html, body {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
    /* overflow: hidden; removed to allow scrolling */
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: #f0f2f5; /* Slightly adjusted background color */
    color: #333;
}

#chart-area {
    width: 100%;
    height: 100%;
    min-width: 100vw; /* Ensure it's at least viewport width */
    min-height: 100vh; /* Ensure it's at least viewport height */
}

#flowchart-svg {
    min-width: 100%;
    min-height: 100%;
}

.link {
    stroke: #999;
    stroke-opacity: 0.6;
    stroke-width: 2px;
}

.arrow-marker {
    fill: #999;
}

/* Temporary line for relinking */
.temp-link {
    stroke: #d62728; /* Red color for temp link */
    stroke-opacity: 0.8;
    stroke-width: 2.5px;
    stroke-dasharray: 5, 5; /* Dashed line */
}

.node rect {
    stroke: #fff;
    stroke-width: 2px;
    fill: #007bff;
    cursor: pointer;
    transition: fill 0.2s;
    width: 120px; /* Node width */
    height: 50px; /* Node height */
}

.node:hover rect {
    fill: #0056b3;
}

.node.selected rect {
    fill: #28a745; /* Green for selected */
    stroke: #208038;
}

.node text {
    font-size: 14px;
    fill: #fff;
    text-anchor: middle;
    dominant-baseline: central; /* Vertical centering */
    pointer-events: none; /* So the rect receives click events */
    font-weight: bold;
}

#details-panel {
    position: absolute;
    top: 20px;
    right: 20px;
    width: 250px;
    padding: 15px;
    background-color: white;
    border: 1px solid #ccc;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
    transition: opacity 0.3s, transform 0.3s;
    opacity: 1;
    transform: translateY(0);
    z-index: 10;
}

#details-panel.hidden {
    opacity: 0;
    transform: translateY(-20px);
    pointer-events: none;
}

/* Context Menu Styling */
.context-menu {
    position: absolute;
    background-color: #fff;
    border: 1px solid #ccc;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
    border-radius: 4px;
    padding: 5px 0;
    z-index: 100;
}

.context-menu.hidden {
    display: none;
}

.context-menu ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.context-menu ul li {
    padding: 8px 15px;
    cursor: pointer;
    font-size: 14px;
}

.context-menu ul li:hover {
    background-color: #f0f0f0;
}

/* IO Buttons Styling */
.io-buttons {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 20;
    display: flex;
    gap: 10px;
}

.io-buttons button {
    padding: 10px 15px;
    font-size: 14px;
    font-weight: bold;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
    transition: background-color 0.2s, transform 0.2s;
}

#export-btn {
    background-color: #28a745;
    color: white;
}
#export-btn:hover { background-color: #218838; }

#import-btn {
    background-color: #17a2b8;
    color: white;
}
#import-btn:hover { background-color: #138496; }

#clear-btn {
    background-color: #dc3545;
    color: white;
}
#clear-btn:hover { background-color: #c82333; }

#reset-layout-btn {
    background-color: #ffc107;
    color: #212529;
}
#reset-layout-btn:hover { background-color: #e0a800; }

.hidden {
    display: none;
}

/* Read-only mode styles */
body.read-only .io-buttons,
body.read-only .context-menu {
    display: none !important;
}

/* Modal Styling */
#modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
    z-index: 199;
    display: flex;
    align-items: center;
    justify-content: center;
}

#modal-overlay.hidden {
    display: none;
}

#node-modal {
    background: #fff;
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.3);
    width: 350px;
    display: flex;
    flex-direction: column;
}

#node-modal h2 {
    margin-top: 0;
    margin-bottom: 20px;
}

#node-modal label {
    margin-bottom: 5px;
    font-weight: bold;
}

#node-modal input, #node-modal textarea {
    width: 100%;
    padding: 8px;
    margin-bottom: 15px;
    border: 1px solid #ccc;
    border-radius: 4px;
    box-sizing: border-box;
}

.modal-buttons {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
}

.modal-buttons button {
    padding: 10px 15px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

#modal-save-btn {
    background-color: #007bff;
    color: white;
}

#modal-cancel-btn {
    background-color: #6c757d;
    color: white;
}