/* ユランシアの書入門サイト — 共通スタイル（コズミック・テーマ） */

:root {
  --color-bg: #070914;
  --color-bg-panel: #10142450;
  --color-ink: #e9ecf6;
  --color-ink-soft: #b7bfd6;
  --color-accent: #d9b06a;      /* 星の金 */
  --color-accent-light: #f0cd8e;
  --color-violet: #8b93e0;      /* 深宇宙の紫青 */
  --color-line: #2a2f47;
  --font-serif: "Yu Mincho", "Hiragino Mincho ProN", "Noto Serif JP", serif;
  --font-sans: "Hiragino Sans", "Yu Gothic", "Noto Sans JP", sans-serif;
}

* { box-sizing: border-box; }

html { background: var(--color-bg); }

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-ink);
  font-family: var(--font-sans);
  line-height: 1.9;
  font-size: 16px;
  position: relative;
  overflow-x: hidden;
}

/* --- 星空レイヤー（CSSのみ、画像不要） --- */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  background-color: var(--color-bg);
  background-image:
    radial-gradient(1.6px 1.6px at 20px 30px, #fff, transparent),
    radial-gradient(1.2px 1.2px at 90px 120px, #fff, transparent),
    radial-gradient(1.8px 1.8px at 160px 60px, #fff, transparent),
    radial-gradient(1px 1px at 210px 180px, #fff, transparent),
    radial-gradient(1.4px 1.4px at 50px 200px, #fff, transparent),
    radial-gradient(1px 1px at 130px 15px, #fff, transparent),
    radial-gradient(1.6px 1.6px at 240px 100px, #fff, transparent),
    radial-gradient(1px 1px at 5px 140px, #fff, transparent);
  background-repeat: repeat;
  background-size: 260px 260px;
  opacity: 0.55;
}

/* ほのかな星雲の光暈 */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(ellipse 60% 40% at 15% 10%, rgba(139,147,224,0.16), transparent 60%),
    radial-gradient(ellipse 50% 35% at 90% 80%, rgba(217,176,106,0.10), transparent 60%);
}

header.site-header {
  background: rgba(7, 9, 20, 0.85);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--color-line);
  color: #fff;
  padding: 1.2rem 2rem;
  position: sticky;
  top: 0;
  z-index: 10;
}

.site-header .inner {
  max-width: 960px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.site-title {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  letter-spacing: 0.05em;
  color: var(--color-accent-light);
  text-decoration: none;
}

nav.main-nav a {
  color: var(--color-ink-soft);
  text-decoration: none;
  margin-left: 1.5rem;
  font-size: 0.95rem;
  transition: color 0.2s ease;
}

nav.main-nav a:hover,
nav.main-nav a[aria-current="page"] {
  color: var(--color-accent-light);
  border-bottom: 1px solid var(--color-accent);
}

main {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 1.5rem 4rem;
  position: relative;
  z-index: 1;
}

/* --- ヒーロー（星雲写真つき） --- */
.hero {
  text-align: center;
  padding: 6rem 1.5rem 5rem;
  margin: 0 calc(50% - 50vw) 3rem;
  width: 100vw;
  max-width: 100vw;
  background-size: cover;
  background-position: center;
  position: relative;
  border-bottom: 1px solid var(--color-line);
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(7,9,20,0.55) 0%, rgba(7,9,20,0.80) 55%, rgba(7,9,20,1) 100%);
}

.hero > * {
  position: relative;
  z-index: 1;
}

.hero.hero-cover   { background-image: url("/images/urantia-cover.jpg"); background-position: center 30%; }
.hero.hero-carina  { background-image: url("https://images-assets.nasa.gov/image/carina_nebula/carina_nebula~large.jpg"); }
.hero.hero-eagle   { background-image: url("https://images-assets.nasa.gov/image/PIA24577/PIA24577~large.jpg"); }
.hero.hero-deepfield { background-image: url("https://images-assets.nasa.gov/image/GSFC_20171208_Archive_e001651/GSFC_20171208_Archive_e001651~large.jpg"); }

.hero h1 {
  font-family: var(--font-serif);
  font-size: 2.3rem;
  margin-bottom: 0.6rem;
  color: #fff;
  text-shadow: 0 2px 18px rgba(0,0,0,0.6);
}

.hero p.lead {
  font-size: 1.15rem;
  color: #dfe3f2;
  max-width: 32rem;
  margin: 0 auto;
}

/* ヒーローがないページ用の簡易タイトル */
.page-title {
  font-family: var(--font-serif);
  font-size: 1.8rem;
  color: var(--color-accent-light);
  text-align: center;
  padding: 3rem 0 1rem;
}

h1, h2, h3 {
  font-family: var(--font-serif);
  color: var(--color-accent-light);
}

h2 {
  font-size: 1.5rem;
  margin-top: 2.8rem;
  border-left: 4px solid var(--color-violet);
  padding-left: 0.7rem;
}

a { color: var(--color-violet); }
a:hover { color: var(--color-accent-light); }

.cta-box {
  background: rgba(16, 20, 36, 0.75);
  border: 1px solid var(--color-line);
  border-radius: 10px;
  padding: 1.8rem;
  margin: 2.5rem 0;
  text-align: center;
  box-shadow: 0 0 40px rgba(139,147,224,0.06);
}

.cta-box a.button {
  display: inline-block;
  margin-top: 0.9rem;
  background: linear-gradient(135deg, var(--color-accent), #b8863f);
  color: #1b1300;
  font-weight: 600;
  text-decoration: none;
  padding: 0.8rem 1.8rem;
  border-radius: 999px;
  font-size: 0.95rem;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.cta-box a.button:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 18px rgba(217,176,106,0.35);
}

footer.site-footer {
  text-align: center;
  padding: 2.5rem 1.5rem;
  color: #7c86a3;
  font-size: 0.85rem;
  border-top: 1px solid var(--color-line);
  position: relative;
  z-index: 1;
}

.notice {
  background: rgba(217, 176, 106, 0.08);
  border: 1px solid rgba(217, 176, 106, 0.35);
  color: var(--color-ink-soft);
  padding: 1.1rem 1.3rem;
  border-radius: 6px;
  font-size: 0.9rem;
  margin: 2.2rem 0;
}

.credit {
  font-size: 0.85rem;
  color: #7c86a3;
  margin-top: 3rem;
}

/* テーマカラーに合わせた本文リンクの下線調整 */
main p a { text-decoration: underline; text-underline-offset: 2px; }

/* 会員専用エリア用の控えめなヘッダー帯 */
.members-banner {
  background: linear-gradient(135deg, rgba(139,147,224,0.14), rgba(217,176,106,0.10));
  border: 1px solid var(--color-line);
  border-radius: 8px;
  padding: 1.2rem 1.5rem;
  margin: 2rem 0;
  font-size: 0.92rem;
  color: var(--color-ink-soft);
}