/* CSS Variables */
:root {
    --primary-color: #3B82F6;
    --primary-dark: #2563EB;
    --secondary-color: #10B981;
    --text-color: #1F2937;
    --text-light: #6B7280;
    --bg-color: #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), 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);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
}

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

html {
    scroll-behavior: smooth;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.2s;
}

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

ul {
    list-style: none;
}

/* Header & Navigation */
header {
    background: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

header nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 24px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--text-color);
}

.logo-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: var(--primary-color);
    color: white;
    border-radius: var(--radius-sm);
    font-weight: 700;
    font-size: 1.25rem;
}

.logo-img {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    color: var(--text-light);
    font-weight: 500;
    padding: 8px 0;
    border-bottom: 2px solid transparent;
    transition: all 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

/* Hero Section */
.hero {
    padding: 80px 0;
    background: linear-gradient(135deg, #EFF6FF 0%, #DBEAFE 100%);
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-content h1 {
    font-size: 3rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 20px;
    color: var(--text-color);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-light);
    margin-bottom: 32px;
    line-height: 1.7;
}

/* Store Buttons */
.store-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.store-buttons.centered {
    justify-content: center;
}

.store-button {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 24px;
    background: #000;
    color: #fff;
    border-radius: var(--radius-md);
    transition: transform 0.2s, box-shadow 0.2s;
}

.store-button:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    color: #fff;
}

.store-button svg {
    flex-shrink: 0;
}

.store-button .small {
    display: block;
    font-size: 0.75rem;
    opacity: 0.8;
}

.store-button .big {
    display: block;
    font-size: 1.125rem;
    font-weight: 600;
}

/* Phone Mockup */
.hero-image {
    display: flex;
    justify-content: center;
}

.phone-mockup {
    width: 280px;
    height: 560px;
    background: #1F2937;
    border-radius: 36px;
    padding: 12px;
    box-shadow: var(--shadow-lg);
}

.sudoku-preview {
    width: 100%;
    height: 100%;
    background: #fff;
    border-radius: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.grid-preview {
    display: grid;
    grid-template-columns: repeat(3, 50px);
    grid-template-rows: repeat(3, 50px);
    gap: 4px;
    background: var(--primary-color);
    padding: 4px;
    border-radius: var(--radius-sm);
}

.grid-preview .cell {
    display: flex;
    align-items: center;
    justify-content: center;
    background: #fff;
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-color);
}

.grid-preview .cell.empty {
    background: #F3F4F6;
}

/* Features Section */
.features {
    padding: 80px 0;
    background: var(--bg-secondary);
}

.features h2 {
    text-align: center;
    font-size: 2.25rem;
    margin-bottom: 48px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.feature-card {
    background: var(--bg-color);
    padding: 32px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    text-align: center;
    transition: transform 0.2s, box-shadow 0.2s;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* CTA Section */
.cta {
    padding: 80px 0;
    background: var(--primary-color);
    color: white;
    text-align: center;
}

.cta h2 {
    font-size: 2.25rem;
    margin-bottom: 16px;
}

.cta p {
    font-size: 1.125rem;
    opacity: 0.9;
    margin-bottom: 32px;
}

/* Footer */
footer {
    background: #1F2937;
    color: #9CA3AF;
    padding: 48px 0 24px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 24px;
    border-bottom: 1px solid #374151;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer-logo .logo-icon {
    background: var(--primary-color);
}

.footer-logo .logo-text {
    color: white;
    font-weight: 600;
}

.footer-links {
    display: flex;
    gap: 32px;
}

.footer-links a {
    color: #9CA3AF;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 24px;
    font-size: 0.875rem;
}

/* Legal Pages */
.legal-page {
    padding: 60px 0;
}

.legal-page h1 {
    font-size: 2.5rem;
    margin-bottom: 8px;
}

.last-updated {
    color: var(--text-light);
    margin-bottom: 40px;
}

.legal-section {
    margin-bottom: 40px;
}

.legal-section h2 {
    font-size: 1.5rem;
    margin-bottom: 16px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--border-color);
}

.legal-section h3 {
    font-size: 1.125rem;
    margin: 20px 0 12px;
    color: var(--text-color);
}

.legal-section p {
    margin-bottom: 16px;
    color: var(--text-light);
}

.legal-section ul {
    margin: 16px 0;
    padding-left: 24px;
}

.legal-section li {
    list-style: disc;
    margin-bottom: 8px;
    color: var(--text-light);
}

/* Contact Page */
.contact-page {
    padding: 60px 0;
}

.contact-page h1 {
    font-size: 2.5rem;
    margin-bottom: 12px;
}

.page-subtitle {
    color: var(--text-light);
    font-size: 1.125rem;
    margin-bottom: 48px;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 48px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.contact-card {
    background: var(--bg-secondary);
    padding: 24px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.contact-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    background: var(--primary-color);
    color: white;
    border-radius: var(--radius-md);
    margin-bottom: 16px;
}

.contact-card h3 {
    font-size: 1.25rem;
    margin-bottom: 8px;
}

.contact-card p {
    color: var(--text-light);
    margin-bottom: 8px;
}

.contact-link {
    font-weight: 500;
}

.faq-section h2 {
    font-size: 1.75rem;
    margin-bottom: 24px;
}

.faq-item {
    background: var(--bg-secondary);
    padding: 20px 24px;
    border-radius: var(--radius-md);
    margin-bottom: 16px;
    border: 1px solid var(--border-color);
}

.faq-item h4 {
    font-size: 1rem;
    margin-bottom: 8px;
    color: var(--text-color);
}

.faq-item p {
    color: var(--text-light);
    font-size: 0.95rem;
}

.response-time {
    margin-top: 48px;
    padding: 24px;
    background: #EFF6FF;
    border-radius: var(--radius-md);
    text-align: center;
}

.response-time h3 {
    color: var(--primary-color);
    margin-bottom: 8px;
}

.response-time p {
    color: var(--text-light);
}

/* Responsive Design */
@media (max-width: 968px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-content h1 {
        font-size: 2.25rem;
    }

    .store-buttons {
        justify-content: center;
    }

    .hero-image {
        order: -1;
    }

    .phone-mockup {
        width: 220px;
        height: 440px;
    }

    .grid-preview {
        grid-template-columns: repeat(3, 40px);
        grid-template-rows: repeat(3, 40px);
    }

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

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

@media (max-width: 640px) {
    .nav-links {
        display: none;
    }

    .hero-content h1 {
        font-size: 1.875rem;
    }

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

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

    .footer-content {
        flex-direction: column;
        gap: 24px;
        text-align: center;
    }

    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
        gap: 16px;
    }

    .store-buttons {
        flex-direction: column;
        align-items: center;
    }

    .store-button {
        width: 100%;
        max-width: 280px;
        justify-content: center;
    }
}