/* ===== FPGA Roadmap — Blueprint Theme ===== */

@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@400;500;600;700&family=IBM+Plex+Mono:wght@400;500;600;700&family=IBM+Plex+Serif:ital@0;1&display=swap');

:root{
  --bg: #0C1F30;
  --bg-panel: #12293D;
  --bg-panel-2: #17324A;
  --bg-raised: #1C3B56;
  --line: #35597A;
  --line-dim: #24455F;
  --line-bright: #6FA8C9;
  --accent: #E8A33D;
  --accent-dim: #B9822E;
  --accent-soft: rgba(232,163,61,0.13);
  --text: #EAF3F7;
  --text-dim: #A9C2D1;
  --text-faint: #6C8798;
  --radius: 3px;
  --maxw: 980px;
}

*{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }

body{
  margin:0;
  background:
    linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0) 300px),
    var(--bg);
  background-image:
    linear-gradient(var(--line-dim) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-dim) 1px, transparent 1px);
  background-size: 28px 28px;
  background-attachment: fixed;
  color: var(--text);
  font-family: 'IBM Plex Sans', system-ui, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a{ color: var(--accent); text-decoration: none; }
a:hover{ text-decoration: underline; }
a:focus-visible, button:focus-visible{
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.mono{ font-family:'IBM Plex Mono', monospace; }

/* ===== Top bar ===== */
.topbar{
  position: sticky; top:0; z-index: 50;
  background: rgba(12,31,48,0.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--line-dim);
}
.topbar-inner{
  max-width: var(--maxw); margin:0 auto; padding: 14px 20px;
  display:flex; align-items:center; justify-content:space-between; gap:16px;
}
.brand{
  display:flex; align-items:center; gap:10px;
  font-family:'IBM Plex Mono', monospace; font-weight:600; letter-spacing:.03em;
  color: var(--text); font-size:.95rem;
}
.brand .chip{
  width:20px; height:20px; border:1.5px solid var(--accent); border-radius:2px;
  position:relative; flex:none;
}
.brand .chip::before, .brand .chip::after{
  content:""; position:absolute; background:var(--accent);
  width:4px; height:1.5px; top:50%; transform:translateY(-50%);
}
.brand .chip::before{ left:-5px; }
.brand .chip::after{ right:-5px; }
.brand small{ color: var(--text-faint); font-weight:400; }

.topnav{ display:flex; gap:18px; font-family:'IBM Plex Mono', monospace; font-size:.8rem; }
.topnav a{ color: var(--text-dim); }
.topnav a.current, .topnav a:hover{ color: var(--accent); }

/* ===== Layout shells ===== */
.wrap{ max-width: var(--maxw); margin:0 auto; padding: 0 20px; }
.page-body{ padding: 40px 0 100px; }

/* ===== Hero (home) ===== */
.hero{ padding: 64px 0 30px; }
.eyebrow{
  font-family:'IBM Plex Mono', monospace; font-size:.78rem; letter-spacing:.12em;
  color: var(--accent); text-transform:uppercase; margin:0 0 14px;
  display:flex; align-items:center; gap:10px;
}
.eyebrow::before{ content:""; width:26px; height:1px; background:var(--accent); display:inline-block; }

.hero h1{
  font-size: clamp(2rem, 5vw, 3.1rem); line-height:1.08; margin:0 0 18px;
  font-weight:700; letter-spacing:-0.01em;
  max-width: 16ch;
}
.hero h1 .hl{ color: var(--accent); }
.hero p.lede{
  font-family:'IBM Plex Serif', serif; font-style:italic;
  font-size:1.15rem; color: var(--text-dim); max-width: 62ch; margin: 0 0 8px;
}
.hero .sub{ color: var(--text-faint); font-size:.92rem; max-width:60ch; }

/* ===== Signal chain (phase index on home) ===== */
.chain-section{ padding: 30px 0 10px; }
.chain-title{
  font-family:'IBM Plex Mono', monospace; font-size:.8rem; letter-spacing:.1em;
  color:var(--text-faint); text-transform:uppercase; margin-bottom:18px;
  display:flex; align-items:center; gap:10px;
}
.chain-title::after{ content:""; flex:1; height:1px; background:var(--line-dim); }

.chain{
  position:relative; display:flex; flex-direction:column; gap:0;
  border-left: 2px solid var(--line);
  margin-left: 14px;
}
.chain-node{
  position:relative; padding: 18px 0 18px 28px; border-bottom: 1px dashed var(--line-dim);
}
.chain-node:last-child{ border-bottom:none; }
.chain-node::before{
  content:""; position:absolute; left:-7px; top:26px;
  width:12px; height:12px; border-radius:50%;
  background: var(--bg); border:2px solid var(--line-bright);
}
.chain-node:hover::before{ background: var(--accent); border-color: var(--accent); }
.chain-node::after{
  content:""; position:absolute; left:-2px; top:32px; width:26px; height:1px;
  background: var(--line);
}
.chain-link{ display:flex; align-items:baseline; gap:16px; flex-wrap:wrap; color:var(--text); }
.chain-num{
  font-family:'IBM Plex Mono', monospace; color: var(--accent); font-size:.85rem;
  min-width:64px;
}
.chain-name{ font-size:1.15rem; font-weight:600; }
.chain-node:hover .chain-name{ color: var(--accent); }
.chain-desc{ color: var(--text-dim); font-size:.9rem; margin: 6px 0 0 80px; max-width:64ch; }
.chain-time{
  margin-left:auto; font-family:'IBM Plex Mono', monospace; font-size:.75rem;
  color: var(--text-faint); border:1px solid var(--line-dim); border-radius: 20px; padding:2px 10px;
}
.chain-node a.stretch{ position:absolute; inset:0; }

/* ===== Concept chips grid (home) ===== */
.concepts-section{ padding: 56px 0 10px; }
.concepts-grid{
  display:grid; grid-template-columns: repeat(auto-fill, minmax(230px,1fr));
  gap:14px; margin-top: 20px;
}
.ic-card{
  background: var(--bg-panel); border:1px solid var(--line-dim); border-radius: var(--radius);
  padding: 16px 16px 14px; position:relative;
}
.ic-card::before, .ic-card::after{
  content:""; position:absolute; left:14px; right:14px; height:1px;
  background: repeating-linear-gradient(90deg, var(--line) 0 6px, transparent 6px 12px);
}
.ic-card::before{ top:-1px; }
.ic-card::after{ bottom:-1px; }
.ic-tag{
  font-family:'IBM Plex Mono', monospace; font-size:.68rem; color: var(--accent);
  letter-spacing:.08em; margin-bottom:6px; display:block;
}
.ic-card h3{ margin:0 0 6px; font-size:1rem; }
.ic-card p{ margin:0; font-size:.85rem; color: var(--text-dim); }

/* ===== Footer ===== */
.site-footer{
  border-top:1px solid var(--line-dim); padding: 26px 0 60px; margin-top:40px;
  color: var(--text-faint); font-family:'IBM Plex Mono', monospace; font-size:.78rem;
}

/* ===== Phase page ===== */
.phase-hero{ padding: 30px 0 10px; }
.stage-marker{
  display:inline-flex; align-items:center; gap:10px;
  font-family:'IBM Plex Mono', monospace; color:var(--accent); font-size:.85rem;
  border:1px solid var(--accent-dim); background: var(--accent-soft);
  padding:5px 12px; border-radius:20px; margin-bottom:18px;
}
.phase-hero h1{ font-size: clamp(1.7rem, 4vw, 2.5rem); margin:0 0 10px; line-height:1.15; }
.phase-hero .tagline{ color: var(--text-dim); font-size:1.05rem; max-width:66ch; }

.section{ margin-top: 44px; }
.section-label{
  font-family:'IBM Plex Mono', monospace; font-size:.75rem; letter-spacing:.12em;
  color: var(--text-faint); text-transform:uppercase; margin-bottom:14px;
  display:flex; align-items:center; gap:10px;
}
.section-label::after{ content:""; flex:1; height:1px; background:var(--line-dim); }

.prose p{ margin: 0 0 16px; color: var(--text); font-size:1.02rem; max-width: 72ch; }
.prose strong{ color: var(--accent); font-weight:600; }
.prose code{
  font-family:'IBM Plex Mono', monospace; background: var(--bg-panel-2);
  padding: 1px 6px; border-radius:3px; font-size:.9em; color:#CFE6F2;
  border:1px solid var(--line-dim);
}

.callout{
  border-left:3px solid var(--accent); background: var(--accent-soft);
  padding: 16px 20px; border-radius: 0 var(--radius) var(--radius) 0; margin: 24px 0;
}
.callout .callout-label{
  font-family:'IBM Plex Mono', monospace; font-size:.72rem; color: var(--accent);
  text-transform:uppercase; letter-spacing:.1em; margin-bottom:8px; display:block;
}
.callout p{ margin:0; color: var(--text); font-size:.98rem; }

/* Visual / SVG panel */
.visual-panel{
  background: var(--bg-panel); border:1px solid var(--line-dim); border-radius: var(--radius);
  padding: 22px; margin: 26px 0; overflow-x:auto;
}
.visual-panel svg{ display:block; margin:0 auto; max-width:100%; height:auto; }
.visual-caption{
  text-align:center; font-family:'IBM Plex Mono', monospace; font-size:.72rem;
  color: var(--text-faint); margin-top:10px; letter-spacing:.03em;
}

/* Concepts list on phase page */
.concept-list{ list-style:none; margin:0; padding:0; display:grid; gap:10px; }
.concept-list li{
  background: var(--bg-panel); border:1px solid var(--line-dim); border-radius: var(--radius);
  padding: 12px 16px; font-size:.95rem; color: var(--text-dim);
}
.concept-list li strong{ color: var(--text); }

/* Resources */
.resource-grid{ display:grid; gap:10px; }
.resource{
  display:flex; gap:14px; align-items:flex-start;
  background: var(--bg-panel); border:1px solid var(--line-dim); border-radius: var(--radius);
  padding: 14px 16px; transition: border-color .15s, background .15s;
}
.resource:hover{ border-color: var(--accent-dim); background: var(--bg-panel-2); text-decoration:none; }
.resource-type{
  font-family:'IBM Plex Mono', monospace; font-size:.65rem; color: var(--bg);
  background: var(--accent); border-radius: 3px; padding: 3px 7px; white-space:nowrap;
  height: fit-content; letter-spacing:.05em; margin-top:2px;
}
.resource-body strong{ display:block; color: var(--text); font-size:.95rem; margin-bottom:2px; }
.resource-body span{ display:block; color: var(--text-faint); font-size:.8rem; }
.resource-arrow{ margin-left:auto; color: var(--text-faint); font-family:'IBM Plex Mono',monospace; }

/* Prev/next pager */
.pager{
  display:flex; justify-content:space-between; gap:16px; margin-top:60px;
  border-top:1px solid var(--line-dim); padding-top:24px;
}
.pager a{
  flex:1; border:1px solid var(--line-dim); border-radius: var(--radius); padding:16px 18px;
  color: var(--text); display:block;
}
.pager a:hover{ border-color: var(--accent); text-decoration:none; }
.pager .dir{
  font-family:'IBM Plex Mono', monospace; font-size:.7rem; color: var(--text-faint);
  text-transform:uppercase; letter-spacing:.1em; display:block; margin-bottom:6px;
}
.pager .next{ text-align:right; }
.pager .ph-name{ font-weight:600; }

/* Home CTA back link on phase pages */
.back-home{ font-family:'IBM Plex Mono', monospace; font-size:.8rem; color: var(--text-dim); }

/* Responsive */
@media (max-width: 640px){
  .topnav{ display:none; }
  .chain-desc{ margin-left:0; }
  .chain-time{ display:none; }
  .pager{ flex-direction:column; }
  .pager .next{ text-align:left; }
}

@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior:auto; }
  *{ transition:none !important; }
}