:root {
    --main-color: #7b6ef6;     /* 薄紫 */
    --accent-color: #5bd1c1;   /* 青緑 */
    --text-color: #555;
    --bg-color: #fafafa;
    --max-width: 1000px;
}

*{
    box-sizing: border-box;
}

a,
a:visited,
a:active {
  color: inherit;
  text-decoration: none;
}


body {
    font-family: "Noto Sans JP", sans-serif;
    color: var(--text-color);
    margin: 0;
    line-height: 1.6;
}

header {
    background: var(--bg-color);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

header .inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0.8em 1.5em;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

header h1 {
    font-size: 1.2em;
    color: var(--main-color);
    margin: 0;
    display: flex;
    align-items: center;
}

header h1 img{
    height: 1.25em;
    margin-right: 0.25em;
}

header nav a {
    margin-left: 1em;
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
}

section {
    max-width: var(--max-width);
    margin: 4em auto;
    padding: 0 1em;
    scroll-margin-top: 80px; /* ヘッダの高さに合わせる */
}

section h3 {
    text-align: center;
    font-size: 1.8em;
    margin-bottom: 1.5em;
}

.material-icons-round {
  vertical-align: middle;
  line-height: 1;
}

a {
    transition: 0.3s;
    cursor: pointer;
}

a:hover {
    opacity: 0.5;
}

/* トップビジュアル */
.hero {
    text-align: center;
    background-color: var(--bg-color);
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    padding: 2em;
    /*flex-direction: row-reverse;*/
    max-width: calc(var(--max-width) - 4em);
    width: calc(100% - 4em);
}

.hero::before{/* 二重線用 */
    content: "";
    position: absolute;
    top: -2em;
    left: -2em;
    width: calc(100% + 2em);
    height: calc(100% + 2em);
    border: 1em solid var(--bg-color);
    z-index: -1;
}

.hero-content {
    flex: 1 1 240px;          /* 幅が狭くなったら自動で縦に落ちる */
    padding-bottom: 2em;
}

.hero h2 {
    font-size: 2.2em;
    margin-bottom: 0.5em;
}

.hero p {
    font-size: 1.1em;
    opacity: 0.9;
    margin-bottom: 1.5em;
}

.hero a.button {
    display: inline-block;
    padding: 0.8em 1.8em;
    background: linear-gradient(135deg, var(--main-color), var(--accent-color));
    color: var(--bg-color);
    border-radius: 9999px;
    font-weight: bold;
    text-decoration: none;
    transition: 0.3s;
}

.hero a.button:hover {
    opacity: 0.5;
}

.hero-visual {
    flex: 1 1 500px;
}

.hero-visual img {
  width: 100%;
  max-width: 500px;
  height: auto;
}

/* 特徴カード */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2em;
}

.feature {
    background: white;
    padding: 2em;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    text-align: center;
}

.feature h4 {
    color: var(--main-color);
    margin-top: 0.5em;
}

.feature p {
    font-size: 0.95em;
    opacity: 0.85;
}

/* 機能紹介 */
.screenshot {
    text-align: center;
}

.screenshot img, .screenshot video {
    max-width: 100%;
    border-radius: 12px;
    box-shadow: 0 3px 12px rgba(0,0,0,0.1);
}

.screenshot > div {
    display: flex;
    align-items: center;
    gap: 2em;
    padding: 1em;
    margin-bottom: 5em;
    flex-wrap: wrap-reverse;
}

.screenshot > div:nth-child(even) {
    flex-direction: row-reverse;
}

.screenshot-content {
    flex: 1 1 280px;
    padding: 1em 2em;
}

.screenshot-content h4 {
    color: var(--main-color);
    margin-top: 1em;
}

.screenshot-visual {
    flex: 1 1 480px;
}

/* 動作環境 */
#system div{
    text-align: center;
}

/* 注意事項 */
.notice {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.notice h4{
    background-color: var(--bg-color);
    padding: 0.5em 1em;
    margin-top: 0;
    border-radius: 0.5em;
    border: 5px solid rgba(255, 212, 58, 0.638);
}

.notice ul li span{
    display: inline-block;
    position: relative;
}

.notice ul li span::after{
    content: "";
    height: 1em;
    width: 100%;
    background-color: #f5e296;
    position: absolute;
    bottom: 0;
    left: 0;
    z-index: -1;
    opacity: 0.5;
}


/* ダウンロードリンク */
#download > div{
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: 1em;
}

#download a img {
    border-radius: 9999px;
}

#booth img{
    max-width: 400px;
}

/* サンプルゲーム */
#sample{
    text-align: center;   
}

/* リンク */
.link nav {
    display: flex;
    flex-direction: column;
    gap: 1em;
}

.link nav a, .link-button {
    width: 100%;
    max-width: 450px;
    display: block;
    padding: 0.75em 2em;
    margin: 0 auto;
    background: var(--bg-color);
    border-radius: 9999px;
    box-shadow: 0 3px 5px rgba(0,0,0,0.1);
    font-weight: 500;
}

/* フッタ */
footer {
    text-align: center;
    padding: 2em 1em;
    font-size: 0.9em;
    background: #f0f0f0;
    color: #666;
}

footer a {
    color: var(--main-color);
    text-decoration: none;
}


/* 汎用 */
.fade-up {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

/* 表示状態になったとき */
.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}


.grad {
    background: linear-gradient(45deg, #BFFEEB, #E7CFF0);
    background-size: 400% 400%;
    animation: GradientBackground 10s ease infinite;
}

@keyframes GradientBackground {
    0% {
    background-position: 0% 50%;
    }

    50% {
    background-position: 100% 50%;
    }

    100% {
    background-position: 0% 50%;
    }
};