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

.container {
    max-width: 1200px;
    margin: 20px auto;
    padding: 20px;
}

.header {
    text-align: center;
    margin-bottom: 30px;
}

.header h1 {
    color: #333;
    font-size: 24px;
}

.header .version {
    font-size: 14px;
    color: #666;
    font-weight: normal;
}

.footer {
    text-align: center;
    margin-top: 40px;
    padding-top: 20px;
    border-top: 1px solid #e0e0e0;
    color: #666;
}

.footer a {
    color: #00a651;
    text-decoration: none;
}

.footer a:hover {
    text-decoration: underline;
}

.tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    border-bottom: 1px solid #e0e0e0;
    padding-bottom: 10px;
}

.tab-btn {
    padding: 8px 16px;
    border: none;
    background: none;
    cursor: pointer;
    font-size: 14px;
}

.tab-btn.active {
    color: #00a651;
    border-bottom: 2px solid #00a651;
}

.content {
    display: flex;
    gap: 20px;
}

.input-area {
    flex: 1;
}

textarea {
    width: 100%;
    height: 300px;
    padding: 10px;
    border: 1px solid #e0e0e0;
    border-radius: 4px;
    resize: none;
}

textarea.error {
    border-color: #ff4444;
    background-color: #fff8f8;
}

.length-indicator {
    margin-top: 5px;
    font-size: 12px;
    color: #666;
    text-align: right;
}

.length-indicator.warning {
    color: #ff4444;
    font-weight: bold;
}

.controls {
    margin-top: 20px;
    display: flex;
    gap: 10px;
}

.preview-area {
    width: 300px;
    text-align: center;
}

#qrcode {
    width: 250px;
    height: 250px;
    margin: 0 auto 20px;
    padding: 10px;
    border: 1px solid #e0e0e0;
}

.primary-btn {
    padding: 8px 16px;
    background-color: #00a651;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

.primary-btn:hover {
    background-color: #008c44;
}