size: 13px;
    padding: 0 10px 20px;
}

.col-form p a {
    text-decoration: none;
    color: #1c1e21;
    font-weight: 600;
}

.col-form p a:hover {
    text-decoration: underline;
}

/* ===== FOOTER MOBILE ===== */

.footer-contents {
    max-width: 1000px;
    margin: 0 auto;
    padding: 12px 16px 20px;
}

footer ol {
    display: flex;
    flex-wrap: wrap;
    list-style-type: none;
    padding: 8px 0;
}

footer ol:first-child {
    border-bottom: 1px solid #dddfe2;
}

footer ol:first-child li:last-child button {
    background-color: #f5f6f7;
    border: 1px solid #ccd0d5;
    outline: none;
    color: #4b4f56;
    padding: 0 8px;
    font-weight: 700;
    font-size: 14px;
    cursor: pointer;
}

footer ol li {
    padding-right: 12px;
    font-size: 12px;
    color: #385898;
    margin-bottom: 4px;
}

footer ol li a {
    text-decoration: none;
    color: #385898;
}

footer ol li a:hover {
    text-decoration: underline;
}

footer small {
    font-size: 11px;
    color: #737373;
}

/* ===== DESKTOP / TABLET (>= 900px) ===== */

@media (min-width: 900px) {
    main {
        height: 70vh;
    }

    footer {
        height: 30vh;
    }

    .row {
        flex-direction: row;         /* chia 2 cột */
        justify-content: space-around;
        align-items: center;
        padding: 0;
    }

    .col-logo {
        flex: 0 0 50%;
        text-align: left;
    }

    .col-form {
        flex: 0 0 40%;
        text-align: center;
    }

    .col-logo h2 {
        font-size: 26px;
        padding: 0 30px;
        line-height: 32px;
    }

    .col-form p {
        text-align: center;
        padding: 0;
    }
}