:root {
    --primary-color: #10b981;
    --text-color: #1f2937;
    --bg-color: #ffffff;
    --secondary-bg: #f3f4f6;
    --max-width: 1024px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    margin: 0;
    padding: 0;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background-color: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid #e5e7eb;
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 15px 0;
}

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

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.logo a {
    text-decoration: none;
    color: inherit;
}

.nav a {
    margin-left: 20px;
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
}

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

/* Hero Section */
.hero {
    text-align: center;
    padding: 80px 0 60px;
    background: linear-gradient(to bottom, #ffffff, #f0fdf4);
}

.hero-title {
    font-size: 3rem;
    margin-bottom: 20px;
    color: #111827;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: #4b5563;
    margin-bottom: 40px;
}

.app-icon-placeholder img {
    width: 128px;
    height: 128px;
    border-radius: 24px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

/* Features */
.features {
    padding: 80px 0;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
}

.feature-item {
    background: #fff;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    border: 1px solid #f3f4f6;
    transition: transform 0.2s;
}

.feature-item:hover {
    transform: translateY(-5px);
}

.feature-item h3 {
    margin-top: 0;
    color: var(--primary-color);
    font-size: 1.25rem;
}

/* Contact */
.contact {
    background-color: var(--secondary-bg);
    text-align: center;
    padding: 60px 0;
}

.email-link {
    display: inline-block;
    margin-top: 10px;
    font-size: 1.2rem;
    color: var(--primary-color);
    text-decoration: none;
    border-bottom: 2px solid transparent;
}

.email-link:hover {
    border-bottom-color: var(--primary-color);
}

/* Footer */
.footer {
    padding: 40px 0;
    text-align: center;
    color: #6b7280;
    border-top: 1px solid #e5e7eb;
}

.footer a {
    color: #6b7280;
    text-decoration: none;
}

.footer a:hover {
    text-decoration: underline;
}

/* Privacy Page Specific */
.privacy-content {
    padding: 40px 0;
}

.privacy-content h1 {
    text-align: center;
    margin-bottom: 10px;
}

.privacy-content .update-time {
    text-align: center;
    color: #6b7280;
    margin-bottom: 40px;
}

.privacy-content h2 {
    color: #111827;
    margin-top: 30px;
    border-bottom: 1px solid #e5e7eb;
    padding-bottom: 10px;
}

.privacy-content ul {
    padding-left: 20px;
}

.privacy-content li {
    margin-bottom: 10px;
}

@media (max-width: 768px) {
    .hero-title {
        font-size: 2rem;
    }
    .feature-grid {
        grid-template-columns: 1fr;
    }
}