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

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Заголовок */
.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
    padding: 20px 0;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 15px;
}

.logo i {
    font-size: 2.5rem;
    color: #667eea;
}

.logo h1 {
    font-size: 1.8rem;
    font-weight: 600;
    color: #2d3748;
}

.lab-info {
    text-align: right;
}

.lab-info h2 {
    font-size: 1.3rem;
    color: #4a5568;
    font-weight: 600;
}

.lab-info p {
    color: #718096;
    font-size: 1rem;
    margin: 5px 0;
}

.grade {
    background: linear-gradient(45deg, #667eea, #764ba2);
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
    display: inline-block;
}

/* Навигация */
.navigation {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    padding: 15px 0;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.nav-tabs {
    display: flex;
    list-style: none;
    gap: 10px;
    justify-content: center;
    flex-wrap: wrap;
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 20px;
    border: none;
    background: transparent;
    color: #4a5568;
    font-size: 1rem;
    font-weight: 500;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.nav-btn:hover {
    background: rgba(102, 126, 234, 0.1);
    color: #667eea;
    transform: translateY(-2px);
}

.nav-btn.active {
    background: linear-gradient(45deg, #667eea, #764ba2);
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

/* Основной контент */
.main-content {
    padding: 40px 0;
}

.content-section {
    display: none;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    margin-bottom: 20px;
}

.content-section.active {
    display: block;
    animation: fadeIn 0.5s ease-in-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.section-header {
    text-align: center;
    margin-bottom: 40px;
}

.section-header h2 {
    font-size: 2.2rem;
    color: #2d3748;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
}

.section-header h2 i {
    color: #667eea;
}

.section-header p {
    color: #718096;
    font-size: 1.1rem;
}

/* Теоретический раздел */
.theory-grid {
    display: grid;
    gap: 30px;
}

.theory-card {
    background: linear-gradient(135deg, #f7fafc 0%, #edf2f7 100%);
    border-radius: 15px;
    padding: 25px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease;
}

.theory-card:hover {
    transform: translateY(-5px);
}

.theory-card h3 {
    color: #2d3748;
    font-size: 1.4rem;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.theory-card h3 i {
    color: #667eea;
}

/* Структура белков */
.protein-levels {
    display: grid;
    gap: 20px;
}

.level-item {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    background: white;
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
}

.level-number {
    width: 40px;
    height: 40px;
    background: linear-gradient(45deg, #667eea, #764ba2);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 1.2rem;
    flex-shrink: 0;
}

.level-content h4 {
    color: #2d3748;
    font-size: 1.1rem;
    margin-bottom: 8px;
}

.level-content p {
    color: #4a5568;
    line-height: 1.5;
}

/* Визуализация структур */
.structure-visual {
    margin-top: 15px;
    padding: 20px;
    background: #f7fafc;
    border-radius: 8px;
    border: 2px dashed #cbd5e0;
    min-height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 5px;
}

.amino-acid {
    background: #667eea;
    color: white;
    padding: 5px 10px;
    border-radius: 5px;
    font-size: 0.9rem;
    font-weight: 500;
}

.peptide-bond {
    color: #718096;
    font-weight: bold;
    font-size: 1.2rem;
}

.structure-buttons {
    display: flex;
    gap: 10px;
    margin-bottom: 15px;
}

.structure-btn {
    padding: 8px 15px;
    border: 2px solid #667eea;
    background: transparent;
    color: #667eea;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

.structure-btn:hover,
.structure-btn.active {
    background: #667eea;
    color: white;
}

.alpha-helix {
    width: 60px;
    height: 60px;
    background: conic-gradient(#667eea, #764ba2, #667eea);
    border-radius: 50%;
    position: relative;
}

.alpha-helix::before {
    content: 'α';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-weight: bold;
    font-size: 1.5rem;
}

.beta-sheet {
    width: 80px;
    height: 40px;
    background: linear-gradient(90deg, #667eea 0%, #764ba2 50%, #667eea 100%);
    position: relative;
    display: none;
}

.beta-sheet::before {
    content: 'β';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-weight: bold;
    font-size: 1.2rem;
}

/* Связи в белках */
.bonds-info {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 15px;
}

.bond-type {
    padding: 5px 12px;
    border-radius: 15px;
    font-size: 0.85rem;
    font-weight: 500;
}

.bond-type.hydrogen {
    background: #e6fffa;
    color: #00b5d8;
    border: 1px solid #00b5d8;
}

.bond-type.ionic {
    background: #fef5e7;
    color: #d69e2e;
    border: 1px solid #d69e2e;
}

.bond-type.disulfide {
    background: #fed7d7;
    color: #e53e3e;
    border: 1px solid #e53e3e;
}

.bond-type.hydrophobic {
    background: #f0fff4;
    color: #38a169;
    border: 1px solid #38a169;
}

/* Четвертичная структура */
.quaternary-example {
    display: flex;
    gap: 10px;
    align-items: center;
    justify-content: center;
    margin-top: 15px;
}

.subunit {
    width: 50px;
    height: 50px;
    background: linear-gradient(45deg, #667eea, #764ba2);
    color: white;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    font-weight: 500;
    position: relative;
}

.subunit:nth-child(even) {
    background: linear-gradient(45deg, #764ba2, #667eea);
}

/* Факторы денатурации */
.factors-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.factor-item {
    background: white;
    padding: 20px;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease;
}

.factor-item:hover {
    transform: translateY(-3px);
}

.factor-item i {
    font-size: 2rem;
    color: #667eea;
    margin-bottom: 10px;
}

.factor-item h4 {
    color: #2d3748;
    margin-bottom: 8px;
}

.factor-item p {
    color: #4a5568;
    font-size: 0.9rem;
    line-height: 1.4;
}

/* Цветные реакции */
.reactions-info {
    background: white;
    padding: 20px;
    border-radius: 10px;
    margin-top: 20px;
}

.reaction-list {
    display: grid;
    gap: 15px;
    margin-top: 20px;
}

.reaction-item {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 15px;
    background: #f7fafc;
    border-radius: 8px;
    border-left: 4px solid #667eea;
}

.reaction-color {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    flex-shrink: 0;
    border: 2px solid #e2e8f0;
}

.reaction-color.biuret {
    background: linear-gradient(45deg, #9f7aea, #667eea);
}

.reaction-color.ninhydrin {
    background: linear-gradient(45deg, #667eea, #4c51bf);
}

.reaction-color.xanthoprotein {
    background: linear-gradient(45deg, #f6e05e, #d69e2e);
}

.reaction-color.millon {
    background: linear-gradient(45deg, #fc8181, #e53e3e);
}

.reaction-details h4 {
    color: #2d3748;
    margin-bottom: 5px;
}

.reaction-details p {
    color: #4a5568;
    font-size: 0.9rem;
    margin: 2px 0;
}

/* Кнопки */
.btn-primary,
.btn-secondary,
.btn-success {
    padding: 12px 24px;
    border: none;
    border-radius: 25px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(45deg, #667eea, #764ba2);
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: transparent;
    color: #667eea;
    border: 2px solid #667eea;
}

.btn-secondary:hover {
    background: #667eea;
    color: white;
    transform: translateY(-2px);
}

.btn-success {
    background: linear-gradient(45deg, #38a169, #48bb78);
    color: white;
    box-shadow: 0 4px 15px rgba(56, 161, 105, 0.3);
}

.btn-success:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(56, 161, 105, 0.4);
}

.theory-footer {
    text-align: center;
    margin-top: 40px;
}

/* Лабораторный рабочий стол */
.lab-workspace {
    background: linear-gradient(135deg, #f7fafc 0%, #edf2f7 100%);
    border-radius: 15px;
    padding: 30px;
    margin-bottom: 30px;
}

.experiment-setup {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin-bottom: 30px;
}

.lab-table {
    background: white;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
}

.protein-sample {
    margin-bottom: 30px;
}

.sample-container {
    background: linear-gradient(135deg, #e6fffa 0%, #b2f5ea 100%);
    border: 3px dashed #00b5d8;
    border-radius: 15px;
    padding: 30px;
    text-align: center;
    position: relative;
    min-height: 150px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.protein-molecule {
    width: 80px;
    height: 80px;
    position: relative;
    margin-bottom: 15px;
    transition: all 0.8s ease;
}

.protein-molecule.native {
    animation: float 2s ease-in-out infinite;
}

.protein-molecule.denatured {
    animation: shake 0.5s ease-in-out;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    10%, 30%, 50%, 70%, 90% { transform: translateX(-5px); }
    20%, 40%, 60%, 80% { transform: translateX(5px); }
}

.protein-core {
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, #667eea, #764ba2);
    border-radius: 50%;
    position: relative;
    transition: all 0.8s ease;
}

.protein-structure {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 120%;
    height: 120%;
    border: 3px solid #00b5d8;
    border-radius: 50%;
    border-style: dashed;
    animation: rotate 3s linear infinite;
    transition: all 0.8s ease;
}

@keyframes rotate {
    from { transform: translate(-50%, -50%) rotate(0deg); }
    to { transform: translate(-50%, -50%) rotate(360deg); }
}

.protein-molecule.denatured .protein-core {
    background: radial-gradient(circle, #e53e3e, #fc8181);
    border-radius: 20%;
    transform: scale(1.2);
}

.protein-molecule.denatured .protein-structure {
    border-color: #e53e3e;
    animation: none;
    transform: translate(-50%, -50%) scale(1.5) rotate(45deg);
    border-style: solid;
}

.sample-container label {
    color: #00695c;
    font-weight: 500;
    font-size: 0.9rem;
}

.reagents-shelf h3 {
    color: #2d3748;
    margin-bottom: 20px;
    font-size: 1.2rem;
}

.reagent-buttons {
    display: grid;
    gap: 10px;
}

.reagent-btn {
    padding: 12px 20px;
    border: 2px solid #cbd5e0;
    background: white;
    color: #4a5568;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.95rem;
}

.reagent-btn:hover {
    border-color: #667eea;
    background: #f7fafc;
    color: #667eea;
    transform: translateX(5px);
}

.reagent-btn.selected {
    background: linear-gradient(45deg, #667eea, #764ba2);
    color: white;
    border-color: transparent;
}

.observation-panel {
    background: white;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
}

.observation-panel h3 {
    color: #2d3748;
    margin-bottom: 20px;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.observation-panel h3 i {
    color: #667eea;
}

.observation-content {
    background: #f7fafc;
    padding: 20px;
    border-radius: 8px;
    border-left: 4px solid #667eea;
    color: #4a5568;
    line-height: 1.6;
    min-height: 100px;
    margin-bottom: 20px;
}

.experiment-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 20px;
}

.timer-display {
    font-family: 'Courier New', monospace;
    font-size: 1.1rem;
    color: #2d3748;
}

#timer {
    font-weight: bold;
    color: #667eea;
}

/* Результаты экспериментов */
.results-section {
    background: white;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
}

.results-section h3 {
    color: #2d3748;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.results-section h3 i {
    color: #667eea;
}

.results-table {
    overflow-x: auto;
}

#results-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

#results-table th,
#results-table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #e2e8f0;
}

#results-table th {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    font-weight: 500;
}

#results-table tr:hover {
    background: #f7fafc;
}

/* Цветные реакции */
.reactions-workspace {
    background: linear-gradient(135deg, #f7fafc 0%, #edf2f7 100%);
    border-radius: 15px;
    padding: 30px;
}

.test-tubes-rack {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
    margin-bottom: 30px;
}

.tube-setup {
    display: flex;
    justify-content: space-around;
    align-items: flex-end;
    gap: 20px;
    flex-wrap: wrap;
}

.test-tube {
    text-align: center;
    cursor: pointer;
    transition: transform 0.3s ease;
}

.test-tube:hover {
    transform: translateY(-5px);
}

.test-tube .solution {
    width: 60px;
    height: 120px;
    background: #f7fafc;
    border: 3px solid #cbd5e0;
    border-bottom-left-radius: 30px;
    border-bottom-right-radius: 30px;
    margin: 0 auto 10px;
    position: relative;
    overflow: hidden;
    transition: all 0.8s ease;
}

.test-tube .solution::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 20%;
    background: rgba(102, 126, 234, 0.3);
    transition: all 0.8s ease;
}

.test-tube .solution.has-protein::before {
    height: 40%;
    background: rgba(102, 126, 234, 0.6);
}

.test-tube .solution.reacted[data-reaction="biuret"]::before {
    background: linear-gradient(0deg, #9f7aea, #667eea);
    height: 60%;
}

.test-tube .solution.reacted[data-reaction="ninhydrin"]::before {
    background: linear-gradient(0deg, #667eea, #4c51bf);
    height: 60%;
}

.test-tube .solution.reacted[data-reaction="xanthoprotein"]::before {
    background: linear-gradient(0deg, #f6e05e, #d69e2e);
    height: 60%;
}

.test-tube .solution.reacted[data-reaction="millon"]::before {
    background: linear-gradient(0deg, #fc8181, #e53e3e);
    height: 60%;
}

.test-tube label {
    display: block;
    color: #4a5568;
    font-size: 0.85rem;
    line-height: 1.3;
    font-weight: 500;
}

.reaction-controls {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin-bottom: 30px;
}

.reagent-addition {
    background: white;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
}

.reagent-addition h3 {
    color: #2d3748;
    margin-bottom: 20px;
}

.reagent-grid {
    display: grid;
    gap: 10px;
}

.add-reagent-btn {
    padding: 10px 15px;
    border: 2px solid #cbd5e0;
    background: white;
    color: #4a5568;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.9rem;
}

.add-reagent-btn:hover:not(:disabled) {
    border-color: #667eea;
    background: #f7fafc;
    color: #667eea;
}

.add-reagent-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.add-reagent-btn.completed {
    background: linear-gradient(45deg, #38a169, #48bb78);
    color: white;
    border-color: transparent;
}

.reaction-progress {
    background: white;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
}

.reaction-progress h3 {
    color: #2d3748;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.reaction-progress h3 i {
    color: #667eea;
}

.progress-indicators {
    display: grid;
    gap: 15px;
}

.reaction-status {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 15px;
    background: #f7fafc;
    border-radius: 8px;
}

.reaction-name {
    font-weight: 500;
    color: #2d3748;
}

.status-indicator {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #cbd5e0;
    transition: all 0.3s ease;
}

.status-indicator.in-progress {
    background: linear-gradient(45deg, #f6e05e, #d69e2e);
    animation: pulse 1s ease-in-out infinite;
}

.status-indicator.completed {
    background: linear-gradient(45deg, #38a169, #48bb78);
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.6; }
}

.status-text {
    font-size: 0.85rem;
    color: #718096;
}

.reaction-results {
    background: white;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
}

.reaction-results h3 {
    color: #2d3748;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.reaction-results h3 i {
    color: #667eea;
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.result-card {
    background: #f7fafc;
    padding: 20px;
    border-radius: 10px;
    text-align: center;
    border: 2px solid #e2e8f0;
    transition: all 0.3s ease;
}

.result-card.completed {
    border-color: #38a169;
    background: #f0fff4;
}

.result-card h4 {
    color: #2d3748;
    margin-bottom: 15px;
    font-size: 1rem;
}

.result-card .result-color {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    margin: 0 auto 15px;
    background: #e2e8f0;
    transition: all 0.8s ease;
    border: 3px solid #cbd5e0;
}

.result-card .result-description {
    color: #4a5568;
    font-size: 0.9rem;
    line-height: 1.4;
}

/* Тестирование */
.quiz-container {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
}

.quiz-progress {
    margin-bottom: 30px;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: #e2e8f0;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 10px;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(45deg, #667eea, #764ba2);
    width: 10%;
    transition: width 0.3s ease;
}

.progress-text {
    color: #4a5568;
    font-size: 0.9rem;
}

.question-container {
    background: #f7fafc;
    padding: 25px;
    border-radius: 10px;
    margin-bottom: 20px;
    min-height: 200px;
}

.question {
    margin-bottom: 20px;
}

.question h3 {
    color: #2d3748;
    margin-bottom: 15px;
    font-size: 1.1rem;
    line-height: 1.4;
}

.answers {
    display: grid;
    gap: 10px;
}

.answer-option {
    padding: 15px 20px;
    background: white;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 12px;
}

.answer-option:hover {
    border-color: #667eea;
    background: #f7fafc;
}

.answer-option.selected {
    border-color: #667eea;
    background: rgba(102, 126, 234, 0.1);
}

.answer-option.correct {
    border-color: #38a169;
    background: #f0fff4;
}

.answer-option.incorrect {
    border-color: #e53e3e;
    background: #fed7d7;
}

.option-letter {
    width: 30px;
    height: 30px;
    background: #e2e8f0;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 500;
    color: #4a5568;
    flex-shrink: 0;
}

.answer-option.selected .option-letter {
    background: #667eea;
    color: white;
}

.answer-option.correct .option-letter {
    background: #38a169;
    color: white;
}

.answer-option.incorrect .option-letter {
    background: #e53e3e;
    color: white;
}

.quiz-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 20px;
}

.quiz-results {
    text-align: center;
    padding: 30px;
}

.quiz-results h3 {
    color: #2d3748;
    margin-bottom: 30px;
    font-size: 1.4rem;
}

.score-display {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 30px;
    margin-bottom: 20px;
}

.score-circle {
    width: 120px;
    height: 120px;
    border: 8px solid #e2e8f0;
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
}

.score-circle.excellent {
    border-color: #38a169;
}

.score-circle.good {
    border-color: #d69e2e;
}

.score-circle.poor {
    border-color: #e53e3e;
}

.score-value {
    font-size: 2rem;
    font-weight: bold;
    color: #2d3748;
}

.score-total {
    color: #718096;
}

.score-percentage {
    font-size: 3rem;
    font-weight: bold;
    color: #667eea;
}

.score-interpretation {
    color: #4a5568;
    font-size: 1.1rem;
    margin-bottom: 20px;
    padding: 15px;
    background: #f7fafc;
    border-radius: 8px;
}

/* Отчет */
.report-workspace {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
}

.report-form {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
}

.student-info h3,
.experiment-summary h3,
.results-summary h3,
.conclusions h3 {
    color: #2d3748;
    margin-bottom: 20px;
    font-size: 1.2rem;
    border-bottom: 2px solid #e2e8f0;
    padding-bottom: 10px;
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-bottom: 25px;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    color: #4a5568;
    margin-bottom: 5px;
    font-weight: 500;
    font-size: 0.9rem;
}

.form-input,
.form-textarea {
    padding: 10px 15px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 0.95rem;
    transition: border-color 0.3s ease;
    font-family: inherit;
}

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: #667eea;
}

.form-textarea {
    resize: vertical;
    min-height: 80px;
}

.auto-fill-notice {
    display: flex;
    align-items: center;
    gap: 10px;
    color: #718096;
    font-size: 0.9rem;
    background: #f7fafc;
    padding: 15px;
    border-radius: 8px;
    border-left: 4px solid #667eea;
}

.auto-fill-notice i {
    color: #667eea;
}

.report-actions {
    display: flex;
    gap: 15px;
    margin-top: 25px;
    flex-wrap: wrap;
}

.report-preview {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
    max-height: 600px;
    overflow-y: auto;
}

.preview-content {
    background: #f7fafc;
    padding: 25px;
    border-radius: 8px;
    font-family: 'Times New Roman', serif;
    line-height: 1.6;
}

.preview-content h1,
.preview-content h2,
.preview-content h3 {
    color: #2d3748;
    margin-bottom: 15px;
}

.preview-content p {
    margin-bottom: 10px;
}

/* Подвал */
.footer {
    background: rgba(0, 0, 0, 0.8);
    color: white;
    padding: 30px 0;
    margin-top: 40px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
}

.footer-info p {
    margin: 5px 0;
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.8);
}

.footer-links {
    display: flex;
    gap: 20px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: #667eea;
}

/* Адаптивный дизайн */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }
    
    .header-content {
        flex-direction: column;
        text-align: center;
    }
    
    .lab-info {
        text-align: center;
    }
    
    .nav-tabs {
        flex-direction: column;
        gap: 5px;
    }
    
    .nav-btn {
        width: 100%;
        justify-content: center;
    }
    
    .experiment-setup {
        grid-template-columns: 1fr;
    }
    
    .reaction-controls {
        grid-template-columns: 1fr;
    }
    
    .tube-setup {
        flex-direction: column;
        align-items: center;
    }
    
    .report-workspace {
        grid-template-columns: 1fr;
    }
    
    .form-grid {
        grid-template-columns: 1fr;
    }
    
    .quiz-controls {
        flex-direction: column;
        gap: 10px;
    }
    
    .score-display {
        flex-direction: column;
        gap: 20px;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
    
    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
    }
}

/* Анимации */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.content-section.active {
    animation: fadeInUp 0.6s ease-out;
}

/* Скрытие/показ элементов */
.hidden {
    display: none !important;
}

.invisible {
    opacity: 0;
    pointer-events: none;
}

/* Индикаторы загрузки */
.loading {
    position: relative;
    overflow: hidden;
}

.loading::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.8), transparent);
    animation: loading 1.5s infinite;
}

@keyframes loading {
    0% {
        left: -100%;
    }
    100% {
        left: 100%;
    }
}