/* ============================================================
   Blankenburg Science — shared stylesheet
   Aesthetic: deep-blue scientific × tech/engineer mono accents
   ============================================================ */

:root {
  /* type */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-serif: 'Source Serif 4', 'Source Serif Pro', Georgia, serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, monospace;

  /* dark (default) — deep navy */
  --bg: #0a1428;
  --bg-elev: #0f1d36;
  --bg-card: #122242;
  --bg-card-hover: #16294f;
  --border: #1f3358;
  --border-strong: #2c4b85;
  --text: #e8eef9;
  --text-dim: #a4b4d1;
  --text-faint: #6b7fa3;
  --accent: #4a90ff;
  --accent-dim: #2d5fa8;
  --accent-glow: rgba(74, 144, 255, 0.18);

  /* tag colors */
  --tag-bg: rgba(74, 144, 255, 0.10);
  --tag-border: rgba(74, 144, 255, 0.32);

  /* spacing scale */
  --s-1: 4px;
  --s-2: 8px;
  --s-3: 12px;
  --s-4: 16px;
  --s-5: 24px;
  --s-6: 32px;
  --s-7: 48px;
  --s-8: 64px;
  --s-9: 96px;

  /* layout */
  --maxw: 1200px;
  --maxw-text: 720px;
}

[data-theme="light"] {
  --bg: #fbfaf6;
  --bg-elev: #ffffff;
  --bg-card: #ffffff;
  --bg-card-hover: #f3f1ea;
  --border: #e2dfd6;
  --border-strong: #c8c3b3;
  --text: #0a1428;
  --text-dim: #4a5878;
  --text-faint: #8a93a8;
  --accent-glow: rgba(74, 144, 255, 0.12);
  --tag-bg: rgba(74, 144, 255, 0.08);
  --tag-border: rgba(74, 144, 255, 0.28);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.15s, border-color 0.15s;
}
a:hover { color: var(--text); }

::selection { background: var(--accent); color: var(--bg); }

/* ---------- container ---------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--s-5);
}
.container-text {
  width: 100%;
  max-width: var(--maxw-text);
  margin: 0 auto;
  padding: 0 var(--s-5);
}

/* ---------- header / nav ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(140%) blur(12px);
  -webkit-backdrop-filter: saturate(140%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.site-header .inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: var(--s-4) var(--s-5);
  display: flex;
  align-items: center;
  gap: var(--s-5);
}
.brand {
  display: flex;
  align-items: center;
  gap: var(--s-3);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.02em;
}
.brand-mark {
  width: 28px;
  height: 28px;
  border: 1.5px solid var(--accent);
  border-radius: 4px;
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 13px;
  color: var(--accent);
  background: var(--accent-glow);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-text small { color: var(--text-faint); font-size: 11px; letter-spacing: 0.08em; text-transform: uppercase; }

nav.primary {
  display: flex;
  gap: var(--s-2);
  margin-left: auto;
  align-items: center;
}
nav.primary a {
  color: var(--text-dim);
  font-family: var(--font-mono);
  font-size: 13px;
  padding: 8px 12px;
  border-radius: 6px;
  border: 1px solid transparent;
}
nav.primary a:hover { color: var(--text); background: var(--bg-card); }
nav.primary a.active {
  color: var(--accent);
  border-color: var(--border);
  background: var(--bg-card);
}
nav.primary a.active::before {
  content: "▸ ";
  color: var(--accent);
}

.lang-toggle {
  display: inline-flex;
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
  font-family: var(--font-mono);
  font-size: 12px;
  margin-left: var(--s-3);
}
.lang-toggle button {
  background: transparent;
  border: none;
  color: var(--text-faint);
  padding: 6px 10px;
  cursor: pointer;
  font-family: inherit;
  font-size: inherit;
  letter-spacing: 0.04em;
}
.lang-toggle button.active {
  background: var(--accent);
  color: #fff;
}
[data-theme="light"] .lang-toggle button.active { color: #fff; }

.theme-toggle {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
  width: 32px;
  height: 32px;
  border-radius: 6px;
  cursor: pointer;
  display: grid;
  place-items: center;
  margin-left: var(--s-2);
  transition: all 0.15s;
}
.theme-toggle:hover { border-color: var(--accent); color: var(--accent); }
.theme-toggle svg { width: 16px; height: 16px; }

/* mobile nav */
.menu-btn {
  display: none;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 10px;
  border-radius: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  cursor: pointer;
}

@media (max-width: 820px) {
  .menu-btn { display: inline-block; margin-left: auto; }
  nav.primary {
    display: none;
    position: absolute;
    top: 100%; left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    background: var(--bg-elev);
    border-bottom: 1px solid var(--border);
    padding: var(--s-3);
    margin: 0;
  }
  nav.primary.open { display: flex; }
  nav.primary a { padding: 12px; border-radius: 4px; }
  .lang-toggle, .theme-toggle { margin-top: var(--s-3); }
}

/* ---------- footer ---------- */
.site-footer {
  margin-top: auto;
  border-top: 1px solid var(--border);
  background: var(--bg-elev);
  padding: var(--s-7) 0 var(--s-5);
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-dim);
}
.site-footer .inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--s-5);
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: var(--s-6);
}
.site-footer h4 {
  font-family: var(--font-mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-faint);
  margin: 0 0 var(--s-3);
  font-weight: 500;
}
.site-footer ul { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 6px; }
.site-footer .copy {
  max-width: var(--maxw);
  margin: var(--s-7) auto 0;
  padding: var(--s-4) var(--s-5) 0;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: var(--text-faint);
  letter-spacing: 0.04em;
}
@media (max-width: 720px) {
  .site-footer .inner { grid-template-columns: 1fr; }
  .site-footer .copy { flex-direction: column; gap: var(--s-2); }
}

/* ---------- typography ---------- */
h1, h2, h3, h4 {
  color: var(--text);
  font-family: var(--font-sans);
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: 0 0 var(--s-4);
}
h1 { font-size: clamp(36px, 6vw, 64px); line-height: 1.05; letter-spacing: -0.025em; font-weight: 500; }
h2 { font-size: clamp(24px, 3.2vw, 32px); line-height: 1.15; }
h3 { font-size: 19px; line-height: 1.25; }
h4 { font-size: 15px; }

p { margin: 0 0 var(--s-4); color: var(--text-dim); text-wrap: pretty; }
p.lead {
  font-size: 19px;
  line-height: 1.55;
  color: var(--text);
  font-family: var(--font-serif);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: var(--s-4);
}
.eyebrow::before {
  content: "";
  width: 24px;
  height: 1px;
  background: var(--accent);
}

/* ---------- page header (sub-pages) ---------- */
.page-head {
  padding: var(--s-9) 0 var(--s-7);
  border-bottom: 1px solid var(--border);
}
.page-head h1 {
  font-size: clamp(40px, 5.5vw, 56px);
  margin-bottom: var(--s-3);
}
.page-head p.lead {
  max-width: 640px;
  color: var(--text-dim);
  font-size: 18px;
  font-family: var(--font-serif);
}

/* ---------- sections ---------- */
section { padding: var(--s-8) 0; }
section.tight { padding: var(--s-7) 0; }

.section-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: var(--s-5);
  display: flex;
  align-items: center;
  gap: var(--s-3);
}
.section-label::before {
  content: "";
  flex: 0 0 32px;
  height: 1px;
  background: var(--border-strong);
}
.section-label::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--border);
}

/* ---------- cards / generic ---------- */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: var(--s-5);
  transition: border-color 0.15s, transform 0.15s, background 0.15s;
}
.card:hover {
  border-color: var(--border-strong);
  background: var(--bg-card-hover);
}

/* ---------- tag / chip ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: var(--tag-bg);
  border: 1px solid var(--tag-border);
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  padding: 3px 8px;
  border-radius: 4px;
  text-transform: lowercase;
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  padding: 10px 18px;
  border-radius: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.02em;
  cursor: pointer;
  border: 1px solid var(--border-strong);
  background: transparent;
  color: var(--text);
  transition: all 0.15s;
}
.btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.btn.primary:hover {
  background: var(--text);
  border-color: var(--text);
  color: var(--bg);
}
.btn .arrow { transition: transform 0.15s; }
.btn:hover .arrow { transform: translateX(3px); }

/* ---------- terminal-flavored details ---------- */
.term-line {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-faint);
  letter-spacing: 0.02em;
}
.term-line .prompt { color: var(--accent); }
.term-line .key { color: var(--text-dim); }

/* ---------- hidden language ---------- */
[data-i18n-de], [data-i18n-en] { display: none; }
html[lang="en"] [data-i18n-en] { display: inline; }
html[lang="de"] [data-i18n-de] { display: inline; }
html[lang="en"] [data-i18n-en].block,
html[lang="de"] [data-i18n-de].block { display: block; }
html[lang="en"] [data-i18n-en].flex,
html[lang="de"] [data-i18n-de].flex { display: flex; }

/* When a parent itself is the i18n target */
html[lang="en"] [data-i18n-only="de"] { display: none !important; }
html[lang="de"] [data-i18n-only="en"] { display: none !important; }

/* ---------- tweaks panel ---------- */
.tweaks-panel {
  position: fixed;
  bottom: 20px;
  right: 20px;
  width: 280px;
  background: var(--bg-elev);
  border: 1px solid var(--border-strong);
  border-radius: 10px;
  box-shadow: 0 10px 40px rgba(0,0,0,0.4);
  padding: var(--s-4);
  z-index: 100;
  font-family: var(--font-mono);
  font-size: 12px;
  display: none;
}
.tweaks-panel.open { display: block; }
.tweaks-panel h5 {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-faint);
  margin: 0 0 var(--s-3);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.tweaks-panel h5 button {
  background: transparent;
  border: none;
  color: var(--text-faint);
  cursor: pointer;
  font-size: 14px;
}
.tweak-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--s-2) 0;
  border-top: 1px solid var(--border);
}
.tweak-row:first-of-type { border-top: none; }
.tweak-row label { color: var(--text-dim); }
.swatches { display: flex; gap: 6px; }
.swatch {
  width: 22px; height: 22px; border-radius: 4px; border: 2px solid transparent; cursor: pointer;
  transition: transform 0.1s;
}
.swatch:hover { transform: scale(1.1); }
.swatch.active { border-color: var(--text); }
.hero-variant-buttons {
  display: flex; gap: 4px;
}
.hero-variant-buttons button {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 4px 8px;
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
  font-size: 11px;
}
.hero-variant-buttons button.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

/* ---------- responsive grid utilities ---------- */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: var(--s-5); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--s-5); }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--s-5); }
@media (max-width: 1100px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 820px) {
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: 1fr; }
}

/* ---------- meta block (key/value) ---------- */
.meta {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: var(--s-2) var(--s-4);
  font-family: var(--font-mono);
  font-size: 13px;
  border-top: 1px solid var(--border);
  padding-top: var(--s-4);
  margin-top: var(--s-4);
}
.meta dt { color: var(--text-faint); text-transform: lowercase; letter-spacing: 0.02em; }
.meta dd { color: var(--text); margin: 0; }
@media (max-width: 600px) {
  .meta { grid-template-columns: 1fr; gap: 2px var(--s-4); }
  .meta dd { margin-bottom: var(--s-2); }
}