body {
    background-color: #F4F6F8;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    margin: 0;
}

.auth-container {
    width: 100%;
    max-width: 420px;
    margin: 20px;
    background-color: #fff;
    padding: 25px 30px;
    border-radius: 8px;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.08);
}

.auth-title {
    font-size: 26px;
    font-weight: 600;
    color: #333;
    text-align: center;
    margin-bottom: 30px;
}

.form-group {
    margin-bottom: 18px;
}

.form-group label {
    display: block;
    font-size: 14px;
    color: #555;
    margin-bottom: 8px;
    font-weight: 500;
}

.form-control {
    display: block;
    width: 100%;
    height: 44px;
    padding: 10px 15px;
    font-size: 16px;
    line-height: 1.5;
    color: #495057;
    background-color: #fff;
    background-clip: padding-box;
    border: 1px solid #ced4da;
    border-radius: 5px;
    box-sizing: border-box;
    transition: border-color .15s ease-in-out,box-shadow .15s ease-in-out;
}

.form-control:focus {
    color: #495057;
    background-color: #fff;
    border-color: #4A90E2;
    outline: 0;
    box-shadow: 0 0 0 0.2rem rgba(74, 144, 226, 0.25);
}

.input-group {
    display: flex;
}

.input-group .form-control {
    flex: 1 1 auto;
    border-top-right-radius: 0;
    border-bottom-right-radius: 0;
}

.input-group-btn {
    flex-shrink: 0;
    display: flex;
}

.input-group-btn .btn, #verify_img {
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
    height: 44px;
}

.btn {
    display: inline-block;
    font-weight: 500;
    text-align: center;
    vertical-align: middle;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    border: 1px solid transparent;
    padding: 10px 15px;
    font-size: 16px;
    line-height: 1.5;
    border-radius: 5px;
    cursor: pointer;
    transition: all .15s ease-in-out;
}

.btn-primary {
    color: #fff;
    background-color: #4A90E2;
    border-color: #4A90E2;
}

.btn-primary:hover {
    background-color: #357ABD;
    border-color: #357ABD;
}

.btn-block {
    display: block;
    width: 100%;
}

#verify_img {
    cursor: pointer;
    border: 1px solid #ced4da;
    border-left: 0;
    width: 120px;
}

.link-area {
    text-align: center;
    margin-top: 25px;
    font-size: 14px;
}

.link-area a {
    color: #4A90E2;
    text-decoration: none;
    font-weight: 500;
}
.link-area a:hover {
    text-decoration: underline;
}