/* =====================================================
   ELECTRICAL POWER CALCULATOR - MAIN STYLESHEET
   Light Theme with Modern, Clean Design
   ===================================================== */

/* CSS Variables for Easy Theming */
:root {
    /* Primary Colors - Electric Blue Theme */
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --primary-lighter: #60a5fa;
    --primary-bg: #eff6ff;
    
    /* Secondary Colors */
    --secondary-color: #0891b2;
    --secondary-dark: #0e7490;
    --secondary-light: #06b6d4;
    
    /* Accent Colors */
    --accent-yellow: #fbbf24;
    --accent-orange: #f97316;
    --accent-green: #10b981;
    --accent-red: #ef4444;
    
    /* Neutral Colors */
    --white: #ffffff;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    
    /* Typography */
    --font-display: 'Outfit', sans-serif;
    --font-body: 'DM Sans', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-glow: 0 0 30px rgba(37, 99, 235, 0.15);
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;
}

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

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

body {
    font-family: var(--font-body);
    background: linear-gradient(180deg, var(--gray-50) 0%, var(--white) 50%, var(--primary-bg) 100%);
    color: var(--gray-800);
    line-height: 1.7;
    min-height: 100vh;
    overflow-x: hidden;
}

/* Background Pattern */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 20% 20%, rgba(37, 99, 235, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(8, 145, 178, 0.03) 0%, transparent 50%),
        url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%232563eb' fill-opacity='0.02'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    z-index: -1;
    pointer-events: none;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 700;
    line-height: 1.3;
    color: var(--gray-900);
}

h1 { font-size: clamp(2rem, 5vw, 3rem); }
h2 { font-size: clamp(1.5rem, 4vw, 2.25rem); }
h3 { font-size: clamp(1.25rem, 3vw, 1.5rem); }
h4 { font-size: 1.125rem; }

p {
    margin-bottom: 1rem;
    color: var(--gray-600);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--primary-dark);
}

/* Container */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* =====================================================
   HEADER & NAVIGATION
   ===================================================== */
.header {
    background: var(--white);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--gray-100);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.5rem;
    max-width: 1280px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-icon {
    width: 44px;
    height: 44px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 1.25rem;
    box-shadow: var(--shadow-md);
}

.logo-text {
    font-family: var(--font-display);
    font-weight: 800;
    font-size: 1.25rem;
    color: var(--gray-900);
}

.logo-text span {
    color: var(--primary-color);
}

/* Main Navigation */
.main-nav {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-link {
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    color: var(--gray-600);
    font-weight: 500;
    font-size: 0.9rem;
    transition: all var(--transition-fast);
}

.nav-link:hover {
    background: var(--gray-100);
    color: var(--gray-900);
}

.nav-link.active {
    background: var(--primary-bg);
    color: var(--primary-color);
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 0.5rem;
    background: none;
    border: none;
    cursor: pointer;
}

.mobile-menu-toggle span {
    width: 24px;
    height: 2px;
    background: var(--gray-700);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: flex;
    }
    
    .main-nav {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: 1rem;
        gap: 0.25rem;
        border-top: 1px solid var(--gray-100);
        box-shadow: var(--shadow-lg);
        display: none;
    }
    
    .main-nav.active {
        display: flex;
    }
    
    .nav-link {
        width: 100%;
        text-align: center;
        padding: 0.75rem 1rem;
    }
}

/* =====================================================
   HERO SECTION
   ===================================================== */
.hero {
    padding: 4rem 0 3rem;
    text-align: center;
}

.hero h1 {
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--gray-900) 0%, var(--primary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--gray-500);
    max-width: 600px;
    margin: 0 auto 2rem;
}

/* Search Box */
.search-box {
    max-width: 500px;
    margin: 0 auto;
    position: relative;
}

.search-box input {
    width: 100%;
    padding: 1rem 1.25rem 1rem 3rem;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-full);
    font-family: var(--font-body);
    font-size: 1rem;
    background: var(--white);
    transition: all var(--transition-fast);
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
}

.search-box svg {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--gray-400);
    width: 20px;
    height: 20px;
}

/* =====================================================
   CALCULATOR GRID
   ===================================================== */
.calculators-section {
    padding: 2rem 0 4rem;
}

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.section-title {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.section-icon {
    width: 40px;
    height: 40px;
    background: var(--primary-bg);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
}

/* Category Filter */
.category-filter {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.5rem 1rem;
    border: 1px solid var(--gray-200);
    background: var(--white);
    border-radius: var(--radius-full);
    font-family: var(--font-body);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-600);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.filter-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.filter-btn.active {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: var(--white);
}

/* Calculator Cards Grid */
.calc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.25rem;
}

.calc-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    border: 1px solid var(--gray-100);
    transition: all var(--transition-normal);
    display: flex;
    flex-direction: column;
    cursor: pointer;
    text-decoration: none;
    position: relative;
    overflow: hidden;
}

.calc-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transform: scaleX(0);
    transition: transform var(--transition-normal);
}

.calc-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.calc-card:hover::before {
    transform: scaleX(1);
}

.calc-card-icon {
    width: 48px;
    height: 48px;
    background: var(--primary-bg);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.calc-card h3 {
    font-size: 1rem;
    margin-bottom: 0.5rem;
    color: var(--gray-900);
}

.calc-card p {
    font-size: 0.875rem;
    color: var(--gray-500);
    margin-bottom: 0;
    flex-grow: 1;
}

.calc-card-arrow {
    position: absolute;
    right: 1rem;
    top: 1.5rem;
    color: var(--gray-300);
    transition: all var(--transition-fast);
}

.calc-card:hover .calc-card-arrow {
    color: var(--primary-color);
    transform: translateX(4px);
}

/* =====================================================
   CALCULATOR PAGE STYLES
   ===================================================== */
.calculator-page {
    padding: 2rem 0 4rem;
}

.breadcrumb {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    font-size: 0.875rem;
    color: var(--gray-500);
}

.breadcrumb a {
    color: var(--gray-500);
}

.breadcrumb a:hover {
    color: var(--primary-color);
}

.breadcrumb svg {
    width: 16px;
    height: 16px;
}

/* Calculator Container */
.calculator-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    align-items: start;
}

@media (max-width: 900px) {
    .calculator-container {
        grid-template-columns: 1fr;
    }
}

/* Calculator Card (Main) */
.calculator-main {
    background: var(--white);
    border-radius: var(--radius-xl);
    padding: 2rem;
    border: 1px solid var(--gray-100);
    box-shadow: var(--shadow-lg);
}

.calculator-title {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.calculator-title-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 1.5rem;
    box-shadow: var(--shadow-md);
}

/* Form Styles */
.calc-form {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--gray-700);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.form-group label svg {
    width: 16px;
    height: 16px;
    color: var(--gray-400);
}

.input-wrapper {
    position: relative;
    display: flex;
}

.input-wrapper input,
.input-wrapper select {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    font-family: var(--font-body);
    font-size: 1rem;
    background: var(--white);
    transition: all var(--transition-fast);
}

.input-wrapper input:focus,
.input-wrapper select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
}

.input-wrapper .unit {
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--gray-400);
    font-weight: 500;
    font-size: 0.875rem;
    pointer-events: none;
}

.input-with-select {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 0.5rem;
}

.input-with-select input {
    border-radius: var(--radius-md) 0 0 var(--radius-md);
}

.input-with-select select {
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    border-left: none;
    min-width: 80px;
    cursor: pointer;
}

/* Current Type Selector */
.current-type-selector {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.5rem;
    padding: 0.25rem;
    background: var(--gray-100);
    border-radius: var(--radius-md);
}

.current-type-btn {
    padding: 0.75rem 1rem;
    border: none;
    background: transparent;
    border-radius: var(--radius-sm);
    font-family: var(--font-body);
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--gray-600);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.current-type-btn:hover {
    color: var(--gray-900);
}

.current-type-btn.active {
    background: var(--white);
    color: var(--primary-color);
    box-shadow: var(--shadow-sm);
}

@media (max-width: 480px) {
    .current-type-selector {
        grid-template-columns: 1fr;
    }
}

/* Calculate Button */
.btn-calculate {
    width: 100%;
    padding: 1rem 2rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    border: none;
    border-radius: var(--radius-md);
    color: var(--white);
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

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

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

/* Reset Button */
.btn-reset {
    padding: 0.75rem 1.5rem;
    background: var(--gray-100);
    border: none;
    border-radius: var(--radius-md);
    color: var(--gray-600);
    font-family: var(--font-body);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-reset:hover {
    background: var(--gray-200);
    color: var(--gray-700);
}

/* Result Section */
.result-section {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 2px solid var(--gray-100);
}

.result-box {
    background: linear-gradient(135deg, var(--primary-bg) 0%, #e0f2fe 100%);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    text-align: center;
    border: 1px solid rgba(37, 99, 235, 0.1);
}

.result-label {
    font-size: 0.875rem;
    color: var(--gray-600);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.result-value {
    font-family: var(--font-display);
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary-color);
    line-height: 1.2;
}

.result-unit {
    font-size: 1.25rem;
    color: var(--primary-dark);
    font-weight: 600;
}

.result-formula {
    margin-top: 1rem;
    padding: 1rem;
    background: var(--white);
    border-radius: var(--radius-md);
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--gray-600);
}

/* Info Panel (Right Side) */
.info-panel {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.info-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    border: 1px solid var(--gray-100);
}

.info-card h3 {
    font-size: 1rem;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.info-card h3 svg {
    color: var(--primary-color);
}

/* Formula Display */
.formula-display {
    background: var(--gray-50);
    border-radius: var(--radius-md);
    padding: 1.25rem;
    margin-bottom: 1rem;
}

.formula-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--gray-200);
}

.formula-item:last-child {
    border-bottom: none;
}

.formula-type {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--white);
    background: var(--primary-color);
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
    min-width: 80px;
    text-align: center;
}

.formula-text {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--gray-700);
}

/* Quick Reference Table */
.quick-ref-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
}

.quick-ref-table th,
.quick-ref-table td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--gray-100);
}

.quick-ref-table th {
    font-weight: 600;
    color: var(--gray-700);
    background: var(--gray-50);
}

.quick-ref-table tr:hover td {
    background: var(--primary-bg);
}

/* =====================================================
   FAQ SECTION
   ===================================================== */
.faq-section {
    padding: 3rem 0;
    background: var(--white);
    margin-top: 2rem;
    border-top: 1px solid var(--gray-100);
}

.faq-header {
    text-align: center;
    margin-bottom: 2rem;
}

.faq-header h2 {
    margin-bottom: 0.5rem;
}

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

.faq-item {
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-md);
    margin-bottom: 0.75rem;
    overflow: hidden;
    transition: all var(--transition-fast);
}

.faq-item:hover {
    border-color: var(--primary-light);
}

.faq-question {
    width: 100%;
    padding: 1.25rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    background: var(--white);
    border: none;
    cursor: pointer;
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 600;
    color: var(--gray-800);
    text-align: left;
    transition: all var(--transition-fast);
}

.faq-question:hover {
    background: var(--gray-50);
}

.faq-question svg {
    flex-shrink: 0;
    width: 20px;
    height: 20px;
    color: var(--primary-color);
    transition: transform var(--transition-fast);
}

.faq-item.active .faq-question svg {
    transform: rotate(180deg);
}

.faq-answer {
    padding: 0 1.25rem;
    max-height: 0;
    overflow: hidden;
    transition: all var(--transition-normal);
}

.faq-item.active .faq-answer {
    padding: 0 1.25rem 1.25rem;
    max-height: 500px;
}

.faq-answer p {
    color: var(--gray-600);
    line-height: 1.7;
}

/* =====================================================
   CONTENT SECTION
   ===================================================== */
.content-section {
    padding: 3rem 0;
}

.content-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 2rem;
}

@media (max-width: 900px) {
    .content-grid {
        grid-template-columns: 1fr;
    }
}

.content-main h2 {
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--primary-bg);
}

.content-main h3 {
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--primary-dark);
}

.content-main p {
    margin-bottom: 1rem;
    text-align: justify;
}

.content-main ul,
.content-main ol {
    margin-bottom: 1rem;
    padding-left: 1.5rem;
}

.content-main li {
    margin-bottom: 0.5rem;
    color: var(--gray-600);
}

/* Sidebar */
.content-sidebar {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.sidebar-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    border: 1px solid var(--gray-100);
}

.sidebar-card h4 {
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary-bg);
}

.related-calcs {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.related-calc-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem;
    background: var(--gray-50);
    border-radius: var(--radius-md);
    color: var(--gray-700);
    font-size: 0.875rem;
    transition: all var(--transition-fast);
}

.related-calc-link:hover {
    background: var(--primary-bg);
    color: var(--primary-color);
}

.related-calc-link svg {
    width: 16px;
    height: 16px;
    color: var(--primary-color);
}

/* =====================================================
   FOOTER
   ===================================================== */
.footer {
    background: var(--gray-900);
    color: var(--gray-400);
    padding: 3rem 0 1.5rem;
    margin-top: 3rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

@media (max-width: 768px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 480px) {
    .footer-grid {
        grid-template-columns: 1fr;
    }
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--white);
}

.footer-logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.footer-logo-text {
    font-family: var(--font-display);
    font-weight: 800;
    font-size: 1.125rem;
}

.footer-brand p {
    font-size: 0.875rem;
    color: var(--gray-500);
    margin: 0;
}

.footer-col h5 {
    color: var(--white);
    font-size: 0.875rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.footer-links a {
    color: var(--gray-400);
    font-size: 0.875rem;
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    padding-top: 1.5rem;
    border-top: 1px solid var(--gray-800);
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
    font-size: 0.875rem;
}

.footer-bottom p {
    margin: 0;
    color: var(--gray-500);
}

/* =====================================================
   UTILITY CLASSES
   ===================================================== */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.hidden { display: none !important; }

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* =====================================================
   ANIMATIONS
   ===================================================== */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.animate-fade-in {
    animation: fadeIn var(--transition-normal) ease forwards;
}

.animate-slide-up {
    animation: slideUp var(--transition-slow) ease forwards;
}

/* Staggered animations for cards */
.calc-card {
    opacity: 0;
    animation: slideUp 0.5s ease forwards;
}

.calc-card:nth-child(1) { animation-delay: 0.05s; }
.calc-card:nth-child(2) { animation-delay: 0.1s; }
.calc-card:nth-child(3) { animation-delay: 0.15s; }
.calc-card:nth-child(4) { animation-delay: 0.2s; }
.calc-card:nth-child(5) { animation-delay: 0.25s; }
.calc-card:nth-child(6) { animation-delay: 0.3s; }
.calc-card:nth-child(7) { animation-delay: 0.35s; }
.calc-card:nth-child(8) { animation-delay: 0.4s; }
.calc-card:nth-child(9) { animation-delay: 0.45s; }
.calc-card:nth-child(10) { animation-delay: 0.5s; }
.calc-card:nth-child(11) { animation-delay: 0.55s; }
.calc-card:nth-child(12) { animation-delay: 0.6s; }

/* =====================================================
   PRINT STYLES
   ===================================================== */
@media print {
    .header,
    .footer,
    .btn-calculate,
    .btn-reset,
    .category-filter,
    .search-box {
        display: none !important;
    }
    
    body {
        background: white;
    }
    
    .calculator-main {
        box-shadow: none;
        border: 1px solid #ddd;
    }
}