.percentage-calculator-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px;
    color: #475569;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

.percentage-calculator-container h1 {
    color: #1e293b;
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 16px;
    line-height: 1.2;
}

.subtitle {
    font-size: 1.25rem;
    color: #64748b;
    max-width: 700px;
    margin-bottom: 40px;
    line-height: 1.5;
}

.features-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
    margin-bottom: 32px;
}

.feature-item {
    background: #f8fafc;
    border-radius: 16px;
    padding: 28px;
    text-align: center;
    transition: transform 0.2s;
    border: 1px solid #e2e8f0;
}

.feature-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.feature-item h3 {
    color: #1e293b;
    margin: 16px 0 12px;
    font-size: 1.25rem;
}

.security-badge {
    background: #f0fdf4;
    border-radius: 16px;
    padding: 20px;
    border: 1px solid #bbf7d0;
    margin: 32px 0;
}

.security-badge p {
    margin: 0;
    color: #166534;
    font-size: 1.05rem;
    line-height: 1.6;
}

.calculator-card {
    background: white;
    border-radius: 20px;
    padding: 32px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    border: 1px solid #e2e8f0;
    max-width: 600px;
    margin: 0 auto 40px;
}

.input-group {
    margin-bottom: 24px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #1e293b;
    font-size: 1.05rem;
}

.value-input {
    width: 100%;
    padding: 14px;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    font-size: 1.1rem;
    transition: border-color 0.2s;
    font-family: inherit;
}

.value-input:focus {
    outline: none;
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

.calculate-btn {
    background: #3b82f6;
    color: white;
    border: none;
    border-radius: 12px;
    padding: 14px 24px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    width: 100%;
    transition: background 0.2s;
}

.calculate-btn:hover {
    background: #2563eb;
}

.calculate-btn svg {
    stroke: currentColor;
}

.result-container {
    margin-top: 32px;
    padding-top: 24px;
    border-top: 1px solid #e2e8f0;
    text-align: center;
}

.result-placeholder {
    color: #94a3b8;
    font-size: 1.1rem;
    padding: 20px 0;
}

.result-value {
    font-size: 2.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin: 10px 0;
}

.result-value.increase {
    color: #15803d;
}

.result-value.decrease {
    color: #b91c1c;
}

.result-description {
    font-size: 1.1rem;
    color: #475569;
    margin-top: 8px;
}

.formula-box {
    background: #f8fafc;
    border-radius: 16px;
    padding: 24px;
    border: 1px solid #e2e8f0;
    max-width: 600px;
    margin: 0 auto;
}

.formula {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
    font-size: 1.4rem;
    font-weight: 600;
    color: #1e293b;
}

.highlight {
    color: #3b82f6;
}

.examples-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
    margin: 32px 0;
}

.example-card {
    background: #f8fafc;
    border-radius: 16px;
    padding: 24px;
    border: 1px solid #e2e8f0;
}

.example-card h3 {
    color: #1e293b;
    margin-top: 0;
    font-size: 1.3rem;
}

.example-result {
    font-size: 2.2rem;
    font-weight: 700;
    margin: 12px 0;
}

.example-result.negative {
    color: #b91c1c;
}

.use-cases-table {
    width: 100%;
    border-collapse: collapse;
    margin: 24px 0;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.use-cases-table th {
    background: #f1f5f9;
    padding: 16px;
    text-align: left;
    font-weight: 600;
    color: #1e293b;
}

.use-cases-table td {
    padding: 16px;
    border-bottom: 1px solid #e2e8f0;
    color: #475569;
}

.use-cases-table tr:last-child td {
    border-bottom: none;
}

.faq-section {
    margin-top: 40px;
}

.faq-item {
    background: #f8fafc;
    border-radius: 16px;
    padding: 24px;
    margin-bottom: 20px;
    border: 1px solid #e2e8f0;
}

.faq-item h3 {
    color: #1e293b;
    margin-top: 0;
    font-size: 1.3rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 10px;
}

.faq-item h3::before {
    content: "▸";
    color: #3b82f6;
    font-size: 1.2rem;
}

.faq-item p {
    margin-top: 12px;
    color: #475569;
    line-height: 1.6;
}

@media (max-width: 768px) {
    .percentage-calculator-container {
        padding: 20px 15px;
    }
    
    .calculator-card, .formula-box {
        padding: 24px 20px;
    }
    
    .percentage-calculator-container h1 {
        font-size: 2rem;
    }
}