/* =========================================================
   SLIP — Scalable Locomotion for Imperfect Places
   ========================================================= */

/* Dark theme — the site's only theme */
:root{
  --bg:            #0b0c0e;
  --bg-rgb:        11,12,14;
  --bg-alt:        #101215;
  --surface:       #16181c;
  --surface-2:     #1c1f24;
  --border:        #2a2d33;
  --text:          #eef0f2;
  --text-dim:      #a7acb4;
  --text-faint:    #6c7178;
  --accent:        #ff7a1a;
  --accent-soft:   #ffb37a;
  --accent-dim:    #4a3122;
  --wash-1:        rgba(255,255,255,.02);
  --wash-2:        rgba(255,255,255,.06);
  --field-glow:    #17130d;
  --status-dot:    #5ee08a;
  --mono: 'IBM Plex Mono', ui-monospace, monospace;
  --sans: 'Manrope', -apple-system, BlinkMacSystemFont, sans-serif;
  --display: 'Sora', var(--sans);
  --maxw: 1180px;
  --radius: 14px;
}

body{ transition:background-color .25s ease, color .25s ease; }
.site-header, .section, .spec-card, .flow-node, .status-strip, .roadmap, .g-item,
.field-card, .about-link, .ct-row, .chip-row li, .btn-ghost, .site-nav, .mess-item{
  transition:background-color .25s ease, border-color .25s ease, color .25s ease;
}

*,*::before,*::after{ box-sizing:border-box; }
html{ scroll-behavior:smooth; }
body{
  margin:0;
  background:var(--bg);
  color:var(--text);
  font-family:var(--sans);
  font-size:16px;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
img,video{ max-width:100%; display:block; }
a{ color:inherit; }
h1,h2,h3,h4{ font-family:var(--display); font-weight:600; margin:0 0 .5em; letter-spacing:-0.01em; }
p{ margin:0 0 1em; }
ul{ margin:0; padding:0; list-style:none; }

.noise-overlay{
  position:fixed; inset:0; pointer-events:none; z-index:2000;
  opacity:.025; mix-blend-mode:overlay;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ---------- Header ---------- */
.site-header{
  position:sticky; top:0; z-index:1000;
  background:rgba(var(--bg-rgb),.78);
  backdrop-filter:blur(10px);
  border-bottom:1px solid var(--border);
}
.header-inner{
  max-width:var(--maxw); margin:0 auto; padding:14px 24px;
  display:flex; align-items:center; justify-content:space-between; gap:24px;
}
.brand{ display:flex; flex-direction:column; text-decoration:none; line-height:1.15; }
.brand-mark{ font-family:var(--display); font-weight:700; font-size:1.15rem; letter-spacing:.04em; color:var(--text); }
.brand-sub{ font-family:var(--mono); font-size:.62rem; text-transform:uppercase; letter-spacing:.06em; color:var(--text-faint); }

.header-right{ display:flex; align-items:center; gap:8px; }
.site-nav{ display:flex; align-items:center; gap:22px; }
.site-nav a{
  text-decoration:none; color:var(--text-dim); font-size:.88rem; font-weight:500;
  transition:color .15s ease;
}
.site-nav a:hover{ color:var(--text); }
.site-nav a.ext-link{ color:var(--accent-soft); }
.site-nav a.ext-link:hover{ color:var(--accent); }
.nav-cta{
  border:1px solid var(--border); padding:7px 14px; border-radius:999px;
  color:var(--accent-soft) !important; font-family:var(--mono); font-size:.75rem !important;
}
.nav-cta:hover{ border-color:var(--accent); color:var(--accent) !important; }

.nav-toggle{
  display:none; flex-direction:column; gap:4px; background:none; border:none; cursor:pointer; padding:8px;
}
.nav-toggle span{ width:20px; height:2px; background:var(--text); display:block; }

/* ---------- Hero ---------- */
.hero{
  position:relative; min-height:100svh; display:flex; align-items:flex-end;
  overflow:hidden;
}
.hero-media{ position:absolute; inset:0; z-index:0; }
.hero-media img{ width:100%; height:100%; object-fit:cover; object-position:center 65%; }
.hero-scrim{
  /* Uses the current theme's own background color for the scrim, so the photo
     is darkened in dark mode and softly lightened in light mode — matching
     whichever theme is active instead of staying a fixed dark slab. */
  position:absolute; inset:0;
  background:
    linear-gradient(180deg, rgba(var(--bg-rgb),.4) 0%, rgba(var(--bg-rgb),.6) 45%, rgba(var(--bg-rgb),.97) 92%),
    linear-gradient(90deg, rgba(var(--bg-rgb),.8) 0%, rgba(var(--bg-rgb),.2) 55%);
}
/* Finishes the blend into whichever section follows, right at the hero's own
   bottom padding so it never touches the chip row or buttons above it. */
.hero-fade{
  position:absolute; left:0; right:0; bottom:0; height:60px; z-index:0;
  background:linear-gradient(180deg, transparent, var(--bg)); pointer-events:none;
}
.hero-content{
  position:relative; z-index:1; max-width:var(--maxw); margin:0 auto; padding:0 24px 88px; width:100%;
}
.eyebrow{
  font-family:var(--mono); text-transform:uppercase; letter-spacing:.08em; font-size:.78rem;
  color:var(--accent-soft); margin-bottom:18px;
}
.hero h1{
  font-size:clamp(2.6rem, 7vw, 5rem); line-height:.98; margin-bottom:20px; color:var(--text);
  display:flex; flex-direction:column; gap:10px;
}
.hero-h1-sub{
  font-family:var(--sans); font-weight:500; font-size:clamp(1rem,2.2vw,1.4rem);
  color:var(--text-dim); letter-spacing:0;
}
.hero-lede{ max-width:640px; font-size:1.05rem; color:var(--text-dim); margin-bottom:32px; }
.hero-actions{ display:flex; flex-wrap:wrap; gap:14px; margin-bottom:34px; }

.btn{
  display:inline-flex; align-items:center; gap:8px; padding:13px 22px; border-radius:999px;
  font-weight:600; font-size:.92rem; text-decoration:none; transition:all .18s ease; border:1px solid transparent;
  cursor:pointer;
}
.btn-primary{ background:var(--accent); color:#1a0d02; }
.btn-primary:hover{ background:var(--accent-soft); transform:translateY(-1px); }
.btn-ghost{ border-color:var(--border); color:var(--text); background:var(--wash-1); }
.btn-ghost:hover{ border-color:var(--text-faint); background:var(--wash-2); }

.chip-row{ display:flex; flex-wrap:wrap; gap:10px; }
.chip-row li{
  font-family:var(--mono); font-size:.72rem; letter-spacing:.03em; color:var(--text-dim);
  border:1px solid var(--border); padding:6px 12px; border-radius:999px; background:var(--wash-1);
}

.scroll-cue{
  position:absolute; bottom:28px; left:50%; transform:translateX(-50%); z-index:1;
  width:26px; height:42px; border:1.5px solid var(--text-faint); border-radius:14px; opacity:.7;
}
.scroll-cue span{
  position:absolute; top:8px; left:50%; width:4px; height:8px; margin-left:-2px;
  background:var(--accent-soft); border-radius:2px; animation:scrollcue 1.8s infinite;
}
@keyframes scrollcue{ 0%{ opacity:1; transform:translateY(0);} 70%{ opacity:0; transform:translateY(14px);} 100%{opacity:0;} }

/* ---------- Sections ---------- */
.section{ padding:110px 0; }
.section.alt{ background:var(--bg-alt); border-top:1px solid var(--border); border-bottom:1px solid var(--border); }
.section-inner{ max-width:var(--maxw); margin:0 auto; padding:0 24px; }
.section-inner.narrow{ max-width:840px; }
.section-kicker{
  font-family:var(--mono); text-transform:uppercase; letter-spacing:.1em; font-size:.75rem;
  color:var(--accent); margin-bottom:18px;
}
.section h2{ font-size:clamp(1.7rem,3.6vw,2.5rem); max-width:760px; margin-bottom:22px; color:var(--text); }
.section-intro{ color:var(--text-dim); max-width:700px; font-size:1.02rem; margin-bottom:40px; }

.reveal{ opacity:0; transform:translateY(24px); transition:opacity .7s ease, transform .7s ease; }
.reveal.is-visible{ opacity:1; transform:translateY(0); }

/* ---------- Overview / Abstract ---------- */
.abstract-grid{ display:grid; grid-template-columns:1.2fr 1fr; gap:56px; align-items:start; }
.abstract-lead{ font-size:1.18rem; color:var(--text-dim); line-height:1.75; }
.abstract-lead strong{ color:var(--text); }
.abstract-facts{ display:flex; flex-direction:column; gap:22px; border-left:1px solid var(--border); padding-left:24px; }
.fact-label{ display:block; font-family:var(--mono); font-size:.7rem; text-transform:uppercase; letter-spacing:.08em; color:var(--accent-soft); margin-bottom:6px; }
.fact-value{ display:block; color:var(--text-dim); font-size:.94rem; }

/* ---------- Platform / spec cards ---------- */
.spec-columns{ display:grid; grid-template-columns:1fr 1fr; gap:24px; margin-bottom:56px; }
.spec-card{
  background:var(--surface); border:1px solid var(--border); border-radius:var(--radius); padding:28px 30px;
}
.spec-card h3{ font-size:1.05rem; color:var(--text); margin-bottom:16px; }
.spec-list{ display:flex; flex-direction:column; gap:13px; }
.spec-list li{
  display:flex; justify-content:space-between; gap:18px; font-size:.9rem;
  padding-bottom:13px; border-bottom:1px solid var(--border);
}
.spec-list li:last-child{ border-bottom:none; padding-bottom:0; }
.spec-list li span:first-child{ color:var(--text-faint); font-family:var(--mono); font-size:.78rem; flex-shrink:0; }
.spec-list li span:last-child{ color:var(--text); text-align:right; }

/* ---------- Media gallery (masonry-ish grid) ---------- */
.media-gallery{
  display:grid; grid-template-columns:repeat(4,1fr); grid-auto-flow:dense; gap:14px;
}
.g-item{
  position:relative; margin:0; border-radius:10px; overflow:hidden; background:var(--surface-2);
  border:1px solid var(--border); aspect-ratio:4/3;
}
.g-item.g-wide{ grid-column:span 2; grid-row:span 2; aspect-ratio:auto; }
.g-item img, .g-item video{ width:100%; height:100%; object-fit:cover; }
.g-item figcaption{
  position:absolute; left:0; right:0; bottom:0; padding:10px 12px 8px;
  font-size:.72rem; color:var(--text-dim);
  background:linear-gradient(180deg, transparent, rgba(0,0,0,.85));
}
.video-item .play-badge{
  position:absolute; inset:0; margin:auto; width:44px; height:44px; border-radius:50%;
  background:rgba(0,0,0,.45); border:1px solid rgba(255,255,255,.4); pointer-events:none;
}
.video-item .play-badge::after{
  content:''; position:absolute; top:50%; left:54%; transform:translate(-50%,-50%);
  border-style:solid; border-width:7px 0 7px 11px; border-color:transparent transparent transparent #fff;
}
.video-item.is-playing .play-badge{ display:none; }

/* ---------- Pipeline flow ---------- */
.pipeline-flow{
  display:flex; align-items:stretch; gap:0; margin-bottom:48px; overflow-x:auto; padding-bottom:8px;
}
.flow-node{
  flex:1 0 150px; background:var(--surface); border:1px solid var(--border); border-radius:12px;
  padding:20px 18px; position:relative;
}
.flow-node-end{ border-color:var(--accent-dim); background:linear-gradient(160deg, var(--surface), var(--accent-dim) 220%); }
.flow-index{ font-family:var(--mono); font-size:.7rem; color:var(--accent-soft); }
.flow-node h4{ font-size:.95rem; margin:8px 0 6px; color:var(--text); }
.flow-node p{ font-size:.8rem; color:var(--text-dim); margin:0; }
.flow-arrow{
  flex:0 0 28px; align-self:center; height:2px; background:var(--border); position:relative; margin:0 -1px;
}
.flow-arrow::after{
  content:''; position:absolute; right:0; top:50%; transform:translateY(-50%);
  border-style:solid; border-width:5px 0 5px 7px; border-color:transparent transparent transparent var(--text-faint);
}

.status-strip{
  border:1px solid var(--border); border-radius:var(--radius); padding:22px 26px; margin-bottom:56px;
  background:var(--surface); display:flex; flex-wrap:wrap; align-items:center; gap:18px 28px;
}
.status-strip-title{ font-family:var(--mono); font-size:.75rem; color:var(--text-faint); margin:0; text-transform:uppercase; letter-spacing:.05em; }
.status-list{ display:flex; flex-wrap:wrap; gap:10px 22px; }
.status-list li{ font-size:.86rem; color:var(--text); position:relative; padding-left:18px; }
.status-list li::before{
  content:''; position:absolute; left:0; top:.5em; width:7px; height:7px; border-radius:50%; background:var(--status-dot);
}

.two-col{ display:grid; grid-template-columns:1.1fr 1fr; gap:32px; align-items:start; }
.video-card video{ width:100%; border-radius:var(--radius); border:1px solid var(--border); background:#000; }
.video-card-full{ max-width:640px; margin:0 0 48px; }
.video-row{ display:grid; grid-template-columns:1fr 1fr; gap:24px; margin:0 0 48px; }
.video-caption{ font-size:.86rem; color:var(--text-dim); margin-top:12px; }
.mapping-grid-label{
  font-family:var(--mono); font-size:.72rem; text-transform:uppercase; letter-spacing:.08em;
  color:var(--text-faint); margin-bottom:16px;
}
.mapping-grid{ display:grid; grid-template-columns:1fr 1fr; gap:12px; }
.mapping-grid-3{ grid-template-columns:repeat(3,1fr); }
.mapping-grid figure{ margin:0; }
.mapping-grid img{ border-radius:10px; border:1px solid var(--border); aspect-ratio:4/3; object-fit:cover; width:100%; }
.mapping-grid figcaption{ font-size:.72rem; color:var(--text-faint); margin-top:6px; }

/* ---------- Challenges table ---------- */
.challenge-table{ max-width:840px; border:1px solid var(--border); border-radius:var(--radius); overflow:hidden; }
.ct-row{ display:grid; grid-template-columns:.9fr 1.5fr 1.5fr; }
.ct-row + .ct-row{ border-top:1px solid var(--border); }
.ct-row span{ padding:16px 18px; font-size:.88rem; }
.ct-head{ background:var(--surface-2); }
.ct-head span{ font-family:var(--mono); font-size:.7rem; text-transform:uppercase; letter-spacing:.06em; color:var(--text-faint); padding:12px 18px; }
.ct-row:not(.ct-head) span:first-child{ color:var(--accent-soft); font-weight:600; }
.ct-row:not(.ct-head) span:nth-child(2){ color:var(--text-dim); }
.ct-row:not(.ct-head):hover{ background:var(--wash-1); }

.mess-intro{ margin:56px 0 28px; }
.mess-intro h3{ font-size:1.05rem; color:var(--text); margin-bottom:8px; }
.mess-intro p{ color:var(--text-dim); font-size:.92rem; max-width:60ch; }
.mess-list{ display:flex; flex-direction:column; gap:24px; max-width:980px; }
.mess-item{
  display:grid; grid-template-columns:380px 1fr; gap:0; align-items:stretch;
  background:var(--surface); border:1px solid var(--border); border-radius:var(--radius); overflow:hidden;
}
.mess-item figure, .mess-video{ margin:0; height:100%; }
.mess-item img, .mess-item video{ width:100%; height:100%; min-height:240px; object-fit:cover; display:block; background:#000; }
.mess-media-pair{ display:flex; flex-direction:column; height:100%; }
.mess-media-pair .mess-video, .mess-media-pair figure{ flex:1; min-height:0; }
.mess-media-pair img, .mess-media-pair video{ min-height:160px; }
.mess-copy{ padding:22px 26px; display:flex; flex-direction:column; justify-content:center; }
.mess-copy h4{ font-size:1rem; color:var(--text); margin-bottom:10px; }
.mess-copy p{ font-size:.9rem; color:var(--text-dim); line-height:1.65; }
.placeholder-text{
  font-size:.86rem; font-style:italic; color:var(--text-faint); margin:0;
  border-left:2px solid var(--accent-dim); padding-left:11px;
}

/* ---------- Field deployment ---------- */
.field-section{ background:radial-gradient(120% 100% at 20% 0%, var(--field-glow) 0%, var(--bg) 60%); }
.field-scroll{
  display:flex; gap:18px; overflow-x:auto; padding:6px 6px 20px; scroll-snap-type:x proximity;
  margin:0 -6px;
}
.field-card{
  flex:0 0 auto; width:min(78vw, 300px); margin:0; scroll-snap-align:start;
  background:var(--surface); border:1px solid var(--border); border-radius:var(--radius); overflow:hidden;
}
.field-card video{ width:100%; aspect-ratio:9/16; object-fit:cover; background:#000; }
.field-card figcaption{ padding:14px 16px 18px; font-size:.84rem; color:var(--text-dim); }
.field-card.is-landscape{ width:min(90vw, 460px); }
.field-card.is-landscape video{ aspect-ratio:16/9; }
.field-note{ color:var(--text-faint); font-size:.85rem; max-width:640px; margin-top:8px; }

/* ---------- Research ---------- */
.research-list{ display:flex; flex-direction:column; gap:22px; margin-bottom:52px; }
.research-item{
  border-left:2px solid var(--accent-dim); padding-left:22px; position:relative;
}
.research-item::before{
  content:''; position:absolute; left:-5px; top:6px; width:8px; height:8px; border-radius:50%; background:var(--accent);
}
.research-item h4{ font-size:1rem; color:var(--text); margin-bottom:6px; }
.research-item p{ color:var(--text-dim); font-size:.94rem; margin:0; }

.roadmap{ background:var(--surface); border:1px solid var(--border); border-radius:var(--radius); padding:28px 30px; }
.roadmap h3{ font-size:1rem; color:var(--text); margin-bottom:16px; }
.roadmap-list{ display:flex; flex-direction:column; gap:11px; }
.roadmap-list li{
  font-size:.9rem; color:var(--text-dim); padding-left:22px; position:relative;
}
.roadmap-list li::before{
  content:'→'; position:absolute; left:0; color:var(--accent-soft); font-family:var(--mono);
}

.research-item code, .mess-copy code{
  font-family:var(--mono); font-size:.82rem; background:var(--surface-2); border:1px solid var(--border);
  padding:2px 7px; border-radius:5px; color:var(--accent-soft); white-space:nowrap;
}

/* ---------- Timeline ---------- */
.timeline{ position:relative; padding-left:32px; }
.timeline::before{ content:''; position:absolute; left:5px; top:6px; bottom:6px; width:2px; background:var(--border); }
.tl-item{ position:relative; padding-bottom:52px; }
.tl-item:last-child{ padding-bottom:0; }
.tl-marker{
  position:absolute; left:-32px; top:4px; width:12px; height:12px; border-radius:50%;
  background:var(--bg-alt); border:2px solid var(--accent);
}
.tl-date{ font-family:var(--mono); font-size:.76rem; color:var(--accent-soft); text-transform:uppercase; letter-spacing:.05em; }
.tl-content h4{ font-size:1.15rem; margin:6px 0 10px; color:var(--text); }
.tl-content p{ color:var(--text-dim); max-width:620px; }
.tl-content video, .tl-content img{ width:100%; max-width:520px; border-radius:12px; border:1px solid var(--border); margin-top:14px; background:#000; display:block; }
.tl-caption{ font-size:.8rem; color:var(--text-faint); max-width:520px; margin-top:8px; }

/* ---------- About ---------- */
.about-grid{ display:grid; grid-template-columns:.85fr 1.15fr; gap:40px; align-items:center; }
.about-photo{ border-radius:var(--radius); border:1px solid var(--border); aspect-ratio:3/4; object-fit:cover; }
.about-role{ font-family:var(--mono); font-size:.82rem; color:var(--accent-soft); margin-bottom:16px; }
.about-copy p{ color:var(--text-dim); }
.about-links{ display:flex; flex-wrap:wrap; gap:12px; margin-top:8px; }
.about-link{
  border:1px solid var(--border); padding:9px 16px; border-radius:999px; text-decoration:none;
  font-size:.85rem; color:var(--text); transition:all .15s ease;
}
.about-link:hover{ border-color:var(--accent); color:var(--accent-soft); }
.roadmap .about-link{ display:inline-flex; margin-top:20px; }
.about-link.ext-link{ color:var(--accent-soft); }

/* ---------- Footer ---------- */
.site-footer{ border-top:1px solid var(--border); padding:32px 24px; }
.footer-inner{
  max-width:var(--maxw); margin:0 auto; display:flex; flex-wrap:wrap; gap:8px;
  font-size:.8rem; color:var(--text-faint); font-family:var(--mono);
}
.footer-sep{ opacity:.5; }

/* ---------- Responsive ---------- */
@media (max-width: 900px){
  .abstract-grid, .spec-columns, .two-col, .about-grid, .video-row{ grid-template-columns:1fr; }
  .abstract-facts{ border-left:none; padding-left:0; border-top:1px solid var(--border); padding-top:20px; }
  .mapping-grid{ grid-template-columns:1fr 1fr; }
  .mapping-grid-3{ grid-template-columns:1fr; }
  .about-photo{ aspect-ratio:16/9; max-width:340px; }
}
@media (max-width: 760px){
  .nav-toggle{ display:flex; }
  .site-nav{
    position:absolute; top:100%; left:0; right:0; background:var(--bg);
    flex-direction:column; align-items:flex-start; padding:18px 24px 26px; gap:16px;
    border-bottom:1px solid var(--border); display:none;
  }
  .site-nav.is-open{ display:flex; }
  .nav-cta{ align-self:flex-start; }
  .media-gallery{ grid-template-columns:repeat(2,1fr); }
  .g-item.g-wide{ grid-column:span 2; grid-row:span 1; aspect-ratio:4/3; }
  .ct-row{ grid-template-columns:1fr; }
  .mess-item{ grid-template-columns:1fr; }
  .mess-item img, .mess-item video{ height:auto; max-height:220px; min-height:0; aspect-ratio:4/3; }
  .mess-media-pair{ flex-direction:row; }
  .mess-media-pair img, .mess-media-pair video{ max-height:160px; }
  .ct-row span{ padding:8px 18px; }
  .ct-row:not(.ct-head) span:first-child{ padding-top:16px; }
  .ct-row:not(.ct-head) span:last-child{ padding-bottom:16px; }
  .ct-head{ display:none; }
  .ct-row:not(.ct-head) span::before{ content: attr(data-label) ': '; font-family:var(--mono); font-size:.68rem; color:var(--text-faint); display:block; margin-bottom:2px; }
}
@media (max-width: 520px){
  .section{ padding:76px 0; }
  .media-gallery{ grid-template-columns:repeat(2,1fr); }
}