/* ===================================
   Color Code Converter - Premium Styles
   =================================== */

/* CSS Variables - Design System */
:root {
    /* Primary Colors */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --primary-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);

    /* Secondary Colors */
    --secondary: #f59e0b;
    --secondary-dark: #d97706;
    --accent: #ec4899;

    /* Neutral Colors */
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-card: #1e293b;
    --bg-card-hover: #2d3a4f;

    /* Text Colors */
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    /* Border Colors */
    --border: #334155;
    --border-light: #475569;

    /* Status Colors */
    --success: #22c55e;
    --error: #ef4444;
    --warning: #f59e0b;
    --info: #3b82f6;

    /* 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 40px rgba(99, 102, 241, 0.15);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 300ms ease;
    --transition-slow: 500ms ease;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;

    /* Font Family */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

    /* Container Width */
    --container-max: 1200px;
    --container-padding: 1.5rem;
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-primary);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    min-height: 100vh;
}

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

ul,
ol {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

button {
    cursor: pointer;
    font-family: inherit;
    border: none;
    background: none;
}

input,
select,
textarea {
    font-family: inherit;
    font-size: inherit;
}

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

/* ===================================
   Header & Navigation
   =================================== */
.header {
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
    gap: 2rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    transition: var(--transition-fast);
}

.logo i {
    color: var(--primary);
    font-size: 1.5rem;
}

.logo:hover {
    color: var(--primary-light);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-menu a {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.nav-menu a.active {
    background: var(--primary);
    color: white;
}

.mobile-menu-toggle {
    display: none;
    padding: 0.5rem;
    color: var(--text-primary);
    font-size: 1.25rem;
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    padding: 4rem 0 3rem;
    background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    border-bottom: 1px solid var(--border);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.15) 0%, transparent 70%);
    pointer-events: none;
}

.hero-content {
    text-align: center;
    position: relative;
    z-index: 1;
}

.hero h1 {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 800;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.hero h1 i {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto 2rem;
    line-height: 1.7;
}

.hero-features {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.feature-badge {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.feature-badge i {
    color: var(--primary);
}

/* ===================================
   Calculator Section
   =================================== */
.calculator-section {
    padding: 3rem 0;
}

.calculator-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 2rem;
    box-shadow: var(--shadow-xl), var(--shadow-glow);
    position: relative;
}

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

.calculator-header h2 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
}

.calculator-header h2 i {
    color: var(--primary);
}

.calculator-header p {
    color: var(--text-secondary);
}

/* Input Methods Selector */
.input-methods {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.method-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.25rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition-fast);
}

.method-btn:hover {
    background: var(--bg-card-hover);
    color: var(--text-primary);
    border-color: var(--border-light);
}

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

.method-btn i {
    font-size: 1rem;
}

/* Input Sections */
.input-section {
    margin-bottom: 1.5rem;
}

.input-section.hidden {
    display: none;
}

/* Color Picker */
.color-picker-wrapper {
    text-align: center;
}

.color-picker-wrapper label {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.picker-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
}

#colorPicker {
    width: 150px;
    height: 150px;
    border: none;
    border-radius: var(--radius-xl);
    cursor: pointer;
    background: none;
    padding: 0;
    appearance: none;
    -webkit-appearance: none;
}

#colorPicker::-webkit-color-swatch-wrapper {
    padding: 0;
    border-radius: var(--radius-xl);
}

#colorPicker::-webkit-color-swatch {
    border: 4px solid var(--border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
}

#colorPicker::-moz-color-swatch {
    border: 4px solid var(--border);
    border-radius: var(--radius-xl);
}

#colorPicker:hover::-webkit-color-swatch {
    border-color: var(--primary);
}

.picker-hint {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Input Groups */
.input-group {
    margin-bottom: 1rem;
}

.input-group label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
}

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

.input-prefix {
    position: absolute;
    left: 1rem;
    color: var(--text-muted);
    font-weight: 600;
    font-size: 1.125rem;
}

.input-group input,
.input-group select {
    width: 100%;
    padding: 0.875rem 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    transition: var(--transition-fast);
}

.input-group input:focus,
.input-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

#hexInput {
    padding-left: 2.25rem;
    text-transform: uppercase;
    font-family: 'Courier New', monospace;
    font-weight: 600;
    letter-spacing: 0.1em;
}

/* RGB/HSL/CMYK Input Grids */
.rgb-inputs,
.hsl-inputs {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

.cmyk-inputs {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
}

@media (max-width: 640px) {

    .rgb-inputs,
    .hsl-inputs {
        grid-template-columns: 1fr;
    }

    .cmyk-inputs {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Color Preview */
.color-preview-section {
    margin: 2rem 0;
}

.preview-box {
    width: 100%;
    height: 120px;
    background: #6366f1;
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    box-shadow: var(--shadow-lg);
    transition: background var(--transition-fast);
}

.preview-label {
    background: rgba(0, 0, 0, 0.5);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 500;
}

/* Conversion Results */
.conversion-results {
    background: var(--bg-tertiary);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.conversion-results h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
}

.conversion-results h3 i {
    color: var(--primary);
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

.result-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.875rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
}

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

.result-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    white-space: nowrap;
}

.result-label i {
    color: var(--primary);
}

.result-value {
    flex: 1;
    font-family: 'Courier New', monospace;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.copy-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    transition: var(--transition-fast);
}

.copy-btn:hover {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

/* Calculator Actions */
.calculator-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn-primary,
.btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-lg);
    transition: var(--transition-fast);
}

.btn-primary {
    background: var(--primary-gradient);
    color: white;
    border: none;
    box-shadow: 0 4px 14px rgba(99, 102, 241, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.5);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: var(--bg-card-hover);
    color: var(--text-primary);
    border-color: var(--border-light);
}

/* Copy Notification */
.copy-notification {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 1.5rem;
    background: var(--success);
    color: white;
    border-radius: var(--radius-lg);
    font-weight: 600;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    z-index: 1000;
}

.copy-notification.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
    visibility: visible;
}

/* ===================================
   Related Converters Section
   =================================== */
.related-converters {
    padding: 4rem 0;
    background: var(--bg-secondary);
}

.section-title {
    font-size: 1.75rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
}

.section-title i {
    color: var(--primary);
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
}

.converters-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.converter-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 1.5rem;
    transition: all var(--transition-normal);
}

.converter-card:hover {
    transform: translateY(-4px);
    border-color: var(--primary);
    box-shadow: var(--shadow-xl), var(--shadow-glow);
}

.converter-icon {
    width: 60px;
    height: 60px;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.converter-icon.hex {
    background: linear-gradient(135deg, #f59e0b 0%, #f97316 100%);
    color: white;
}

.converter-icon.rgb {
    background: linear-gradient(135deg, #22c55e 0%, #16a34a 100%);
    color: white;
}

.converter-icon.hsl {
    background: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    color: white;
}

.converter-icon.cmyk {
    background: linear-gradient(135deg, #ec4899 0%, #f43f5e 100%);
    color: white;
}

.converter-icon.palette {
    background: linear-gradient(135deg, #06b6d4 0%, #0891b2 100%);
    color: white;
}

.converter-icon.contrast {
    background: linear-gradient(135deg, #1f2937 0%, #374151 100%);
    color: white;
}

.converter-card h3 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.converter-card p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 1rem;
    line-height: 1.6;
}

.card-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary);
    font-size: 0.875rem;
    font-weight: 600;
}

.card-link i {
    transition: transform var(--transition-fast);
}

.converter-card:hover .card-link i {
    transform: translateX(4px);
}

/* ===================================
   Features Section
   =================================== */
.features-section {
    padding: 4rem 0;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.feature-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 2rem;
    text-align: center;
    transition: all var(--transition-normal);
}

.feature-item:hover {
    border-color: var(--primary);
    transform: translateY(-2px);
}

.feature-item .feature-icon {
    width: 70px;
    height: 70px;
    background: var(--primary-gradient);
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.25rem;
    font-size: 1.5rem;
    color: white;
}

.feature-item h3 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.feature-item p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.6;
}

/* ===================================
   How To Section
   =================================== */
.how-to-section {
    padding: 4rem 0;
    background: var(--bg-secondary);
}

.steps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.step-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 2rem;
    text-align: center;
    position: relative;
}

.step-number {
    width: 50px;
    height: 50px;
    background: var(--primary-gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    font-weight: 700;
    color: white;
    margin: 0 auto 1rem;
}

.step-item h3 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.step-item p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.6;
}

/* ===================================
   Info Section
   =================================== */
.info-section {
    padding: 4rem 0;
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.info-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 1.5rem;
}

.info-card h3 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

.info-card p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.7;
    margin-bottom: 0.75rem;
}

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

.info-card a:hover {
    text-decoration: underline;
}

.info-card code {
    background: var(--bg-tertiary);
    padding: 0.125rem 0.375rem;
    border-radius: var(--radius-sm);
    font-size: 0.85em;
    color: var(--secondary);
}

/* ===================================
   Articles Section
   =================================== */
.articles-section {
    padding: 4rem 0;
    background: var(--bg-secondary);
}

.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.article-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 1.5rem;
    transition: all var(--transition-normal);
}

.article-card:hover {
    border-color: var(--primary);
    transform: translateY(-2px);
}

.article-icon {
    width: 50px;
    height: 50px;
    background: var(--primary-gradient);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    color: white;
    margin-bottom: 1rem;
}

.article-card h3 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.article-card h3 a {
    color: var(--text-primary);
    transition: color var(--transition-fast);
}

.article-card h3 a:hover {
    color: var(--primary);
}

.article-card p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.6;
    margin-bottom: 1rem;
}

.read-more {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary);
    font-size: 0.875rem;
    font-weight: 600;
}

.read-more i {
    transition: transform var(--transition-fast);
}

.article-card:hover .read-more i {
    transform: translateX(4px);
}

/* ===================================
   FAQ Section
   =================================== */
.faq-section {
    padding: 4rem 0;
}

.faq-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 1.5rem;
}

.faq-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 1.5rem;
}

.faq-item h3 {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.faq-item h3 i {
    color: var(--primary);
    margin-top: 0.25rem;
    font-size: 0.75rem;
}

.faq-item p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.7;
    padding-left: 1.25rem;
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--bg-secondary);
    padding: 4rem 0 2rem;
    border-top: 1px solid var(--border);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr repeat(3, 1fr);
    gap: 2rem;
    margin-bottom: 3rem;
}

.footer-col h4 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.footer-col p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.7;
    margin-bottom: 1rem;
}

.footer-col ul li {
    margin-bottom: 0.5rem;
}

.footer-col ul a {
    color: var(--text-secondary);
    font-size: 0.875rem;
    transition: color var(--transition-fast);
}

.footer-col ul a:hover {
    color: var(--primary);
}

.social-links {
    display: flex;
    gap: 0.75rem;
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 1rem;
    transition: all var(--transition-fast);
}

.social-links a:hover {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
}

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

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 992px) {
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    :root {
        --container-padding: 1rem;
    }

    .mobile-menu-toggle {
        display: block;
    }

    .nav-menu {
        position: fixed;
        top: 65px;
        left: 0;
        right: 0;
        background: var(--bg-secondary);
        flex-direction: column;
        padding: 1rem;
        border-bottom: 1px solid var(--border);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-normal);
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-menu a {
        justify-content: center;
        padding: 0.875rem;
    }

    .hero {
        padding: 3rem 0 2rem;
    }

    .hero h1 {
        flex-direction: column;
        gap: 0.5rem;
    }

    .calculator-card {
        padding: 1.5rem;
    }

    .method-btn span {
        display: none;
    }

    .method-btn {
        padding: 0.75rem;
    }

    .results-grid {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .social-links {
        justify-content: center;
    }

    .faq-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-features {
        flex-direction: column;
        align-items: center;
    }

    .feature-badge {
        width: 100%;
        justify-content: center;
    }

    .calculator-actions {
        flex-direction: column;
    }

    .btn-primary,
    .btn-secondary {
        width: 100%;
        justify-content: center;
    }

    #colorPicker {
        width: 120px;
        height: 120px;
    }
}

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

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

/* Focus Styles for Accessibility */
*:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* Selection Styles */
::selection {
    background: var(--primary);
    color: white;
}

/* Scrollbar Styles */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--border-light);
}