/* 星空観測ノート — ダーク＋シアン（セピア・小麦色サイトと差別化） */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
    --void: #070b14;
    --night: #0f1628;
    --night2: #162238;
    --cyan: #5ee7df;
    --cyan-dim: #3db9b3;
    --text: #e8f4f3;
    --muted: #8aa7a5;
    --line: rgba(94, 231, 223, 0.18);
    --glow: 0 0 40px rgba(94, 231, 223, 0.15);
    --radius: 14px;
    --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

html { scroll-behavior: smooth; }

body {
    font-family: "Noto Sans JP", system-ui, sans-serif;
    background: var(--void);
    color: var(--text);
    line-height: 1.75;
    font-size: 16px;
}

h1, h2, h3 {
    font-family: "Noto Sans JP", system-ui, sans-serif;
    font-weight: 600;
    letter-spacing: 0.08em;
}

a { color: var(--cyan); text-decoration: none; }
a:hover { color: #8ffcf5; }

.wrap { max-width: 960px; margin: 0 auto; padding: 0 1.25rem; }

/* バー型ナビ（中央寄せ） */
.site-bar {
    position: sticky;
    top: 0;
    z-index: 400;
    background: rgba(7, 11, 20, 0.88);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--line);
}
.site-bar__inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.65rem;
    padding: 0.85rem 0;
}
.site-bar__brand {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text);
    text-align: center;
}
.site-bar__brand small { display: block; font-size: 0.68rem; color: var(--muted); font-weight: 400; margin-top: 0.25rem; }

.site-nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.35rem;
}
.site-nav__a {
    padding: 0.35rem 0.7rem;
    font-size: 0.78rem;
    color: var(--muted);
    border-radius: 999px;
    border: 1px solid transparent;
    transition: border-color 0.2s, color 0.2s, box-shadow 0.2s;
}
.site-nav__a:hover { border-color: var(--line); color: var(--text); }
.site-nav__a.is-on {
    color: var(--void);
    background: var(--cyan);
    box-shadow: var(--glow);
}

.site-bar__toggle {
    display: none;
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    width: 44px;
    height: 44px;
    border: 1px solid var(--line);
    border-radius: 10px;
    background: var(--night2);
    cursor: pointer;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
}
.site-bar__toggle span { display: block; width: 20px; height: 2px; background: var(--cyan); }

@media (max-width: 820px) {
    .site-bar { position: relative; }
    .site-bar__inner { align-items: flex-start; padding-right: 3.5rem; }
    .site-bar__toggle { display: flex; }
    .site-nav {
        display: none;
        width: 100%;
        flex-direction: column;
        align-items: stretch;
    }
    .site-nav.is-open { display: flex; }
}

.hero {
    position: relative;
    min-height: 46vh;
    display: flex;
    align-items: flex-end;
    overflow: hidden;
}
.hero__canvas {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    pointer-events: none;
}
.hero__bg {
    position: absolute;
    inset: 0;
    z-index: 0;
    background-size: cover;
    background-position: center;
}
.hero__overlay {
    position: absolute;
    inset: 0;
    z-index: 2;
    background: linear-gradient(180deg, rgba(7, 11, 20, 0.25) 0%, rgba(7, 11, 20, 0.92) 85%);
}
.hero__inner { position: relative; z-index: 3; padding: 2.5rem 0 2.75rem; }
.hero__tag { font-size: 0.72rem; letter-spacing: 0.35em; color: var(--cyan-dim); margin-bottom: 0.6rem; }
.hero__h1 { font-size: clamp(1.45rem, 3.5vw, 2.05rem); margin-bottom: 0.75rem; }
.hero__lead { max-width: 46ch; font-size: 0.92rem; color: var(--muted); }

.content { padding: 2.25rem 0 3.5rem; }

.section__h2 {
    font-size: 1.28rem;
    margin-bottom: 1rem;
    color: var(--cyan);
}

.bento {
    display: grid;
    gap: 1rem;
}
@media (min-width: 680px) {
    .bento { grid-template-columns: 1fr 1fr; }
    .bento .tile--wide { grid-column: 1 / -1; }
}

.tile {
    background: linear-gradient(145deg, var(--night) 0%, var(--night2) 100%);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    overflow: hidden;
    transition: transform 0.35s var(--ease), box-shadow 0.35s;
}
.tile:hover { transform: translateY(-3px); box-shadow: var(--glow); }
.tile__img { width: 100%; aspect-ratio: 16/10; object-fit: cover; display: block; opacity: 0.95; }
.tile__body { padding: 1rem 1.15rem 1.25rem; }
.tile__h3 { font-size: 1rem; margin-bottom: 0.35rem; }
.tile__p { font-size: 0.86rem; color: var(--muted); }

.article p { margin-bottom: 1rem; }
.article ul, .article ol { margin: 0 0 1rem 1.2rem; }

/* 星座ページ：トグル */
.toggle-block {
    margin: 1.25rem 0;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    overflow: hidden;
    background: var(--night);
}
.toggle-block__btn {
    width: 100%;
    padding: 0.85rem 1rem;
    text-align: left;
    font-family: inherit;
    font-size: 0.95rem;
    color: var(--text);
    background: var(--night2);
    border: none;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.toggle-block__btn::after { content: "+"; color: var(--cyan); font-size: 1.2rem; }
.toggle-block__btn.is-open::after { content: "−"; }
.toggle-block__panel {
    display: none;
    padding: 0 1rem 1rem;
    font-size: 0.92rem;
    color: var(--muted);
}
.toggle-block__panel.is-open { display: block; }

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(170px, 1fr));
    gap: 0.6rem;
}
.gallery-grid button {
    border: none;
    padding: 0;
    cursor: pointer;
    border-radius: 10px;
    overflow: hidden;
    aspect-ratio: 1;
    border: 1px solid var(--line);
}
.gallery-grid img { width: 100%; height: 100%; object-fit: cover; }

.lightbox {
    position: fixed;
    inset: 0;
    z-index: 500;
    background: rgba(4, 8, 16, 0.94);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.35s, visibility 0.35s;
}
.lightbox.is-open { opacity: 1; visibility: visible; }
.lightbox__img { max-width: min(880px, 100%); max-height: 85vh; border-radius: 10px; }
.lightbox__close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    width: 44px;
    height: 44px;
    border: none;
    border-radius: 50%;
    background: var(--cyan);
    color: var(--void);
    font-size: 1.4rem;
    cursor: pointer;
}

.contact-box {
    background: var(--night);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1.75rem;
}

.site-ft {
    border-top: 1px solid var(--line);
    padding: 1.5rem 0;
    font-size: 0.76rem;
    color: var(--muted);
    text-align: center;
}

.to-top {
    position: fixed;
    bottom: 1.2rem;
    right: 1.2rem;
    width: 46px;
    height: 46px;
    border-radius: 50%;
    border: 1px solid var(--line);
    background: var(--night2);
    color: var(--cyan);
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
    z-index: 250;
}
.to-top.is-visible { opacity: 1; visibility: visible; }

.reveal {
    opacity: 0;
    transform: translateY(12px);
    transition: opacity 0.55s var(--ease), transform 0.55s;
}
.reveal.is-inview { opacity: 1; transform: none; }

.skip-link { position: absolute; left: -9999px; }
.skip-link:focus {
    left: 1rem;
    top: 1rem;
    z-index: 500;
    padding: 0.5rem 1rem;
    background: var(--cyan);
    color: var(--void);
}