:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --success-color: #4caf50;
    --info-color: #2196f3;
    --warning-color: #ff9800;
    --danger-color: #f44336;
    --dark-color: #333;
    --light-color: #f5f5f5;
    --border-radius: 12px;
    --transition: all 0.3s ease;
    --background-gradient: linear-gradient(135deg, #f5f7fa 0%, #e4e8ec 100%);
    --card-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    --hover-shadow: 0 8px 30px rgba(102, 126, 234, 0.3);
}

* {
    box-sizing: border-box;
}

.symbols-section {
    padding: 20px 0;
    min-height: 100vh;
    background: var(--background-gradient);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

.calculator-header {
    text-align: center;
    margin-bottom: 30px;
    padding: 40px 20px;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
}

.header-content {
    max-width: 800px;
    margin: 0 auto;
}

.calculator-title {
    font-size: 2.5rem;
    color: var(--dark-color);
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
}

.calculator-title i {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.calculator-subtitle {
    font-size: 1.1rem;
    color: #666;
    margin-bottom: 20px;
}

.calculator-badge {
    display: flex;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
}

.badge-item {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.85rem;
}

.search-box {
    margin-bottom: 20px;
}

.search-input-wrapper {
    position: relative;
    max-width: 500px;
    margin: 0 auto;
}

.search-input-wrapper i {
    position: absolute;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    color: #999;
}

.search-input {
    width: 100%;
    padding: 15px 20px 15px 50px;
    border: 2px solid #e0e0e0;
    border-radius: 30px;
    font-size: 1rem;
    transition: var(--transition);
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.symbol-categories {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 25px;
    justify-content: center;
}

.category-btn {
    padding: 10px 20px;
    background: white;
    border: 2px solid #e0e0e0;
    border-radius: 25px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.95rem;
    color: var(--dark-color);
}

.category-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.category-btn.active {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-color: transparent;
    color: white;
}

.category-btn i {
    font-size: 0.9rem;
}

.calculator-main {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
    padding: 30px;
    margin-bottom: 30px;
}

.symbols-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    gap: 15px;
}

.symbol-card {
    position: relative;
    padding: 20px 15px;
    background: #f8f9fa;
    border-radius: 10px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
}

.symbol-card:hover {
    background: #f0f0f0;
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.symbol-card.hidden {
    display: none;
}

.symbol-content {
    font-size: 2rem;
    margin-bottom: 8px;
    min-height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.symbol-name {
    font-size: 0.8rem;
    color: #666;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.symbol-card .copy-btn {
    position: absolute;
    top: 8px;
    right: 8px;
    width: 28px;
    height: 28px;
    background: var(--primary-color);
    border: none;
    border-radius: 50%;
    color: white;
    cursor: pointer;
    opacity: 0;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.symbol-card:hover .copy-btn {
    opacity: 1;
}

.copy-btn:hover {
    transform: scale(1.1);
}

.no-results {
    text-align: center;
    padding: 60px 20px;
    color: #999;
}

.no-results i {
    font-size: 4rem;
    margin-bottom: 20px;
    display: block;
}

.no-results p {
    font-size: 1.1rem;
}

.toast {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%) translateY(-100px);
    background: var(--success-color);
    color: white;
    padding: 15px 30px;
    border-radius: 30px;
    display: flex;
    align-items: center;
    gap: 10px;
    box-shadow: 0 5px 20px rgba(76, 175, 80, 0.3);
    transition: transform 0.3s ease;
    z-index: 9999;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
}

.calculator-info {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
    padding: 30px;
    margin-bottom: 30px;
}

.info-section {
    margin-bottom: 25px;
}

.info-section:last-child {
    margin-bottom: 0;
}

.info-title {
    font-size: 1.3rem;
    color: var(--dark-color);
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.info-title i {
    color: var(--primary-color);
}

.info-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.info-list li {
    padding: 10px 0;
    border-bottom: 1px solid #f0f0f0;
    color: #666;
    line-height: 1.6;
}

.info-list li:last-child {
    border-bottom: none;
}

.info-list li strong {
    color: var(--dark-color);
}

.related-section {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
    padding: 30px;
}

.related-title {
    font-size: 1.5rem;
    color: var(--dark-color);
    margin-bottom: 20px;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.related-title i {
    color: var(--primary-color);
}

.related-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
}

.related-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 15px 20px;
    background: #f8f9fa;
    border-radius: 10px;
    text-decoration: none;
    color: var(--dark-color);
    transition: var(--transition);
}

.related-item:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    transform: translateY(-3px);
}

.related-item i {
    font-size: 1.2rem;
    color: var(--primary-color);
}

.related-item:hover i {
    color: white;
}

@media (max-width: 768px) {
    .calculator-title {
        font-size: 1.8rem;
    }

    .calculator-header {
        padding: 25px 15px;
    }

    .calculator-main {
        padding: 20px 15px;
    }

    .symbols-grid {
        grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
        gap: 10px;
    }

    .symbol-content {
        font-size: 1.6rem;
    }

    .category-btn {
        padding: 8px 15px;
        font-size: 0.85rem;
    }
}

@keyframes bounce {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.2);
    }
}

.symbol-card.copied .symbol-content {
    animation: bounce 0.3s ease;
}