/* ========================================
   Cosmonologue -- Gray Theme
   ======================================== */

:root {
  /* Colors - neutral gray */
  --c-text: #2a2a2a;
  --c-text-muted: #909090;
  --c-link: #505050;
  --c-accent: #505050;
  --c-accent-light: #c0c0c0;
  --c-border: #e0e0e0;
  --c-bg: #f8f8f8;
  --c-bg-card: #fff;
  --c-bg-subtle: #f0f0f0;

  /* Typography - System fonts */
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-serif: Georgia, "Times New Roman", serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;

  /* Layout */
  --max-width: 960px;
  --gutter: 1.5rem;
  --radius: 12px;
}

/* ----------------------------------------
   Base
   ---------------------------------------- */

*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  font: 1.0625rem/1.8 var(--font-sans);
  letter-spacing: 0.02em;
  color: var(--c-text);
  background: var(--c-bg) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='80' height='80'%3E%3Ccircle cx='40' cy='40' r='30' fill='none' stroke='%23d4d4d4' stroke-width='0.4'/%3E%3Cpolygon points='40,10 65.98,55 14.02,55' fill='none' stroke='%23d4d4d4' stroke-width='0.5'/%3E%3Cpolygon points='40,70 14.02,25 65.98,25' fill='none' stroke='%23d4d4d4' stroke-width='0.5'/%3E%3C/svg%3E");
  margin: 0;
  min-height: 100vh;
}

body::before {
  content: "";
  display: block;
  height: 4px;
  background: var(--c-accent);
}

::selection {
  background: var(--c-border);
}

/* ----------------------------------------
   Layout
   ---------------------------------------- */

header, main, aside, nav, footer, body > h4 {
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

header { padding-block: 1.5rem 1rem; }
main { padding-bottom: 0.5rem; }

/* ----------------------------------------
   Header
   ---------------------------------------- */

header p {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  margin: 0;
}

header p + p {
  font-size: 0.85rem;
  font-weight: 400;
  color: var(--c-accent);
  letter-spacing: 0.02em;
  margin-top: 0.25rem;
}

header p + p strong {
  letter-spacing: 0.1em;
}

header a {
  color: var(--c-text);
  text-decoration: none;
  background: none;
  transition: opacity 0.2s;
}

header a:hover {
  opacity: 0.6;
  background: none;
}

header hr {
  display: none;
}

/* ----------------------------------------
   Article
   ---------------------------------------- */

article {
  background: var(--c-bg-card);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: 0 1px 3px rgb(0 0 0 / 4%), 0 4px 12px rgb(0 0 0 / 3%);
}

article h1 {
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.5;
  letter-spacing: 0.04em;
  margin: 0 0 0.5rem;
}

article h1 + p { margin-top: 1.5rem; }

article h2 {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  margin: 1.5rem 0 0.75rem;
}

article h2::before {
  display: none;
}

article h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin: 2.5rem 0 0.75rem;
}

article h4,
article h5,
article h6 {
  font-size: 1rem;
  font-weight: 600;
  margin: 2rem 0 0.5rem;
}

article a { font-weight: 500; text-decoration: underline; background-image: none; }
article a:hover { background-image: none; }

article em,
article strong {
  font-style: normal;
  font-weight: 600;
}

/* ----------------------------------------
   Typography
   ---------------------------------------- */

p { margin: 0 0 1.5rem; }

a {
  color: var(--c-link);
  text-decoration: none;
  background: linear-gradient(var(--c-accent), var(--c-accent)) 0 100% / 0% 2px no-repeat;
  transition: background-size 0.25s;
}

a:hover { background-size: 100% 2px; }

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

/* ----------------------------------------
   Lists
   ---------------------------------------- */

ul, ol {
  margin: 0 0 1.5rem;
  padding-left: 1.25rem;
}

li {
  margin: 0.25rem 0;
  padding-left: 0.5rem;
}

li::marker { color: var(--c-accent); }

/* ----------------------------------------
   Blockquote
   ---------------------------------------- */

blockquote {
  margin: 2rem 0;
  padding: 1.5rem 2rem;
  background: linear-gradient(135deg, #faf7f7, var(--c-bg-subtle));
  border-left: 4px solid var(--c-accent);
  border-radius: var(--radius);
  font: italic 1.125rem var(--font-serif);
}

blockquote p { margin: 0; }

/* ----------------------------------------
   Code
   ---------------------------------------- */

code, tt {
  font: 0.875em var(--font-mono);
  background: var(--c-bg-subtle);
  border-radius: 6px;
  padding: 0.2em 0.5em;
}

pre {
  font: 0.875rem/1.7 var(--font-mono);
  background: var(--c-bg-subtle);
  color: var(--c-link);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  margin: 2rem 0;
  overflow-x: auto;
}

pre code,
pre tt {
  background: none;
  padding: 0;
}

/* ----------------------------------------
   Table
   ---------------------------------------- */

table {
  width: 100%;
  border-collapse: collapse;
  border-radius: var(--radius);
  margin: 2rem 0;
  font-size: 0.9375rem;
  overflow: hidden;
}

th, td {
  text-align: left;
  padding: 0.4rem 1.25rem;
}

th {
  font-weight: 600;
  background: var(--c-bg-subtle);
  border-bottom: 2px solid var(--c-border);
}

td { border-bottom: 1px solid var(--c-border); }
tr:last-child td { border-bottom: none; }
tr:hover td { background: #faf7f7; }

/* ----------------------------------------
   Misc Elements
   ---------------------------------------- */

hr {
  border: none;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--c-border), transparent);
  margin: 1.5rem 0;
}

img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius);
  margin: 1rem 0;
}

img.card {
  max-width: 160px;
  /* filter: grayscale(100%) invert(100%); */
  opacity: 0.96;
}

#cards-ref img {
  margin-bottom: 0;
}

#cards-ref a {
  background-image: none;
}

#cards-ref a:hover {
  background-image: none;
}

time {
  display: block;
  margin-top: 2.5rem;
  font-size: 0.9375rem;
  text-align: right;
}

article[lang="ja"] {
  font-size: 0.999rem;
}

/* ----------------------------------------
   Navigation
   ---------------------------------------- */

body > h4 {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--c-text-muted);
  margin: 1rem auto 0.75rem;
}

nav { margin-bottom: 1rem; }

nav ul {
  list-style: none;
  display: grid;
  gap: 0.75rem;
  padding: 0;
  margin: 0;
}

nav li {
  margin: 0;
  padding: 0;
}

nav a {
  display: block;
  padding: 1rem 1.25rem;
  background: var(--c-bg-card);
  border-radius: var(--radius);
  font-weight: 500;
  color: var(--c-text);
  box-shadow: 0 1px 2px rgb(0 0 0 / 4%);
  transition: transform 0.15s, box-shadow 0.15s;
}

nav a,
nav a:hover { background-image: none; }

nav a:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgb(0 0 0 / 8%);
}

nav a > span::after {
  content: " →";
  color: var(--c-accent);
  opacity: 0;
  transition: opacity 0.15s;
}

nav a:hover > span::after { opacity: 1; }

nav a small { font-weight: normal; }

/* ----------------------------------------
   Aside & Footer
   ---------------------------------------- */

aside {
  font-size: 0.9375rem;
  color: var(--c-text-muted);
  margin-bottom: 0;
}

aside p { margin: 0; }

footer {
  padding: 1rem var(--gutter);
  margin-top: 0;
  text-align: center;
  font-size: 0.8125rem;
  color: var(--c-text-muted);
}

footer a,
footer a:hover { background-image: none; }
footer a { color: var(--c-text-muted); }
footer a:hover { color: var(--c-accent); }

/* ----------------------------------------
   Responsive
   ---------------------------------------- */

@media (max-width: 640px) {
  :root { --gutter: 0.8rem; }

  header { padding-top: 2.5rem; }

  article {
    margin-inline: calc(-1 * var(--gutter));
    padding: var(--gutter);
    border-radius: 0;
    border-block: 1px solid var(--c-border);
    box-shadow: none;
  }

  article h1 { font-size: 1.875rem; }
  article h2 { font-size: 1.25rem; }

  blockquote {
    padding: 1rem 1.25rem;
    margin: 1.5rem 0;
  }

  pre {
    margin-inline: calc(-1 * var(--gutter));
    padding: 1.25rem var(--gutter);
    border-radius: 0;
  }
}

/* ----------------------------------------
   Embeds (YouTube etc.)
   ---------------------------------------- */

iframe {
  max-width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  display: block;
  margin: 1rem 0;
}

/* ----------------------------------------
   Subscribe Form
   ---------------------------------------- */

#subscribe-form {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
  margin: 1rem 0;
}

#subscribe-form input[type="email"] {
  font: 0.875rem var(--font-sans);
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--c-border);
  border-radius: 6px;
  background: var(--c-bg-card);
  color: var(--c-text);
  width: 220px;
  max-width: 50vw;
}

#subscribe-form input[type="email"]:focus {
  outline: 2px solid var(--c-accent);
  outline-offset: 1px;
}

#subscribe-form button {
  font: 600 0.875rem var(--font-sans);
  padding: 0.5rem 1rem;
  border: 1px solid var(--c-accent);
  border-radius: 6px;
  background: var(--c-accent);
  color: var(--c-bg);
  cursor: pointer;
  transition: opacity 0.2s;
}

#subscribe-form button:hover {
  opacity: 0.8;
}

/* ----------------------------------------
   Paywall Prompt
   ---------------------------------------- */

.paywall-prompt {
  text-align: center;
  padding: 2rem 1rem;
  margin-top: 1.5rem;
}

.paywall-prompt button {
  font: 600 1rem var(--font-sans);
  padding: 0.75rem 2rem;
  border: 1px solid var(--c-accent);
  border-radius: 6px;
  background: var(--c-accent);
  color: var(--c-bg);
  cursor: pointer;
  transition: opacity 0.2s;
}

.paywall-prompt button:hover { opacity: 0.8; }

.paywall-note {
  font-size: 0.875rem;
  color: var(--c-text-muted);
}

/* ----------------------------------------
   Print
   ---------------------------------------- */

/* TTS play button */
#tts-btn {
  display: inline-flex; align-items: center;
  vertical-align: middle;
  margin-left: 0.4em; padding: 0;
  border: none; background: transparent; cursor: pointer;
  font-size: 1.1rem; color: var(--c-accent);
}

@media print {
  body::before { display: none; }
  body { background: #fff; font-size: 11pt; }

  article { box-shadow: none; padding: 0; }
  header, nav, aside, footer, h4, #subscribe-form, .paywall-prompt { display: none; }

  a { color: inherit; }
}