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

:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #ec4899;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --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);
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    padding: 1rem 0;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
}

.logo-img {
    width: 2rem;
    height: 2rem;
    object-fit: cover;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-sm);
}

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

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

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

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

/* Buttons */
.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 600;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    display: inline-block;
    border: none;
    cursor: pointer;
}

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

.btn-secondary {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s ease;
    display: inline-block;
}

.btn-secondary:hover {
    background-color: var(--border-color);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

/* Hero Section */
.hero {
    padding: 8rem 0 4rem;
    background: linear-gradient(135deg, #f9fafb 0%, #ffffff 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 70%;
    height: 150%;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.1) 0%, transparent 70%);
    pointer-events: none;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-content {
    z-index: 1;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.gradient-text {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.app-mockup {
    width: 300px;
    height: 600px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    border-radius: 2rem;
    padding: 1rem;
    box-shadow: var(--shadow-xl);
    transform: perspective(1000px) rotateY(-15deg);
    transition: transform 0.3s ease;
}

.app-mockup:hover {
    transform: perspective(1000px) rotateY(-10deg) translateY(-10px);
}

.mockup-screen {
    width: 100%;
    height: 100%;
    background: white;
    border-radius: 1.5rem;
    padding: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.sudoku-grid-preview {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.5rem;
    width: 100%;
}

.grid-cell {
    aspect-ratio: 1;
    background: var(--bg-secondary);
    border-radius: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.grid-cell.filled {
    background: linear-gradient(135deg, var(--primary-light), var(--primary-color));
    color: white;
}

/* Features Section */
.features {
    padding: 6rem 0;
    background-color: var(--bg-primary);
}

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

.section-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 4rem;
}

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

.feature-card {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: 1rem;
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

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

.feature-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

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

/* About Section */
.about {
    padding: 6rem 0;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-text {
    max-width: 600px;
}

.about-text .section-title {
    text-align: left;
    margin-bottom: 1.5rem;
}

.about-text p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.about-stats {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

.stat-card {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    text-align: center;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

.stat-number {
    font-size: 3rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 1.125rem;
    color: var(--text-secondary);
    font-weight: 600;
}

/* Privacy Section */
.privacy {
    padding: 6rem 0;
    background-color: var(--bg-primary);
}

.privacy-content {
    max-width: 900px;
    margin: 0 auto;
}

.privacy-text {
    margin-top: 3rem;
    background: var(--bg-secondary);
    padding: 3rem;
    border-radius: 1rem;
    border: 1px solid var(--border-color);
}

.privacy-text p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.privacy-text p:last-child {
    margin-bottom: 0;
}

.placeholder-text {
    font-style: italic;
    color: var(--text-light);
    text-align: center;
    padding: 2rem;
}

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

.link:hover {
    text-decoration: underline;
}

/* Data Request Page */
.form-page {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 6rem 1.5rem;
}

.data-request {
    width: 100%;
}

.form-card {
    background: var(--bg-primary);
    border-radius: 1.5rem;
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-color);
    padding: 3rem;
    max-width: 720px;
    margin: 0 auto;
}

.form-card h1 {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.form-card p {
    color: var(--text-secondary);
    font-size: 1.05rem;
    line-height: 1.8;
}

.form-card p + p {
    margin-top: 1rem;
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.5rem;
    margin-top: 2.5rem;
}

.form-grid-full {
    grid-column: 1 / -1;
}

.form-field {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.form-field label {
    font-weight: 600;
    color: var(--text-primary);
}

.form-help {
    font-size: 0.9rem;
    color: var(--text-light);
    line-height: 1.5;
}

.form-field input,
.form-field select,
.form-field textarea {
    padding: 0.85rem 1rem;
    border-radius: 0.75rem;
    border: 1px solid var(--border-color);
    background: var(--bg-secondary);
    font-size: 1rem;
    color: var(--text-primary);
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.form-field input:focus,
.form-field select:focus,
.form-field textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

.form-field textarea {
    resize: vertical;
    min-height: 160px;
}

.form-checkbox {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.form-checkbox input {
    margin-top: 0.3rem;
}

.form-actions {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-top: 2rem;
}

.form-status {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.form-status.is-success {
    color: var(--primary-dark);
}

.form-status.is-error {
    color: #dc2626;
}

/* Footer */
.footer {
    background-color: var(--text-primary);
    color: white;
    padding: 4rem 0 2rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 3fr;
    gap: 4rem;
    margin-bottom: 3rem;
}

.footer-brand .logo {
    color: white;
    margin-bottom: 1rem;
}

.footer-description {
    color: var(--text-light);
    max-width: 300px;
}

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

.footer-column h4 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.footer-column a {
    display: block;
    color: var(--text-light);
    text-decoration: none;
    margin-bottom: 0.75rem;
    transition: color 0.3s ease;
}

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

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

/* Responsive Design */
@media (max-width: 968px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .hero-image {
        display: none;
    }
    
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .about-text .section-title {
        text-align: center;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .nav-links {
        gap: 1rem;
    }
    
    .nav-links a:not(.btn-primary) {
        display: none;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.125rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .download-buttons {
        grid-template-columns: 1fr;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
    }

    .form-card {
        padding: 2.5rem 2rem;
    }
}