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

:root {
    /* Color Palette */
    --color-primary: #1A1A2E;
    --color-secondary: #16213E;
    --color-tertiary: #0F3460;
    --color-accent: #E94560;
    --color-white: #FFFFFF;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 50%, var(--color-tertiary) 100%);
    --gradient-accent: linear-gradient(135deg, var(--color-accent) 0%, #ff6b7a 100%);
    --gradient-card: linear-gradient(145deg, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0.05) 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 */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 25px rgba(0,0,0,0.15);
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* Base Styles */
html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-white);
    background: var(--gradient-primary);
    min-height: 100vh;
    overflow-x: hidden;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Header */
.header {
    background: rgba(255,255,255,0.1);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255,255,255,0.1);
    padding: var(--spacing-lg) 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.header__title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-white);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.header__title i {
    color: var(--color-accent);
}

.header__nav {
    display: flex;
    gap: var(--spacing-sm);
}

/* Main Content */
.main {
    padding: var(--spacing-2xl) 0;
    min-height: calc(100vh - 200px);
}

/* Calculator Section */
.calculator {
    background: var(--gradient-card);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
    box-shadow: var(--shadow-xl);
}

.calculator__header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.calculator__header h2 {
    font-size: var(--font-size-3xl);
    margin-bottom: var(--spacing-sm);
    color: var(--color-white);
}

.calculator__header p {
    color: rgba(255,255,255,0.8);
    font-size: var(--font-size-lg);
}

/* Form Styles */
.calculator__form {
    max-width: 600px;
    margin: 0 auto;
}

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

.form-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 600;
    color: var(--color-white);
    margin-bottom: var(--spacing-sm);
    font-size: var(--font-size-lg);
}

.form-input,
.form-select {
    width: 100%;
    padding: var(--spacing-md);
    border: 2px solid rgba(255,255,255,0.2);
    border-radius: var(--radius-md);
    background: rgba(255,255,255,0.1);
    color: var(--color-white);
    font-size: var(--font-size-base);
    transition: var(--transition-base);
    backdrop-filter: blur(10px);
}

.form-input:focus,
.form-select:focus {
    outline: none;
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(233, 69, 96, 0.2);
}

.form-input::placeholder {
    color: rgba(255,255,255,0.6);
}

.form-help {
    color: rgba(255,255,255,0.7);
    font-size: var(--font-size-sm);
    margin-top: var(--spacing-xs);
    display: block;
}

/* Checkbox Styles */
.form-checkbox {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    cursor: pointer;
    font-size: var(--font-size-base);
    color: var(--color-white);
}

.form-checkbox input[type="checkbox"] {
    display: none;
}

.checkmark {
    width: 20px;
    height: 20px;
    border: 2px solid rgba(255,255,255,0.3);
    border-radius: var(--radius-sm);
    background: rgba(255,255,255,0.1);
    position: relative;
    transition: var(--transition-base);
}

.form-checkbox input[type="checkbox"]:checked + .checkmark {
    background: var(--color-accent);
    border-color: var(--color-accent);
}

.form-checkbox input[type="checkbox"]:checked + .checkmark::after {
    content: '✓';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-weight: bold;
    font-size: 12px;
}

/* Button Styles */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition-base);
    position: relative;
    overflow: hidden;
}

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

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

.btn--secondary {
    background: rgba(255,255,255,0.1);
    color: var(--color-white);
    border: 1px solid rgba(255,255,255,0.2);
}

.btn--secondary:hover {
    background: rgba(255,255,255,0.2);
    border-color: rgba(255,255,255,0.3);
}

.btn--large {
    padding: var(--spacing-lg) var(--spacing-2xl);
    font-size: var(--font-size-lg);
}

.btn--small {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-sm);
}

/* Form Actions */
.form-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    margin-top: var(--spacing-2xl);
}

/* Results Section */
.results {
    background: var(--gradient-card);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
    box-shadow: var(--shadow-xl);
}

.results__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-2xl);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.results__header h3 {
    font-size: var(--font-size-2xl);
    color: var(--color-white);
}

.results__actions {
    display: flex;
    gap: var(--spacing-sm);
}

.results__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-2xl);
}

/* Result Cards */
.result-card {
    background: rgba(255,255,255,0.05);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    transition: var(--transition-base);
}

.result-card:hover {
    background: rgba(255,255,255,0.1);
    transform: translateY(-2px);
}

.result-card--highlight {
    background: var(--gradient-accent);
    border-color: var(--color-accent);
}

.result-card__icon {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: rgba(255,255,255,0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-xl);
    color: var(--color-white);
}

.result-card--highlight .result-card__icon {
    background: rgba(255,255,255,0.2);
}

.result-card__content h4 {
    font-size: var(--font-size-sm);
    color: rgba(255,255,255,0.8);
    margin-bottom: var(--spacing-xs);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.result-value {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--color-white);
}

.result-value--large {
    font-size: var(--font-size-2xl);
}

/* Breakdown */
.breakdown {
    background: rgba(255,255,255,0.05);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.breakdown h4 {
    margin-bottom: var(--spacing-md);
    color: var(--color-white);
    font-size: var(--font-size-lg);
}

.breakdown__content {
    color: rgba(255,255,255,0.9);
    line-height: 1.8;
}

/* Alerts */
.alerts {
    margin-top: var(--spacing-lg);
}

.alert {
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-sm);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.alert--warning {
    background: rgba(255, 193, 7, 0.2);
    border: 1px solid rgba(255, 193, 7, 0.4);
    color: #ffc107;
}

.alert--info {
    background: rgba(13, 202, 240, 0.2);
    border: 1px solid rgba(13, 202, 240, 0.4);
    color: #0dcaf0;
}

/* FAQ Section */
.faq {
    background: var(--gradient-card);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
    box-shadow: var(--shadow-xl);
}

.faq h3 {
    font-size: var(--font-size-2xl);
    margin-bottom: var(--spacing-xl);
    text-align: center;
    color: var(--color-white);
}

.faq__item {
    border-bottom: 1px solid rgba(255,255,255,0.1);
    margin-bottom: var(--spacing-md);
}

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

.faq__question:hover {
    background: rgba(255,255,255,0.05);
}

.faq__question i {
    transition: var(--transition-base);
}

.faq__item.active .faq__question i {
    transform: rotate(180deg);
}

.faq__answer {
    max-height: 0;
    overflow: hidden;
    transition: var(--transition-base);
}

.faq__item.active .faq__answer {
    max-height: 200px;
}

.faq__answer p {
    padding: 0 var(--spacing-lg) var(--spacing-lg);
    color: rgba(255,255,255,0.8);
    line-height: 1.8;
}

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-base);
}

.modal.active {
    opacity: 1;
    visibility: visible;
}

.modal__backdrop {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.8);
    backdrop-filter: blur(5px);
}

.modal__content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0.9);
    background: var(--gradient-primary);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: var(--radius-xl);
    max-width: 600px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: var(--shadow-xl);
    transition: var(--transition-base);
}

.modal.active .modal__content {
    transform: translate(-50%, -50%) scale(1);
}

.modal__header {
    padding: var(--spacing-xl);
    border-bottom: 1px solid rgba(255,255,255,0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal__header h3 {
    color: var(--color-white);
    font-size: var(--font-size-xl);
}

.modal__close {
    background: none;
    border: none;
    color: rgba(255,255,255,0.7);
    font-size: var(--font-size-xl);
    cursor: pointer;
    padding: var(--spacing-sm);
    transition: var(--transition-base);
}

.modal__close:hover {
    color: var(--color-white);
}

.modal__body {
    padding: var(--spacing-xl);
    color: rgba(255,255,255,0.9);
    line-height: 1.8;
}

/* Offcanvas Styles */
.offcanvas {
    position: fixed;
    top: 0;
    right: -400px;
    width: 400px;
    height: 100%;
    z-index: 1000;
    transition: var(--transition-base);
}

.offcanvas.active {
    right: 0;
}

.offcanvas__backdrop {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-base);
}

.offcanvas.active .offcanvas__backdrop {
    opacity: 1;
    visibility: visible;
}

.offcanvas__content {
    height: 100%;
    background: var(--gradient-primary);
    border-left: 1px solid rgba(255,255,255,0.2);
    box-shadow: var(--shadow-xl);
    display: flex;
    flex-direction: column;
}

.offcanvas__header {
    padding: var(--spacing-xl);
    border-bottom: 1px solid rgba(255,255,255,0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.offcanvas__header h3 {
    color: var(--color-white);
    font-size: var(--font-size-xl);
}

.offcanvas__close {
    background: none;
    border: none;
    color: rgba(255,255,255,0.7);
    font-size: var(--font-size-xl);
    cursor: pointer;
    padding: var(--spacing-sm);
    transition: var(--transition-base);
}

.offcanvas__close:hover {
    color: var(--color-white);
}

.offcanvas__body {
    flex: 1;
    padding: var(--spacing-xl);
    overflow-y: auto;
    color: rgba(255,255,255,0.9);
}

/* Tooltip Styles */
.tooltip {
    position: relative;
    cursor: help;
    color: var(--color-accent);
}

.tooltip-popup {
    position: absolute;
    background: var(--color-primary);
    color: var(--color-white);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    box-shadow: var(--shadow-lg);
    z-index: 1001;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-fast);
    max-width: 250px;
    word-wrap: break-word;
}

.tooltip-popup.active {
    opacity: 1;
    visibility: visible;
}

/* Footer */
.footer {
    background: rgba(0,0,0,0.3);
    border-top: 1px solid rgba(255,255,255,0.1);
    padding: var(--spacing-lg) 0;
    text-align: center;
    color: rgba(255,255,255,0.7);
}

.footer a {
    color: var(--color-accent);
    text-decoration: none;
    transition: var(--transition-base);
}

.footer a:hover {
    color: var(--color-white);
}

/* Utility Classes */
.hidden {
    display: none !important;
}

.text-center {
    text-align: center;
}

.text-right {
    text-align: right;
}

.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }
.mt-5 { margin-top: var(--spacing-xl); }

.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }
.mb-5 { margin-bottom: var(--spacing-xl); }

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .header .container {
        flex-direction: column;
        text-align: center;
    }
    
    .header__title {
        font-size: var(--font-size-xl);
    }
    
    .calculator,
    .results,
    .faq {
        padding: var(--spacing-lg);
    }
    
    .results__header {
        flex-direction: column;
        align-items: stretch;
        text-align: center;
    }
    
    .results__actions {
        justify-content: center;
    }
    
    .results__grid {
        grid-template-columns: 1fr;
    }
    
    .form-actions {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
    
    .modal__content {
        width: 95%;
        margin: var(--spacing-md);
    }
    
    .offcanvas {
        width: 100%;
        right: -100%;
    }
    
    .offcanvas__content {
        border-left: none;
    }
}

@media (max-width: 480px) {
    .header__title {
        font-size: var(--font-size-lg);
    }
    
    .calculator__header h2 {
        font-size: var(--font-size-2xl);
    }
    
    .result-card {
        flex-direction: column;
        text-align: center;
    }
    
    .result-card__icon {
        margin-bottom: var(--spacing-sm);
    }
    
    .faq__question {
        font-size: var(--font-size-base);
        padding: var(--spacing-md);
    }
}

/* Print Styles */
@media print {
    .header__nav,
    .form-actions,
    .results__actions,
    .btn {
        display: none !important;
    }
    
    body {
        background: white !important;
        color: black !important;
    }
    
    .calculator,
    .results,
    .faq {
        background: white !important;
        border: 1px solid #ccc !important;
        box-shadow: none !important;
    }
    
    .result-card {
        background: #f8f9fa !important;
        border: 1px solid #dee2e6 !important;
    }
}

/* Animation Classes */
.fade-in {
    animation: fadeIn 0.5s ease-in-out;
}

.slide-up {
    animation: slideUp 0.5s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Focus Styles for Accessibility */
.btn:focus,
.form-input:focus,
.form-select:focus,
.form-checkbox:focus {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

/* High Contrast Mode Support */
@media (prefers-contrast: high) {
    :root {
        --color-primary: #000000;
        --color-secondary: #1a1a1a;
        --color-tertiary: #333333;
        --color-white: #ffffff;
    }
    
    .form-input,
    .form-select {
        border-width: 3px;
    }
}

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