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

:root {
    /* Color Palette */
    --color-primary: #F8B195;
    --color-secondary: #F67280;
    --color-accent: #C06C84;
    --color-dark: #6C5B7B;
    --color-darker: #355C7D;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #F8B195 0%, #F67280 50%, #C06C84 100%);
    --gradient-secondary: linear-gradient(135deg, #C06C84 0%, #6C5B7B 50%, #355C7D 100%);
    --gradient-accent: linear-gradient(45deg, #F67280 0%, #C06C84 100%);
    
    /* Typography */
    --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border Radius */
    --border-radius-sm: 0.375rem;
    --border-radius-md: 0.5rem;
    --border-radius-lg: 0.75rem;
    --border-radius-xl: 1rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
    --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.2);
    
    /* Transitions */
    --transition-fast: 0.15s ease-in-out;
    --transition-normal: 0.3s ease-in-out;
    --transition-slow: 0.5s ease-in-out;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--color-darker);
    background: var(--gradient-primary);
    min-height: 100vh;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-md);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    padding: var(--spacing-xl) 0;
}

.header__title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: white;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    margin-bottom: var(--spacing-sm);
}

.header__subtitle {
    font-size: var(--font-size-lg);
    color: rgba(255, 255, 255, 0.9);
    font-weight: 300;
}

/* Main Content */
.main {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2xl);
}

/* Calculator */
.calculator {
    background: white;
    border-radius: var(--border-radius-xl);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
}

.calculator__form {
    padding: var(--spacing-2xl);
}

/* Form Groups */
.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group--advanced {
    margin-bottom: var(--spacing-md);
}

.form-group__label {
    display: block;
    font-weight: 600;
    color: var(--color-darker);
    margin-bottom: var(--spacing-sm);
    font-size: var(--font-size-base);
}

.form-group__input,
.form-group__select {
    width: 100%;
    padding: var(--spacing-md);
    border: 2px solid #e5e7eb;
    border-radius: var(--border-radius-md);
    font-size: var(--font-size-base);
    transition: var(--transition-normal);
    background: white;
    color: var(--color-darker);
}

.form-group__input:focus,
.form-group__select:focus {
    outline: none;
    border-color: var(--color-secondary);
    box-shadow: 0 0 0 3px rgba(246, 114, 128, 0.1);
}
.form-period{
   width: 50%;
    padding: var(--spacing-md);
    border: 2px solid #e5e7eb;
    border-radius: var(--border-radius-md);
    font-size: var(--font-size-base);
    transition: var(--transition-normal);
    background: white;
    color: var(--color-darker);
}
.form-period-type {
    width: 50%;
    padding: var(--spacing-md);
    border: 2px solid #e5e7eb;
    border-radius: var(--border-radius-md);
    font-size: var(--font-size-base);
    transition: var(--transition-normal);
    background: white;
    color: var(--color-darker);
}

.form-group__input--inline {
    flex: 1;
}

.form-group__row {
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
}

.form-group__suffix {
    font-weight: 600;
    color: var(--color-accent);
    white-space: nowrap;
    font-size: var(--font-size-sm);
}

.form-group__help {
    display: block;
    font-size: var(--font-size-sm);
    color: #6b7280;
    margin-top: var(--spacing-xs);
    font-style: italic;
}

/* Advanced Options */
.advanced-options {
    background: #f9fafb;
    border-radius: var(--border-radius-md);
    padding: var(--spacing-lg);
    margin-top: var(--spacing-md);
    border: 1px solid #e5e7eb;
}
.footer__link {
    color: var(--light-color);
    text-decoration: none;
    transition: var(--transition);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    border: none;
    border-radius: var(--border-radius-md);
    font-size: var(--font-size-base);
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition-normal);
    min-height: 48px;
    width: 100%;
}

.btn--primary {
    background: var(--gradient-accent);
    color: white;
    box-shadow: var(--shadow-md);
}

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

.btn--primary:active {
    transform: translateY(0);
}

.btn--secondary {
    background: var(--gradient-secondary);
    color: white;
    box-shadow: var(--shadow-sm);
}

.btn--secondary:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

/* Results */
.results {
    padding: var(--spacing-2xl);
    background: #f9fafb;
    border-top: 1px solid #e5e7eb;
}

.results__title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-darker);
    margin-bottom: var(--spacing-xl);
    text-align: center;
}

.results__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

/* Result Cards */
.result-card {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
    text-align: center;
    transition: var(--transition-normal);
}

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

.result-card__title {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--color-dark);
    margin-bottom: var(--spacing-sm);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.result-card__value {
    font-size: var(--font-size-xl);
    font-weight: 700;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Comparison */
.comparison {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
    margin-bottom: var(--spacing-xl);
}

.comparison__title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-darker);
    margin-bottom: var(--spacing-md);
    text-align: center;
}

.comparison__content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.comparison__item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid #f3f4f6;
}

.comparison__item:last-child {
    border-bottom: none;
}

.comparison__item--highlight {
    background: var(--gradient-primary);
    padding: var(--spacing-md);
    border-radius: var(--border-radius-md);
    color: white;
    font-weight: 600;
    border-bottom: none;
}

.comparison__label {
    font-weight: 500;
}

.comparison__value {
    font-weight: 700;
}

/* Chart Container */
.chart-container {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
}

.chart-container__title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-darker);
    margin-bottom: var(--spacing-md);
    text-align: center;
}

.chart-container__canvas {
    width: 100%;
    height: 300px;
    border-radius: var(--border-radius-md);
}

/* FAQ */
.faq {
    background: white;
    border-radius: var(--border-radius-xl);
    box-shadow: var(--shadow-lg);
    padding: var(--spacing-2xl);
}

.faq__title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-darker);
    margin-bottom: var(--spacing-xl);
    text-align: center;
}

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

.faq__item {
    border: 1px solid #e5e7eb;
    border-radius: var(--border-radius-md);
    overflow: hidden;
}

.faq__question {
    width: 100%;
    padding: var(--spacing-lg);
    background: #f9fafb;
    border: none;
    text-align: left;
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--color-darker);
    cursor: pointer;
    transition: var(--transition-normal);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.faq__question:hover {
    background: #f3f4f6;
}

.faq__icon {
    font-size: var(--font-size-lg);
    font-weight: 300;
    transition: var(--transition-normal);
}

.faq__item.active .faq__icon {
    transform: rotate(45deg);
}

.faq__answer {
    padding: 0 var(--spacing-lg);
    max-height: 0;
    overflow: hidden;
    transition: var(--transition-normal);
}

.faq__item.active .faq__answer {
    padding: var(--spacing-lg);
    max-height: 200px;
}

.faq__answer p {
    color: #6b7280;
    line-height: 1.6;
}

/* Footer */
.footer {
    margin-top: var(--spacing-2xl);
    padding: var(--spacing-xl) 0;
    text-align: center;
}

.footer__text {
    color: rgba(255, 255, 255, 0.8);
    font-size: var(--font-size-sm);
    font-weight: 300;
}

/* Loading States */
.loading {
    opacity: 0.6;
    pointer-events: none;
}

.loading .btn {
    background: #9ca3af;
    cursor: not-allowed;
}

/* Error States */
.form-group__input.error,
.form-group__select.error {
    border-color: #ef4444;
    box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.1);
}

.form-group__error {
    display: block;
    color: #ef4444;
    font-size: var(--font-size-sm);
    margin-top: var(--spacing-xs);
    font-weight: 500;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: var(--spacing-sm);
    }
    
    .header__title {
        font-size: var(--font-size-2xl);
    }
    
    .calculator__form {
        padding: var(--spacing-lg);
    }
    
    .results {
        padding: var(--spacing-lg);
    }
    
    .results__grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .form-group__row {
        flex-direction: column;
        align-items: stretch;
    }
    
    .form-group__suffix {
        text-align: center;
        padding: var(--spacing-sm);
        background: #f9fafb;
        border-radius: var(--border-radius-sm);
    }
    
    .comparison__content {
        gap: var(--spacing-xs);
    }
    
    .faq {
        padding: var(--spacing-lg);
    }
}

@media (max-width: 480px) {
    .header__title {
        font-size: var(--font-size-xl);
    }
    
    .calculator__form {
        padding: var(--spacing-md);
    }
    
    .btn {
        padding: var(--spacing-md);
        font-size: var(--font-size-sm);
    }
    
    .result-card__value {
        font-size: var(--font-size-lg);
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus visible for better keyboard navigation */
.btn:focus-visible,
.form-group__input:focus-visible,
.form-group__select:focus-visible,
.faq__question:focus-visible {
    outline: 2px solid var(--color-secondary);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
        --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
        --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.4);
        --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.5);
    }
    
    .form-group__input,
    .form-group__select {
        border-width: 3px;
    }
}

/* Print styles */
@media print {
    body {
        background: white;
        color: black;
    }
    
    .header,
    .faq,
    .footer {
        display: none;
    }
    
    .calculator {
        box-shadow: none;
        border: 1px solid black;
    }
    
    .btn {
        display: none;
    }
    
    .results {
        background: white;
        border: none;
    }
}