:root {
    --primary-color: #2196F3;
    --hover-color: #1976D2;
    --background-color: #f5f5f5;
    --text-color: #333;
    --border-color: #ddd;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
}

.container {
    max-width: 1000px;
    margin: 2rem auto;
    padding: 2rem;
}

h1 {
    text-align: center;
    margin-bottom: 2rem;
    color: var(--primary-color);
}

.upload-section {
    text-align: center;
    margin-bottom: 2rem;
}

.file-upload {
    margin-bottom: 1rem;
}

.file-input {
    display: none;
}

.file-label {
    display: inline-block;
    padding: 1rem 2rem;
    background-color: var(--primary-color);
    color: white;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.file-label:hover {
    background-color: var(--hover-color);
}

.upload-icon {
    margin-right: 0.5rem;
}

.file-name {
    margin-top: 0.5rem;
    font-size: 0.9rem;
    color: #666;
}

.options-section {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.input-group {
    display: flex;
    flex-direction: column;
}

.input-group label {
    margin-bottom: 0.5rem;
}

.input-group input,
.input-group select {
    padding: 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
}

.convert-btn {
    display: block;
    width: 100%;
    padding: 1rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: background-color 0.3s;
    margin-bottom: 2rem;
}

.convert-btn:hover {
    background-color: var(--hover-color);
}

.result-section {
    background-color: white;
    border-radius: 4px;
    padding: 1rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    display: flex;
    flex-direction: column;
}

@media (min-width: 1024px) {
    .result-section {
        flex-direction: row;
        gap: 1rem;
    }

    .code-panel {
        flex: 1;
        min-width: 0;
    }

    .vertical-divider {
        width: 1px;
        background-color: var(--border-color);
        margin: 0 1rem;
    }
}

.code-panel {
    display: flex;
    flex-direction: column;
}

.code-panel + .code-panel {
    margin-top: 1rem;
}

@media (min-width: 1024px) {
    .code-panel + .code-panel {
        margin-top: 0;
    }
}

.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.panel-title {
    font-size: 1.1rem;
    color: var(--text-color);
}

.copy-btn {
    padding: 0.5rem 1rem;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.copy-btn:hover {
    background-color: #388E3C;
}

.result-code {
    background-color: #2d2d2d !important;
    padding: 1rem !important;
    border-radius: 4px;
    overflow-x: auto;
    margin: 0 !important;
}

.result-code code {
    font-family: 'Consolas', 'Monaco', 'Andale Mono', monospace;
    font-size: 14px;
    white-space: pre;
    word-spacing: normal;
    word-break: normal;
    line-height: 1.5;
    tab-size: 4;
}

.feedback-section {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.feedback-section h2 {
    text-align: center;
    color: var(--text-color);
    margin-bottom: 1.5rem;
}

.feedback-form {
    max-width: 600px;
    margin: 0 auto;
}

.feedback-form .input-group {
    margin-bottom: 1rem;
}

.feedback-form textarea {
    width: 100%;
    min-height: 120px;
    padding: 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-family: inherit;
    font-size: 1rem;
    resize: vertical;
}

.submit-btn {
    display: block;
    width: 100%;
    padding: 1rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: background-color 0.3s;
}

.submit-btn:hover {
    background-color: var(--hover-color);
}