/* Reset và base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #4361ee;
    --primary-dark: #3a56d4;
    --secondary-color: #7209b7;
    --accent-color: #f72585;
    --success-color: #4CAF50;
    --warning-color: #FF9800;
    --danger-color: #F44336;
    --text-color: #333;
    --text-light: #666;
    --bg-color: #f8f9fa;
    --card-bg: #fff;
    --border-color: #e1e5e9;
    --shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    --shadow-hover: 0 10px 25px rgba(0, 0, 0, 0.1);
    --radius: 12px;
    --transition: all 0.3s ease;
}

.dark-mode {
    --primary-color: #4cc9f0;
    --primary-dark: #3aa8cc;
    --secondary-color: #9d4edd;
    --accent-color: #f72585;
    --success-color: #4CAF50;
    --warning-color: #FF9800;
    --danger-color: #F44336;
    --text-color: #f8f9fa;
    --text-light: #adb5bd;
    --bg-color: #121212;
    --card-bg: #1e1e1e;
    --border-color: #333;
    --shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    --shadow-hover: 0 10px 25px rgba(0, 0, 0, 0.3);
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: var(--transition);
    min-height: 100vh;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
    margin-bottom: 30px;
    border-bottom: 1px solid var(--border-color);
}

.logo-link {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: inherit;
}

.logo-icon {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-right: 15px;
}

.logo-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 5px;
}

.logo-subtitle {
    font-size: 0.9rem;
    color: var(--text-light);
}

.header-actions {
    display: flex;
    gap: 15px;
}

/* Buttons */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: var(--radius);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-size: 0.95rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(67, 97, 238, 0.3);
}

.btn-secondary {
    background-color: transparent;
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

.dark-mode .btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.05);
}

.btn-calculate {
    background: linear-gradient(135deg, var(--accent-color), #e11575);
    color: white;
    width: 100%;
    padding: 16px;
    font-size: 1rem;
    margin-top: auto;
    margin-bottom: 15px;
}

.btn-calculate:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(247, 37, 133, 0.3);
}

/* Hero Section */
.hero {
    text-align: center;
    margin-bottom: 40px;
    padding: 40px 30px;
    background: linear-gradient(135deg, rgba(67, 97, 238, 0.1), rgba(114, 9, 183, 0.1));
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.hero-title {
    font-size: 2.2rem;
    margin-bottom: 15px;
    color: var(--primary-color);
    line-height: 1.3;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--text-light);
    max-width: 800px;
    margin: 0 auto 25px;
}

.hero-stats {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 20px;
    margin-top: 30px;
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 10px;
    background: var(--card-bg);
    padding: 12px 20px;
    border-radius: var(--radius);
    color: var(--primary-color);
    font-weight: 500;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.stat-item i {
    font-size: 1.2rem;
}

/* Tool Tabs */
.tool-tabs {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.tool-tab {
    padding: 12px 24px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    color: var(--text-color);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
}

.tool-tab:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.tool-tab.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.tool-tab-content {
    display: none;
}

.tool-tab-content.active {
    display: block;
}

/* Tool Grid */
.tool-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 25px;
    margin-bottom: 40px;
}

/* Calculator Cards */
.calculator-card {
    background-color: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: var(--transition);
    height: 100%;
    display: flex;
    flex-direction: column;
    border: 1px solid var(--border-color);
}

.calculator-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.calculator-header {
    padding: 20px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    display: flex;
    align-items: center;
}

.calculator-icon {
    font-size: 1.5rem;
    margin-right: 12px;
    background: rgba(255, 255, 255, 0.2);
    padding: 10px;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.calculator-title {
    font-size: 1.2rem;
    font-weight: 600;
    flex: 1;
}

.calculator-body {
    padding: 25px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.input-group {
    margin-bottom: 20px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-color);
    font-size: 0.95rem;
}

.input-group input,
.input-group select {
    width: 100%;
    padding: 14px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background-color: var(--bg-color);
    color: var(--text-color);
    font-size: 1rem;
    transition: var(--transition);
}

.input-group input:focus,
.input-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
}

.input-group select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='%23333' viewBox='0 0 16 16'%3E%3Cpath d='M7.247 11.14 2.451 5.658C1.885 5.013 2.345 4 3.204 4h9.592a1 1 0 0 1 .753 1.659l-4.796 5.48a1 1 0 0 1-1.506 0z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 15px center;
    background-size: 12px;
    padding-right: 40px;
    cursor: pointer;
}

.dark-mode .input-group select {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='%23fff' viewBox='0 0 16 16'%3E%3Cpath d='M7.247 11.14 2.451 5.658C1.885 5.013 2.345 4 3.204 4h9.592a1 1 0 0 1 .753 1.659l-4.796 5.48a1 1 0 0 1-1.506 0z'/%3E%3C/svg%3E");
}

/* Results */
.result-container {
    margin-top: 20px;
    padding: 20px;
    background: linear-gradient(135deg, rgba(67, 97, 238, 0.05), rgba(114, 9, 183, 0.05));
    border-radius: var(--radius);
    border-left: 4px solid var(--primary-color);
}

.result-label {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 5px;
    display: flex;
    align-items: center;
    gap: 5px;
}

.result-value {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 10px;
    line-height: 1.2;
}

.result-breakdown {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px dashed var(--border-color);
}

.result-breakdown strong {
    color: var(--primary-color);
    font-weight: 600;
}

/* Formula Display */
.formula-display {
    margin-top: 15px;
    padding: 12px 15px;
    background: rgba(0, 0, 0, 0.03);
    border-radius: var(--radius);
    font-size: 0.85rem;
    color: var(--text-light);
    border-left: 3px solid var(--primary-color);
    font-family: 'Courier New', monospace;
    font-weight: 500;
}

.dark-mode .formula-display {
    background: rgba(255, 255, 255, 0.03);
}

/* Progress Bar */
.progress-bar-container {
    margin-top: 20px;
}

.progress-bar {
    height: 10px;
    background: var(--border-color);
    border-radius: 5px;
    overflow: hidden;
    margin-bottom: 5px;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    border-radius: 5px;
    transition: width 0.5s ease;
}

.progress-text {
    text-align: right;
    font-size: 0.9rem;
    color: var(--text-light);
    font-weight: 500;
}

/* Contribution Chart */
.contribution-chart {
    margin-top: 20px;
    text-align: center;
    height: 200px;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* Quick Calculations */
.quick-calculations {
    background-color: var(--card-bg);
    padding: 30px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 50px;
    border: 1px solid var(--border-color);
}

.quick-calculations-title {
    font-size: 1.5rem;
    margin-bottom: 20px;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 10px;
}

.quick-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 25px;
}

.quick-btn {
    padding: 12px 20px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border: none;
    border-radius: var(--radius);
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
    flex: 1;
    min-width: 70px;
    max-width: 90px;
}

.quick-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 10px rgba(67, 97, 238, 0.2);
}

.quick-input-container {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

#quickValue {
    padding: 16px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background-color: var(--bg-color);
    color: var(--text-color);
    font-size: 1rem;
    transition: var(--transition);
}

#quickValue:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
}

.quick-result {
    padding: 20px;
    background: linear-gradient(135deg, rgba(67, 97, 238, 0.05), rgba(114, 9, 183, 0.05));
    border-radius: var(--radius);
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--primary-color);
    text-align: center;
    min-height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border-color);
}

/* Examples Section */
.examples-section {
    margin-bottom: 50px;
}

.examples-title {
    font-size: 1.5rem;
    margin-bottom: 25px;
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--primary-color);
}

.examples-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.example-card {
    background-color: var(--card-bg);
    padding: 25px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border-top: 4px solid var(--secondary-color);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.example-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
}

.example-card-title {
    font-size: 1.1rem;
    margin-bottom: 10px;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 10px;
}

.example-card-description {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.5;
}

/* Footer */
.footer {
    margin-top: 50px;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.footer-info {
    flex: 1;
}

.footer-title {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--primary-color);
}

.footer-description {
    color: var(--text-light);
    margin-bottom: 20px;
    max-width: 500px;
    line-height: 1.6;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin-top: 25px;
}

.footer-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: var(--transition);
    padding: 8px 0;
}

.footer-link:hover {
    color: var(--primary-dark);
    transform: translateX(5px);
}

.tool-summary {
    background: rgba(67, 97, 238, 0.05);
    padding: 20px;
    border-radius: var(--radius);
    border-left: 4px solid var(--primary-color);
    border: 1px solid var(--border-color);
}

.tool-summary-title {
    font-size: 1.2rem;
    margin-bottom: 15px;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 10px;
}

.tool-summary-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 10px;
}

.tool-summary-item {
    padding: 10px 15px;
    background: var(--card-bg);
    border-radius: 6px;
    font-size: 0.9rem;
    color: var(--text-color);
    border: 1px solid var(--border-color);
    text-align: center;
    font-weight: 500;
}

.footer-copyright {
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    color: var(--text-light);
    font-size: 0.9rem;
    text-align: center;
    line-height: 1.6;
}

.footer-note {
    margin-top: 10px;
    font-size: 0.85rem;
    color: var(--text-light);
    opacity: 0.8;
}

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    padding: 20px;
}

.modal.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background-color: var(--card-bg);
    width: 90%;
    max-width: 700px;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
    transform: translateY(-20px);
    transition: var(--transition);
    max-height: 90vh;
    overflow-y: auto;
}

.modal.active .modal-content {
    transform: translateY(0);
}

.modal-header {
    padding: 25px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 1;
}

.modal-title {
    font-size: 1.5rem;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    color: white;
    font-size: 2rem;
    cursor: pointer;
    line-height: 1;
    transition: var(--transition);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
}

.modal-close:hover {
    background: rgba(255, 255, 255, 0.1);
}

.modal-body {
    padding: 25px;
    line-height: 1.7;
}

.modal-body h4 {
    margin: 20px 0 10px;
    color: var(--primary-color);
    font-size: 1.2rem;
}

.modal-body p {
    margin-bottom: 15px;
    color: var(--text-color);
}

.modal-body ul {
    margin-left: 20px;
    margin-bottom: 20px;
}

.modal-body li {
    margin-bottom: 8px;
    color: var(--text-color);
}

.modal-footer {
    padding: 20px 25px;
    background: rgba(0, 0, 0, 0.03);
    text-align: right;
    border-top: 1px solid var(--border-color);
}

.dark-mode .modal-footer {
    background: rgba(255, 255, 255, 0.03);
}

/* Shortcuts Grid */
.shortcuts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 15px;
    margin: 20px 0;
}

.shortcut-item {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 12px;
    background: rgba(0, 0, 0, 0.03);
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
}

.dark-mode .shortcut-item {
    background: rgba(255, 255, 255, 0.03);
}

.shortcut-item kbd {
    padding: 6px 12px;
    background: var(--primary-color);
    color: white;
    border-radius: 6px;
    font-family: 'Courier New', monospace;
    font-weight: bold;
    min-width: 60px;
    text-align: center;
    display: inline-block;
    font-size: 0.9rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.shortcut-item span {
    color: var(--text-color);
    font-size: 0.95rem;
}

/* Notification Styles */
.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    background-color: var(--card-bg);
    color: var(--text-color);
    padding: 15px 20px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-hover);
    display: flex;
    align-items: center;
    justify-content: space-between;
    z-index: 1001;
    max-width: 400px;
    transform: translateX(150%);
    transition: transform 0.4s ease;
    border-left: 4px solid var(--primary-color);
    border: 1px solid var(--border-color);
}

.notification-success {
    border-left-color: var(--success-color);
}

.notification-warning {
    border-left-color: var(--warning-color);
}

.notification-info {
    border-left-color: var(--primary-color);
}

.notification-content {
    display: flex;
    align-items: center;
    gap: 10px;
    flex: 1;
}

.notification-close {
    background: none;
    border: none;
    color: var(--text-light);
    cursor: pointer;
    margin-left: 15px;
    font-size: 1.2rem;
    transition: var(--transition);
    padding: 5px;
    border-radius: 4px;
}

.notification-close:hover {
    background: rgba(0, 0, 0, 0.05);
    color: var(--text-color);
}

.dark-mode .notification-close:hover {
    background: rgba(255, 255, 255, 0.05);
}

.notification.show {
    transform: translateX(0);
}

/* Responsive Design */
@media (max-width: 1200px) {
    .tool-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 992px) {
    .tool-grid {
        grid-template-columns: 1fr;
    }
    
    .examples-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .hero-stats {
        gap: 15px;
    }
    
    .stat-item {
        padding: 10px 15px;
        font-size: 0.9rem;
        flex: 1;
        min-width: 160px;
        justify-content: center;
    }
    
    .shortcuts-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .header {
        flex-direction: column;
        align-items: flex-start;
        gap: 20px;
    }
    
    .header-actions {
        width: 100%;
        justify-content: flex-end;
    }
    
    .hero-title {
        font-size: 1.8rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    .tool-tabs {
        flex-direction: column;
    }
    
    .tool-tab {
        width: 100%;
        justify-content: center;
    }
    
    .examples-grid {
        grid-template-columns: 1fr;
    }
    
    .quick-buttons {
        justify-content: center;
    }
    
    .quick-btn {
        min-width: 60px;
        max-width: 70px;
        padding: 10px 5px;
        font-size: 0.9rem;
    }
    
    .footer-links {
        flex-direction: column;
        gap: 15px;
    }
    
    .tool-summary-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .modal-content {
        width: 95%;
        max-height: 85vh;
    }
    
    .modal-header {
        padding: 20px;
    }
    
    .modal-body {
        padding: 20px;
    }
    
    .modal-footer {
        padding: 15px 20px;
    }
    
    .shortcuts-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 576px) {
    .container {
        padding: 0 15px;
    }
    
    .calculator-body {
        padding: 20px;
    }
    
    .hero {
        padding: 25px 20px;
    }
    
    .quick-calculations {
        padding: 20px;
    }
    
    .result-value {
        font-size: 1.5rem;
    }
    
    .tool-summary-grid {
        grid-template-columns: 1fr;
    }
    
    .modal {
        padding: 10px;
    }
    
    .modal-content {
        width: 100%;
        max-height: 80vh;
    }
    
    .stat-item {
        min-width: 140px;
        font-size: 0.85rem;
        padding: 8px 12px;
    }
    
    .stat-item i {
        font-size: 1rem;
    }
    
    .notification {
        max-width: 90%;
        left: 5%;
        right: 5%;
        top: 10px;
    }
}

/* Print Styles */
@media print {
    .header-actions,
    .tool-tabs,
    .quick-calculations,
    .footer,
    .modal {
        display: none !important;
    }
    
    .tool-grid {
        display: block;
    }
    
    .calculator-card {
        break-inside: avoid;
        margin-bottom: 20px;
        box-shadow: none;
        border: 1px solid #000;
    }
    
    body {
        background: white;
        color: black;
    }
    
    .container {
        max-width: 100%;
        padding: 0;
    }
}

/* Animation for calculator cards */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.calculator-card {
    animation: fadeIn 0.5s ease-out forwards;
}

.calculator-card:nth-child(2) {
    animation-delay: 0.1s;
}

.calculator-card:nth-child(3) {
    animation-delay: 0.2s;
}

.calculator-card:nth-child(4) {
    animation-delay: 0.3s;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-color);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-dark);
}

/* Selection Color */
::selection {
    background-color: rgba(67, 97, 238, 0.3);
    color: var(--text-color);
}

::-moz-selection {
    background-color: rgba(67, 97, 238, 0.3);
    color: var(--text-color);
}

/* Loading Animation */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid var(--border-color);
    border-radius: 50%;
    border-top-color: var(--primary-color);
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Tooltip */
.tooltip {
    position: relative;
    display: inline-block;
    cursor: help;
}

.tooltip .tooltiptext {
    visibility: hidden;
    width: 200px;
    background-color: var(--card-bg);
    color: var(--text-color);
    text-align: center;
    border-radius: var(--radius);
    padding: 10px;
    position: absolute;
    z-index: 1;
    bottom: 125%;
    left: 50%;
    transform: translateX(-50%);
    opacity: 0;
    transition: opacity 0.3s;
    font-size: 0.85rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.tooltip:hover .tooltiptext {
    visibility: visible;
    opacity: 1;
}

.tooltip .tooltiptext::after {
    content: "";
    position: absolute;
    top: 100%;
    left: 50%;
    margin-left: -5px;
    border-width: 5px;
    border-style: solid;
    border-color: var(--card-bg) transparent transparent transparent;
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles for accessibility */
:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

:focus:not(:focus-visible) {
    outline: none;
}

:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}