/* ============================================================
   MERIDIAN · research-instrument aesthetic
   Deep slate ground · Fraunces serif display · muted domain palette
   ============================================================ */

:root{
  --ink:        #0e1419;
  --ink-2:      #141d24;
  --ink-3:      #1d2932;
  --line:       #28343e;
  --line-soft:  #1c262e;
  --signal:     #4cc9b0;   /* muted teal · primary action */
  --paper:      #eaeef0;
  --paper-2:    #a3b2bc;
  --paper-3:    #6b7a85;
  --coral:      #e07a5f;
  --gold:       #e9c46a;
  --sage:       #81b29a;
  --slateblue:  #6699cc;
  --radius:     4px;
  --radius-lg:  7px;
  --maxw:       1240px;
  --mono: 'IBM Plex Mono', ui-monospace, monospace;
  --disp: 'Fraunces', Georgia, serif;
  --body: 'Inter', system-ui, sans-serif;
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{background:var(--ink);color:var(--paper);font-family:var(--body);line-height:1.55;-webkit-font-smoothing:antialiased;overflow-x:hidden}
a{color:inherit;text-decoration:none}
em{font-style:italic;color:var(--signal);font-weight:500}

#grain{position:fixed;inset:0;pointer-events:none;z-index:9999;opacity:.022;
  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='0.85' numOctaves='3'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E")}

/* MASTHEAD */
.masthead{position:sticky;top:0;z-index:100;background:rgba(14,20,25,.84);backdrop-filter:blur(14px) saturate(140%);border-bottom:1px solid var(--line)}
.mast-inner{max-width:var(--maxw);margin:0 auto;padding:14px 28px;display:flex;align-items:center;justify-content:space-between;gap:24px}
.brand{display:flex;align-items:center;gap:13px}
.brand-mark{color:var(--paper-2);display:flex}
.brand-text h1{font-family:var(--disp);font-weight:600;font-size:1.4rem;letter-spacing:-.01em;line-height:1;font-optical-sizing:auto}
.brand-sub{font-family:var(--mono);font-size:.62rem;color:var(--paper-3);letter-spacing:.03em}
.mast-nav{display:flex;gap:30px}
.mast-nav a{font-family:var(--mono);font-size:.78rem;color:var(--paper-2);transition:color .18s;position:relative;padding:4px 0}
.mast-nav a:hover{color:var(--signal)}
.mast-nav a::after{content:'';position:absolute;left:0;bottom:-2px;width:0;height:1px;background:var(--signal);transition:width .22s}
.mast-nav a:hover::after{width:100%}

.pulse{border-top:1px solid var(--line-soft);background:linear-gradient(90deg,rgba(76,201,176,.04),transparent 60%);display:flex;align-items:center;overflow:hidden;height:34px}
.pulse-label{font-family:var(--mono);font-size:.6rem;font-weight:600;letter-spacing:.2em;color:var(--signal);padding:0 16px;white-space:nowrap;border-right:1px solid var(--line);height:100%;display:flex;align-items:center;background:rgba(76,201,176,.05)}
.pulse-label::before{content:'';width:6px;height:6px;border-radius:50%;background:var(--signal);margin-right:8px;animation:ping 2.4s ease-out infinite}
.pulse-track{display:flex;align-items:center;gap:36px;white-space:nowrap;padding-left:24px;animation:marquee 46s linear infinite}
.pulse:hover .pulse-track{animation-play-state:paused}
@keyframes marquee{from{transform:translateX(0)}to{transform:translateX(-50%)}}
.pulse-item{font-family:var(--mono);font-size:.74rem;color:var(--paper-2);display:inline-flex;align-items:center;gap:8px}
.pulse-item b{color:var(--paper);font-weight:500}
.pulse-item .pv{color:var(--signal);font-weight:600}
.pulse-item .pyr{color:var(--paper-3)}
.pdelta.up{color:var(--sage)}
.pdelta.down{color:var(--coral)}
.pulse-loading{font-family:var(--mono);font-size:.74rem;color:var(--paper-3);padding-left:6px}

/* HERO */
.hero{position:relative;overflow:hidden;border-bottom:1px solid var(--line)}
.hero-grid{position:absolute;inset:0;opacity:.5;
  background-image:linear-gradient(var(--line-soft) 1px,transparent 1px),linear-gradient(90deg,var(--line-soft) 1px,transparent 1px);
  background-size:46px 46px;mask-image:radial-gradient(ellipse 78% 80% at 28% 18%,#000 22%,transparent 72%)}
.hero-inner{position:relative;max-width:var(--maxw);margin:0 auto;padding:88px 28px 72px}
.hero-eyebrow{display:inline-flex;align-items:center;gap:9px;font-family:var(--mono);font-size:.72rem;color:var(--paper-2);margin-bottom:28px;padding:6px 13px;border:1px solid var(--line);border-radius:100px;background:var(--ink-2)}
.hero-eyebrow .dot{width:7px;height:7px;border-radius:50%;background:var(--signal);animation:ping 2.4s ease-out infinite}
@keyframes ping{0%{box-shadow:0 0 0 0 rgba(76,201,176,.5)}70%{box-shadow:0 0 0 8px rgba(76,201,176,0)}100%{box-shadow:0 0 0 0 rgba(76,201,176,0)}}
.hero-title{font-family:var(--disp);font-weight:500;font-size:clamp(2.5rem,5.6vw,4.6rem);line-height:1.04;letter-spacing:-.018em;margin-bottom:26px;font-optical-sizing:auto}
.hero-lede{max-width:600px;font-size:1.06rem;color:var(--paper-2);line-height:1.64;margin-bottom:34px}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap;margin-bottom:38px}
.btn{font-family:var(--mono);font-size:.82rem;font-weight:500;padding:13px 22px;border-radius:var(--radius);cursor:pointer;border:1px solid transparent;transition:all .18s;display:inline-flex;align-items:center;gap:8px}
.btn-sm{padding:10px 18px;font-size:.78rem}
.btn-primary{background:var(--signal);color:#06120f;font-weight:600}
.btn-primary:hover{background:#5fd9c0;transform:translateY(-1px);box-shadow:0 6px 20px rgba(76,201,176,.2)}
.btn-ghost{background:transparent;color:var(--paper);border-color:var(--line)}
.btn-ghost:hover{border-color:var(--signal);color:var(--signal)}
.hero-domains{display:flex;flex-wrap:wrap;gap:9px;margin-bottom:42px}
.hd-tag{font-family:var(--mono);font-size:.72rem;color:var(--c);padding:5px 12px;border:1px solid var(--c);border-radius:100px;opacity:.85;background:color-mix(in srgb,var(--c) 8%,transparent)}
.hero-meta{display:flex;gap:48px;flex-wrap:wrap}
.hm-item{display:flex;flex-direction:column;gap:4px}
.hm-num{font-family:var(--mono);font-size:1.7rem;font-weight:600;color:var(--paper);letter-spacing:-.01em}
.hm-lab{font-family:var(--mono);font-size:.7rem;color:var(--paper-3)}

/* SECTION HEADS */
section{max-width:var(--maxw);margin:0 auto;padding:74px 28px}
.sec-head{display:flex;gap:22px;align-items:flex-start;margin-bottom:36px}
.sec-index{font-family:var(--mono);font-size:.82rem;color:var(--signal);font-weight:600;padding-top:9px;border-top:2px solid var(--signal);letter-spacing:.05em}
.sec-title{font-family:var(--disp);font-weight:500;font-size:2rem;letter-spacing:-.015em;margin-bottom:7px;font-optical-sizing:auto}
.sec-sub{color:var(--paper-2);font-size:.98rem;max-width:620px}

/* THEME GALLERY */
.theme-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:16px}
.theme-card{text-align:left;background:var(--ink-2);border:1px solid var(--line);border-radius:var(--radius-lg);padding:22px 21px;cursor:pointer;transition:all .2s;position:relative;overflow:hidden;display:flex;flex-direction:column;gap:11px;min-height:188px;font-family:inherit;color:inherit}
.theme-card::before{content:'';position:absolute;top:0;left:0;width:100%;height:2px;background:var(--tc,var(--signal));transform:scaleX(0);transform-origin:left;transition:transform .25s}
.theme-card:hover{border-color:var(--ink-3);transform:translateY(-3px)}
.theme-card:hover::before{transform:scaleX(1)}
.tc-domain{font-family:var(--mono);font-size:.64rem;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:var(--tc,var(--signal))}
.tc-title{font-family:var(--disp);font-weight:600;font-size:1.18rem;letter-spacing:-.01em;line-height:1.18;font-optical-sizing:auto}
.tc-q{font-size:.86rem;color:var(--paper-2);line-height:1.5;flex:1}
.tc-go{font-family:var(--mono);font-size:.72rem;color:var(--paper-3);display:flex;align-items:center;gap:6px;transition:gap .2s,color .2s}
.theme-card:hover .tc-go{color:var(--tc,var(--signal));gap:10px}

/* EXPLORER */
.explorer-shell{display:grid;grid-template-columns:280px 1fr;gap:22px;align-items:start}
.explorer-controls{background:var(--ink-2);border:1px solid var(--line);border-radius:var(--radius-lg);padding:22px;position:sticky;top:120px;display:flex;flex-direction:column;gap:24px}
.ctrl-group{display:flex;flex-direction:column;gap:9px}
.ctrl-label{font-family:var(--mono);font-size:.68rem;font-weight:600;letter-spacing:.1em;text-transform:uppercase;color:var(--paper-3);display:flex;align-items:center;gap:8px}
.ctrl-cap{font-weight:400;letter-spacing:.02em;text-transform:none;color:var(--paper-3);opacity:.7;font-size:.64rem}
.ctrl-select,.ctrl-num{background:var(--ink);border:1px solid var(--line);color:var(--paper);font-family:var(--body);font-size:.88rem;padding:10px 12px;border-radius:var(--radius);width:100%;transition:border-color .16s;cursor:pointer}
.ctrl-select:hover,.ctrl-num:hover{border-color:var(--ink-3)}
.ctrl-select:focus,.ctrl-num:focus{outline:none;border-color:var(--signal)}
.ctrl-select optgroup{font-family:var(--mono);font-size:.7rem;color:var(--paper-3);background:var(--ink-2)}
.ctrl-select option{font-family:var(--body);color:var(--paper);background:var(--ink)}
.ctrl-hint{font-family:var(--mono);font-size:.68rem;color:var(--paper-3);line-height:1.45}
.chips{display:flex;flex-wrap:wrap;gap:7px}
.chip{display:inline-flex;align-items:center;gap:7px;font-family:var(--mono);font-size:.74rem;padding:5px 9px;border-radius:100px;border:1px solid var(--line);background:var(--ink)}
.chip .swatch{width:8px;height:8px;border-radius:2px}
.chip .x{cursor:pointer;color:var(--paper-3);font-weight:600}
.chip .x:hover{color:var(--coral)}
.range-row{display:flex;align-items:center;gap:10px}
.ctrl-num{width:auto;flex:1;text-align:center;font-family:var(--mono);cursor:text}
.range-sep{font-family:var(--mono);font-size:.74rem;color:var(--paper-3)}
.seg{display:flex;background:var(--ink);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden}
.seg-btn{flex:1;background:transparent;border:none;color:var(--paper-2);font-family:var(--mono);font-size:.76rem;padding:9px;cursor:pointer;transition:all .15s}
.seg-btn.active{background:var(--signal);color:#06120f;font-weight:600}
.seg-btn:not(.active):hover{color:var(--paper)}

.explorer-canvas{background:var(--ink-2);border:1px solid var(--line);border-radius:var(--radius-lg);padding:22px;min-height:500px;display:flex;flex-direction:column}
.canvas-head{display:flex;justify-content:space-between;align-items:flex-start;gap:16px;margin-bottom:18px}
.canvas-titlewrap{display:flex;flex-direction:column;gap:7px}
.domain-tag{font-family:var(--mono);font-size:.62rem;font-weight:600;letter-spacing:.12em;text-transform:uppercase;padding:3px 9px;border:1px solid;border-radius:100px;width:fit-content}
.canvas-title{font-family:var(--disp);font-weight:600;font-size:1.24rem;letter-spacing:-.01em;line-height:1.25;font-optical-sizing:auto}
.canvas-source{font-family:var(--mono);font-size:.7rem;color:var(--paper-3)}
.export-btn{font-family:var(--mono);font-size:.72rem;color:var(--paper-2);background:var(--ink);border:1px solid var(--line);padding:7px 12px;border-radius:var(--radius);cursor:pointer;transition:all .15s;white-space:nowrap}
.export-btn:hover{border-color:var(--signal);color:var(--signal)}
.canvas-plot{position:relative;flex:1;min-height:370px}
.plot-loading{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:14px;background:var(--ink-2);z-index:5;font-family:var(--mono);font-size:.78rem;color:var(--paper-3);transition:opacity .3s}
.plot-loading.hidden{opacity:0;pointer-events:none}
.spinner{width:26px;height:26px;border:2px solid var(--line);border-top-color:var(--signal);border-radius:50%;animation:spin .8s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}
.canvas-foot{font-family:var(--mono);font-size:.72rem;color:var(--paper-3);margin-top:14px;min-height:18px}

/* BUILDER */
.builder-shell{display:grid;grid-template-columns:1fr;gap:20px}
.builder-controls{background:var(--ink-2);border:1px solid var(--line);border-radius:var(--radius-lg);padding:22px}
.bc-row{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-bottom:18px}
.builder-canvas{background:var(--ink-2);border:1px solid var(--line);border-radius:var(--radius-lg);padding:22px;min-height:430px;display:flex;flex-direction:column}
.builder-canvas .canvas-plot{min-height:350px}
.builder-note{font-family:var(--mono);font-size:.72rem;color:var(--paper-3);margin-top:14px;font-style:italic}

/* ABOUT */
.about{border-top:1px solid var(--line)}
.about-inner{display:grid;grid-template-columns:auto 1fr;gap:40px;max-width:860px;margin:0 auto}
.about-index{font-family:var(--mono);font-size:.82rem;color:var(--signal);font-weight:600;border-top:2px solid var(--signal);padding-top:9px;height:fit-content}
.about-title{font-family:var(--disp);font-weight:500;font-size:1.7rem;letter-spacing:-.015em;margin-bottom:18px;font-optical-sizing:auto}
.about-body p{color:var(--paper-2);font-size:.98rem;line-height:1.7;margin-bottom:16px}
.about-body strong{color:var(--paper);font-weight:600}
.about-sources{display:flex;flex-wrap:wrap;gap:9px;margin:22px 0}
.src-tag{font-family:var(--mono);font-size:.72rem;color:var(--paper-2);padding:6px 12px;border:1px solid var(--line);border-radius:100px;background:var(--ink)}
.about-link a{font-family:var(--mono);font-size:.84rem;color:var(--signal);transition:opacity .15s}
.about-link a:hover{opacity:.75}

/* FOOTER */
.footer{max-width:var(--maxw);margin:0 auto;padding:30px 28px;border-top:1px solid var(--line);display:flex;justify-content:space-between;font-family:var(--mono);font-size:.74rem;color:var(--paper-3);flex-wrap:wrap;gap:10px}
.footer>span:first-child{font-family:var(--disp);font-weight:600;color:var(--paper-2)}

/* RESPONSIVE */
@media(max-width:880px){
  .explorer-shell{grid-template-columns:1fr}
  .explorer-controls{position:static}
  .bc-row{grid-template-columns:1fr}
  .mast-nav{display:none}
  .about-inner{grid-template-columns:1fr;gap:18px}
  .hero-meta{gap:30px}
}
@media(max-width:560px){
  .mast-inner{padding:12px 18px}
  section{padding:54px 18px}
  .hero-inner{padding:60px 18px 52px}
  .hm-num{font-size:1.4rem}
}

:focus-visible{outline:2px solid var(--signal);outline-offset:2px}
@media(prefers-reduced-motion:reduce){*{animation-duration:.001ms!important;transition-duration:.05ms!important}.pulse-track{animation:none;padding-left:24px}}