:root {
    --bg-color: #1a1a1a;
    --text-color: #e0e0e0;
    --link-color: #8ab4f8;
    --item-bg: #2d2d2d;
    --hover-bg: #3d3d3d;
    --header-bg: #1e2a4a;
    /* Dark blue header for center box */
}

body {
    margin: 0;
    padding: 0;
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    overflow-x: hidden;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

#app {
    display: flex;
    flex-direction: column;
    height: 100%;
    width: 100%;
}

/* Toolbar Section */
#toolbar {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
    padding: 10px;
    background-color: #fff;
    /* White background as per screenshot */
    border-bottom: 1px solid #ccc;
    width: 100%;
    box-sizing: border-box;
}

.toolbar-item {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    transition: transform 0.2s;
}

.toolbar-item img {
    width: 32px;
    height: 32px;
}

.toolbar-item span {
    display: none;
    /* Hide labels in toolbar */
}

/* Main Content Grid */
#main-content {
    display: grid;
    grid-template-columns: 250px 1fr 300px;
    /* Left, Center, Right */
    flex: 1;
    padding: 20px;
    gap: 20px;
    max-width: 1600px;
    margin: 0 auto;
    width: 100%;
    box-sizing: border-box;
}

/* Left Panel */
#left-panel {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    /* Right align text */
    padding-right: 20px;
}

.group-label {
    cursor: pointer;
    padding: 5px 10px;
    color: #e0e0e0;
    /* Grey text */
    font-weight: bold;
    text-align: right;
    transition: color 0.2s;
    font-size: 14px;
}

.group-label:hover,
.group-label.active {
    color: #42aaff;
    /* Black on hover */
}

/* Center Panel */
#center-panel {
    background-color: #d0d0d0;
    /* Light grey background for the box */
    border-radius: 8px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    height: fit-content;
    min-height: 400px;
}

#center-header {
    background-color: var(--header-bg);
    color: #fff;
    padding: 15px;
    font-weight: bold;
    font-size: 1.1em;
}

#center-list {
    padding: 20px;
}

.center-link {
    display: block;
    color: #0056b3;
    /* Blue links */
    text-decoration: none;
    margin-bottom: 8px;
    font-size: 14px;
}

.center-link::before {
    content: "▶ ";
    font-size: 0.8em;
    color: #555;
    margin-right: 5px;
}

.center-link:hover {
    text-decoration: underline;
}

/* Right Panel */
#right-panel {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.sidebar-box {
    background-color: #f0f0f0;
    border: 1px solid #ccc;
    border-radius: 5px;
    padding: 10px;
}

.sidebar-link {
    display: block;
    color: #0056b3;
    text-decoration: none;
    margin-bottom: 5px;
    font-size: 13px;
}

.sidebar-link::before {
    content: "- ";
    color: #777;
}

.sidebar-link:hover {
    text-decoration: underline;
}

/* Dark Mode Overrides (if needed, but screenshot looks light/mixed) */
/* Actually, the screenshot shows a white toolbar and light grey content area. 
   I will stick to the screenshot's light theme for the main layout but keep the dark header for the center box. */