* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #007AFF;
    --primary-dark: #0051D5;
    --dark: #1C1C1E;
    --light-gray: #F2F2F7;
    --text-primary: #000000;
    --text-secondary: #6E6E73;
    --accent-orange: #FF9500;
    --success-green: #34C759;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'SF Pro Text', sans-serif;
    line-height: 1.5;
    color: var(--text-primary);
    background-color: var(--light-gray);
}

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

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

/* Header */
header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    color: var(--text-primary);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 0.5px solid rgba(0, 0, 0, 0.3);
}

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

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-orange);
    text-decoration: none;
}

.logo::before {
    content: '';
    display: inline-block;
    width: 24px;
    height: 24px;
    margin-right: 8px;
    vertical-align: middle;
    background-image: url('images/logo-24px.jpg');
    background-size: cover;
    background-repeat: no-repeat;
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

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

.nav-links a:hover {
    opacity: 0.6;
}

/* Hero Section */
.hero {
    background: var(--light-gray);
    padding: 2rem 0 4rem 0;
}

.hero-card {
    background: linear-gradient(135deg, var(--accent-orange) 0%, var(--primary) 100%);
    color: white;
    padding: 3rem 2rem;
    border-radius: 20px;
    text-align: center;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    letter-spacing: -0.5px;
}

.hero p {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    opacity: 0.95;
    font-weight: 400;
}

.cta-button-primary {
    display: inline-block;
    background: var(--primary);
    color: white;
    padding: 0.875rem 2rem;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: transform 0.2s, opacity 0.2s;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.cta-button-primary:hover {
    transform: scale(1.02);
    opacity: 0.9;
}

.cta-button-secondary {
    display: inline-block;
    background: var(--light-gray);
    color: var(--primary);
    padding: 0.875rem 2rem;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: transform 0.2s, opacity 0.2s;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.cta-button-secondary:hover {
    transform: scale(1.02);
    opacity: 0.9;
}

/* Features Section */
.features {
    padding: 3rem 0;
    background: var(--light-gray);
}

.section-title {
    text-align: center;
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 2rem;
    letter-spacing: -0.5px;
}

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

.feature-card {
    background: white;
    padding: 1.5rem;
    border-radius: 16px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    transition: transform 0.2s, box-shadow 0.2s;
}

.feature-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 0.75rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-primary);
}

.feature-card li,
.feature-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.5;
}

.feature-card li {
    margin-left: 15px;
}

/* Activities Section */
.activities {
    padding: 3rem 0;
    background: var(--light-gray);
}

.activity-list {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1.5rem;
    margin-top: 2rem;
}

.activity-badge {
    background: white;
    color: var(--dark);
    padding: 0.625rem 1.25rem;
    border-radius: 5px;
    font-weight: 600;
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

/* Technical Details */
.tech-details {
    padding: 3rem 0;
    background: white;
}

.tech-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.tech-details .tech-grid .tech-item{
    background-color: var(--light-gray);
}

.tech-item {
    background: white;
    padding: 1.25rem;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.tech-item h4 {
    color: var(--text-primary);
    margin-bottom: 0.625rem;
    font-weight: 600;
    font-size: 1.1rem;
}

.tech-item ul {
    list-style: none;
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.6;
}

.tech-item ul li {
    padding-left: 1.25rem;
    position: relative;
    margin-bottom: 0.375rem;
}

.tech-item ul li:before {
    content: "•";
    color: var(--primary);
    font-weight: bold;
    position: absolute;
    left: 0;
}

/* Screenshots Section */
.screenshots {
    padding: 3rem 0;
    background: white;
}

.screenshots-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.screenshot-card {
    background: var(--light-gray);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
    transition: transform 0.2s;
}

.screenshot-card img {
    width: 100%;
    display: block;
    aspect-ratio: 9 / 19.5;
    object-fit: cover;
}

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

.screenshot-placeholder {
    aspect-ratio: 9 / 19.5;
    background: linear-gradient(135deg, #E5E5EA 0%, #D1D1D6 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    font-size: 3rem;
    position: relative;
}

.screenshot-placeholder::after {
    content: 'Screenshot';
    position: absolute;
    bottom: 2rem;
    font-size: 1rem;
    font-weight: 500;
}

.screenshot-caption {
    padding: 1rem;
    text-align: center;
    background: white;
}

.screenshot-caption h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.screenshot-caption p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Privacy Section */
.privacy {
    padding: 3rem 0;
    text-align: center;
    background: var(--light-gray);
}

.privacy-content {
    max-width: 800px;
    margin: 0 auto;
}

.privacy-badge {
    display: inline-block;
    background: transparent;
    color: var(--success-green);
    border: var(--success-green) 1px solid;
    border-radius: 12px;
    padding: 0.5rem 1rem;
    margin-bottom: 1rem;
    font-weight: 400;
    font-size: 0.95rem;
    text-decoration: none;
    transition: background 0.6s ease, color 1s ease;
}
.privacy-badge:hover {
    background: var(--success-green);
    color: white;
}

/* Footer */
footer {
    background: white;
    color: var(--text-secondary);
    padding: 2rem 0;
    text-align: center;
    border-top: 0.5px solid rgba(0, 0, 0, 0.1);
}

footer p {
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 1.75rem;
    }

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

    .nav-links {
        display: none;
    }

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

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

    .screenshots-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}

/* Scroll animations */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}