:root{--ink:#1a1f2e;--muted:#5a6477;--line:#e4e8ee;--accent:#0f7b6c;--accent-soft:#e8f3f1;--bg:#fafbfc;--card:#ffffff;--nav-bg:rgba(255,255,255,0.92)}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;color:var(--ink);line-height:1.6;background:var(--bg);-webkit-font-smoothing:antialiased}

/* Navigation */
.nav{position:sticky;top:0;z-index:100;background:var(--nav-bg);backdrop-filter:blur(12px);border-bottom:1px solid var(--line);padding:1rem 1.5rem}
.nav-inner{max-width:1140px;margin:0 auto;display:flex;align-items:center;justify-content:space-between}
.nav-brand{font-weight:700;font-size:1.1rem;text-decoration:none;color:var(--ink);letter-spacing:-0.01em}
.nav-brand::before{content:"◐";color:var(--accent);margin-right:0.4rem}
.nav-links{display:flex;gap:1.75rem;list-style:none;margin:0;padding:0}
.nav-links a{text-decoration:none;color:var(--muted);font-weight:500;font-size:0.95rem;transition:color 0.15s;border-bottom:2px solid transparent;padding-bottom:2px}
.nav-links a:hover,.nav-links a.active{color:var(--accent)}

/* Containers */
.container{max-width:1140px;margin:0 auto;padding:0 1.5rem}
.container-narrow{max-width:840px;margin:0 auto;padding:0 1.5rem}

/* Home hero */
.hero-home{padding:4rem 1.5rem 3rem}
.hero-home h1{font-size:2.75rem;line-height:1.1;margin:0 0 1rem;font-weight:700;letter-spacing:-0.025em;max-width:800px}
.hero-home .lede{font-size:1.2rem;color:var(--muted);max-width:680px;margin:0 0 1.5rem}
.hero-home .accent{color:var(--accent)}

/* Project hero */
.hero-project{background-image:linear-gradient(180deg,rgba(15,30,40,.4),rgba(15,30,40,.85)),url('hero-bg.jpg');background-size:cover;background-position:center;color:#fff;padding:5rem 1.5rem 4rem}
.hero-project h1{font-size:2.5rem;line-height:1.12;margin:0 0 1rem;color:#fff;text-shadow:0 2px 12px rgba(0,0,0,.5)}
.hero-project .lede{font-size:1.2rem;color:rgba(255,255,255,.93);max-width:680px;text-shadow:0 1px 6px rgba(0,0,0,.4)}
.hero-project .badge{background:rgba(15,123,108,.85);border:1px solid rgba(255,255,255,.2)}

/* Badge */
.badge{display:inline-block;font-size:0.75rem;font-weight:600;letter-spacing:0.05em;text-transform:uppercase;color:#fff;background:var(--accent);padding:0.4rem 0.85rem;border-radius:999px;margin-bottom:1.25rem}

/* Filter chips */
.filters{display:flex;flex-wrap:wrap;gap:0.5rem;margin:2rem 0 1.5rem}
.filter{background:var(--card);border:1px solid var(--line);padding:0.5rem 1rem;border-radius:999px;font-size:0.9rem;cursor:pointer;color:var(--ink);font-weight:500;transition:all 0.15s;font-family:inherit}
.filter:hover{border-color:var(--accent);color:var(--accent)}
.filter.active{background:var(--accent);color:#fff;border-color:var(--accent)}

/* Sections */
.projects-section{padding:2rem 0 4rem}
.section-title{font-size:1.5rem;font-weight:700;margin:0 0 0.5rem;display:flex;align-items:center}
.section-title::before{content:"";display:inline-block;width:4px;height:1.2rem;background:var(--accent);margin-right:0.7rem;border-radius:2px}
.section-subtitle{color:var(--muted);margin:0 0 1.5rem}

/* Project grid + card */
.projects-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(320px,1fr));gap:1.5rem;margin:1.5rem 0}
.project-card{background:var(--card);border:1px solid var(--line);border-radius:12px;overflow:hidden;transition:all 0.2s;text-decoration:none;color:inherit;display:flex;flex-direction:column}
.project-card[href]:hover{transform:translateY(-3px);border-color:var(--accent);box-shadow:0 12px 30px rgba(15,30,40,.1)}
.project-card-image{height:160px;background:linear-gradient(135deg,#2a4858 0%,#0f7b6c 100%);display:flex;align-items:center;justify-content:center;color:rgba(255,255,255,.9);font-size:3rem;font-weight:700}
.project-card-body{padding:1.25rem;flex:1;display:flex;flex-direction:column}
.project-card-tags{display:flex;flex-wrap:wrap;gap:0.35rem;margin-bottom:0.75rem}
.tag{font-size:0.72rem;padding:0.2rem 0.55rem;background:var(--accent-soft);color:var(--accent);border-radius:999px;font-weight:500}
.project-card-title{font-size:1.15rem;font-weight:600;margin:0 0 0.5rem;letter-spacing:-0.01em}
.project-card-desc{color:var(--muted);font-size:0.92rem;margin:0 0 1rem;line-height:1.5;flex:1}
.project-card-meta{font-size:0.82rem;color:var(--muted);display:flex;justify-content:space-between;align-items:center;border-top:1px solid var(--line);padding-top:0.85rem}
.project-card-status{display:flex;align-items:center;gap:0.4rem}
.dot{display:inline-block;width:7px;height:7px;border-radius:50%;background:#22c55e;box-shadow:0 0 0 3px rgba(34,197,94,.18)}
.dot-paused{background:#f59e0b;box-shadow:0 0 0 3px rgba(245,158,11,.18)}
.dot-planned{background:#94a3b8;box-shadow:0 0 0 3px rgba(148,163,184,.18)}

/* Content sections (detail pages) */
.content{padding:0 0 4rem}
.content h2{font-size:1.4rem;margin:2.5rem 0 0.75rem;font-weight:600;display:flex;align-items:center}
.content h2::before{content:"";display:inline-block;width:4px;height:1.15rem;background:var(--accent);margin-right:0.7rem;border-radius:2px}
.content p{margin:0 0 1rem}
.content ul{padding-left:1.25rem;margin:0 0 1rem}
.content li{margin:0.4rem 0}
.content a{color:var(--accent);text-decoration:none;border-bottom:1px solid var(--accent-soft)}
.content a:hover{border-color:var(--accent)}
.content strong{color:var(--ink);font-weight:600}
.content code{background:#f1f3f5;padding:1px 6px;border-radius:3px;font-size:0.9em;font-family:'SF Mono',Menlo,Consolas,monospace}

/* Stats grid - elevated above hero */
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:1rem;margin:-2.25rem 0 2.5rem;position:relative;z-index:2}
.stat{background:var(--card);padding:1.5rem 1.25rem;border-radius:10px;border:1px solid var(--line);box-shadow:0 4px 20px rgba(15,30,40,.1)}
.stat-num{font-size:2rem;font-weight:700;color:var(--accent);line-height:1;margin-bottom:0.4rem}
.stat-label{font-size:0.85rem;color:var(--muted)}

/* Status, highlight, chips, timeline */
.status-row{display:flex;align-items:center;gap:0.6rem;font-size:0.9rem;margin:1rem 0 1.5rem;padding:0.85rem 1.1rem;background:var(--card);border:1px solid var(--line);border-radius:6px}
.highlight{background:var(--accent-soft);border-left:3px solid var(--accent);padding:1rem 1.25rem;border-radius:0 6px 6px 0;margin:1.25rem 0}
.highlight strong{color:var(--accent)}
.chips{display:flex;flex-wrap:wrap;gap:0.45rem;margin:0.75rem 0 1.25rem}
.chip{font-size:0.8rem;padding:0.3rem 0.7rem;background:var(--accent-soft);color:var(--accent);border-radius:999px;font-weight:500}
.timeline{margin:1rem 0;border-left:2px solid var(--line);padding-left:1.25rem}
.timeline-item{margin-bottom:1.15rem;position:relative}
.timeline-item::before{content:"";position:absolute;left:-1.45rem;top:0.45rem;width:11px;height:11px;background:var(--accent);border-radius:50%;border:2px solid var(--bg)}
.timeline-date{font-size:0.78rem;color:var(--muted);font-weight:600;text-transform:uppercase;letter-spacing:0.05em;margin-bottom:0.15rem}

/* Buttons */
.btn{display:inline-block;padding:0.7rem 1.25rem;border-radius:6px;text-decoration:none;font-weight:500;font-size:0.95rem;transition:all 0.15s;border:none;cursor:pointer;font-family:inherit}
.btn-primary{background:var(--accent);color:#fff;box-shadow:0 4px 14px rgba(15,123,108,.4)}
.btn-primary:hover{background:#0a5c50;transform:translateY(-1px)}
.btn-secondary{background:transparent;color:var(--ink);border:1px solid var(--line)}
.btn-secondary:hover{border-color:var(--ink)}
.hero-project .btn-secondary{background:rgba(255,255,255,.12);color:#fff;border-color:rgba(255,255,255,.35)}
.ctas{display:flex;gap:0.75rem;flex-wrap:wrap;margin-top:1.25rem}

/* Misc */
.back-link{display:inline-block;margin:1.5rem 0 0;color:var(--muted);font-size:0.9rem;text-decoration:none}
.back-link:hover{color:var(--accent)}
footer{margin-top:4rem;padding:2rem 1.5rem;border-top:1px solid var(--line);background:var(--card)}
.footer-inner{max-width:1140px;margin:0 auto;display:flex;justify-content:space-between;flex-wrap:wrap;gap:1rem;color:var(--muted);font-size:0.9rem}
.footer-links{display:flex;gap:1.25rem}
.footer-links a{color:var(--muted);text-decoration:none}
.footer-links a:hover{color:var(--accent)}

@media (max-width:700px){
  .hero-home{padding:2.5rem 1rem 2rem}
  .hero-home h1{font-size:1.85rem}
  .hero-project{padding:3.5rem 1rem 3rem}
  .hero-project h1{font-size:1.85rem}
  .container,.container-narrow{padding:0 1rem}
  .nav-links{gap:1rem}
  .nav-links a{font-size:0.88rem}
  .stat-num{font-size:1.6rem}
}

/* Copy email button feedback */
.btn.copied,.copy-link.copied{background:#22c55e !important;color:#fff !important;border-color:#22c55e !important}
.copy-link{background:none;border:none;color:var(--accent);font-family:inherit;font-size:inherit;cursor:pointer;padding:0;border-bottom:1px solid var(--accent-soft);transition:all .15s}
.copy-link:hover{border-color:var(--accent)}
.copy-link.copied{border-bottom-color:#22c55e !important}

/* ============================================================
   HOMEPAGE — Featured project card
============================================================ */
.featured-card{background:linear-gradient(135deg,#ffffff 0%,#f0f9f6 100%);border:1px solid var(--accent-soft);border-radius:14px;padding:2rem 2rem 1.75rem;margin:1.5rem 0 2.5rem;box-shadow:0 8px 30px rgba(15,123,108,.08);position:relative;overflow:hidden}
.featured-card::before{content:"";position:absolute;top:0;left:0;width:4px;height:100%;background:var(--accent)}
.featured-meta{display:flex;align-items:center;gap:.5rem;font-size:.78rem;color:var(--muted);text-transform:uppercase;letter-spacing:.05em;font-weight:600;margin-bottom:.75rem}
.featured-title{font-size:1.8rem;font-weight:700;margin:0 0 .75rem;letter-spacing:-.02em;color:var(--ink)}
.featured-desc{font-size:1.02rem;color:var(--muted);margin:0 0 1.5rem;line-height:1.6;max-width:760px}
.featured-stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(110px,1fr));gap:1rem;padding:1.15rem 0;margin:1rem 0;border-top:1px solid var(--accent-soft);border-bottom:1px solid var(--accent-soft)}
.featured-stats > div{display:flex;flex-direction:column;text-align:left}
.featured-stat-num{font-size:1.6rem;font-weight:700;color:var(--accent);line-height:1}
.featured-stat-label{font-size:.78rem;color:var(--muted);text-transform:uppercase;letter-spacing:.05em;margin-top:.3rem}

/* HOMEPAGE — Direct-link shortcuts box */
.shortcuts-section{padding:1.5rem 0 4rem}
.shortcuts{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:1.25rem 1.5rem;font-size:.95rem;line-height:2.1;color:var(--ink)}
.shortcuts code{background:var(--accent-soft);color:var(--accent);padding:3px 8px;border-radius:4px;font-size:.88em;font-family:'SF Mono',Menlo,Consolas,monospace}

/* ============================================================
   DESERTFLOW — Abstract callout
============================================================ */
.callout{background:linear-gradient(135deg,#fefbf3 0%,#fef3c7 100%);border:1px solid #fcd34d;border-radius:10px;padding:1.5rem 1.75rem;margin:2rem 0;font-size:.98rem;line-height:1.7;color:#78350f;box-shadow:0 4px 15px rgba(252,211,77,.15)}
.callout strong{color:#78350f}

/* Table of contents */
.toc{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:1.25rem 1.5rem;margin:1.5rem 0 2.5rem}
.toc-title{font-size:.78rem;font-weight:700;color:var(--muted);text-transform:uppercase;letter-spacing:.08em;margin-bottom:.85rem}
.toc ol{padding-left:1.5rem;margin:0;columns:2;column-gap:1.5rem}
.toc li{margin:.3rem 0;break-inside:avoid;font-size:.92rem}
.toc a{color:var(--ink);text-decoration:none;border:none}
.toc a:hover{color:var(--accent)}

/* Text/ASCII diagram block */
.diagram{background:#0f1e28;color:#a7f3d0;padding:1.5rem 1.25rem;border-radius:8px;font-family:'SF Mono',Menlo,Consolas,monospace;font-size:.78rem;line-height:1.45;overflow-x:auto;white-space:pre;margin:1.5rem 0;border:1px solid #1f3a48}

/* Module grid */
.module-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:1rem;margin:1.5rem 0}
.module-group{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:1rem 1.25rem}
.module-title{font-weight:700;font-size:.95rem;color:var(--accent);margin-bottom:.6rem;text-transform:uppercase;letter-spacing:.04em;font-size:.78rem}
.module-group ul{padding-left:1.25rem;margin:0;font-size:.9rem}
.module-group li{margin:.3rem 0;color:var(--ink)}

/* Results table */
.results-table{width:100%;border-collapse:collapse;margin:1.5rem 0;font-size:.94rem}
.results-table thead{background:var(--accent-soft)}
.results-table th{text-align:left;padding:.85rem 1rem;font-weight:600;color:var(--accent);border-bottom:2px solid var(--accent)}
.results-table td{padding:.7rem 1rem;border-bottom:1px solid var(--line)}
.results-table tr:hover td{background:#f9fafb}
.results-table strong{color:var(--accent)}

/* Open problems grid */
.problem-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:1rem;margin:1.5rem 0}
.problem-card{background:var(--card);border:1px solid var(--line);border-left:3px solid #f59e0b;border-radius:0 8px 8px 0;padding:1rem 1.25rem}
.problem-card strong{color:#b45309;display:block;margin-bottom:.4rem;font-size:1rem}
.problem-card p{margin:0;font-size:.9rem;color:var(--muted);line-height:1.5}

/* Roadmap */
.roadmap{margin:1.5rem 0}
.roadmap-phase{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:1.25rem 1.5rem;margin-bottom:1rem;border-left:3px solid var(--accent)}
.roadmap-phase-title{font-weight:700;color:var(--accent);font-size:1.02rem;margin-bottom:.6rem}
.roadmap-phase ul{margin:0;padding-left:1.25rem}
.roadmap-phase li{margin:.3rem 0;font-size:.92rem}

/* References list */
.ref-list{padding-left:1.25rem}
.ref-list li{margin:.5rem 0;font-size:.92rem;color:var(--ink);line-height:1.5}
.ref-list li strong{color:var(--accent)}

/* FAQ - using native <details>/<summary> */
.faq{background:var(--card);border:1px solid var(--line);border-radius:8px;margin:.6rem 0;overflow:hidden;transition:all .15s}
.faq:hover{border-color:var(--accent-soft)}
.faq[open]{border-color:var(--accent);box-shadow:0 4px 15px rgba(15,123,108,.06)}
.faq summary{padding:1rem 1.25rem;cursor:pointer;font-weight:600;color:var(--ink);font-size:.98rem;list-style:none;position:relative;padding-right:2.5rem;transition:color .15s}
.faq summary:hover{color:var(--accent)}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";position:absolute;right:1.25rem;top:50%;transform:translateY(-50%);font-size:1.4rem;color:var(--accent);font-weight:300;transition:transform .2s}
.faq[open] summary::after{content:"−"}
.faq p{padding:0 1.25rem 1rem;margin:0;color:var(--muted);font-size:.94rem;line-height:1.6}

/* Smooth-scroll for in-page anchors */
html{scroll-behavior:smooth}

@media (max-width:700px){
  .toc ol{columns:1}
  .featured-card{padding:1.5rem 1.25rem}
  .featured-title{font-size:1.4rem}
  .diagram{font-size:.6rem}
  .results-table{font-size:.82rem}
  .results-table th,.results-table td{padding:.5rem .6rem}
}