/* HomeWattly - Modern Stylesheet */

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

:root {
    /* Modern Color Palette - Deep Blue + Electric Green */
    --primary-blue: #1e3a8a;
    --primary-blue-dark: #0f172a;
    --secondary-blue: #3b82f6;
    --accent-green: #10b981;
    --accent-green-dark: #059669;
    --accent-green-light: #34d399;

    /* Neutral Colors */
    --text-dark: #1e293b;
    --text-medium: #475569;
    --text-light: #64748b;
    --bg-white: #ffffff;
    --bg-light: #f8fafc;
    --bg-lighter: #f1f5f9;
    --border-color: #e2e8f0;
    --border-light: #f1f5f9;

    /* Status Colors */
    --error-color: #ef4444;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --info-color: #3b82f6;

    /* Typography */
    --font-main: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Courier New', monospace;

    /* Spacing Scale */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;

    /* Shadows - Layered depth */
    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    --shadow-glow: 0 0 20px rgba(16, 185, 129, 0.3);

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

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: 600ms cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    color: var(--text-dark);
    line-height: 1.6;
    background-color: var(--bg-light);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===== Header & Navigation ===== */
header {
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: all var(--transition-base);
}

header.scrolled {
    box-shadow: var(--shadow-md);
    background-color: rgba(255, 255, 255, 0.98);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-sm) var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo .logo-text {
    font-size: 1.5rem;
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--accent-green) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
    letter-spacing: -0.02em;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-xs);
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-medium);
    font-weight: 500;
    font-size: 0.9375rem;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    position: relative;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%) scaleX(0);
    width: 80%;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-blue), var(--accent-green));
    border-radius: var(--radius-full);
    transition: transform var(--transition-base);
}

.nav-menu a:hover {
    color: var(--primary-blue);
}

.nav-menu a:hover::after {
    transform: translateX(-50%) scaleX(1);
}

.nav-menu a.active {
    color: var(--primary-blue);
    background-color: rgba(30, 58, 138, 0.08);
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    z-index: 1001;
}

.mobile-menu-toggle svg {
    width: 24px;
    height: 24px;
    stroke: var(--text-dark);
}

/* ===== Main Content ===== */
main {
    min-height: calc(100vh - 200px);
}

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

/* ===== Hero Section ===== */
.hero {
    background: linear-gradient(135deg, var(--primary-blue-dark) 0%, var(--primary-blue) 50%, var(--secondary-blue) 100%);
    color: white;
    padding: var(--spacing-3xl) var(--spacing-md);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image:
        radial-gradient(circle at 20% 50%, rgba(16, 185, 129, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(59, 130, 246, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.hero::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image:
        repeating-linear-gradient(90deg, rgba(255,255,255,0.03) 0px, transparent 1px, transparent 40px, rgba(255,255,255,0.03) 41px),
        repeating-linear-gradient(0deg, rgba(255,255,255,0.03) 0px, transparent 1px, transparent 40px, rgba(255,255,255,0.03) 41px);
    pointer-events: none;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    margin: 0 auto;
    opacity: 0;
    animation: fadeInUp 0.8s var(--transition-base) forwards;
}

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

.hero-content h1 {
    font-size: clamp(2rem, 5vw, 3rem);
    margin-bottom: var(--spacing-md);
    font-weight: 800;
    letter-spacing: -0.03em;
    line-height: 1.2;
}

.hero-content p {
    font-size: clamp(1rem, 2.5vw, 1.25rem);
    margin-bottom: var(--spacing-xl);
    line-height: 1.6;
    opacity: 0.95;
}

/* ===== Buttons ===== */
.cta-button {
    display: inline-block;
    background: linear-gradient(135deg, var(--accent-green) 0%, var(--accent-green-dark) 100%);
    color: white;
    padding: 1rem 2rem;
    border-radius: var(--radius-xl);
    text-decoration: none;
    font-weight: 600;
    font-size: 1.0625rem;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-lg), 0 0 0 rgba(16, 185, 129, 0);
    border: none;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.cta-button::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    transition: width 0.6s, height 0.6s;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl), var(--shadow-glow);
}

.cta-button:hover::before {
    width: 300px;
    height: 300px;
}

.cta-button:active {
    transform: translateY(0);
}

.secondary-button {
    display: inline-block;
    background-color: white;
    color: var(--primary-blue);
    padding: 0.875rem 1.75rem;
    border-radius: var(--radius-xl);
    text-decoration: none;
    font-weight: 600;
    transition: all var(--transition-base);
    border: 2px solid var(--border-color);
    cursor: pointer;
    margin-left: var(--spacing-sm);
}

.secondary-button:hover {
    background-color: var(--bg-lighter);
    border-color: var(--accent-green);
    color: var(--accent-green);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* ===== Section Utilities ===== */
.section-reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s var(--transition-base), transform 0.6s var(--transition-base);
}

.section-reveal.revealed {
    opacity: 1;
    transform: translateY(0);
}

/* ===== Features Section ===== */
.features {
    padding: var(--spacing-3xl) 0;
    background-color: var(--bg-white);
}

.features h2 {
    text-align: center;
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    margin-bottom: var(--spacing-xl);
    color: var(--text-dark);
    font-weight: 700;
    letter-spacing: -0.02em;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.feature-card {
    background-color: var(--bg-white);
    padding: var(--spacing-xl) var(--spacing-lg);
    border-radius: var(--radius-xl);
    text-align: center;
    transition: all var(--transition-base);
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-blue), var(--accent-green));
    transform: scaleX(0);
    transition: transform var(--transition-base);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--accent-green);
}

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

.feature-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, rgba(30, 58, 138, 0.1), rgba(16, 185, 129, 0.1));
    border-radius: var(--radius-xl);
    font-size: 2rem;
    transition: transform var(--transition-bounce);
}

.feature-card:hover .feature-icon {
    transform: scale(1.1) rotate(5deg);
}

.feature-card h3 {
    margin-bottom: var(--spacing-sm);
    color: var(--text-dark);
    font-weight: 600;
    font-size: 1.25rem;
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.7;
}

/* ===== How It Works Section ===== */
.how-it-works {
    padding: var(--spacing-3xl) 0;
    background: linear-gradient(180deg, var(--bg-light) 0%, var(--bg-white) 100%);
}

.how-it-works h2 {
    text-align: center;
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    margin-bottom: var(--spacing-xl);
    font-weight: 700;
    color: var(--text-dark);
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.step {
    background-color: var(--bg-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
    position: relative;
}

.step:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary-blue), var(--accent-green));
    color: white;
    border-radius: var(--radius-full);
    font-weight: 700;
    font-size: 1.25rem;
    margin-bottom: var(--spacing-md);
    box-shadow: var(--shadow-md);
}

.step h3 {
    margin-bottom: var(--spacing-sm);
    color: var(--text-dark);
    font-weight: 600;
    font-size: 1.125rem;
}

.step p {
    color: var(--text-light);
    line-height: 1.7;
}

/* ===== CTA Section ===== */
.cta-section {
    padding: var(--spacing-3xl) 0;
    background-color: var(--bg-white);
    text-align: center;
}

.cta-section h2 {
    font-size: clamp(1.5rem, 3.5vw, 2.25rem);
    margin-bottom: var(--spacing-md);
    font-weight: 700;
    color: var(--text-dark);
}

.cta-section p {
    font-size: 1.125rem;
    color: var(--text-light);
    margin-bottom: var(--spacing-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* ===== Calculator Page ===== */
.calculator-section {
    padding: var(--spacing-xl) 0;
    background: var(--bg-light);
}

.calculator-section h1 {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    margin-bottom: var(--spacing-sm);
    color: var(--text-dark);
    font-weight: 700;
}

.intro-text {
    font-size: 1.125rem;
    color: var(--text-light);
    margin-bottom: var(--spacing-xl);
}

.calculator-container {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

@media (min-width: 1024px) {
    .calculator-container {
        grid-template-columns: 1fr 1fr;
    }
}

.calculator-card,
.results-card {
    background-color: var(--bg-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
}

.calculator-card h3,
.results-card h3 {
    margin-bottom: var(--spacing-lg);
    color: var(--text-dark);
    font-size: 1.5rem;
    font-weight: 700;
}

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

.form-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    color: var(--text-dark);
    font-size: 0.9375rem;
}

.form-group input {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    font-size: 1rem;
    transition: all var(--transition-base);
    font-family: var(--font-main);
    background-color: var(--bg-white);
}

.form-group input:hover {
    border-color: var(--text-light);
}

.form-group input:focus {
    outline: none;
    border-color: var(--accent-green);
    box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}

.form-group input.input-error {
    border-color: var(--error-color);
    box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.1);
}

/* Inline form error summary */
.form-errors {
    display: none;
    background: linear-gradient(135deg, #fef2f2, #fee2e2);
    border: 1px solid #fecaca;
    border-left: 4px solid var(--error-color);
    color: #991b1b;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-lg);
    font-size: 0.9375rem;
    line-height: 1.5;
}

.form-errors strong {
    display: block;
    margin-bottom: var(--spacing-xs);
}

.form-errors ul {
    margin-left: var(--spacing-lg);
    list-style: disc;
}

.form-errors li {
    margin-bottom: var(--spacing-xs);
}

.form-group small {
    display: block;
    margin-top: var(--spacing-xs);
    color: var(--text-light);
    font-size: 0.875rem;
    line-height: 1.5;
}

.highlight-field {
    animation: highlightPulse 0.6s ease;
}

@keyframes highlightPulse {
    0%, 100% {
        border-color: var(--border-color);
        box-shadow: none;
    }
    50% {
        border-color: var(--warning-color);
        box-shadow: 0 0 0 3px rgba(245, 158, 11, 0.2);
    }
}

/* ===== Results Display ===== */
.results-card {
    animation: slideInRight 0.5s var(--transition-base);
}

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

.appliance-name-display {
    background: linear-gradient(135deg, rgba(30, 58, 138, 0.05), rgba(16, 185, 129, 0.05));
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-lg);
    font-size: 1.0625rem;
    border: 1px solid var(--border-light);
}

.result-section {
    margin-bottom: var(--spacing-xl);
}

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

.result-section h4 {
    margin-bottom: var(--spacing-md);
    color: var(--text-dark);
    font-weight: 600;
    padding-bottom: var(--spacing-xs);
    border-bottom: 2px solid var(--accent-green);
    display: inline-block;
}

.result-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--border-light);
}

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

.result-item.highlight {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.05), rgba(30, 58, 138, 0.02));
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-sm);
    border: 1px solid rgba(16, 185, 129, 0.1);
}

.result-label {
    font-weight: 600;
    color: var(--text-medium);
    font-size: 0.9375rem;
}

.result-value {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-blue), var(--accent-green));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Counter animation for result values */
.result-value.animating {
    animation: countUp 0.6s ease-out;
}

@keyframes countUp {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== Formula Explanation ===== */
.formula-explanation {
    background-color: var(--bg-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-md);
    margin-bottom: var(--spacing-xl);
    border: 1px solid var(--border-color);
}

.formula-explanation h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-dark);
    font-weight: 700;
}

.formula-box {
    background: linear-gradient(135deg, var(--bg-light), var(--bg-lighter));
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-lg);
    border-left: 4px solid var(--accent-green);
    box-shadow: var(--shadow-xs);
}

.formula-box:last-child {
    margin-bottom: 0;
}

.formula-box h4 {
    margin-bottom: var(--spacing-sm);
    color: var(--text-dark);
    font-weight: 600;
}

.formula {
    background-color: var(--bg-white);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin: var(--spacing-md) 0;
    font-family: var(--font-mono);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-xs);
}

.formula code {
    color: var(--primary-blue);
    font-weight: 600;
    font-size: 0.9375rem;
}

.explanation {
    color: var(--text-light);
    line-height: 1.7;
}

.formula-box ul {
    margin-left: var(--spacing-lg);
    color: var(--text-light);
}

.formula-box ul li {
    margin-bottom: var(--spacing-xs);
    line-height: 1.6;
}

/* ===== Appliance Presets ===== */
.appliance-presets {
    background-color: var(--bg-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

.appliance-presets h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--text-dark);
    font-weight: 700;
}

.warning-text {
    background: linear-gradient(135deg, #fffbeb, #fef3c7);
    border-left: 4px solid var(--warning-color);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-lg);
    color: #92400e;
    font-size: 0.9375rem;
    line-height: 1.6;
    box-shadow: var(--shadow-xs);
}

.presets-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: var(--spacing-md);
}

.preset-btn {
    background-color: var(--bg-light);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    cursor: pointer;
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: var(--spacing-xs);
    position: relative;
    overflow: hidden;
}

.preset-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(16, 185, 129, 0.1), transparent);
    transition: left 0.5s;
}

.preset-btn:hover::before {
    left: 100%;
}

.preset-btn:hover {
    border-color: var(--accent-green);
    background-color: rgba(16, 185, 129, 0.05);
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.preset-btn:active {
    transform: translateY(-2px);
}

.preset-btn strong {
    color: var(--text-dark);
    font-size: 0.9375rem;
    font-weight: 600;
}

.preset-btn span {
    color: var(--text-light);
    font-size: 0.875rem;
    font-weight: 500;
}

/* ===== Articles Page ===== */
.articles-section {
    padding: var(--spacing-xl) 0;
    background: var(--bg-light);
}

.articles-intro {
    background-color: var(--bg-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-md);
    margin-bottom: var(--spacing-xl);
    border: 1px solid var(--border-color);
}

.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-xl);
}

.article-card {
    background-color: var(--bg-white);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
    border: 1px solid var(--border-color);
    position: relative;
}

.article-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-blue), var(--accent-green));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-base);
}

.article-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

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

.article-card-content {
    padding: var(--spacing-lg);
    flex-grow: 1;
}

.article-card h3 {
    color: var(--text-dark);
    margin-bottom: var(--spacing-sm);
    font-size: 1.25rem;
    font-weight: 600;
    line-height: 1.4;
}

.article-card p {
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
}

.read-more {
    color: var(--accent-green);
    text-decoration: none;
    font-weight: 600;
    transition: all var(--transition-base);
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
}

.read-more:hover {
    color: var(--accent-green-dark);
    gap: 0.5rem;
}

/* ===== About & Contact Pages ===== */
.content-section {
    padding: var(--spacing-xl) 0;
    background: var(--bg-light);
}

.content-box {
    background-color: var(--bg-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-md);
    margin-bottom: var(--spacing-xl);
    border: 1px solid var(--border-color);
}

.content-box h1,
.content-box h2 {
    font-size: 2rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-dark);
    font-weight: 700;
}

.content-box h3 {
    font-size: 1.375rem;
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    color: var(--text-dark);
    font-weight: 600;
}

.content-box p {
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
}

.content-box ul,
.content-box ol {
    margin-left: var(--spacing-xl);
    color: var(--text-light);
    line-height: 1.8;
}

.content-box li {
    margin-bottom: var(--spacing-sm);
}

.info-box {
    background: linear-gradient(135deg, #ecfdf5, #d1fae5);
    border-left: 4px solid var(--success-color);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    margin: var(--spacing-lg) 0;
    box-shadow: var(--shadow-xs);
}

.warning-box {
    background: linear-gradient(135deg, #fffbeb, #fef3c7);
    border-left: 4px solid var(--warning-color);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    margin: var(--spacing-lg) 0;
    box-shadow: var(--shadow-xs);
}

/* ===== Footer ===== */
footer {
    background: linear-gradient(180deg, var(--primary-blue-dark) 0%, #0a0f1e 100%);
    color: white;
    padding: var(--spacing-3xl) 0 var(--spacing-lg);
    margin-top: var(--spacing-3xl);
    position: relative;
    overflow: hidden;
}

footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image:
        repeating-linear-gradient(90deg, rgba(255,255,255,0.02) 0px, transparent 1px, transparent 60px, rgba(255,255,255,0.02) 61px),
        repeating-linear-gradient(0deg, rgba(255,255,255,0.02) 0px, transparent 1px, transparent 60px, rgba(255,255,255,0.02) 61px);
    pointer-events: none;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
    position: relative;
    z-index: 1;
}

.footer-section h3 {
    margin-bottom: var(--spacing-md);
    background: linear-gradient(135deg, white, var(--accent-green-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.7;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: var(--spacing-sm);
}

.footer-section a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: all var(--transition-base);
    display: inline-block;
}

.footer-section a:hover {
    color: var(--accent-green-light);
    transform: translateX(4px);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-lg);
    text-align: center;
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.875rem;
    position: relative;
    z-index: 1;
}

/* ===== Responsive Design ===== */
@media (max-width: 1024px) {
    :root {
        --spacing-xl: 2.5rem;
        --spacing-2xl: 3rem;
        --spacing-3xl: 4rem;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 100%;
        max-width: 320px;
        height: 100vh;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        flex-direction: column;
        padding: var(--spacing-3xl) var(--spacing-lg);
        gap: var(--spacing-md);
        box-shadow: var(--shadow-2xl);
        transition: right var(--transition-base);
        z-index: 1000;
    }

    .nav-menu.active {
        right: 0;
    }

    .nav-menu a {
        font-size: 1.125rem;
        padding: var(--spacing-md);
        width: 100%;
        border-radius: var(--radius-lg);
    }

    .nav-menu a::after {
        display: none;
    }

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

    .mobile-menu-overlay {
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: rgba(0, 0, 0, 0.5);
        backdrop-filter: blur(4px);
        -webkit-backdrop-filter: blur(4px);
        opacity: 0;
        pointer-events: none;
        transition: opacity var(--transition-base);
        z-index: 999;
    }

    .mobile-menu-overlay.active {
        opacity: 1;
        pointer-events: all;
    }

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

    .feature-grid,
    .steps {
        grid-template-columns: 1fr;
    }

    .calculator-container {
        grid-template-columns: 1fr;
    }

    .cta-button,
    .secondary-button {
        display: block;
        width: 100%;
        margin: var(--spacing-sm) 0;
        text-align: center;
    }

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

@media (max-width: 480px) {
    :root {
        --spacing-sm: 0.75rem;
        --spacing-md: 1rem;
        --spacing-lg: 1.5rem;
        --spacing-xl: 2rem;
        --spacing-2xl: 2.5rem;
        --spacing-3xl: 3rem;
    }

    .logo .logo-text {
        font-size: 1.25rem;
    }

    .hero-content h1 {
        font-size: 1.75rem;
    }

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

/* ===== Accessibility ===== */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }

    .hero-content {
        opacity: 1;
        animation: none;
    }

    .section-reveal {
        opacity: 1;
        transform: none;
    }
}

/* Focus styles for keyboard navigation */
a:focus-visible,
button:focus-visible,
input:focus-visible {
    outline: 2px solid var(--accent-green);
    outline-offset: 2px;
    border-radius: var(--radius-sm);
}

/* Screen reader only content */
.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;
}

/* Print styles */
@media print {
    header,
    footer,
    .cta-button,
    .secondary-button,
    .mobile-menu-toggle {
        display: none;
    }

    body {
        background: white;
    }

    .calculator-card,
    .results-card,
    .content-box {
        box-shadow: none;
        border: 1px solid #ddd;
    }
}