body {
    font-family: 'Arial', sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f8f9fa;
    color: #202124;
}

.main-container {
    display: flex;
    height: 100vh;
}

.editor-pane {
    flex: 1;
    display: flex;
    flex-direction: column;
    border-right: 1px solid #dadce0;
}

.toolbar {
    padding: 8px 16px;
    background-color: #edf2fa;
    border-bottom: 1px solid #dadce0;
    display: flex;
    align-items: center;
}

.toolbar button {
    background-color: transparent;
    border: none;
    cursor: pointer;
    font-size: 18px;
    margin-right: 16px;
    padding: 4px;
}

.toolbar button:hover {
    background-color: #d2e3fc;
}

.markdown-input {
    flex: 1;
    padding: 48px;
    border: none;
    font-size: 16px;
    line-height: 1.6;
    resize: none;
    background-color: #fff;
}

.preview-pane {
    flex: 1;
    padding: 48px;
    background-color: #f8f9fa;
    overflow-y: auto;
}

.preview-output {
    max-width: 8.5in;
    margin: 0 auto;
    background-color: #fff;
    padding: 1in;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}

.styles-pane {
    width: 250px;
    padding: 20px;
    background-color: #edf2fa;
    border-left: 1px solid #dadce0;
}

#styles-list {
    margin-top: 20px;
}

.style-item {
    padding: 10px;
    margin-bottom: 10px;
    background-color: #fff;
    border: 1px solid #dadce0;
    cursor: pointer;
}

.style-item:hover {
    background-color: #d2e3fc;
}

.modal {
    display: none;
    position: fixed;
    z-index: 1;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0,0,0,0.4);
}

.modal-content {
    background-color: #fefefe;
    margin: 15% auto;
    padding: 20px;
    border: 1px solid #888;
    width: 80%;
    max-width: 500px;
}

.close-button {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
}

.close-button:hover,
.close-button:focus {
    color: black;
    text-decoration: none;
    cursor: pointer;
}