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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f5f7fa;
    font-size: 14px;
}

.container { max-width: 1100px; margin: 0 auto; padding: 2rem 1rem; }

header {
    margin-bottom: 2rem; background: white; padding: 1.5rem;
    border-radius: 8px; box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
header h1 { font-size: 1.8rem; margin-bottom: 0.5rem; font-weight: 500; color: #2c3e50; }
header p { font-size: 0.95rem; color: #666; }

/* Buttons */
.btn {
    padding: 0.5rem 1rem; font-size: 0.85rem; border: 1px solid #ddd;
    border-radius: 4px; background: #fff; color: #333; cursor: pointer;
    transition: all 0.2s ease;
}
.btn:hover { background: #f8f9fa; border-color: #aaa; }
.btn.primary { background: #3498db; border-color: #3498db; color: white; }
.btn.primary:hover { background: #2980b9; }
.btn.success { background: #27ae60; border-color: #27ae60; color: white; }
.btn.success:hover { background: #219a52; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn.large { padding: 0.75rem 1.5rem; font-size: 1rem; font-weight: 500; }

/* Steps */
.step-section {
    background: white; padding: 1.5rem; border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1); margin-bottom: 1.5rem;
}
.step-section.hidden { display: none; }
.step-section h2 {
    font-size: 1.2rem; font-weight: 500; margin-bottom: 1rem; color: #2c3e50;
    display: flex; align-items: center; gap: 0.5rem;
}
.step-badge {
    background: #27ae60; color: white; padding: 0.2rem 0.6rem;
    border-radius: 4px; font-size: 0.8rem;
}

/* Info boxes */
.explanation-box {
    background: #f0f4f8; border-left: 4px solid #3498db; color: #2c3e50;
    padding: 1rem; border-radius: 4px; margin-bottom: 1rem;
}
.explanation-box h4 { font-size: 0.95rem; margin-bottom: 0.5rem; color: #2c3e50; }
.explanation-box p { font-size: 0.9rem; color: #444; }

.insight-box {
    background: #fef9e7; border-left: 4px solid #f39c12; color: #2c3e50;
    padding: 1rem; border-radius: 4px; margin-bottom: 1rem;
}
.insight-box h4 { font-size: 0.95rem; margin-bottom: 0.5rem; color: #d68910; }
.insight-box p, .insight-box li { font-size: 0.85rem; color: #555; }
.insight-box ul { margin-left: 1.2rem; margin-top: 0.5rem; }
.insight-box li { margin-bottom: 0.3rem; }

.concept-box {
    background: #eaf2f8; border-left: 4px solid #2980b9; color: #2c3e50;
    padding: 1rem; border-radius: 4px; margin-bottom: 1rem;
}
.concept-box h4 { font-size: 0.95rem; margin-bottom: 0.5rem; color: #2980b9; }
.concept-box p { font-size: 0.85rem; color: #444; margin-bottom: 0.5rem; }

/* Side-by-side formula + example */
.formula-example-row {
    display: flex; gap: 1rem; margin-bottom: 1rem;
}
.formula-example-row > .math-section,
.formula-example-row > .calc-detail {
    flex: 1; min-width: 0; margin-bottom: 0;
}

.math-section {
    background: #f8f9fa; border: 1px solid #e0e0e0; border-radius: 6px;
    padding: 1rem; margin-bottom: 1rem;
}
.math-section h4 {
    font-size: 0.95rem; color: #2c3e50; margin-bottom: 0.75rem;
    border-bottom: 1px solid #e0e0e0; padding-bottom: 0.5rem;
}
.math-content { font-size: 0.9rem; line-height: 1.8; }
.math-formula { text-align: center; margin: 0.75rem 0; }

.continue-container {
    margin-top: 1.5rem; padding-top: 1rem;
    border-top: 1px solid #e0e0e0; text-align: center;
}

/* Data table */
.data-table-wrapper {
    overflow-x: auto; margin-bottom: 1rem; border-radius: 6px; border: 1px solid #ddd;
}

table.feature-table {
    width: 100%; border-collapse: collapse; font-size: 0.9rem;
    min-width: 500px; table-layout: fixed;
}
table.feature-table th:first-child,
table.feature-table td:first-child { width: 150px; }

table.feature-table th, table.feature-table td {
    padding: 0.6rem 0.8rem; text-align: center; border: 1px solid #e0e0e0;
}
table.feature-table thead th {
    background: #eaf0f6; color: #2c3e50; font-weight: 600;
    position: relative; border-bottom: 2px solid #b0bec5;
}
table.feature-table thead th input.col-name-input {
    border: none; background: transparent; text-align: center; font-size: 0.9rem;
    font-weight: 600; color: #2c3e50; width: 60px; outline: none; padding: 0;
}
table.feature-table thead th input.col-name-input:focus { border-bottom: 1px solid #3498db; }
table.feature-table thead th .remove-col-btn {
    position: absolute; top: 2px; right: 2px; background: rgba(0,0,0,0.08);
    border: none; color: #999; cursor: pointer; font-size: 0.7rem;
    border-radius: 2px; padding: 0 4px; line-height: 1.4;
}
table.feature-table thead th .remove-col-btn:hover { background: rgba(231,76,60,0.2); color: #c0392b; }

/* Ghost column */
table.feature-table .ghost-col { cursor: pointer; min-width: 60px; }
table.feature-table thead th.ghost-col { color: #aaa; font-weight: 400; }
table.feature-table td.ghost-col { color: #ccc; }
table.feature-table .ghost-col input {
    border: none; background: transparent; text-align: center;
    font-size: 0.85rem; color: #333; width: 70px; outline: none;
}
table.feature-table .ghost-col input::placeholder { color: #bbb; }
table.feature-table .ghost-col.active { cursor: default; }

/* Toggle details */
.calc-toggle-btn {
    background: none; border: 1px solid #ccc; border-radius: 4px;
    padding: 0.4rem 0.8rem; font-size: 0.85rem; color: #555;
    cursor: pointer; margin-bottom: 0.75rem; transition: all 0.2s ease;
}
.calc-toggle-btn:hover { background: #f0f4f8; border-color: #3498db; color: #2980b9; }
.calc-details-collapsible { display: none; }
.calc-details-collapsible.open { display: block; }

table.feature-table tbody tr:nth-child(even):not(.mean-row):not(.std-row):not(.total-row) { background: #f8f9fa; }
table.feature-table tbody tr:not(.mean-row):not(.std-row):not(.total-row):hover { background: #eef2f7; }

table.feature-table td.doc-label {
    font-weight: 600; background: #ecf0f1; color: #2c3e50;
    text-align: left; white-space: nowrap; position: relative;
}
table.feature-table td.doc-label input.doc-name-input {
    border: none; background: transparent; font-size: 0.9rem; font-weight: 600;
    color: #2c3e50; width: 65px; outline: none; padding: 0;
}
table.feature-table td.doc-label input.doc-name-input:focus { border-bottom: 1px solid #3498db; }
table.feature-table td.doc-label .remove-row-btn {
    position: absolute; top: 2px; right: 2px; background: rgba(0,0,0,0.08);
    border: none; color: #999; cursor: pointer; font-size: 0.65rem;
    border-radius: 2px; padding: 0 3px; line-height: 1.4;
}
table.feature-table td.doc-label .remove-row-btn:hover { background: rgba(231,76,60,0.2); color: #c0392b; }

table.feature-table tr.ghost-row-trigger td {
    cursor: pointer; color: #aaa; font-weight: 400; text-align: center; font-size: 0.85rem;
}
table.feature-table tr.ghost-row-trigger td:hover { color: #666; background: #f0f4f8; }

table.feature-table td input {
    width: 60px; text-align: center; border: 1px solid #ccc; border-radius: 3px;
    padding: 0.25rem; font-size: 0.85rem; font-family: 'Courier New', monospace;
}
table.feature-table td input:focus {
    outline: none; border-color: #3498db; box-shadow: 0 0 3px rgba(52,152,219,0.3);
}

/* Total-words column */
table.feature-table th.total-col, table.feature-table td.total-col {
    background: #f0e6f6; border-left: 2px solid #8e44ad;
}
table.feature-table th.total-col { color: #6c3483; font-size: 0.8rem; }

/* Mean row */
table.feature-table tr.mean-row td {
    background: #d5f5e3; font-weight: 600; color: #1e8449; border-top: 3px solid #27ae60;
}
table.feature-table tr.mean-row td.stat-label { background: #27ae60; color: white; }
/* Std dev row */
table.feature-table tr.std-row td {
    background: #fadbd8; font-weight: 600; color: #922b21; border-top: 2px solid #e74c3c;
}
table.feature-table tr.std-row td.stat-label { background: #e74c3c; color: white; }

/* Z-score table */
table.feature-table.z-score-table td { font-family: 'Courier New', monospace; }
table.feature-table.z-score-table td.positive { background: #d4efdf; color: #1e8449; }
table.feature-table.z-score-table td.negative { background: #fadbd8; color: #922b21; }
table.feature-table.z-score-table td.zero { background: #f9f9f9; color: #888; }
table.feature-table.z-score-table tr.stat-row td {
    border-top: 2px solid #999; font-weight: 600; color: #555; background: #f8f8f8;
}
table.feature-table.z-score-table tr.stat-row td.stat-row-label { text-align: left; color: #333; }

/* Normalized table */
table.feature-table.norm-table td:not(.doc-label):not(.stat-label) { font-family: 'Courier New', monospace; }

/* Visualizations row (heatmap + PCA side by side) */
.visualizations-row {
    display: flex; gap: 2rem; margin-bottom: 1rem; flex-wrap: wrap;
    justify-content: center; align-items: stretch;
}
.viz-panel {
    flex: 1; min-width: 300px; max-width: 500px;
    display: flex; flex-direction: column;
}
.viz-panel > div {
    flex: 1; display: flex; flex-direction: column; justify-content: center;
}
.viz-panel h4 {
    font-size: 0.95rem; color: #2c3e50; margin-bottom: 0.75rem;
    text-align: center; border-bottom: 1px solid #e0e0e0; padding-bottom: 0.5rem;
}

/* Heatmap */
#heatmapContainer { display: flex; flex-direction: column; align-items: center; }
.heatmap-wrapper {
    display: flex; flex-direction: column; align-items: center;
}

/* PCA Plot */
#pcaContainer { display: flex; flex-direction: column; align-items: center; }
.pca-svg { background: #fafafa; border: 1px solid #e0e0e0; border-radius: 6px; }
.pca-grid line { stroke: #e8e8e8; stroke-width: 1; }
.pca-axes line { stroke: #999; stroke-width: 1.5; }
.pca-axis-label { font-size: 11px; fill: #555; font-weight: 600; }
.pca-points circle { fill: #3498db; stroke: #2980b9; stroke-width: 1.5; }
.pca-points circle:hover { fill: #2980b9; r: 8; }
.pca-labels text { font-size: 10px; fill: #333; font-weight: 500; }
.heatmap-grid { display: inline-grid; gap: 2px; margin: 1rem 0; }
.heatmap-cell {
    width: 64px; height: 44px; display: flex; align-items: center; justify-content: center;
    font-size: 0.8rem; font-family: 'Courier New', monospace; font-weight: 600;
    border-radius: 3px; transition: transform 0.1s;
}
.heatmap-cell:not(.hm-label):hover { transform: scale(1.1); z-index: 1; box-shadow: 0 2px 8px rgba(0,0,0,0.2); }
.heatmap-cell.hm-label {
    background: transparent; font-weight: 600; color: #2c3e50;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; font-size: 0.8rem;
}
.heatmap-cell.hm-corner { background: transparent; }
.heatmap-legend {
    display: flex; align-items: center; justify-content: center;
    gap: 0.5rem; margin-top: 0.5rem; font-size: 0.8rem; color: #666;
}
.heatmap-legend-bar { width: 200px; height: 14px; border-radius: 3px; border: 1px solid #ddd; }

/* Calculation detail */
.calc-detail {
    background: #fff; border: 1px solid #e0e0e0; border-radius: 6px;
    padding: 0.75rem 1rem; margin-bottom: 0.75rem; font-size: 0.9rem; line-height: 1.8;
}
.calc-detail .col-name { font-weight: 700; color: #2980b9; }

/* Metric selector */
.metric-selector {
    display: flex; align-items: center; gap: 0.75rem; margin-bottom: 1rem;
    flex-wrap: wrap;
}
.metric-selector label { font-weight: 600; color: #2c3e50; font-size: 0.9rem; }
.metric-selector select {
    padding: 0.4rem 0.6rem; border: 1px solid #ccc; border-radius: 4px;
    font-size: 0.9rem; color: #333; background: #fff; cursor: pointer;
}
.metric-selector select:focus { outline: none; border-color: #3498db; }
.metric-description {
    font-size: 0.85rem; color: #555; flex-basis: 100%; margin-top: 0.25rem;
}

/* Highlight animation */
@keyframes highlightFade { 0% { background-color: #fff3cd; } 100% { background-color: transparent; } }
.highlight-flash { animation: highlightFade 1.5s ease-out; }

/* Step 5: Custom document */
#customDocInputs { margin-bottom: 1rem; }
table.data-table {
    width: 100%; border-collapse: collapse; font-size: 0.9rem;
}
.custom-doc-table { margin-bottom: 0; }
.custom-doc-table th, .custom-doc-table td {
    padding: 0.6rem 0.8rem; text-align: center; border: 1px solid #e0e0e0;
}
.custom-doc-table thead th {
    background: #eaf0f6; color: #2c3e50; font-weight: 600;
    border-bottom: 2px solid #b0bec5; vertical-align: middle;
}
.custom-doc-table thead th .col-stats {
    font-size: 0.7rem; font-weight: 400; color: #777;
    margin-top: 0.25rem; line-height: 1.3;
}
.custom-doc-table td.doc-label { background: #ecf0f1; font-weight: 600; text-align: left; }
.custom-doc-table td input {
    width: 70px; text-align: center; border: 1px solid #ccc; border-radius: 3px;
    padding: 0.25rem; font-size: 0.85rem;
}
.custom-doc-table td input#customDocName { width: 100px; text-align: left; }
.custom-doc-table td input:focus {
    outline: none; border-color: #3498db; box-shadow: 0 0 3px rgba(52,152,219,0.3);
}
.custom-doc-table th.total-col, .custom-doc-table td.total-col {
    background: #f0e6f6; border-left: 2px solid #8e44ad;
}
.custom-doc-table th.total-col { color: #6c3483; font-size: 0.8rem; }

.analyze-btn-container {
    text-align: center; margin-top: 1.25rem;
}

.custom-doc-results-content { margin-top: 1.5rem; }
.custom-doc-results-content h4 {
    font-size: 1rem; color: #2c3e50; margin-bottom: 0.75rem;
    border-bottom: 1px solid #e0e0e0; padding-bottom: 0.5rem;
}

.step5-calc-table, .step5-dist-table {
    width: 100%; border-collapse: collapse; font-size: 0.9rem;
    margin-bottom: 1.5rem;
}
.step5-calc-table th, .step5-calc-table td,
.step5-dist-table th, .step5-dist-table td {
    padding: 0.5rem 0.75rem; text-align: center; border: 1px solid #e0e0e0;
}
.step5-calc-table thead th, .step5-dist-table thead th {
    background: #eaf0f6; color: #2c3e50; font-weight: 600;
}
.step5-calc-table td { font-family: 'Courier New', monospace; }
.step5-calc-table td.col-name { font-weight: 600; color: #2980b9; text-align: left; font-family: inherit; }
.step5-calc-table td.positive { background: #d4efdf; color: #1e8449; }
.step5-calc-table td.negative { background: #fadbd8; color: #922b21; }
.step5-calc-table td.zero { background: #f9f9f9; color: #888; }

.step5-dist-table td { font-family: 'Courier New', monospace; }
.step5-dist-table td.doc-label { font-weight: 600; color: #2c3e50; text-align: left; font-family: inherit; }
.step5-dist-table tr.nearest-doc { background: #d4efdf; }
.step5-dist-table tr.nearest-doc td { font-weight: 700; color: #1e8449; }

/* Step 5 results row (distance table + PCA side by side) */
.step5-results-row {
    display: flex; gap: 2rem; margin-bottom: 1rem; flex-wrap: wrap;
    justify-content: center; align-items: flex-start;
}
.step5-results-panel {
    flex: 1; min-width: 280px; max-width: 450px;
}
.step5-results-panel h4 {
    font-size: 0.95rem; color: #2c3e50; margin-bottom: 0.75rem;
    text-align: center; border-bottom: 1px solid #e0e0e0; padding-bottom: 0.5rem;
}
.step5-results-panel .step5-dist-table { margin-bottom: 1rem; }

.nearest-result {
    background: #d4efdf; border: 2px solid #27ae60; border-radius: 6px;
    padding: 0.75rem; text-align: center; font-size: 0.95rem;
}
.nearest-result .nearest-doc-name {
    font-weight: 700; color: #1e8449; font-size: 1rem;
}

/* Custom doc PCA plot */
.custom-pca-container {
    display: flex; flex-direction: column; align-items: center; margin-top: 1rem;
}
.pca-custom-point circle { fill: #e74c3c; stroke: #c0392b; stroke-width: 2; }
.pca-custom-label text { font-size: 11px; fill: #c0392b; font-weight: 700; }
.pca-legend {
    display: flex; gap: 1.5rem; margin-top: 0.75rem; font-size: 0.85rem; color: #555;
}
.pca-legend-item { display: flex; align-items: center; gap: 0.4rem; }
.pca-legend-dot {
    width: 12px; height: 12px; border-radius: 50%; display: inline-block;
}
.pca-legend-dot.corpus { background: #3498db; border: 1.5px solid #2980b9; }
.pca-legend-dot.custom { background: #e74c3c; border: 1.5px solid #c0392b; }

footer {
    text-align: center; margin-top: 2rem; padding: 1.5rem;
    background: white; border-radius: 8px; box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
footer a { color: #3498db; text-decoration: none; }
footer a:hover { text-decoration: underline; }

@media (max-width: 768px) {
    .container { padding: 1rem; }
    .formula-example-row { flex-direction: column; }
    table.feature-table td input { width: 50px; }
}