/* Root variables for color palette */
:root {
    --primary-color: #4A90E2; /* Blue */
    --secondary-bg-color: #F5F7FA; /* Light Grey */
    --text-color: #333333; /* Dark Grey */
    --white-color: #FFFFFF;
    --success-color: #50E3C2; /* Teal */
    --error-color: #D0021B; /* Red */
    --border-color: #E0E6ED; /* Light Grey Border */
}

/* Global Styles */
body {
    font-family: 'Pretendard', 'Noto Sans KR', sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    background-color: var(--secondary-bg-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

header {
    background-color: var(--white-color);
    padding: 20px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
    text-align: center;
}

header h1 {
    margin: 0;
    color: var(--primary-color);
    font-size: 28px;
}

.container {
    display: flex;
    flex-grow: 1;
    padding: 20px;
    gap: 20px;
    max-width: 1200px;
    margin: 20px auto;
}

/* Card Styles */
.card {
    background-color: var(--white-color);
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.05);
    padding: 20px;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.card h2 {
    margin-top: 0;
    color: var(--text-color);
    font-size: 22px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 10px;
    margin-bottom: 20px;
}

/* Input and Output Sections */
.input-section, .output-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

textarea {
    width: 100%;
    flex-grow: 1;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 16px;
    font-family: 'Pretendard', 'Noto Sans KR', sans-serif;
    resize: vertical;
    min-height: 150px;
    box-sizing: border-box; /* Include padding in width/height */
}

textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(74, 144, 226, 0.2);
}

.char-count {
    text-align: right;
    font-size: 14px;
    color: #666;
    margin-top: 5px;
}

/* Radio Button Group */
.radio-group {
    display: flex;
    gap: 15px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.radio-group input[type="radio"] {
    display: none;
}

.radio-group label {
    background-color: var(--secondary-bg-color);
    color: var(--text-color);
    padding: 10px 15px;
    border-radius: 20px;
    cursor: pointer;
    transition: background-color 0.2s, color 0.2s;
    border: 1px solid var(--border-color);
    font-size: 14px;
}

.radio-group input[type="radio"]:checked + label {
    background-color: var(--primary-color);
    color: var(--white-color);
    border-color: var(--primary-color);
}

/* Button Styles */
.primary-button, .secondary-button {
    padding: 12px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    font-weight: bold;
    transition: background-color 0.2s ease;
    width: 100%;
    box-sizing: border-box;
}

.primary-button {
    background-color: var(--primary-color);
    color: var(--white-color);
    margin-top: auto; /* Push to bottom of card */
}

.primary-button:hover {
    background-color: #3a7bd5; /* Slightly darker blue */
}

.secondary-button {
    background-color: var(--secondary-bg-color);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    margin-top: 15px;
}

.secondary-button:hover {
    background-color: #e0e6ed;
}

/* Feedback Message */
.feedback-message {
    margin-top: 10px;
    padding: 10px;
    border-radius: 4px;
    text-align: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.feedback-message.show {
    opacity: 1;
}

.feedback-message.success {
    background-color: rgba(80, 227, 194, 0.2); /* Light success color */
    color: var(--success-color);
}

.feedback-message.error {
    background-color: rgba(208, 2, 27, 0.2); /* Light error color */
    color: var(--error-color);
}

/* Footer */
footer {
    text-align: center;
    padding: 20px;
    background-color: var(--white-color);
    color: #666;
    font-size: 14px;
    margin-top: auto;
    box-shadow: 0 -2px 4px rgba(0, 0, 0, 0.03);
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        flex-direction: column;
        padding: 15px;
        margin: 15px auto;
    }

    header h1 {
        font-size: 24px;
    }

    .card {
        padding: 15px;
    }

    .card h2 {
        font-size: 20px;
        margin-bottom: 15px;
    }

    .radio-group {
        flex-direction: column;
        gap: 10px;
    }

    .radio-group label {
        width: calc(100% - 30px); /* Adjust for padding */
        text-align: center;
    }
}