@font-face {
    font-family: "BIZ UDPGothic";
    src: local("BIZ UDPGothic Regular"),
         local("BIZUDPGothic-Regular"),
         url(/BIZUDPGothic-Regular.woff2) format("woff2");
    font-style: normal;
    font-display: swap;
}

:root {
    --color-bg-1: #0f2c4c;
    --color-bg-2: #2f6fb5;
    --color-bg-3: #7fc1ff;
    --color-text: #16202c;
    --color-surface: rgba(255, 255, 255, 0.14);
    --color-surface-border: rgba(255, 255, 255, 0.35);
    --color-accent-a: #4fd3c4;
    --color-accent-b: #2b8fe0;
    --color-accent-a-hover: #3cc0b1;
    --color-accent-b-hover: #1f79c4;
    --radius-lg: 28px;
    --radius-lg-sm: 22px;
    --radius-pill: 999px;
    --space-1: 0.5rem;
    --space-2: 1rem;
    --space-3: 1.5rem;
    --space-4: 2rem;
}

* {
    box-sizing: border-box;
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

body {
    background:
        radial-gradient(circle at 15% 10%, rgba(79, 211, 196, 0.25), transparent 45%),
        radial-gradient(circle at 85% 0%, rgba(255, 255, 255, 0.2), transparent 40%),
        linear-gradient(160deg, var(--color-bg-1) 0%, var(--color-bg-2) 55%, var(--color-bg-3) 100%);
    font-family: "BIZ UDPGothic", "BIZ UDPゴシック", sans-serif;
    margin: 0;
    padding: clamp(16px, 4vw, 32px);
    padding-top: max(clamp(16px, 4vw, 32px), env(safe-area-inset-top));
    padding-right: max(clamp(16px, 4vw, 32px), env(safe-area-inset-right));
    padding-bottom: max(clamp(16px, 4vw, 32px), env(safe-area-inset-bottom));
    padding-left: max(clamp(16px, 4vw, 32px), env(safe-area-inset-left));
    min-height: 100vh;
    min-height: 100dvh;
    color: var(--color-text);
}

.ren-box {
    opacity: 1;
    padding: clamp(1.25rem, 3vw, 2.5rem);
    max-width: 1200px;
    width: min(92%, 1200px);
    border-radius: var(--radius-lg);
    margin: clamp(1rem, 4vw, 2.5rem) auto;
    background:
        linear-gradient(180deg, rgba(255,255,255,0.22), rgba(255,255,255,0.08)),
        var(--color-surface);
    backdrop-filter: blur(18px) saturate(140%);
    -webkit-backdrop-filter: blur(18px) saturate(140%);
    box-shadow:
        0 1px 0 rgba(255, 255, 255, 0.4) inset,
        0 20px 40px -20px rgba(6, 20, 40, 0.45);
    border: 1px solid var(--color-surface-border);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.ren-box:hover {
    transform: translateY(-6px);
    box-shadow:
        0 1px 0 rgba(255, 255, 255, 0.4) inset,
        0 30px 55px -20px rgba(6, 20, 40, 0.55);
}

p, ul, li, hr {
    color: #eaf3ff;
    line-height: 1.7;
    overflow-wrap: break-word;
    word-break: break-word;
    font-size: clamp(0.95rem, 0.9rem + 0.2vw, 1.05rem);
}

a, h1, h2, h3, h4, h5, h6 {
    color: #ffffff;
    margin-top: 1.4rem;
    margin-bottom: 0.75rem;
    letter-spacing: -0.015em;
    font-weight: 700;
    overflow-wrap: break-word;
}

h1 { font-size: clamp(1.6rem, 1.2rem + 2vw, 2.4rem); }
h2 { font-size: clamp(1.3rem, 1.05rem + 1.2vw, 1.8rem); }

a {
    font-weight: 500;
    text-decoration: none;
    background-image: linear-gradient(var(--color-accent-a), var(--color-accent-a));
    background-repeat: no-repeat;
    background-position: 0 100%;
    background-size: 0% 2px;
    transition: background-size 0.25s ease, color 0.25s ease;
    padding-bottom: 2px;
}

a:hover {
    background-size: 100% 2px;
    color: var(--color-accent-a);
}

a:has(button) {
    display: inline-block;
    background-image: none;
    padding-bottom: 0;
}

a:has(button):hover {
    background-size: 0 0;
    color: inherit;
}

a:focus-visible,
button:focus-visible {
    outline: 2px solid var(--color-accent-a);
    outline-offset: 3px;
    border-radius: 4px;
}

button {
    appearance: none;
    -webkit-appearance: none;
    border: none;
    background: linear-gradient(120deg, var(--color-accent-a), var(--color-accent-b));
    background-size: 160% 160%;
    background-position: 0% 50%;
    border-radius: var(--radius-pill);
    padding: 12px 26px;
    cursor: pointer;
    color: #062033;
    font-family: inherit;
    font-weight: 700;
    font-size: 0.95rem;
    box-shadow: 0 6px 18px -6px rgba(43, 143, 224, 0.6);
    transition: transform 0.2s ease, box-shadow 0.2s ease, background-position 0.4s ease;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

button:hover {
    transform: translateY(-2px) scale(1.02);
    background-position: 100% 50%;
    box-shadow: 0 10px 24px -6px rgba(43, 143, 224, 0.75);
}

button:active {
    transform: translateY(0) scale(0.98);
}

.upbar {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    overflow-x: auto;
    overflow-y: hidden;
    white-space: nowrap;
    padding: var(--space-2);
    scrollbar-width: thin;
    scrollbar-color: rgba(255,255,255,0.6) transparent;
    -webkit-overflow-scrolling: touch;
    -webkit-mask-image: linear-gradient(90deg, transparent, #000 24px, #000 calc(100% - 24px), transparent);
    mask-image: linear-gradient(90deg, transparent, #000 24px, #000 calc(100% - 24px), transparent);
}

.upbar::-webkit-scrollbar {
    height: 6px;
}

.upbar::-webkit-scrollbar-track {
    background: transparent;
}

.upbar::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.5);
    border-radius: 4px;
}

.upbar::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.75);
}

.upbar > * {
    flex-shrink: 0;
}

.upbar button {
    white-space: nowrap;
    padding: 10px 22px;
}

@media (max-width: 768px) {
    body {
        padding: 16px;
        padding-top: max(16px, env(safe-area-inset-top));
        padding-right: max(16px, env(safe-area-inset-right));
        padding-bottom: max(16px, env(safe-area-inset-bottom));
        padding-left: max(16px, env(safe-area-inset-left));
    }
    .ren-box {
        padding: 1.5rem;
        width: 95%;
        margin: 1rem auto;
        border-radius: var(--radius-lg-sm);
    }
    .upbar {
        flex-direction: column;
        align-items: stretch;
        white-space: normal;
        text-align: center;
        border-radius: var(--radius-lg-sm);
        mask-image: none;
        -webkit-mask-image: none;
    }
    button {
        width: 100%;
        text-align: center;
        justify-content: center;
    }
}

hr {
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.4), transparent);
    border: none;
    margin: 28px 0;
}

html {
    scroll-behavior: smooth;
}