@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@300;400;500&family=DM+Serif+Display:ital@0;1&display=swap');

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:       #0a0a0a;
  --surface:  #111111;
  --border:   #1e1e1e;
  --muted:    #3a3a3a;
  --text:     #c8c8c8;
  --bright:   #f0f0f0;
  --accent:   #00e5a0;
  --accent2:  #005c40;
  --mono:     'IBM Plex Mono', monospace;
  --serif:    'DM Serif Display', serif;
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.7;
  min-height: 100vh;
}

nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2.5rem;
  height: 56px;
  background: rgba(10,10,10,0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.nav-logo {
  font-family: var(--mono);
  font-weight: 500;
  font-size: 13px;
  color: var(--bright);
  text-decoration: none;
  letter-spacing: 0.08em;
}

.nav-logo span { color: var(--accent); }

nav ul { display: flex; gap: 2rem; list-style: none; }

nav ul a {
  color: var(--muted);
  text-decoration: none;
  font-size: 12px;
  letter-spacing: 0.06em;
  transition: color 0.15s;
}

nav ul a:hover { color: var(--accent); }

.nav-cta {
  background: var(--accent);
  color: #000 !important;
  padding: 6px 16px;
  font-size: 12px !important;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-decoration: none;
  transition: opacity 0.15s;
}

.nav-cta:hover { opacity: 0.85; }

.hero {
  padding: 140px 2.5rem 100px;
  max-width: 900px;
  margin: 0 auto;
}

.hero-tag {
  display: inline-block;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--accent);
  border: 1px solid var(--accent2);
  padding: 3px 10px;
  margin-bottom: 2.5rem;
  text-transform: uppercase;
}

.hero h1 {
  font-family: var(--serif);
  font-size: clamp(2.8rem, 6vw, 5.2rem);
  line-height: 1.08;
  color: var(--bright);
  font-weight: 400;
  margin-bottom: 2rem;
}

.hero h1 em { font-style: italic; color: var(--accent); }

.hero-sub {
  font-size: 14px;
  color: var(--text);
  max-width: 520px;
  margin-bottom: 3rem;
  line-height: 1.8;
}

.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; align-items: center; }

.btn-primary {
  background: var(--accent);
  color: #000;
  padding: 11px 28px;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-decoration: none;
  text-transform: uppercase;
  transition: opacity 0.15s;
  display: inline-block;
}

.btn-primary:hover { opacity: 0.85; }

.btn-ghost {
  color: var(--muted);
  padding: 11px 28px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-decoration: none;
  border: 1px solid var(--border);
  transition: color 0.15s, border-color 0.15s;
  display: inline-block;
}

.btn-ghost:hover { color: var(--bright); border-color: var(--muted); }

.math-strip {
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 1.2rem 0;
  overflow: hidden;
}

.math-strip-inner {
  display: flex;
  gap: 3rem;
  animation: marquee 32s linear infinite;
  width: max-content;
}

.math-strip span {
  font-size: 12px;
  color: var(--muted);
  white-space: nowrap;
  letter-spacing: 0.06em;
  padding: 0 1.5rem;
}

.math-strip span.hi { color: var(--accent); }

@keyframes marquee {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}

section {
  max-width: 900px;
  margin: 0 auto;
  padding: 80px 2.5rem;
}

.section-label {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 3rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.section-label::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

.steps { display: grid; gap: 0; }

.step {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 2rem;
  padding: 2rem 0;
  border-bottom: 1px solid var(--border);
}

.step:first-child { border-top: 1px solid var(--border); }

.step-num { font-size: 11px; color: var(--accent); letter-spacing: 0.1em; padding-top: 3px; }

.step h3 {
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 500;
  color: var(--bright);
  margin-bottom: 0.5rem;
}

.step p { font-size: 13px; color: var(--text); line-height: 1.7; }

.props {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  margin-top: 2rem;
}

.prop { background: var(--bg); padding: 1.8rem; }

.prop-icon { font-size: 18px; margin-bottom: 1rem; display: block; }

.prop h3 { font-size: 13px; font-weight: 500; color: var(--bright); margin-bottom: 0.5rem; }

.prop p { font-size: 12px; color: var(--text); line-height: 1.7; }

.code-block {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 1.8rem;
  margin-top: 2rem;
  position: relative;
  overflow-x: auto;
}

.code-block::before {
  content: attr(data-lang);
  position: absolute;
  top: 0.8rem; right: 1rem;
  font-size: 10px;
  color: var(--muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.code-block pre {
  font-family: var(--mono);
  font-size: 12.5px;
  line-height: 1.8;
  color: var(--text);
  white-space: pre;
}

.code-block .kw  { color: var(--accent); }
.code-block .str { color: #7ec8a0; }
.code-block .cm  { color: var(--muted); }
.code-block .num { color: #a8d8ea; }

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  margin-top: 2rem;
}

.plan { background: var(--bg); padding: 2.4rem 2rem; }

.plan.featured { background: var(--surface); position: relative; }

.plan.featured::before {
  content: 'MOST COMMON';
  position: absolute;
  top: -1px; left: 2rem;
  font-size: 10px;
  letter-spacing: 0.12em;
  background: var(--accent);
  color: #000;
  padding: 2px 8px;
}

.plan-name {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 1.2rem;
}

.plan-price {
  font-family: var(--serif);
  font-size: 2.8rem;
  color: var(--bright);
  line-height: 1;
  margin-bottom: 0.3rem;
}

.plan-price sup { font-family: var(--mono); font-size: 1rem; vertical-align: top; margin-top: 0.5rem; display: inline-block; }
.plan-price sub { font-family: var(--mono); font-size: 0.9rem; color: var(--muted); }

.plan-desc { font-size: 12px; color: var(--text); margin: 1.2rem 0 1.8rem; line-height: 1.6; }

.plan-features { list-style: none; margin-bottom: 2rem; }

.plan-features li {
  font-size: 12px;
  color: var(--text);
  padding: 0.4rem 0;
  border-bottom: 1px solid var(--border);
  display: flex;
  gap: 0.6rem;
}

.plan-features li::before { content: '→'; color: var(--accent); flex-shrink: 0; }

footer {
  border-top: 1px solid var(--border);
  padding: 2.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 11px;
  color: var(--muted);
  letter-spacing: 0.06em;
}

footer a { color: var(--muted); text-decoration: none; }
footer a:hover { color: var(--accent); }

hr.divider { border: none; border-top: 1px solid var(--border); max-width: 900px; margin: 0 auto; }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}

.hero-tag   { animation: fadeUp 0.5s ease both; }
.hero h1    { animation: fadeUp 0.5s 0.1s ease both; }
.hero-sub   { animation: fadeUp 0.5s 0.2s ease both; }
.hero-actions { animation: fadeUp 0.5s 0.3s ease both; }

@media (max-width: 600px) {
  nav ul { display: none; }
  .hero { padding: 110px 1.5rem 70px; }
  section { padding: 60px 1.5rem; }
  footer { flex-direction: column; gap: 1rem; text-align: center; }
}