.card-converter {
    background: #fff;
    border: 1px solid #28a745;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.06);
    padding: 30px;
    max-width: 720px;
    margin: 40px auto;
    font-family: 'Segoe UI', sans-serif;
}
textarea.form-control {
    border-radius: 8px;
    padding: 18px;
    font-size: 16px;
    resize: vertical;
}
button.btn {
    font-weight: 600;
    border-radius: 50px;
    padding: 12px 24px;
}
.btn-success {
    background: linear-gradient(90deg, #28a745, #37c15d);
    border: none;
    color: #fff;
    box-shadow: 0 4px 10px rgba(40,167,69,0.3);
    transition: transform 0.2s ease;
}
.btn-success:hover {
    transform: scale(1.03);
}
.btn-outline-success {
    border: 2px solid #28a745;
    color: #28a745;
    background-color: #fff;
    transition: all 0.2s ease;
}
.btn-outline-success:hover {
    background-color: #28a745;
    color: #fff;
}
#kenucha_word_count {
    font-size: 14px;
    color: #555;
    margin-bottom: 5px;
    text-align: right;
}
.char-progress {
    height: 6px;
    border-radius: 3px;
    background: #e9ecef;
    overflow: hidden;
    margin-bottom: 15px;
}
.char-progress-bar {
    height: 100%;
    background: #28a745;
    width: 0%;
    transition: width 0.2s ease;
}
.button-group-responsive {
    display: flex;
    flex-direction: row;
    gap: 15px;
    margin-top: 20px;
    margin-bottom: 20px;
    justify-content: space-between;
}
@media (max-width: 768px) {
    .button-group-responsive {
        flex-direction: column;
        gap: 12px;
        margin-top: 16px;
        margin-bottom: 16px;
    }
    .card-converter {
        margin: 20px 15px;
        padding: 20px;
    }
    textarea.form-control {
        font-size: 15px;
    }
}