:root {
    --main-color: #007bff;
    --accent-color: #28a745;
    --base-bg: #f9f9f9;
    --text-color: #333;
}

body {
    font-family: "Noto Sans JP", Arial, sans-serif;
    margin: 0;
    padding: 0;
    line-height: 1.8;
    background-color: var(--base-bg);
    color: var(--text-color);
}

.media img {
    width: 100vw;
    height: auto;
}

.container {
    max-width: 850px;
    margin: 0 auto;
    padding: 0 2rem;
}

section {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 4rem 2rem;
    margin-bottom: 20px;
}

h3 {
    margin-top: 3rem;
}

.visual .media {
    width: 100%;
    max-width: 960px;
}

.tagline,
.app-link,
.sns,
footer {
    text-align: center;
}

section p,
section li {
    text-align: left;
}

.visual img,
.visual video {
    width: 100%;
    height: auto;
    border-radius: 8px;
}

.site-title {
    font-size: 2rem;
    margin: 1.5rem 0 0.5rem;
    text-align: center;
}

.app-link,
.about-app,
.details,
.sns {
    background-color: #fff;
    border: 1px solid #ddd;
    border-radius: 8px;
}

.cta-button {
    font-size: 1.2em;
    display: inline-flex;
    align-items: center;
    padding: 0.75rem 1.5rem;
    background-color: var(--accent-color); /* グリーン */
    color: #fff;
    text-decoration: none;
    border-radius: 8px; /* 角丸 */
    font-weight: bold;
    border: none;
    transition: opacity 0.3s; /* opacityの変化にアニメーション */
    opacity: 1;
}

.cta-button:hover {
    opacity: 0.85;
}

.cta-button::after {
    font-size: 1.2em;
    content: "open_in_new";
    font-family: "Material Symbols Outlined";
    font-weight: normal;
    font-style: normal;
    vertical-align: middle;
    display: inline-block;
    color: #fff; /* アイコンも白に */
}

footer {
    text-align: center;
    padding: 1rem;
    color: #777;
}

@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }
    section {
        padding: 2rem 1rem;
    }
}

.link-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: 2rem;
}

h3::after, h3::before {
    font-size: 1.2em;
    content: "bolt";
    font-family: "Material Symbols Outlined";
    font-weight: normal;
    font-style: normal;
    vertical-align: top;
    display: inline-block;
    color: var(--accent-color);
}