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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    color: #333;
}

.container {
    max-width: 900px;
    margin: 0 auto;
}

.back-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(255, 255, 255, 0.2);
    color: white;
    padding: 10px 20px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    margin-bottom: 20px;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

.back-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateX(-5px);
}

/* Card & Header */
.calculator-card {
    background: white;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
    margin-bottom: 30px;
}

.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 40px 30px;
    text-align: center;
}

.header .main-title {
    font-size: 2rem;
    margin-bottom: 10px;
    font-weight: 700;
}

.header p {
    opacity: 0.9;
    font-size: 1.1rem;
}

/* Tabs System */
.tabs {
    display: flex;
    background: #f3f4f6;
    padding: 5px;
    gap: 5px;
    border-bottom: 2px solid #e5e7eb;
}

.tab-btn {
    flex: 1;
    padding: 12px;
    border: none;
    background: transparent;
    color: #666;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    border-radius: 8px;
}

.tab-btn.active {
    background: white;
    color: #667eea;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.tab-content {
    display: none;
    padding: 40px 30px;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.4s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

/* Form Elements */
.form-group {
    margin-bottom: 25px;
}

label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
    color: #333;
    font-size: 0.95rem;
}

input,
select {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: white;
}

input:focus,
select:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.input-group {
    position: relative;
}

.input-prefix {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: #666;
    font-weight: 600;
}

.input-suffix {
    position: absolute;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: #666;
    font-weight: 600;
}

input.with-prefix {
    padding-left: 35px;
}

input.with-suffix {
    padding-right: 35px;
}

/* Buttons */
.button-group {
    display: flex;
    gap: 15px;
    margin-top: 30px;
}

button:not(.tab-btn) {
    padding: 14px 24px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-calculate {
    flex: 2;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-calculate:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
}

.btn-clear {
    flex: 1;
    background: #f3f4f6;
    color: #666;
}

.btn-clear:hover {
    background: #e5e7eb;
}

/* Investment Results */
.results {
    margin-top: 40px;
    padding-top: 40px;
    border-top: 2px solid #f0f0f0;
    display: none;
}

.results.show {
    display: block;
    animation: slideUp 0.5s ease;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.results h2 {
    text-align: center;
    margin-bottom: 30px;
    color: #333;
}

.comparison {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 30px;
}

.comparison-card {
    background: #f9fafb;
    padding: 25px;
    border-radius: 12px;
    border: 2px solid #e5e7eb;
}

.comparison-card h3 {
    font-size: 0.9rem;
    text-transform: uppercase;
    color: #666;
    margin-bottom: 15px;
    letter-spacing: 0.5px;
}

.stat {
    margin-bottom: 15px;
}

.stat-label {
    font-size: 0.85rem;
    color: #666;
    margin-bottom: 5px;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: #333;
}

.highlight {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    color: white;
    padding: 25px;
    border-radius: 12px;
    text-align: center;
}

.highlight h3 {
    font-size: 1.1rem;
    margin-bottom: 10px;
    opacity: 0.9;
}

.highlight .amount {
    font-size: 2.5rem;
    font-weight: 700;
}

.disclaimer {
    margin-top: 30px;
    padding: 20px;
    background: #fef3c7;
    border-left: 4px solid #f59e0b;
    border-radius: 8px;
    font-size: 0.9rem;
    color: #92400e;
}

/* Money Counter Styles */
.section-desc {
    color: #666;
    margin-bottom: 30px;
    text-align: center;
}

.denomination-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.denom-card {
    background: #f9fafb;
    padding: 15px;
    border-radius: 12px;
    border: 2px solid #e5e7eb;
    text-align: center;
}

.denom-label {
    display: block;
    font-size: 0.9rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: #4b5563;
}

.denom-input {
    width: 80px;
    padding: 8px;
    text-align: center;
    border: 2px solid #d1d5db;
    border-radius: 6px;
}

.counter-total {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px;
    border-radius: 12px;
    text-align: center;
    margin-top: 30px;
}

.counter-total h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
}

/* Exchange Styles */
.exchange-form {
    max-width: 500px;
    margin: 0 auto;
}

.exchange-controls {
    display: flex;
    align-items: center;
    gap: 15px;
    margin: 20px 0;
}

.exchange-icon {
    font-size: 1.5rem;
    color: #667eea;
}

.exchange-result {
    margin-top: 30px;
    padding: 20px;
    background: #ecfdf5;
    border: 2px solid #10b981;
    border-radius: 12px;
    text-align: center;
    color: #065f46;
}

/* SEO Article Styles */
.seo-article {
    margin-top: 50px;
    background: white;
    padding: 50px 40px;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.seo-article h2 {
    color: #1a202c;
    font-size: 2.2rem;
    margin-bottom: 25px;
    line-height: 1.2;
}

.seo-article h3 {
    color: #2d3748;
    font-size: 1.6rem;
    margin-top: 40px;
    margin-bottom: 20px;
}

.seo-article p {
    color: #4a5568;
    line-height: 1.7;
    margin-bottom: 20px;
    font-size: 1.1rem;
}

.article-img {
    display: block;
    margin: 30px auto;
    max-width: 100%;
    width: 457px;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.faq-section {
    margin-top: 50px;
    padding-top: 40px;
    border-top: 2px solid #edf2f7;
}

.faq-section h3 {
    color: #2d3748;
    font-size: 1.6rem;
    margin-bottom: 25px;
}

.faq-item {
    margin-bottom: 30px;
}

.faq-item h4 {
    color: #2d3748;
    font-size: 1.25rem;
    margin-bottom: 12px;
}

.faq-item p {
    font-size: 1rem;
    color: #718096;
}

.article-footer {
    margin-top: 50px;
    padding-top: 20px;
    border-top: 1px solid #e2e8f0;
    color: #a0aec0;
    font-size: 0.9rem;
    text-align: center;
}

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

    .seo-article {
        padding: 30px 20px;
    }

    .seo-article h2 {
        font-size: 1.8rem;
    }

    .comparison {
        grid-template-columns: 1fr;
    }

    .header h1 {
        font-size: 1.5rem;
    }

    .tab-content {
        padding: 30px 20px;
    }

    .button-group {
        flex-direction: column;
    }

    .exchange-controls {
        flex-direction: column;
    }

    .exchange-icon {
        transform: rotate(90deg);
    }

    .highlight .amount {
        font-size: 2rem;
    }
}