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

:root {
    --primary-color: #2563eb;
    --secondary-color: #7c3aed;
    --accent-color: #f59e0b;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-warm: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-cool: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --gradient-success: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-secondary);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header & Navigation */
.navbar {
    background: var(--bg-primary);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--primary-color);
}

.logo-icon {
    font-size: 1.75rem;
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.3s;
}

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

.cta-button {
    background: var(--gradient-primary);
    color: white !important;
    padding: 0.5rem 1.5rem;
    border-radius: 9999px;
    font-weight: 600;
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    color: white;
    padding: 5rem 0 4rem;
    text-align: center;
}

.hero-title {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 3rem;
    opacity: 0.95;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    flex-wrap: wrap;
}

.stat-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
}

.stat-label {
    font-size: 0.875rem;
    opacity: 0.9;
}

/* Calculator Section */
.calculator-section {
    padding: 4rem 0;
    margin-top: -3rem;
}

.calculator-card {
    background: var(--bg-primary);
    border-radius: 24px;
    padding: 3rem;
    box-shadow: var(--shadow-xl);
    max-width: 800px;
    margin: 0 auto;
}

.calculator-title {
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 0.5rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.calculator-subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

/* Form Styles */
.calculator-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.form-section {
    margin-bottom: 1rem;
}

.form-label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.unit-toggle {
    display: flex;
    gap: 0.5rem;
    background: var(--bg-secondary);
    padding: 0.25rem;
    border-radius: 12px;
}

.unit-btn {
    flex: 1;
    padding: 0.75rem 1rem;
    border: none;
    background: transparent;
    border-radius: 10px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    color: var(--text-secondary);
}

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

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

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

.form-group input,
.form-group select {
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    font-size: 1rem;
    transition: all 0.3s;
    background: var(--bg-primary);
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.height-inputs {
    position: relative;
}

.height-imperial,
.height-metric {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.height-imperial input,
.height-metric input {
    flex: 1;
}

.input-with-unit {
    position: relative;
}

.input-with-unit input {
    width: 100%;
    padding-right: 3rem;
}

.input-unit {
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    font-weight: 600;
    pointer-events: none;
}

.height-imperial .input-unit,
.height-metric .input-unit {
    position: static;
    transform: none;
    color: var(--text-secondary);
}

.calculate-btn {
    background: var(--gradient-primary);
    color: white;
    padding: 1rem 2rem;
    border: none;
    border-radius: 12px;
    font-size: 1.125rem;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    transition: transform 0.2s, box-shadow 0.3s;
    box-shadow: var(--shadow-lg);
    margin-top: 1rem;
}

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

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

.btn-icon {
    font-size: 1.5rem;
}

/* Results Section */
.results {
    margin-top: 3rem;
    padding-top: 3rem;
    border-top: 2px solid var(--border-color);
}

.results-title {
    font-size: 1.75rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.result-cards {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.result-card {
    background: linear-gradient(135deg, #f9fafb 0%, #ffffff 100%);
    padding: 1.5rem;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    transition: transform 0.3s;
}

.result-card:hover {
    transform: translateY(-4px);
}

.primary-card {
    background: var(--gradient-primary);
    color: white;
}

.result-icon {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.result-label {
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    opacity: 0.8;
}

.primary-card .result-label {
    opacity: 0.95;
}

.result-value {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 0.25rem;
}

.result-sublabel {
    font-size: 0.75rem;
    opacity: 0.7;
}

.primary-card .result-sublabel {
    opacity: 0.9;
}

.result-summary {
    background: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: 16px;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 2rem;
}

.summary-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.summary-label {
    font-weight: 600;
    color: var(--text-secondary);
}

.summary-value {
    font-weight: 700;
    font-size: 1.125rem;
    color: var(--primary-color);
}

.result-cta {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 2rem;
    border-radius: 16px;
    text-align: center;
    color: white;
    margin-bottom: 2rem;
}

.result-cta-text {
    font-size: 1.125rem;
    margin-bottom: 1.5rem;
}

.result-download-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.store-button {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    background: white;
    color: var(--text-primary);
    padding: 0.75rem 1.5rem;
    border-radius: 12px;
    text-decoration: none;
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.store-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.store-icon {
    font-size: 2rem;
}

.store-text {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    text-align: left;
}

.store-label {
    font-size: 0.625rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    opacity: 0.7;
}

.store-name {
    font-size: 1rem;
    font-weight: 700;
    margin-top: -2px;
}

/* App Section */
.app-section {
    padding: 5rem 0;
    background: linear-gradient(135deg, #f9fafb 0%, #e0e7ff 50%, #fce7f3 100%);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 800;
    text-align: center;
    margin-bottom: 1rem;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.125rem;
    margin-bottom: 3rem;
}

.app-features-compact {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.compact-feature {
    display: flex;
    gap: 1.5rem;
    background: var(--bg-primary);
    padding: 2rem;
    border-radius: 20px;
    box-shadow: var(--shadow-md);
    transition: transform 0.3s;
}

.compact-feature:hover {
    transform: translateY(-4px);
}

.compact-icon {
    font-size: 3rem;
    flex-shrink: 0;
}

.compact-content h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.compact-content p {
    color: var(--text-secondary);
    line-height: 1.6;
}

.app-download {
    background: var(--gradient-primary);
    padding: 3rem;
    border-radius: 24px;
    text-align: center;
    color: white;
}

.app-download-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.app-download-text {
    font-size: 1.125rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

.download-badges {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.badge-link img {
    height: 50px;
    transition: transform 0.2s;
}

.badge-link:hover img {
    transform: scale(1.05);
}

/* Info Section */
.info-section {
    padding: 5rem 0;
    background: var(--bg-primary);
}

.info-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.info-card {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: 20px;
    transition: transform 0.3s, box-shadow 0.3s;
}

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

.info-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.info-card-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.info-card-text {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.info-link {
    color: var(--primary-color);
    font-weight: 600;
    text-decoration: none;
    transition: color 0.3s;
}

.info-link:hover {
    color: var(--secondary-color);
}

/* FAQ Section */
.faq-section {
    padding: 5rem 0;
    background: var(--bg-secondary);
}

.faq-container {
    max-width: 800px;
    margin: 3rem auto 0;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.faq-item {
    background: var(--bg-primary);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.faq-question {
    width: 100%;
    padding: 1.5rem;
    background: none;
    border: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    font-size: 1.125rem;
    font-weight: 600;
    text-align: left;
    transition: background 0.3s;
}

.faq-question:hover {
    background: var(--bg-secondary);
}

.faq-icon {
    font-size: 1.5rem;
    font-weight: 300;
    transition: transform 0.3s;
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 1.5rem 1.5rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* Footer */
.footer {
    background: var(--text-primary);
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.footer-text {
    opacity: 0.8;
    line-height: 1.8;
}

.footer-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.footer-links a {
    color: white;
    text-decoration: none;
    opacity: 0.8;
    transition: opacity 0.3s;
}

.footer-links a:hover {
    opacity: 1;
}

.footer-badges {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
    flex-wrap: wrap;
}

.footer-badges a {
    color: white;
    opacity: 0.8;
    text-decoration: none;
    transition: opacity 0.3s;
}

.footer-badges a:hover {
    opacity: 1;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    opacity: 0.6;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

    .hamburger {
        display: flex;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .calculator-card {
        padding: 2rem 1.5rem;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .result-cards {
        grid-template-columns: 1fr;
    }

    .primary-card {
        grid-column: span 1;
    }

    .result-download-buttons {
        flex-direction: column;
        align-items: stretch;
    }

    .store-button {
        width: 100%;
        justify-content: center;
    }

    .app-features-compact {
        grid-template-columns: 1fr;
    }

    .compact-feature {
        flex-direction: column;
        text-align: center;
    }

    .section-title {
        font-size: 2rem;
    }

    .info-cards {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }

    .calculator-title {
        font-size: 1.5rem;
    }

    .hero-stats {
        gap: 1.5rem;
    }

    .stat-number {
        font-size: 1.5rem;
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.results {
    animation: fadeIn 0.5s ease-out;
}

/* Print Styles */
@media print {
    .navbar,
    .hamburger,
    .app-section,
    .footer {
        display: none;
    }
}