:root {
  --bg: #ffffff;
  --text: #0e0e12;
  --muted: #4a4a52;
  --border: #e7e7ea;
  --primary: #111111;
  --shadow: 0 8px 24px rgba(0,0,0,0.08);
}

:root.dark {
  --bg: #0e0e12;
  --text: #f5f5f7;
  --muted: #b7b7c0;
  --border: #1c1c21;
  --primary: #ffffff;
  --shadow: 0 10px 30px rgba(0,0,0,0.35);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: "Noto Sans", system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 20px;
}

a { color: var(--text); text-decoration: none; }
a:hover { text-decoration: underline; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  backdrop-filter: saturate(180%) blur(6px);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 14px 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
}
.brand-mark { display: inline-block; }
.brand-text { font-size: 18px; letter-spacing: 0.4px; }

.main-nav {
  margin-left: auto;
  position: relative;
}
.nav-toggle {
  display: none;
  width: 36px; height: 36px;
  border: 1px solid var(--border);
  background: transparent;
  border-radius: 8px;
}
.nav-toggle::before {
  content: "";
  display: block;
  width: 18px; height: 2px; background: var(--text);
  margin: 16px auto 0;
  box-shadow: 0 6px 0 0 var(--text), 0 -6px 0 0 var(--text);
}
.nav-list {
  display: flex; gap: 18px; list-style: none; margin: 0; padding: 0;
}
.nav-list a {
  padding: 8px 10px;
  border-radius: 8px;
}
.nav-list a:hover {
  background: rgba(127,127,127,0.08);
  text-decoration: none;
}

.theme-toggle {
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text);
  border-radius: 8px;
  padding: 8px 10px;
}

.hero {
  padding: 72px 0 40px;
  border-bottom: 1px solid var(--border);
}
.hero-inner {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 32px;
  align-items: center;
}
.hero-copy h1 {
  font-size: 40px;
  line-height: 1.2;
  margin: 0 0 12px;
}
.lead { color: var(--muted); font-size: 18px; }
.hero-actions { margin-top: 18px; display: flex; gap: 12px; }
.btn {
  display: inline-block;
  border: 1px solid var(--border);
  padding: 10px 14px;
  border-radius: 10px;
  background: transparent;
  color: var(--text);
  transition: transform 120ms ease, background 120ms ease;
}
.btn:hover { transform: translateY(-1px); background: rgba(127,127,127,0.08); }
.btn.primary {
  background: var(--text);
  color: var(--bg);
  border-color: var(--text);
}
.btn.small { padding: 8px 12px; border-radius: 8px; }

.hero-svg { width: 100%; height: auto; color: var(--text); }

.section {
  padding: 52px 0;
}
.section.alt {
  background: rgba(127,127,127,0.06);
}
.section h2 {
  font-size: 28px;
  margin: 0 0 8px;
}
.section-lead { color: var(--muted); margin-bottom: 24px; }

.grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 16px;
}
.cards .card {
  grid-column: span 6;
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
  background: var(--bg);
  box-shadow: var(--shadow);
}
.cards .card h3 { margin-top: 0; }

.info-block {
  margin-top: 18px;
  border: 1px dashed var(--border);
  padding: 16px;
  border-radius: 12px;
}

.simulator {
  display: grid;
  grid-template-columns: 1fr 420px;
  gap: 18px;
  align-items: start;
}
.sim-controls {
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  background: var(--bg);
  box-shadow: var(--shadow);
}
.control { margin-bottom: 14px; }
.control label { display: block; margin-bottom: 6px; font-weight: 600; }
.control input[type="range"] {
  width: 100%;
}
.hint { color: var(--muted); font-size: 12px; }
.gate-row { display: grid; grid-template-columns: 1fr auto auto; gap: 8px; align-items: end; }

.probabilities {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-top: 8px;
  font-family: "Space Mono", monospace;
}
.sequence {
  margin-top: 8px;
  color: var(--muted);
  min-height: 28px;
}

.sim-visual {
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  background: var(--bg);
  box-shadow: var(--shadow);
}
#bloch {
  width: 100%;
  height: auto;
  display: block;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 20px 0;
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.site-footer nav a { margin-right: 12px; }

/* Responsive */
@media (max-width: 980px) {
  .hero-inner { grid-template-columns: 1fr; }
  .simulator { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
  .nav-toggle { display: inline-block; }
  .nav-list {
    position: absolute;
    right: 0;
    top: 48px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 10px;
    display: none;
    flex-direction: column;
    gap: 6px;
    min-width: 180px;
    box-shadow: var(--shadow);
  }
  .nav-list.open { display: flex; }
  .cards .card { grid-column: span 12; }
}