/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

/* Navigation Banner */
.main-nav {
    max-width: 1400px;
    margin: 0 auto 20px;
    background: rgba(255, 255, 255, 0.95);
    padding: 15px;
    border-radius: 16px;
    display: flex;
    justify-content: center;
    gap: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    flex-wrap: wrap;
}

.nav-btn {
    text-decoration: none;
    color: #475569;
    font-weight: 600;
    padding: 10px 25px;
    border-radius: 8px;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.nav-btn:hover {
    background: white;
    color: #667eea;
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.2);
    transform: translateY(-2px);
}

.nav-btn.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.3);
}

.nav-btn.help {
    border: 2px solid #e2e8f0;
    color: #64748b;
}

.nav-btn.help:hover {
    border-color: #667eea;
    color: #667eea;
}

/* Container & Layout */
.container {
    max-width: 1400px;
    margin: 0 auto;
    background: white;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    padding: 40px;
}

h1 {
    color: #333;
    margin-bottom: 10px;
    font-size: 2.5em;
    text-align: center;
}

.subtitle {
    text-align: center;
    color: #666;
    margin-bottom: 30px;
    font-size: 1.1em;
}

/* Upload Section */
.upload-section {
    background: #f8f9fa;
    border: 2px dashed #667eea;
    border-radius: 12px;
    padding: 40px;
    text-align: center;
    margin-bottom: 30px;
    transition: all 0.3s ease;
}

.upload-section:hover {
    border-color: #764ba2;
    background: #f0f1f5;
}

.upload-section.dragover {
    border-color: #38ef7d;
    background: #e8f5e9;
    transform: scale(1.02);
}

.upload-section input[type="file"] {
    display: none;
}

.upload-label {
    display: inline-block;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 15px 40px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1.1em;
    font-weight: bold;
    transition: transform 0.2s ease;
}

.upload-label:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(102, 126, 234, 0.4);
}

.file-info {
    margin-top: 15px;
    color: #666;
    font-size: 0.95em;
}

/* Controls & Inputs */
.controls-section {
    background: #f8f9fa;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 30px;
    display: none;
    text-align: center;
}

.controls-section select {
    padding: 10px 20px;
    font-size: 1em;
    border-radius: 8px;
    border: 2px solid #e2e8f0;
    background: white;
    min-width: 400px;
    cursor: pointer;
}

.controls-section select:focus {
    outline: none;
    border-color: #667eea;
}

/* Buttons */
.btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1em;
    font-weight: bold;
    transition: all 0.3s ease;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #e2e8f0;
    color: #475569;
}

.btn-secondary:hover {
    background: #cbd5e1;
    transform: translateY(-2px);
    box-shadow: none;
}

.download-btn {
    background: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1em;
    font-weight: bold;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(17, 153, 142, 0.4);
}

/* Results & Tables */
#results {
    display: none;
}

.results-header, .evaluation-header, .table-header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 3px solid #667eea;
}

.evaluation-title, .table-title {
    font-size: 1.5em;
    color: #333;
    font-weight: bold;
}

table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    border-radius: 8px;
    overflow: hidden;
    margin-bottom: 20px;
}

thead {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

th {
    padding: 16px;
    text-align: left;
    font-weight: bold;
    font-size: 0.95em;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

th.number, td.number {
    text-align: right;
}

td {
    padding: 14px 16px;
    border-bottom: 1px solid #e9ecef;
    color: #333;
}

tbody tr:hover {
    background: #f8f9fa;
}

/* Specific Table Styles */
.summary-row, tbody tr:last-child {
    /* Often used for totals */
}

/* Asistencia: Last row bold/yellow */
.asistencia-table tbody tr:last-child {
    background: #fff3cd;
    font-weight: bold;
}
.asistencia-table tbody tr:last-child:hover {
    background: #ffe69c;
}

/* Notas por Materia: Highlights */
.highlight-row {
    border-left: 5px solid #10b981;
    background-color: #ecfdf5;
    font-weight: bold;
}
.highlight-row:hover {
    background-color: #d1fae5;
}

/* Notas por Grupo: Status Colors */
.good { color: #10b981; font-weight: bold; }
.bad { color: #ef4444; font-weight: bold; }
.warning { color: #f59e0b; font-weight: bold; }

/* Grouping Interface (Notas por Grupo) */
#grouping-container {
    background: #fff;
    padding: 0;
    margin-bottom: 30px;
    display: none;
}

.group-controls {
    display: flex;
    gap: 15px;
    margin-bottom: 20px;
    padding: 20px;
    background-color: #f8f9fa;
    border-radius: 12px;
    align-items: center;
}

.group-controls input {
    flex: 1;
    padding: 12px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1em;
}

.group-list {
    max-height: 500px;
    overflow-y: auto;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    margin-bottom: 20px;
}

.group-item {
    display: flex;
    align-items: center;
    padding: 15px 20px;
    border-bottom: 1px solid #e2e8f0;
    gap: 15px;
    cursor: grab;
    transition: all 0.2s ease;
    background: white;
}

.group-item:hover {
    background-color: #f8fafc;
}

.group-item.dragging {
    opacity: 0.5;
    background-color: #e2e8f0;
}

.group-item.drag-over {
    background-color: #e0f2fe;
    border: 2px dashed #667eea;
}

.original-name {
    flex: 1;
    font-family: 'Segoe UI', sans-serif;
    color: #475569;
    font-weight: 500;
}

.arrow-icon {
    color: #94a3b8;
}

.mapped-name-input {
    padding: 8px 12px;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    background-color: #f8fafc;
    color: #475569;
    width: 250px;
    pointer-events: none;
    font-weight: 600;
}

/* Tabs */
.tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.tab-btn {
    padding: 12px 24px;
    border: none;
    background: #f1f5f9;
    color: #64748b;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1em;
    font-weight: 600;
    transition: all 0.3s ease;
}

.tab-btn:hover {
    background: #e2e8f0;
    color: #333;
}

.tab-btn.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

.eval-section, .evaluation-section {
    display: none;
    animation: fadeIn 0.4s ease;
}

.eval-section.active, .evaluation-section.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Loading & Error */
.loading {
    text-align: center;
    padding: 40px;
    display: none;
}

.loading.active {
    display: block;
}

.spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #667eea;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin: 0 auto 20px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.error {
    background: #f8d7da;
    border: 1px solid #f5c6cb;
    color: #721c24;
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 20px;
    display: none;
}

.error.active {
    display: block;
}

/* ===== Charts ===== */
.chart-controls {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 16px;
    padding: 14px 18px;
    background: #f8fafc;
    border-radius: 10px;
    flex-wrap: wrap;
}

.chart-control-label {
    font-weight: 600;
    color: #475569;
}

.chart-type-group {
    display: flex;
    gap: 8px;
}

.chart-type-btn {
    padding: 8px 18px;
    border: 2px solid #e2e8f0;
    background: white;
    color: #64748b;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.95em;
    font-weight: 600;
    transition: all 0.2s ease;
}

.chart-type-btn:hover {
    border-color: #667eea;
    color: #667eea;
}

.chart-type-btn.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-color: transparent;
    box-shadow: 0 3px 10px rgba(102,126,234,0.3);
}

.chart-set {
    border: 2px solid #e2e8f0;
    border-radius: 10px;
    margin-bottom: 12px;
    overflow: hidden;
}

.chart-set-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 15px;
    background: #f1f5f9;
    border-bottom: 1px solid #e2e8f0;
}

.chart-set-title {
    font-weight: 600;
    color: #475569;
}

.chart-set-groups {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    padding: 12px 15px;
}

.chart-group-label {
    display: flex;
    align-items: center;
    gap: 6px;
    cursor: pointer;
    padding: 6px 12px;
    border: 1px solid #e2e8f0;
    border-radius: 6px;
    font-size: 0.9em;
    color: #475569;
    transition: all 0.2s;
    user-select: none;
    background: white;
}

.chart-group-label:hover {
    background: #f0f4ff;
    border-color: #667eea;
}

.chart-group-label input {
    accent-color: #667eea;
}

.eval-selector-container {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
    padding: 12px 18px;
    background: #f8fafc;
    border-radius: 10px;
    margin-bottom: 16px;
}

.pie-legend {
    display: flex;
    flex-wrap: wrap;
    gap: 12px 20px;
    margin-top: 16px;
    padding: 10px 14px;
    background: #f8fafc;
    border-radius: 8px;
}

.pie-legend-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.88em;
    color: #475569;
}

.pie-legend-dot {
    width: 13px;
    height: 13px;
    border-radius: 3px;
    flex-shrink: 0;
}

.chart-actions {
    display: flex;
    gap: 12px;
    margin: 16px 0 24px;
}

.chart-wrapper {
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 24px;
    background: white;
}

.chart-section-title {
    font-size: 1.1em;
    font-weight: 600;
    color: #333;
    margin-bottom: 16px;
    padding-bottom: 10px;
    border-bottom: 2px solid #667eea;
}

.canvas-container {
    position: relative;
    width: 100%;
    height: 380px;
}

.pie-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 24px;
    justify-content: flex-start;
}

.pie-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
}

.pie-title {
    font-size: 0.88em;
    font-weight: 600;
    color: #475569;
    text-align: center;
}

/* Responsive */
@media (max-width: 768px) {
    .container { padding: 20px; }
    
    .main-nav {
        flex-direction: column;
        padding: 10px;
    }

    .nav-btn {
        width: 100%;
        text-align: center;
    }

    h1 { font-size: 1.8em; }
    
    .results-header, .evaluation-header, .table-header-container { 
        flex-direction: column; 
        gap: 15px; 
    }
    
    table { display: block; overflow-x: auto; white-space: nowrap; }
    
    .group-item { flex-direction: column; align-items: stretch; }
    .mapped-name-input { width: 100%; }
    .controls-section select { width: 100%; min-width: 0; }
    .download-btn { margin-left: 0; }
}