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

html,
body {
    height: 100%;
    overflow: hidden;
    font-family: Arial, sans-serif;
}

.container {
    display: flex;
    height: 100%;
    width: 100%;
}

.frame-wrapper {
    height: 100%;
    overflow: hidden;
    transition: flex-basis 0.3s ease, opacity 0.3s ease;
}

#nav-wrapper {
    flex-basis: 30%;
    min-width: 0;
}

#plan-wrapper {
    flex-basis: 70%;
    min-width: 0;
}

.frame-wrapper.collapsed {
    flex-basis: 0% !important;
    overflow: hidden;
}

.frame-wrapper iframe {
    width: 100%;
    height: 100%;
    border: none;
}

.divider {
    width: 6px;
    background: #e0e0e0;
    cursor: col-resize;
    position: relative;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.divider::before {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 1px;
    background: #ccc;
}

.toggle-buttons {
    position: absolute;
    display: flex;
    flex-direction: column;
    gap: 4px;
    z-index: 10;
}

.toggle-btn {
    width: 24px;
    height: 24px;
    border: 1px solid #bbb;
    background: rgba(255, 255, 255, 0.85);
    color: #666;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    font-weight: bold;
    border-radius: 3px;
    transition: background 0.2s, color 0.2s;
    user-select: none;
}

.toggle-btn:hover {
    background: rgba(255, 255, 255, 1);
    color: #333;
}

.toggle-btn.hidden {
    display: none;
}