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

:root {
    --bg-gradient-start: #667eea;
    --bg-gradient-end: #764ba2;
    --text-primary: #333333;
    --text-secondary: #555555;
    --text-light: #666666;
    --card-bg: #ffffff;
    --input-bg: #f9f9f9;
    --input-border: #e0e0e0;
    --input-focus-border: #667eea;
    --result-bg: #f8f9fa;
    --result-border-left: #667eea;
    --shadow: rgba(0, 0, 0, 0.1);
    --chart-grid-color: rgba(0, 0, 0, 0.1);
    --header-text: #ffffff;
    --btn-bg: rgba(255, 255, 255, 0.2);
    --btn-hover-bg: rgba(255, 255, 255, 0.3);
    --btn-active-bg: #ffffff;
    --btn-active-text: #667eea;
    --category-title: rgba(255, 255, 255, 0.9);
    --sidebar-bg: rgba(255, 255, 255, 0.08);
    --faq-title: #333333;
    --faq-text: #555555;
    --help-bg: rgba(0, 0, 0, 0.8);
    --help-text: #ffffff;
}

[data-theme="dark"] {
    --bg-gradient-start: #1a1a2e;
    --bg-gradient-end: #16213e;
    --text-primary: #f0f0f0;
    --text-secondary: #cccccc;
    --text-light: #aaaaaa;
    --card-bg: #2d3047;
    --input-bg: #3a3d5c;
    --input-border: #4a4d6c;
    --input-focus-border: #667eea;
    --result-bg: #3a3d5c;
    --result-border-left: #667eea;
    --shadow: rgba(0, 0, 0, 0.3);
    --chart-grid-color: rgba(255, 255, 255, 0.15);
    --header-text: #ffffff;
    --btn-bg: rgba(255, 255, 255, 0.1);
    --btn-hover-bg: rgba(255, 255, 255, 0.2);
    --btn-active-bg: #667eea;
    --btn-active-text: #ffffff;
    --category-title: rgba(255, 255, 255, 0.9);
    --sidebar-bg: rgba(255, 255, 255, 0.05);
    --faq-title: #ffffff;
    --faq-text: #e0e0e0;
    --help-bg: rgba(0, 0, 0, 0.9);
    --help-text: #ffffff;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: linear-gradient(135deg, var(--bg-gradient-start) 0%, var(--bg-gradient-end) 100%);
    min-height: 100vh;
    padding: 20px;
    transition: background 0.3s;
}

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

header {
    margin-bottom: 30px;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
    color: var(--header-text);
}

.header-text {
    flex: 1;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: 700;
}

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

.theme-toggle {
    background: var(--btn-bg);
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 8px;
    padding: 8px 16px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    color: var(--header-text);
    white-space: nowrap;
}

.theme-toggle:hover {
    background: var(--btn-hover-bg);
    border-color: rgba(255, 255, 255, 0.5);
}

.theme-toggle:active {
    transform: scale(0.98);
}

/* Layout Principal: Duas Colunas */
.main-layout {
    display: flex;
    gap: 30px;
    align-items: flex-start;
}

/* Coluna da Esquerda: Seletor Lateral */
.selector-sidebar {
    width: 320px;
    flex-shrink: 0;
    background: var(--sidebar-bg);
    border-radius: 16px;
    padding: 10px 15px 20px 15px;
    position: sticky;
    top: 0px;
    max-height: calc(100vh - 0px);
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    gap: 20px;
}

.category {
    margin-bottom: 0;
}

.category-title {
    color: var(--category-title);
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    padding-bottom: 8px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

/* Seção FAQ */
.faq-category {
    margin-top: 10px;
}

.faq-content {
    padding: 10px 0;
}

.faq-item {
    margin-bottom: 15px;
    padding: 12px 15px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 8px;
    border-left: 3px solid var(--input-focus-border);
}

.faq-item h4 {
    font-size: 0.9rem;
    color: var(--faq-title) !important;
    margin-bottom: 6px;
    font-weight: 600;
}

.faq-item p {
    font-size: 0.85rem;
    color: var(--faq-text) !important;
    line-height: 1.4;
}

[data-theme="dark"] .faq-item h4 {
    color: var(--faq-title) !important;
}

[data-theme="dark"] .faq-item p {
    color: var(--faq-text) !important;
}

.buttons-grid {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.calc-btn {
    padding: 10px 20px;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    background: transparent;
    color: var(--header-text);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    text-align: left;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.calc-btn:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.4);
    transform: translateX(5px);
}

.calc-btn.active {
    background: var(--btn-active-bg);
    color: var(--btn-active-text);
    border-color: var(--btn-active-bg);
    font-weight: 600;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

/* Help Icon */
.help-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    color: var(--header-text);
    font-size: 0.75rem;
    font-weight: 700;
    cursor: help;
    margin-left: 8px;
    position: relative;
    transition: background 0.3s;
}

.help-icon:hover {
    background: rgba(255, 255, 255, 0.4);
}

/* Tooltip */
.help-icon::after {
    content: attr(data-help);
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    bottom: calc(100% + 10px);
    background: #ffffff;
    color: #333333;
    padding: 10px 15px;
    border-radius: 8px;
    font-size: 0.8rem;
    font-weight: 400;
    white-space: normal;
    width: 250px;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s;
    z-index: 1000;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

[data-theme="dark"] .help-icon::after {
    background: #2d3047;
    color: #f0f0f0;
}

.help-icon:hover::after {
    opacity: 1;
}

/* Coluna da Direita: Calculadora Ativa */
.calculator-content {
    flex: 1;
    min-width: 0;
}

.calculator-card {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 10px 30px var(--shadow);
    display: block;
    transition: background 0.3s, box-shadow 0.3s;
}

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

.calculator-card h2 {
    font-size: 1.4rem;
    color: var(--text-primary);
    margin-bottom: 25px;
    padding-bottom: 15px;
    border-bottom: 2px solid var(--input-border);
    transition: color 0.3s, border-color 0.3s;
    display: flex;
    align-items: center;
}

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

.input-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.9rem;
    transition: color 0.3s;
}

.input-group input,
.input-group select {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--input-border);
    border-radius: 10px;
    font-size: 1rem;
    transition: border-color 0.3s, background 0.3s;
    background: var(--input-bg);
    color: var(--text-primary);
}

.input-group input:focus,
.input-group select:focus {
    outline: none;
    border-color: var(--input-focus-border);
}

.periodo-anos {
    display: inline-block;
    margin-top: 8px;
    color: var(--input-focus-border);
    font-size: 0.9rem;
    font-weight: 500;
}

.result {
    background: var(--result-bg);
    padding: 20px;
    border-radius: 12px;
    margin-top: 20px;
    border-left: 4px solid var(--result-border-left);
    transition: background 0.3s;
}

.result-label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-light);
    margin-bottom: 8px;
    transition: color 0.3s;
}

.result-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    transition: color 0.3s;
}

.results-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-top: 20px;
}

.results-grid .result {
    margin-top: 0;
}

/* Seção Explicativa da Calculadora */
.calc-explanation {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 25px;
    margin-bottom: 25px;
    padding: 20px;
    background: var(--result-bg);
    border-radius: 12px;
    border: 1px solid var(--input-border);
}

.explanation-content h4,
.example-content h4 {
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 12px;
    font-weight: 600;
}

.explanation-content p,
.example-content p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 12px;
}

.explanation-content ul {
    margin-left: 20px;
    margin-bottom: 12px;
}

.explanation-content li {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 6px;
}

.explanation-content strong {
    color: var(--text-primary);
}

.example-calc {
    display: flex;
    justify-content: space-between;
    padding: 8px 12px;
    background: var(--input-bg);
    border-radius: 6px;
    margin-bottom: 8px;
    font-size: 0.9rem;
}

.example-calc span {
    color: var(--text-secondary);
}

.example-calc strong {
    color: var(--text-primary);
    font-weight: 600;
}

.example-result {
    display: flex;
    justify-content: space-between;
    padding: 10px 15px;
    background: var(--input-focus-border);
    color: white;
    border-radius: 6px;
    margin-bottom: 12px;
    font-size: 0.95rem;
}

.example-result span {
    opacity: 0.9;
}

.example-result strong {
    font-weight: 700;
}

.example-note {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-style: italic;
    padding-left: 12px;
    border-left: 3px solid var(--input-focus-border);
}

/* Responsivo para mobile */
@media (max-width: 768px) {
    .calc-explanation {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .example-calc,
    .example-result {
        flex-direction: column;
        align-items: flex-start;
        gap: 4px;
    }
    
    .example-calc span,
    .example-result span {
        margin-bottom: 2px;
    }
}

.chart-container {
    position: relative;
    height: 350px;
    margin-top: 25px;
}

/* Scrollbar customizada para a sidebar */
.selector-sidebar::-webkit-scrollbar {
    width: 6px;
}

.selector-sidebar::-webkit-scrollbar-track {
    background: transparent;
}

.selector-sidebar::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.3);
    border-radius: 3px;
}

.selector-sidebar::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.5);
}

@media (max-width: 1024px) {
    .main-layout {
        flex-direction: column;
    }
    
    .selector-sidebar {
        width: 100%;
        position: static;
        max-height: none;
    }
    
    .buttons-grid {
        flex-direction: row;
        flex-wrap: wrap;
    }
    
    .calc-btn {
        text-align: center;
    }
}

@media (max-width: 768px) {
    header h1 {
        font-size: 1.8rem;
    }

    .calculator-card {
        padding: 20px;
    }

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

    .chart-container {
        height: 250px;
    }

    .header-content {
        flex-direction: column;
        text-align: center;
    }

    .theme-toggle {
        order: -1;
    }

    .buttons-grid {
        justify-content: center;
    }

    .calc-btn {
        padding: 8px 14px;
        font-size: 0.85rem;
    }
    
    .help-icon::after {
        width: 200px;
    }
}