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

:root {
    --primary-blue: #2196F3;
    --success-green: #4CAF50;
    --warning-yellow: #FFC107;
    --error-red: #F44336;
    --accent-purple: #9C27B0;
    --background: #f5f5f5;
    --surface: #ffffff;
    --text-primary: #333333;
    --text-secondary: #666666;
    --border: #e0e0e0;
    --shadow: 0 2px 8px rgba(0,0,0,0.1);
    --shadow-hover: 0 4px 16px rgba(0,0,0,0.15);
    --border-radius: 12px;
    --transition: all 0.3s ease;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--background);
    color: var(--text-primary);
    line-height: 1.6;
    padding-bottom: 80px;
}

.app-header {
    background: linear-gradient(135deg, var(--primary-blue), var(--accent-purple));
    color: white;
    padding: 20px;
    text-align: center;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.app-header h1 {
    font-size: 1.5rem;
    font-weight: 600;
}

.app-header i {
    margin-right: 8px;
}

.app-logo {
    height: 28px;
    width: auto;
    margin-right: 8px;
    vertical-align: middle;
    filter: drop-shadow(0 1px 1px rgba(0,0,0,0.2));
}

.app-main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

.section {
    display: none;
    animation: fadeIn 0.3s ease-in;
}

.section.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Home Section */
.welcome-card {
    background: var(--surface);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
    margin-bottom: 30px;
}

.welcome-card h2 {
    color: var(--primary-blue);
    margin-bottom: 15px;
    font-size: 1.8rem;
}

.welcome-card p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.quick-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.stat-card {
    background: var(--surface);
    padding: 20px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    display: grid;
    grid-template-columns: auto 1fr auto;
    grid-template-rows: auto auto;
    align-items: center;
    column-gap: 16px;
    row-gap: 6px;
    transition: var(--transition);
}

.stat-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

.stat-icon {
    grid-row: 1 / span 2;
    grid-column: 1;
    font-size: 2rem;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-blue), var(--success-green));
}

.stat-info {
    display: flex;
    flex-direction: column;
}

.stat-label {
    grid-column: 2;
    grid-row: 1;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.stat-value {
    grid-column: 2;
    grid-row: 2;
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--primary-blue);
}

.stat-unit {
    grid-column: 3;
    grid-row: 2;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.chart-container {
    background: var(--surface);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 30px;
    position: relative;
    height: 400px;
}

.chart-empty {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.safety-margin-gauge {
    background: var(--surface);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
}

.safety-margin-gauge h3 {
    color: var(--primary-blue);
    margin-bottom: 20px;
    font-size: 1.4rem;
}

.gauge-container {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

/* Removido wrapper .gauge-info (conteúdo direto na .gauge-container) */

.gauge-value {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--success-green);
}

.gauge-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Calculator Section */
.calculator-header {
    text-align: center;
    margin-bottom: 30px;
}

.calculator-header h2 {
    color: var(--primary-blue);
    font-size: 1.8rem;
    margin-bottom: 10px;
}

.calculator-header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.calculation-form {
    background: var(--surface);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 30px;
}
 
.form-toolbar {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 15px;
}

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

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-primary);
}

.form-group input {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    transition: var(--transition);
}

.field-hint {
    display: block;
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-top: 6px;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(33, 150, 243, 0.1);
}

.costs-section {
    margin: 30px 0;
    padding: 25px;
    background: #f8f9fa;
    border-radius: var(--border-radius);
    border: 1px solid var(--border);
}

.costs-section h3 {
    color: var(--primary-blue);
    margin-bottom: 20px;
    font-size: 1.3rem;
}

.costs-list {
    margin-bottom: 20px;
}

.cost-item {
    display: grid;
    grid-template-columns: 1fr 1fr auto;
    gap: 15px;
    align-items: center;
    margin-bottom: 15px;
    padding: 15px;
    background: var(--surface);
    border-radius: 8px;
    border: 1px solid var(--border);
}

.cost-name, .cost-value {
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.95rem;
}

.remove-cost-btn {
    background: var(--error-red);
    color: white;
    border: none;
    border-radius: 6px;
    padding: 10px;
    cursor: pointer;
    transition: var(--transition);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.remove-cost-btn:hover {
    background: #d32f2f;
    transform: scale(1.05);
}

.add-cost-btn {
    background: var(--success-green);
    color: white;
    border: none;
    border-radius: 8px;
    padding: 12px 20px;
    cursor: pointer;
    font-size: 0.95rem;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
}

.add-cost-btn:hover {
    background: #388e3c;
    transform: translateY(-1px);
}

.calculate-btn {
    width: 100%;
    background: linear-gradient(135deg, var(--primary-blue), var(--accent-purple));
    color: white;
    border: none;
    border-radius: var(--border-radius);
    padding: 16px 24px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-top: 20px;
}

.calculate-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.results-section {
    background: var(--surface);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-top: 30px;
}

.results-section h3 {
    color: var(--primary-blue);
    margin-bottom: 25px;
    font-size: 1.5rem;
    text-align: center;
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}

.result-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
    background: #f8f9fa;
    border-radius: 8px;
    border-left: 4px solid var(--primary-blue);
}

.result-item.highlight {
    background: linear-gradient(135deg, rgba(33, 150, 243, 0.1), rgba(76, 175, 80, 0.1));
    border-left-color: var(--success-green);
    font-weight: 600;
}

.result-label {
    color: var(--text-primary);
    font-weight: 500;
}

.result-value {
    color: var(--primary-blue);
    font-weight: 700;
    font-size: 1.1rem;
}

/* Scenarios Section */
.scenarios-header {
    text-align: center;
    margin-bottom: 30px;
}

.scenarios-header h2 {
    color: var(--primary-blue);
    font-size: 1.8rem;
    margin-bottom: 10px;
}

.scenarios-header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.scenario-controls {
    background: var(--surface);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 30px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    align-items: end;
}

.control-group {
    display: flex;
    flex-direction: column;
}

.control-group label {
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-primary);
}

.control-group input {
    padding: 12px 16px;
    border: 2px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    transition: var(--transition);
}

.control-group input:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(33, 150, 243, 0.1);
}

.simulate-btn {
    background: var(--warning-yellow);
    color: #333;
    border: none;
    border-radius: 8px;
    padding: 12px 20px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    height: fit-content;
}

.simulate-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.simulate-btn:hover {
    background: #ffb300;
    transform: translateY(-1px);
}

.comparison-section {
    background: var(--surface);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 30px;
}

.comparison-section h3 {
    color: var(--primary-blue);
    margin-bottom: 25px;
    font-size: 1.5rem;
    text-align: center;
}

.comparison-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
    background: var(--surface);
}
.comparison-table thead th {
    background: var(--primary-blue);
    color: #fff;
    font-weight: 600;
    text-align: center;
    padding: 12px;
}
.comparison-table tbody td {
    text-align: center;
    padding: 12px;
    border-top: 1px solid var(--border);
}
.comparison-table tbody tr:nth-child(even) td {
    background: #f8f9fa;
}

.scenario-chart-container {
    background: var(--surface);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    height: 400px;
}

/* FAQ Section */
.faq-header {
    text-align: center;
    margin-bottom: 30px;
}

.faq-header h2 {
    color: var(--primary-blue);
    font-size: 1.8rem;
    margin-bottom: 10px;
}

.faq-header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.faq-controls {
    margin-top: 10px;
    display: flex;
    gap: 10px;
    justify-content: center;
}

.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--surface);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 15px;
    overflow: hidden;
    transition: var(--transition);
}

.faq-item:hover {
    box-shadow: var(--shadow-hover);
}

.faq-question {
    width: 100%;
    background: none;
    border: none;
    padding: 20px 25px;
    text-align: left;
    cursor: pointer;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.faq-question:hover {
    background: #f8f9fa;
}

.faq-question[aria-expanded="true"] {
    background: var(--primary-blue);
    color: white;
}

.faq-icon {
    font-size: 1.2rem;
    font-weight: bold;
    transition: var(--transition);
}

/* Ícone do FAQ alterna via classes (fa-plus/fa-minus) no JS */

.faq-answer {
    padding: 0 25px;
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s ease;
}

.faq-answer.show {
    padding: 20px 25px;
    max-height: 200px;
}

.faq-answer p {
    color: var(--text-secondary);
    line-height: 1.7;
    margin: 0;
}

/* Bottom Navigation */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--surface);
    border-top: 1px solid var(--border);
    display: flex;
    justify-content: space-around;
    padding: 10px 0;
    z-index: 1000;
    box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-decoration: none;
    color: var(--text-secondary);
    padding: 8px 12px;
    border-radius: 8px;
    transition: var(--transition);
    min-width: 60px;
}

.nav-item i {
    font-size: 1.2rem;
    margin-bottom: 4px;
}

.nav-item span {
    font-size: 0.75rem;
    font-weight: 500;
}

.nav-item.active {
    color: var(--primary-blue);
    background: rgba(33, 150, 243, 0.1);
}

.nav-item:hover {
    color: var(--primary-blue);
    background: rgba(33, 150, 243, 0.05);
}

/* Footer */
footer {
    text-align: center;
    padding: 20px;
    color: var(--text-secondary);
    font-size: 0.9rem;
    background: var(--surface);
    margin-top: 40px;
    border-top: 1px solid var(--border);
}

/* Footer links sem aparência de link */
footer a {
    color: inherit;
    text-decoration: none;
    margin: 0 8px;
}

footer a:hover {
    text-decoration: none;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .app-main {
        padding: 15px;
    }
    
    .form-row {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .cost-item {
        grid-template-columns: 1fr;
        gap: 10px;
    }
    
    .scenario-controls {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .stat-card {
        padding: 16px;
        row-gap: 4px;
    }
    .stat-icon {
        width: 44px;
        height: 44px;
        font-size: 1.8rem;
    }
    .stat-value {
        font-size: 1.4rem;
    }
    .comparison-table {
        display: block;
        overflow-x: auto;
        white-space: nowrap;
    }
    
    .quick-stats {
        grid-template-columns: 1fr;
    }
    
    .results-grid {
        grid-template-columns: 1fr;
    }
    
    .stat-card {
        padding: 20px;
    }
    
    .chart-container {
        padding: 20px;
        height: 300px;
    }
    
    .scenario-chart-container {
        padding: 20px;
        height: 300px;
    }
}

@media (max-width: 480px) {
    .app-header {
        padding: 15px;
    }
    
    .app-header h1 {
        font-size: 1.3rem;
    }
    .app-logo {
        height: 24px;
        margin-right: 6px;
    }
    
    .welcome-card {
        padding: 20px;
    }
    
    .welcome-card h2 {
        font-size: 1.5rem;
    }
    
    .calculation-form {
        padding: 20px;
    }
    
    .costs-section {
        padding: 20px;
    }
    
    .nav-item span {
        font-size: 0.7rem;
    }
    
    .nav-item i {
        font-size: 1.1rem;
    }
}

/* Loading Animation */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255,255,255,.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 1s ease-in-out infinite;
}

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

/* Success/Error Messages */
.message {
    padding: 15px 20px;
    border-radius: 8px;
    margin: 15px 0;
    font-weight: 500;
}

.message.success {
    background: rgba(76, 175, 80, 0.1);
    color: var(--success-green);
    border: 1px solid rgba(76, 175, 80, 0.3);
}

.message.error {
    background: rgba(244, 67, 54, 0.1);
    color: var(--error-red);
    border: 1px solid rgba(244, 67, 54, 0.3);
}

/* Smooth scrolling */
html {
    scroll-behavior: smooth;
}

/* Focus styles for accessibility */
button:focus,
input:focus,
.nav-item:focus {
    outline: 2px solid var(--primary-blue);
    outline-offset: 2px;
}

/* Botão base (fallback para botões sem classe específica) */
button {
    -webkit-appearance: none;
    appearance: none;
    background: #f7f9fc;
    color: var(--text-primary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 10px 14px;
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition);
}

button:hover {
    background: #eef3fb;
}

button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* Acessibilidade */
.visually-hidden {
    position: absolute !important;
    height: 1px; width: 1px;
    overflow: hidden;
    clip: rect(1px, 1px, 1px, 1px);
    white-space: nowrap;
}

/* Estados de erro e foco aprimorados */
.form-group input.invalid,
.cost-item .cost-name.invalid,
.cost-item .cost-value.invalid {
    border-color: var(--error-red);
    box-shadow: 0 0 0 3px rgba(244, 67, 54, 0.15);
}

.form-group input.valid,
.cost-item .cost-name.valid,
.cost-item .cost-value.valid {
    border-color: var(--success-green);
}

/* Prefere movimento reduzido */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}