@font-face {
    font-family: "Noto Sans JP";
    src: local("Noto Sans JP Regular"),
         local("NotoSansJP-Regular"),
         url(/NotoSansJP-Regular.woff2) format("woff2");
    font-style: normal;
    font-display: swap;
}

* {
    box-sizing: border-box;
}

body {
    background: linear-gradient(135deg, #0a7ecc 0%, #8fcbff 50%, #e1f0ff 100%);
    font-family: "Noto Sans JP", "Noto Sans CJK JP";
    background-attachment: fixed;
    margin: 0;
    padding: 20px;
    min-height: 100vh;
    backdrop-filter: blur(2px);
}

.ren-box {
    opacity: 1;
    padding: 2rem;
    max-width: 1200px;
    width: 90%;
    border-radius: 32px;
    margin: 2rem auto;
    background-color: rgba(197, 226, 255, 0.5);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.3);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.ren-box:hover {
    transform: translateY(-4px);
    box-shadow: 0 24px 42px -16px rgba(0, 0, 0, 0.25);
}

p, ul, li, hr {
    color: #1a2c3e;
    line-height: 1.5;
}

a, h1, h2, h3, h4, h5, h6 {
    color: #ffffff;
    margin-top: 1.25rem;
    margin-bottom: 0.75rem;
    text-shadow: 0 1px 2px rgba(0,0,0,0.1);
    font-weight: 600;
    letter-spacing: -0.01em;
}

a {
    text-decoration: none;
    border-bottom: 1px solid rgba(255,255,255,0.3);
    transition: border-color 0.2s, opacity 0.2s;
}

a:hover {
    border-bottom-color: #ffffff;
    opacity: 0.85;
}

button {
    border: none;
    background: linear-gradient(120deg, #2ba1ff, #0f97ff);
    border-radius: 40px;
    padding: 10px 24px;
    cursor: pointer;
    color: white;
    font-weight: 500;
    font-size: 0.95rem;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    transition: all 0.25s ease;
}

button:hover {
    transform: scale(1.02);
    background: linear-gradient(120deg, #1f91f0, #0a7ecc);
    box-shadow: 0 6px 14px rgba(0, 0, 0, 0.15);
}

button:active {
    transform: scale(0.98);
}

.upbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
}

@media (max-width: 768px) {
    body {
        padding: 16px;
    }
    .ren-box {
        padding: 1.5rem;
        width: 95%;
        margin: 1rem auto;
    }
    .upbar {
        flex-direction: column;
        align-items: stretch;
        text-align: center;
        border-radius: 28px;
    }
    button {
        width: 100%;
        text-align: center;
        justify-content: center;
    }
}

hr {
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(26,44,62,0.3), transparent);
    border: none;
    margin: 24px 0;
}

html {
    scroll-behavior: smooth;
}