/* ============================================================
   tfr.davestj.com — Ternary Fission Reactor / Stargate Framework
   Dark physics theme: deep space gradient, cyan accent.
   ============================================================ */

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

:root {
    --bg-0: #0f0f23;
    --bg-1: #1a1a2e;
    --bg-2: #16213e;
    --surface: rgba(255, 255, 255, 0.045);
    --surface-2: rgba(255, 255, 255, 0.08);
    --border: rgba(0, 212, 255, 0.18);
    --border-soft: rgba(255, 255, 255, 0.1);
    --ink: #d7dce6;
    --ink-strong: #f2f5fa;
    --ink-soft: #8b95a8;
    --accent: #00d4ff;
    --accent-soft: rgba(0, 212, 255, 0.12);
    --est: #34d399;
    --eng: #60a5fa;
    --theo: #c084fc;
    --todo: #fbbf24;
    --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
    --mono: 'SF Mono', SFMono-Regular, Menlo, Consolas, monospace;
}

html { scroll-behavior: smooth; }

body {
    margin: 0;
    font-family: var(--font);
    font-size: 1.05rem;
    line-height: 1.7;
    color: var(--ink);
    background: linear-gradient(160deg, var(--bg-0) 0%, var(--bg-1) 45%, var(--bg-2) 100%) fixed;
    -webkit-font-smoothing: antialiased;
}

.wrap { width: min(980px, 100% - 2.5rem); margin-inline: auto; }

h1, h2, h3, h4 { color: var(--ink-strong); line-height: 1.25; margin: 1.6em 0 .5em; }
h1 { font-size: 2rem; }
h2 { font-size: 1.45rem; padding-bottom: .4rem; border-bottom: 1px solid var(--border); }
h3 { font-size: 1.15rem; color: var(--accent); }
h4 { font-size: 1.02rem; }

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

p { margin: 0 0 .9em; }
hr { border: 0; border-top: 1px solid var(--border-soft); margin: 2rem 0; }
code {
    font-family: var(--mono);
    font-size: .88em;
    background: var(--surface-2);
    padding: .12em .4em;
    border-radius: 4px;
}
ul, ol { margin: 0 0 1em; padding-left: 1.4rem; }
li { margin-bottom: .35em; }
blockquote { border-left: 3px solid var(--accent); margin: 1em 0; padding: .2em 1em; color: var(--ink-soft); }

/* ---------- Header ---------- */
.site-header {
    position: sticky; top: 0; z-index: 50;
    background: rgba(15, 15, 35, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; min-height: 3.6rem; gap: 1rem; }
.brand { font-weight: 800; font-size: 1.15rem; color: var(--ink-strong); letter-spacing: .03em; white-space: nowrap; }
.brand:hover { text-decoration: none; }
.brand-mark { color: var(--accent); margin-right: .15rem; }
.brand-sub { font-size: .68rem; font-weight: 500; color: var(--ink-soft); letter-spacing: .08em; text-transform: uppercase; margin-left: .5rem; }

.site-nav { display: flex; align-items: center; gap: 1.1rem; flex-wrap: wrap; }
.site-nav a { color: var(--ink); font-size: .88rem; font-weight: 500; }
.site-nav a:hover { color: var(--accent); text-decoration: none; }
.site-nav a.is-active { color: var(--accent); }
.nav-ext { color: var(--ink-soft) !important; }

.nav-toggle { display: none; background: none; border: 0; padding: .5rem; cursor: pointer; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--ink-strong); margin: 5px 0; }

/* ---------- Hero ---------- */
.hero {
    padding: 4.5rem 0 3rem;
    background:
        radial-gradient(ellipse 60% 50% at 70% 20%, rgba(0, 212, 255, 0.12), transparent),
        radial-gradient(ellipse 50% 40% at 20% 80%, rgba(192, 132, 252, 0.08), transparent);
    border-bottom: 1px solid var(--border);
}
.hero-kicker { text-transform: uppercase; letter-spacing: .18em; font-size: .75rem; color: var(--accent); margin-bottom: .8rem; }
.hero-title { font-size: clamp(2.1rem, 5.5vw, 3.1rem); margin: 0 0 .4em; }
.hero-sub { font-size: 1.18rem; color: var(--ink); max-width: 46rem; margin-bottom: 1.6rem; }
.hero-actions { display: flex; gap: .8rem; flex-wrap: wrap; margin-bottom: 2.2rem; }

.btn {
    display: inline-block;
    padding: .65rem 1.4rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: .95rem;
    border: 1px solid transparent;
}
.btn:hover { text-decoration: none; }
.btn-accent { background: var(--accent); color: #06202b; }
.btn-accent:hover { background: #33ddff; }
.btn-ghost { border-color: var(--border); color: var(--ink-strong); background: var(--surface); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

.hero-bases { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 1rem; }
.base-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1rem 1.2rem;
    display: flex; align-items: baseline; gap: .7rem;
    backdrop-filter: blur(10px);
}
.base-n { font-size: 1.9rem; font-weight: 800; color: var(--accent); font-family: var(--mono); }
.base-l { font-size: .82rem; color: var(--ink-soft); line-height: 1.3; }

/* ---------- Document body ---------- */
.doc { padding: 2.5rem 0 1rem; }
.doc h1 { font-size: 1.8rem; margin-top: .5em; }
.doc h1 + h2 { border: 0; color: var(--ink-soft); font-size: 1.15rem; font-weight: 500; margin-top: 0; }
.doc strong { color: var(--ink-strong); }

.math-display {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 1.1rem 1.3rem;
    margin: 1.2rem 0;
    overflow-x: auto;
    text-align: center;
    font-size: 1.05rem;
}
.math-inline { white-space: nowrap; }
.katex { color: var(--ink-strong); }

.table-wrap { overflow-x: auto; margin: 1.4rem 0; border: 1px solid var(--border); border-radius: 10px; }
table { border-collapse: collapse; width: 100%; font-size: .92rem; }
th, td { padding: .6rem .9rem; text-align: left; border-bottom: 1px solid var(--border-soft); }
th { background: var(--accent-soft); color: var(--ink-strong); font-weight: 700; white-space: nowrap; }
tr:last-child td { border-bottom: 0; }

/* status badges */
.badge {
    display: inline-block;
    font-size: .68rem;
    font-weight: 800;
    letter-spacing: .07em;
    padding: .14em .55em;
    border-radius: 5px;
    vertical-align: .1em;
    white-space: nowrap;
}
.badge-est  { background: rgba(52, 211, 153, .15); color: var(--est);  border: 1px solid rgba(52, 211, 153, .4); }
.badge-eng  { background: rgba(96, 165, 250, .15); color: var(--eng);  border: 1px solid rgba(96, 165, 250, .4); }
.badge-theo { background: rgba(192, 132, 252, .15); color: var(--theo); border: 1px solid rgba(192, 132, 252, .4); }
.badge-todo { background: rgba(251, 191, 36, .15); color: var(--todo); border: 1px solid rgba(251, 191, 36, .4); }
.badge-run  { background: rgba(0, 212, 255, .15);  color: var(--accent); border: 1px solid rgba(0, 212, 255, .4); }

/* ---------- Pager ---------- */
.doc-pager {
    display: flex; justify-content: space-between; gap: 1rem;
    padding: 1.5rem 0 3rem;
}
.pager-link {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: .7rem 1.2rem;
    font-size: .92rem;
    font-weight: 600;
    color: var(--ink-strong);
}
.pager-link:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }

/* ---------- Footer ---------- */
.site-footer { border-top: 1px solid var(--border); background: rgba(10, 10, 26, 0.6); padding: 2.5rem 0 1rem; }
.footer-inner { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 2rem; }
.footer-col h3 { font-size: .82rem; text-transform: uppercase; letter-spacing: .1em; color: var(--accent); margin: 0 0 .7rem; }
.footer-col p { font-size: .88rem; color: var(--ink-soft); }
.footer-col nav { display: flex; flex-direction: column; gap: .4rem; }
.footer-col nav a { font-size: .88rem; color: var(--ink); }
.footer-bottom { border-top: 1px solid var(--border-soft); margin-top: 2rem; padding-top: 1rem; }
.footer-bottom p { font-size: .8rem; color: var(--ink-soft); }

/* ---------- Responsive ---------- */
@media (max-width: 860px) {
    .brand-sub { display: none; }
    .nav-toggle { display: block; }
    .site-nav {
        display: none;
        position: absolute; top: 100%; left: 0; right: 0;
        flex-direction: column; align-items: flex-start;
        background: rgba(15, 15, 35, 0.97);
        border-bottom: 1px solid var(--border);
        padding: 1rem 1.25rem 1.25rem;
    }
    .site-nav.is-open { display: flex; }
    .footer-inner { grid-template-columns: 1fr; }
    .doc-pager { flex-direction: column; }
}