/* ===== Base Reset ===== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* ===== Design Tokens ===== */
:root {
    --bg: #0a0a0f;
    --accent: #00ffc8;
    --accent-dim: rgba(0, 255, 200, 0.12);
    --accent-glow: rgba(0, 255, 200, 0.25);
    --text: #e0e0e0;
    --text-muted: #888;
    --border: rgba(0, 255, 200, 0.10);
    --border-hover: rgba(0, 255, 200, 0.35);
    --font-mono: 'JetBrains Mono', 'Menlo', 'Consolas', monospace;
    --font-sans: 'Noto Sans JP', 'Hiragino Kaku Gothic ProN', sans-serif;
    --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Body ===== */
body {
    font-family: var(--font-sans);
    background: var(--bg);
    color: var(--text);
    min-height: 100dvh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem 1rem;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* ===== Grid Canvas (背景) ===== */
#grid-canvas {
    position: fixed;
    inset: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
}

/* ===== Container ===== */
.container {
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: 460px;
}

/* ===== Title ===== */
.site-title {
    font-family: var(--font-mono);
    font-size: clamp(1.1rem, 4vw, 1.4rem);
    font-weight: 500;
    color: var(--accent);
    text-align: center;
    margin-bottom: 2.5rem;
    letter-spacing: 0.12em;
    text-shadow: 0 0 20px rgba(0, 255, 200, 0.3);
}

/* ===== Link List ===== */
.link-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.link-list li {
    opacity: 0;
    animation: fade-up 0.5s ease forwards;
    animation-delay: calc(var(--i) * 0.06s);
}

/* ===== Link Button ===== */
.link-button {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding: 0.95rem 1.25rem;
    background: transparent;
    color: var(--text);
    text-decoration: none;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.95rem;
    font-weight: 300;
    letter-spacing: 0.03em;
    transition:
        border-color var(--transition),
        background var(--transition),
        box-shadow var(--transition),
        transform var(--transition);
    position: relative;
    overflow: hidden;
}

/* ホバー時のスキャンライン */
.link-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, var(--accent-dim), transparent);
    transition: left 0.5s ease;
}

.link-button:hover::before {
    left: 100%;
}

.link-button:hover {
    border-color: var(--border-hover);
    background: rgba(0, 255, 200, 0.04);
    box-shadow: 0 0 20px rgba(0, 255, 200, 0.06);
    transform: translateX(4px);
}

.link-button:active {
    transform: translateX(4px) scale(0.98);
}

/* ===== Link Label & Arrow ===== */
.link-label {
    font-family: var(--font-mono);
    font-weight: 400;
}

.link-arrow {
    font-family: var(--font-mono);
    color: var(--text-muted);
    font-size: 0.85rem;
    transition: color var(--transition), transform var(--transition);
}

.link-button:hover .link-arrow {
    color: var(--accent);
    transform: translateX(3px);
}

/* ===== Animations ===== */
@keyframes fade-up {
    from {
        opacity: 0;
        transform: translateY(12px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== Responsive ===== */
@media (max-width: 480px) {
    body {
        padding: 3rem 1rem;
        align-items: flex-start;
    }

    .site-title {
        margin-bottom: 2rem;
    }

    .link-button {
        padding: 0.85rem 1rem;
        font-size: 0.9rem;
    }
}

@media (max-width: 360px) {
    .link-button {
        padding: 0.75rem 0.85rem;
        font-size: 0.85rem;
    }
}