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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 2rem 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    text-align: center;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    font-weight: 700;
}

.tagline {
    font-size: 1.2rem;
    opacity: 0.9;
    font-weight: 300;
}

main {
    max-width: 1200px;
    margin: 3rem auto;
    padding: 0 2rem;
}

.intro {
    text-align: center;
    margin-bottom: 4rem;
    padding: 2rem;
    background: white;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.intro h2 {
    font-size: 2rem;
    color: #667eea;
    margin-bottom: 1rem;
}

.intro p {
    font-size: 1.1rem;
    color: #666;
    max-width: 800px;
    margin: 0 auto;
}

.apps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 4rem;
}

.app-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    text-decoration: none;
    color: inherit;
    display: block;
}

.app-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.app-card-image {
    width: 100%;
    height: 200px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    color: white;
}

.app-card-content {
    padding: 1.5rem;
}

.app-card h3 {
    font-size: 1.5rem;
    color: #333;
    margin-bottom: 0.5rem;
}

.app-card p {
    color: #666;
    font-size: 0.95rem;
    line-height: 1.6;
}

.app-card-link {
    display: inline-block;
    margin-top: 1rem;
    color: #667eea;
    font-weight: 600;
    text-decoration: none;
}

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

.app-card.new {
    position: relative;
}

.app-card.new::before {
    content: 'New';
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: #ff3b30;
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    z-index: 10;
}

.app-card.developing {
    opacity: 0.85;
    position: relative;
}

.app-card.developing::before {
    content: '開発中';
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: #ffa100;
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    z-index: 10;
}

.app-card.developing .app-card-image {
    filter: grayscale(10%); /* 開発中でも少し色を残す */
}

/* App Backgrounds */
.bg-stamp-log {
    background: 
        radial-gradient(at 0% 0%, rgba(255, 140, 0, 0.15) 0%, transparent 50%),
        radial-gradient(at 100% 100%, rgba(255, 140, 0, 0.1) 0%, transparent 50%),
        linear-gradient(135deg, #1b3022 0%, #2d5036 100%);
    position: relative;
    overflow: hidden;
}

.bg-stamp-log::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='100' height='100' viewBox='0 0 100 100'%3E%3Cpath d='M10,10 Q30,40 50,10 T90,10 M10,30 Q30,60 50,30 T90,30 M10,50 Q30,80 50,50 T90,50 M10,70 Q30,100 50,70 T90,70 M10,90 Q30,120 50,90 T90,90' fill='none' stroke='white' stroke-width='0.5' opacity='0.05'/%3E%3C/svg%3E");
    opacity: 0.3;
    pointer-events: none;
}

footer {
    background: #333;
    color: white;
    text-align: center;
    padding: 2rem;
    margin-top: 4rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

.footer-content p {
    margin-bottom: 0.5rem;
}

.footer-content a {
    color: #667eea;
    text-decoration: none;
}

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

@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }

    .tagline {
        font-size: 1.0rem;
    }

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

    main {
        margin: 2rem auto;
    }
}