/* --- Light Mode (Default) --- */
body {
    font-family: sans-serif;
    background-color: #f8f9fa;
    color: #212529;
}

.drop-zone {
    border: 2px dashed #ccc;
    border-radius: 10px;
    padding: 20px;
    text-align: center;
    height: 200px;
    overflow-y: auto;
    background-color: #fff;
}

.drop-zone.dragover {
    border-color: #007bff;
    background-color: #e9f5ff;
}

.diff-result-area, .modal-content {
    border: 1px solid #ddd;
    border-radius: 5px;
    padding: 15px;
    min-height: 300px;
    background-color: #fff;
}

.group-container {
    margin-bottom: 1.5rem;
    border: 1px solid #ccc;
    border-radius: 5px;
    padding: 1rem;
    background-color: #fff;
}

.group-title {
    font-weight: bold;
    font-size: 1.2rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid #eee;
    cursor: pointer;
}

.group-title:hover {
    color: #0056b3;
}

.diff-row[data-diff-type="added"]    { background-color: #e6ffed; }
.diff-row[data-diff-type="removed"]  { background-color: #ffeef0; }
.diff-row[data-diff-type="modified"] { background-color: #fff3cd; }

.diff-row.focused {
    outline: 2px solid #0d6efd !important;
    box-shadow: 0 0 8px rgba(13, 110, 253, 0.5);
}

.diff-col {
    padding: 0.5rem;
    border-left: 1px solid #eee;
}
.diff-col:first-child { border-left: none; }

.diff-item {
    font-family: monospace;
    white-space: pre-wrap;
    word-break: break-all;
    padding: 0.5rem;
    min-height: 1em;
}

ins { background-color: #a7d7ae; text-decoration: none; border-radius: 3px; }
del { background-color: #f4a9a9; text-decoration: none; border-radius: 3px; }

.toc-link { color: #495057; }
.toc-link:hover { color: #0056b3; border-left-color: #ccc; }
.toc-link.active { color: #0d6efd; font-weight: bold; border-left-color: #0d6efd; }

.toc-toggle-btn { color: #6c757d; }
.toc-toggle-btn:hover { color: #212529; }

/* --- Dark Mode --- */
body.dark-mode {
    background-color: #121212;
    color: #e0e0e0;
}

body.dark-mode .drop-zone {
    border-color: #444;
    background-color: #1e1e1e;
}

body.dark-mode .drop-zone.dragover {
    border-color: #0d6efd;
    background-color: #2a2a2a;
}

body.dark-mode .diff-result-area,
body.dark-mode .modal-content {
    border-color: #444;
    background-color: #1e1e1e;
}

body.dark-mode .group-container {
    border-color: #555;
    background-color: #2a2a2a;
}

body.dark-mode .group-title {
    border-bottom-color: #555;
}

body.dark-mode .group-title:hover {
    color: #a9cfff;
}

body.dark-mode .diff-row[data-diff-type="added"]    { background-color: rgba(26, 92, 51, 0.2); }
body.dark-mode .diff-row[data-diff-type="removed"]  { background-color: rgba(139, 34, 34, 0.2); }
body.dark-mode .diff-row[data-diff-type="modified"] { background-color: rgba(133, 100, 4, 0.15); }

body.dark-mode .diff-row.focused {
    outline-color: #3a9cff !important;
    box-shadow: 0 0 8px rgba(58, 156, 255, 0.6);
}

body.dark-mode .diff-col { border-left-color: #555; }

body.dark-mode ins { background-color: #1A5C33; color: #c7edd1; }
body.dark-mode del { background-color: #8B2222; color: #f8c5c5; }

body.dark-mode .toc-link { color: #adb5bd; }
body.dark-mode .toc-link:hover { color: #f8f9fa; border-left-color: #555; }
body.dark-mode .toc-link.active { color: #3a9cff; border-left-color: #3a9cff; }

body.dark-mode .toc-toggle-btn { color: #adb5bd; }
body.dark-mode .toc-toggle-btn:hover { color: #f8f9fa; }

/* --- Common Styles --- */
.collapse, .collapsing {
    transition-duration: 0s !important;
    animation-duration: 0s !important;
    animation-name: none !important;
}

.toc-container {
    position: sticky;
    top: 20px;
    height: calc(100vh - 40px);
    overflow-y: auto;
}

.toc-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-right: 1rem;
}

.toc-title {
    font-size: 1.1rem;
    font-weight: bold;
    margin-bottom: 1rem;
}

.toc-toggle-btn {
    background: none;
    border: none;
    font-size: 1.8rem;
    line-height: 1;
    padding: 0 0 0.5rem 0.5rem;
    cursor: pointer;
    transition: color 0.2s ease;
}

body.toc-hidden #main-col { flex-grow: 1; }
body.toc-hidden #toc-col { width: auto; flex-grow: 0; }
body.toc-hidden .toc-title, body.toc-hidden #diff-toc { display: none; }

.copy-btn {
    background: none;
    border: none;
    color: #adb5bd;
    padding: 0 0.5rem;
}

.copy-btn:hover { color: #f8f9fa; }

body.dark-mode .copy-btn { color: #6c757d; }
body.dark-mode .copy-btn:hover { color: #adb5bd; }

/* --- Summary --- */
.summary-container {
    margin-top: 1.5rem;
    border-top: 1px solid #eee;
    padding-top: 1rem;
}

.summary-title {
    font-weight: bold;
    margin-bottom: 0.5rem;
}

.summary-content {
    white-space: pre-wrap;
    font-family: monospace;
    background-color: #f8f9fa;
    padding: 1rem;
    border-radius: 5px;
    border: 1px solid #eee;
    font-size: 0.9em;
}

body.summary-hidden .summary-container { display: none; }

/* Dark Mode Summary */
body.dark-mode .summary-container { border-top-color: #555; }
body.dark-mode .summary-content {
    background-color: #121212;
    border-color: #555;
}