/* ===================================
   Variables y Reset
   =================================== */
:root {
    /* Colores principales Toka */
    --color-primary: #001127;
    --color-secondary: #002855;
    
    /* Colores de texto */
    --color-text-primary: #333333;
    --color-text-secondary: #666666;
    --color-text-light: #999999;
    
    /* Colores de fondo */
    --color-bg-white: #FFFFFF;
    --color-bg-light: #F8F9FA;
    --color-bg-lighter: #F0F4F7;
    
    /* Colores de estado */
    --color-error: #E74C3C;
    --color-success: #27AE60;
    --color-info: #E8EEF4;
    
    /* Sombras */
    --shadow-card: 0 4px 20px rgba(0, 17, 39, 0.12);
    --shadow-hover: 0 6px 28px rgba(0, 17, 39, 0.18);
    --shadow-button: 0 2px 10px rgba(0, 17, 39, 0.25);
    
    /* Bordes */
    --border-radius: 12px;
    --border-radius-small: 8px;
    --border-radius-large: 16px;
    
    /* Espaciado */
    --spacing-xs: 8px;
    --spacing-sm: 12px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 48px;
}

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

html {
    font-size: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    color: var(--color-text-primary);
    background: linear-gradient(135deg, var(--color-bg-lighter) 0%, var(--color-bg-white) 100%);
    min-height: 100vh;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===================================
   Utilidades
   =================================== */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

.container {
    width: 100%;
    max-width: 600px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===================================
   Header
   =================================== */
.header {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    color: var(--color-bg-white);
    padding: var(--spacing-xl) 0;
    text-align: center;
    box-shadow: 0 4px 15px rgba(45, 128, 185, 0.2);
}

.header-title {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.5px;
}

.header-subtitle {
    font-size: 1rem;
    font-weight: 400;
    opacity: 0.95;
    max-width: 500px;
    margin: 0 auto;
    line-height: 1.5;
}

/* ===================================
   Main Content
   =================================== */
.main {
    padding: var(--spacing-xl) 0;
    min-height: calc(100vh - 250px);
}

.calculator-card {
    background: var(--color-bg-white);
    border-radius: var(--border-radius-large);
    box-shadow: var(--shadow-card);
    padding: var(--spacing-xl);
    transition: box-shadow 0.3s ease;
}

/* ===================================
   Sections
   =================================== */
.section {
    margin-bottom: var(--spacing-xl);
}

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

.section-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.4;
}

.section-title-resumen {
    text-align: center;
    font-size: 1.5rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xl);
}

/* ===================================
   Input Groups
   =================================== */
.input-group {
    margin-bottom: var(--spacing-lg);
}

.label {
    display: block;
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
}

.input-with-prefix {
    position: relative;
    display: flex;
    align-items: center;
    margin-bottom: var(--spacing-sm);
}

.currency-prefix {
    position: absolute;
    left: var(--spacing-md);
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-text-secondary);
    pointer-events: none;
}

.input-field {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-md) var(--spacing-md) 40px;
    font-size: 1.125rem;
    font-weight: 500;
    border: 2px solid #E0E6EB;
    border-radius: var(--border-radius);
    background: var(--color-bg-white);
    color: var(--color-text-primary);
    transition: all 0.3s ease;
}

.input-field:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(45, 128, 185, 0.1);
}

.input-field::placeholder {
    color: #C4CDD5;
}

.input-field.error {
    border-color: var(--color-error);
}

.help-text {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    line-height: 1.5;
}

.error-message {
    font-size: 0.875rem;
    color: var(--color-error);
    font-weight: 500;
    margin-top: var(--spacing-xs);
    display: none;
}

.error-message:not(:empty) {
    display: block;
}

/* ===================================
   Info Box
   =================================== */
.info-box {
    background: var(--color-info);
    border-left: 4px solid var(--color-primary);
    border-radius: var(--border-radius-small);
    padding: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.info-text {
    font-size: 0.95rem;
    color: var(--color-text-primary);
    line-height: 1.6;
}

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

/* ===================================
   Slider
   =================================== */
.slider-group {
    margin-top: var(--spacing-lg);
}

.slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 8px;
    border-radius: 4px;
    background: linear-gradient(to right, 
        var(--color-primary) 0%, 
        var(--color-secondary) 50%, 
        #E0E6EB 50%, 
        #E0E6EB 100%);
    outline: none;
    transition: opacity 0.2s;
    margin-bottom: var(--spacing-md);
}

.slider:hover {
    opacity: 0.9;
}

/* Webkit (Chrome, Safari) */
.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--color-bg-white);
    border: 3px solid var(--color-primary);
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(45, 128, 185, 0.3);
    transition: all 0.2s ease;
}

.slider::-webkit-slider-thumb:hover {
    transform: scale(1.15);
    box-shadow: 0 3px 12px rgba(45, 128, 185, 0.4);
}

.slider::-webkit-slider-thumb:active {
    transform: scale(1.05);
}

/* Firefox */
.slider::-moz-range-thumb {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--color-bg-white);
    border: 3px solid var(--color-primary);
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(45, 128, 185, 0.3);
    transition: all 0.2s ease;
}

.slider::-moz-range-thumb:hover {
    transform: scale(1.15);
    box-shadow: 0 3px 12px rgba(45, 128, 185, 0.4);
}

.slider::-moz-range-thumb:active {
    transform: scale(1.05);
}

.slider::-moz-range-track {
    background: transparent;
}

/* ===================================
   Resumen
   =================================== */
.section-resumen {
    background: var(--color-bg-lighter);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.resumen-grid {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.resumen-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    border-radius: var(--border-radius-small);
    background: var(--color-bg-white);
    transition: transform 0.2s ease;
}

.resumen-item-secondary {
    opacity: 0.85;
}

.resumen-item-highlight {
    background: linear-gradient(135deg, #FFF8E1 0%, #FFF3CD 100%);
    border: 2px solid #FFD54F;
}

.resumen-item-primary {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    color: var(--color-bg-white);
    padding: var(--spacing-lg);
    transform: scale(1.02);
    box-shadow: var(--shadow-button);
}

.resumen-item-primary .resumen-label,
.resumen-item-primary .resumen-value {
    color: var(--color-bg-white);
}

.resumen-item-info {
    background: var(--color-info);
    border: 2px solid var(--color-secondary);
    padding: var(--spacing-lg);
}

.resumen-label {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    font-weight: 500;
    flex: 1;
}

.resumen-value {
    font-size: 1rem;
    font-weight: 700;
    color: var(--color-text-primary);
    text-align: right;
}

.resumen-value-large {
    font-size: 1.375rem;
}

.resumen-value-xlarge {
    font-size: 1.75rem;
}

.resumen-separator {
    height: 1px;
    background: #E0E6EB;
    margin: var(--spacing-sm) 0;
}

/* ===================================
   Buttons
   =================================== */
.btn-primary {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-bg-white);
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-button);
    margin-top: var(--spacing-xl);
    text-align: center;
}

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

.btn-primary:active {
    transform: translateY(0);
    box-shadow: var(--shadow-button);
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

/* ===================================
   Legal Section
   =================================== */
.section-legal {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-xl);
    border-top: 1px solid #E0E6EB;
}

.legal-text {
    font-size: 0.8125rem;
    color: var(--color-text-light);
    line-height: 1.6;
    margin-bottom: var(--spacing-sm);
}

.legal-text:last-child {
    margin-bottom: 0;
}

.legal-text strong {
    color: var(--color-text-secondary);
    font-weight: 600;
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--color-bg-white);
    border-top: 1px solid #E0E6EB;
    padding: var(--spacing-lg) 0;
    margin-top: var(--spacing-xxl);
    text-align: center;
}

.footer p {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

/* ===================================
   Responsive Design - Tablet
   =================================== */
@media (min-width: 768px) {
    .header-title {
        font-size: 2.25rem;
    }
    
    .header-subtitle {
        font-size: 1.125rem;
    }
    
    .calculator-card {
        padding: var(--spacing-xxl);
    }
    
    .section-title {
        font-size: 1.375rem;
    }
    
    .input-field {
        font-size: 1.25rem;
    }
    
    .resumen-value-xlarge {
        font-size: 2rem;
    }
    
    .btn-primary {
        font-size: 1.25rem;
        padding: var(--spacing-lg) var(--spacing-xl);
    }
}

/* ===================================
   Responsive Design - Desktop
   =================================== */
@media (min-width: 1024px) {
    .container {
        padding: 0 var(--spacing-lg);
    }
    
    .calculator-card:hover {
        box-shadow: var(--shadow-hover);
    }
    
    .resumen-item:hover {
        transform: scale(1.02);
    }
    
    .resumen-item-primary,
    .resumen-item-info {
        transform: scale(1.02);
    }
    
    .resumen-item-primary:hover,
    .resumen-item-info:hover {
        transform: scale(1.04);
    }
}

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

.section {
    animation: fadeIn 0.5s ease-out;
}

/* ===================================
   Print Styles
   =================================== */
@media print {
    .header,
    .footer,
    .btn-primary,
    .slider-group {
        display: none;
    }
    
    .calculator-card {
        box-shadow: none;
        border: 1px solid #E0E6EB;
    }
}