/* ============================================================
   PERIHELION — solar-sail startup
   Art direction: deep-space void · solar gold · plasma cyan
   Type: Sora (display/body) + JetBrains Mono (telemetry)
   ============================================================ */

:root{
  --void:#05060b;
  --void-2:#0a0d16;
  --panel:#0f131f;
  --panel-2:#131828;
  --gold:#ffc24b;
  --gold-hot:#ffe08a;
  --gold-deep:#b3801f;
  --plasma:#46e6ff;
  --plasma-2:#4b7bff;
  --white:#f4f6fb;
  --muted:#8b93a7;
  --muted-2:#5b6377;
  --line:rgba(139,147,167,.18);
  --line-hot:rgba(255,194,75,.30);
  --maxw:1200px;
  --disp:"Sora",system-ui,sans-serif;
  --mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",monospace;
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

body{
  font-family:var(--disp);
  background:var(--void);
  color:var(--white);
  line-height:1.55;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
  font-synthesis:none;
}

a{color:inherit;text-decoration:none}
img,svg,canvas{display:block;max-width:100%}
em{font-style:normal}

:focus-visible{outline:2.5px solid var(--plasma);outline-offset:3px;border-radius:2px}

.skip{
  position:absolute;left:-999px;top:0;z-index:300;
  background:var(--gold);color:var(--void);
  padding:.7rem 1.1rem;font-family:var(--mono);font-size:.72rem;
  letter-spacing:.08em;font-weight:700;border-radius:0 0 6px 0;
}
.skip:focus{left:0}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}

/* ---------- shared mark ---------- */
.brand-mark{
  width:22px;height:22px;border-radius:50%;
  background:radial-gradient(circle at 38% 38%,var(--gold-hot),var(--gold) 42%,var(--gold-deep) 100%);
  box-shadow:0 0 14px 2px rgba(255,194,75,.55);flex:0 0 auto;
}

/* ---------- nav ---------- */
.nav{
  position:fixed;top:0;left:0;right:0;z-index:120;
  display:flex;align-items:center;justify-content:space-between;
  padding:1rem clamp(1rem,4vw,2.5rem);
  background:linear-gradient(to bottom,rgba(5,6,11,.85),rgba(5,6,11,0));
  backdrop-filter:blur(6px);
}
.brand{display:flex;align-items:center;gap:.6rem}
.brand-name{font-weight:800;letter-spacing:.22em;font-size:.95rem}
.nav-links{display:flex;align-items:center;gap:clamp(.9rem,2.4vw,1.9rem)}
.nav-links a{font-family:var(--mono);font-size:.74rem;letter-spacing:.05em;color:var(--muted);transition:color .25s}
.nav-links a:hover{color:var(--white)}
.nav-cta{
  color:var(--gold)!important;border:1px solid var(--line-hot);
  padding:.5rem .9rem;border-radius:100px;
}
.nav-cta:hover{background:rgba(255,194,75,.1)}
@media (max-width:720px){
  .nav-links a:not(.nav-cta){display:none}
}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex;align-items:center;gap:.5rem;
  font-family:var(--mono);font-size:.8rem;letter-spacing:.04em;font-weight:500;
  padding:.85rem 1.5rem;border-radius:100px;cursor:pointer;
  transition:transform .25s cubic-bezier(.2,.8,.2,1),box-shadow .25s,background .25s;
  border:1px solid transparent;text-align:center;
}
.btn-solar{
  background:linear-gradient(100deg,var(--gold-hot),var(--gold));
  color:var(--void);font-weight:700;
  box-shadow:0 0 0 rgba(255,194,75,0);
}
.btn-solar:hover{transform:translateY(-2px);box-shadow:0 10px 30px -8px rgba(255,194,75,.55)}
.btn-ghost{border-color:var(--line);color:var(--white)}
.btn-ghost:hover{border-color:var(--plasma);color:var(--plasma);transform:translateY(-2px)}

/* ---------- eyebrow / section heads ---------- */
.eyebrow{
  display:inline-flex;align-items:center;gap:.55rem;
  font-family:var(--mono);font-size:.72rem;letter-spacing:.08em;
  color:var(--muted);text-transform:uppercase;
}
.eyebrow .dot{width:7px;height:7px;border-radius:50%;background:var(--plasma);box-shadow:0 0 10px var(--plasma);animation:pulse 2.6s ease-in-out infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:.35}}
@media (prefers-reduced-motion:reduce){.eyebrow .dot{animation:none}}

.sec-head{display:flex;align-items:baseline;gap:1rem;margin-bottom:1.8rem}
.sec-index{font-family:var(--mono);font-size:.78rem;color:var(--gold);letter-spacing:.1em}
.sec-kicker{font-family:var(--mono);font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muted)}
.sec-kicker::before{content:"";display:inline-block;width:34px;height:1px;background:var(--line);vertical-align:middle;margin-right:.8rem}

/* ============================================================
   HERO
   ============================================================ */
.hero{
  position:relative;min-height:100svh;
  display:flex;flex-direction:column;justify-content:center;
  padding:6rem clamp(1rem,5vw,4rem) 4rem;
  overflow:hidden;
  background:
    radial-gradient(120% 90% at 88% 30%,rgba(255,194,75,.10),transparent 55%),
    radial-gradient(90% 80% at 8% 90%,rgba(75,123,255,.10),transparent 60%),
    var(--void);
}
.hero-canvas{position:absolute;inset:0;width:100%;height:100%;z-index:0}
.hero-grain{
  position:absolute;inset:0;z-index:1;pointer-events:none;opacity:.5;
  background:radial-gradient(circle at center,transparent 60%,rgba(5,6,11,.55) 100%);
}
.hero-inner{position:relative;z-index:2;max-width:var(--maxw);width:100%;margin:0 auto}
.hero-title{
  font-size:clamp(3.2rem,13vw,8.5rem);
  line-height:.92;font-weight:800;letter-spacing:-.03em;
  margin:1.3rem 0 1.4rem;
}
.hero-title em{
  background:linear-gradient(105deg,var(--gold-hot),var(--gold) 55%,var(--plasma));
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.hero-lede{
  max-width:34rem;font-size:clamp(1rem,2.1vw,1.28rem);
  color:#c8cede;font-weight:300;line-height:1.6;
}
.hero-actions{display:flex;flex-wrap:wrap;gap:.9rem;margin-top:2rem}

/* HUD */
.hud{
  position:absolute;z-index:2;right:clamp(1rem,5vw,4rem);top:clamp(6rem,16vh,10rem);
  width:min(300px,80vw);
  background:linear-gradient(180deg,rgba(15,19,31,.82),rgba(10,13,22,.9));
  border:1px solid var(--line);border-radius:14px;
  padding:1.1rem 1.2rem;backdrop-filter:blur(8px);
  box-shadow:0 20px 60px -30px rgba(0,0,0,.9);
}
.hud-title{font-family:var(--mono);font-size:.64rem;letter-spacing:.1em;color:var(--muted);margin-bottom:.9rem}
.hud-ok{color:var(--plasma)}
.hud-rows{list-style:none;display:flex;flex-direction:column;gap:.6rem}
.hud-rows li{display:grid;grid-template-columns:1fr auto auto;align-items:baseline;gap:.4rem;font-family:var(--mono)}
.hud-rows span{font-size:.62rem;letter-spacing:.06em;color:var(--muted)}
.hud-rows b{font-size:1.15rem;font-weight:700;color:var(--gold);font-variant-numeric:tabular-nums;min-width:0}
.hud-rows i{font-size:.6rem;color:var(--muted-2);font-style:normal}
.hud-foot{margin-top:1rem;padding-top:.8rem;border-top:1px solid var(--line);
  font-family:var(--mono);font-size:.62rem;letter-spacing:.05em;color:var(--muted)}
@media (max-width:860px){
  .hud{position:relative;right:auto;top:auto;margin:2.4rem auto 0;width:100%}
}

.scroll-cue{
  position:absolute;left:50%;bottom:1.4rem;transform:translateX(-50%);z-index:2;
  font-family:var(--mono);font-size:.62rem;letter-spacing:.4em;color:var(--muted);
  animation:cue 2.4s ease-in-out infinite;
}
@keyframes cue{0%,100%{opacity:.35;transform:translate(-50%,0)}50%{opacity:1;transform:translate(-50%,6px)}}
@media (prefers-reduced-motion:reduce){.scroll-cue{animation:none}}
@media (max-width:860px){.scroll-cue{display:none}}

/* ============================================================
   Section shell
   ============================================================ */
section:not(.hero){
  max-width:var(--maxw);margin:0 auto;
  padding:clamp(4.5rem,10vw,8rem) clamp(1.1rem,5vw,2rem);
  position:relative;
}

/* ---------- MISSION ---------- */
.mission-grid{display:grid;grid-template-columns:1.05fr 1fr;gap:clamp(2rem,6vw,4.5rem);align-items:start}
.mission-h{font-size:clamp(1.9rem,4.4vw,3.3rem);line-height:1.06;font-weight:700;letter-spacing:-.02em}
.mission-h em{color:var(--gold)}
.mission-body .lead{font-size:1.15rem;color:var(--white);margin-bottom:1.1rem;font-weight:400}
.mission-body p{color:#aab1c4;margin-bottom:1.1rem;font-weight:300}
.mission-stats{list-style:none;display:grid;grid-template-columns:1fr 1fr;gap:1px;margin-top:2rem;
  background:var(--line);border:1px solid var(--line);border-radius:12px;overflow:hidden}
.mission-stats li{background:var(--void-2);padding:1.2rem 1.3rem}
.mission-stats b{display:block;font-size:1.7rem;font-weight:700;color:var(--gold);font-family:var(--mono)}
.mission-stats span{font-size:.78rem;color:var(--muted)}
@media (max-width:820px){.mission-grid{grid-template-columns:1fr;gap:2rem}}

/* ---------- CRAFT ---------- */
.craft-h{font-size:clamp(1.9rem,4.6vw,3.4rem);line-height:1.04;font-weight:700;letter-spacing:-.02em;margin-bottom:2.6rem}
.craft-layout{display:grid;grid-template-columns:1.1fr .9fr;gap:clamp(2rem,5vw,4rem);align-items:center}
.cutaway{
  background:radial-gradient(90% 90% at 50% 40%,rgba(75,123,255,.08),transparent 70%),var(--void-2);
  border:1px solid var(--line);border-radius:16px;padding:1.4rem;
}
.cutaway-svg{width:100%;height:auto;filter:drop-shadow(0 10px 40px rgba(255,194,75,.12))}
.cutaway figcaption{margin-top:1rem;font-family:var(--mono);font-size:.7rem;color:var(--muted);letter-spacing:.02em;text-align:center}
.spec h3{font-family:var(--mono);font-size:.8rem;letter-spacing:.12em;text-transform:uppercase;color:var(--plasma);margin-bottom:1.2rem}
.spec-list{display:flex;flex-direction:column}
.spec-list>div{display:flex;justify-content:space-between;gap:1rem;padding:.85rem 0;border-bottom:1px solid var(--line)}
.spec-list dt{color:var(--muted);font-size:.9rem;font-weight:300}
.spec-list dd{font-family:var(--mono);font-size:.9rem;color:var(--white);text-align:right}
.spec-list dd span{color:var(--muted-2);font-size:.78rem}
.spec-note{margin-top:1.4rem;font-size:.92rem;color:#aab1c4;font-weight:300;line-height:1.6}
@media (max-width:820px){.craft-layout{grid-template-columns:1fr;gap:2.4rem}}

/* ---------- PHYSICS ---------- */
.physics-intro{max-width:46rem;margin-bottom:3rem}
.physics-h{font-size:clamp(1.9rem,4.6vw,3.4rem);line-height:1.05;font-weight:700;letter-spacing:-.02em;margin-bottom:1.2rem}
.physics-intro p{color:#aab1c4;font-weight:300;font-size:1.08rem}
.physics-intro em{color:var(--gold);font-family:var(--mono);font-size:.95em}

.lab{
  display:grid;grid-template-columns:1fr 1.15fr;gap:clamp(1.5rem,4vw,3rem);
  background:linear-gradient(160deg,var(--panel),var(--void-2));
  border:1px solid var(--line);border-radius:18px;
  padding:clamp(1.4rem,4vw,2.6rem);
}
.lab-controls h3{font-family:var(--mono);font-size:.82rem;letter-spacing:.12em;text-transform:uppercase;color:var(--plasma)}
.lab-sub{color:var(--muted);font-size:.9rem;margin:.5rem 0 1.8rem;font-weight:300}
.ctl{display:block;margin-bottom:1.5rem}
.ctl-top{display:flex;justify-content:space-between;align-items:baseline;font-family:var(--mono);font-size:.78rem;color:var(--muted);margin-bottom:.55rem;letter-spacing:.03em}
.ctl-top b{color:var(--gold);font-size:.92rem}
.ctl input[type=range]{
  -webkit-appearance:none;appearance:none;width:100%;height:3px;border-radius:3px;
  background:linear-gradient(90deg,var(--gold) 0%,var(--gold) var(--fill,50%),rgba(139,147,167,.22) var(--fill,50%));
  cursor:pointer;
}
.ctl input[type=range]::-webkit-slider-thumb{
  -webkit-appearance:none;appearance:none;width:18px;height:18px;border-radius:50%;
  background:var(--gold-hot);border:3px solid var(--void);box-shadow:0 0 12px rgba(255,194,75,.7);cursor:pointer;
}
.ctl input[type=range]::-moz-range-thumb{
  width:16px;height:16px;border-radius:50%;background:var(--gold-hot);border:3px solid var(--void);
  box-shadow:0 0 12px rgba(255,194,75,.7);cursor:pointer;
}

.lab-readout{display:grid;grid-template-columns:1fr 1fr;gap:1px;background:var(--line);
  border:1px solid var(--line);border-radius:12px;overflow:hidden;align-content:start}
.ro{background:var(--void-2);padding:1rem 1.1rem;display:flex;flex-direction:column;gap:.15rem}
.ro span{font-family:var(--mono);font-size:.62rem;letter-spacing:.06em;color:var(--muted);text-transform:uppercase}
.ro b{font-family:var(--mono);font-size:1.35rem;font-weight:700;color:var(--white);font-variant-numeric:tabular-nums}
.ro i{font-family:var(--mono);font-size:.62rem;color:var(--muted-2);font-style:normal}
.ro-big b{color:var(--gold);font-size:1.75rem}
.labcanvas{grid-column:1/-1;width:100%;height:auto;background:var(--void);display:block}
.lab-eq{grid-column:1/-1;background:var(--void);padding:1rem 1.1rem;font-family:var(--mono);
  font-size:.82rem;color:var(--plasma);letter-spacing:.01em}
.lab-eq span{color:var(--muted-2);font-size:.72rem}
.lab-eq sub{font-size:.72em}
@media (max-width:900px){.lab{grid-template-columns:1fr}}
@media (max-width:460px){.lab-readout{grid-template-columns:1fr}}

/* ---------- TEAM ---------- */
.team-h{font-size:clamp(1.9rem,4.6vw,3.4rem);line-height:1.05;font-weight:700;letter-spacing:-.02em;margin-bottom:2.6rem}
.team-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:1.2rem}
.member{
  background:linear-gradient(180deg,var(--panel),var(--void-2));
  border:1px solid var(--line);border-radius:14px;padding:1.6rem;
  transition:border-color .3s,transform .3s;
}
.member:hover{border-color:var(--line-hot);transform:translateY(-4px)}
.m-init{
  display:inline-flex;align-items:center;justify-content:center;width:46px;height:46px;border-radius:50%;
  background:radial-gradient(circle at 40% 35%,rgba(255,194,75,.25),rgba(75,123,255,.15));
  border:1px solid var(--line-hot);font-family:var(--mono);font-weight:700;color:var(--gold);
  font-size:.9rem;letter-spacing:.05em;margin-bottom:1rem;
}
.member h3{font-size:1.15rem;font-weight:600}
.m-role{font-family:var(--mono);font-size:.7rem;letter-spacing:.05em;color:var(--plasma);text-transform:uppercase;margin:.25rem 0 .8rem}
.member p:last-child{color:#aab1c4;font-size:.92rem;font-weight:300}
@media (max-width:760px){.team-grid{grid-template-columns:1fr}}

.backers{margin-top:3rem;border-top:1px solid var(--line);padding-top:2rem}
.backers-label{font-family:var(--mono);font-size:.68rem;letter-spacing:.14em;text-transform:uppercase;color:var(--muted);margin-bottom:1.2rem}
.backers-list{list-style:none;display:flex;flex-wrap:wrap;gap:.7rem 2.4rem}
.backers-list li{font-family:var(--disp);font-size:1.05rem;font-weight:600;color:#c8cede;opacity:.8}

/* ---------- JOIN ---------- */
.join{position:relative}
.join-inner{
  position:relative;background:
    radial-gradient(120% 120% at 80% 0%,rgba(255,194,75,.14),transparent 55%),
    linear-gradient(160deg,var(--panel-2),var(--void-2));
  border:1px solid var(--line-hot);border-radius:22px;
  padding:clamp(2.2rem,6vw,4.5rem);overflow:hidden;
}
.eyebrow-c{color:var(--gold)}
.join-h{font-size:clamp(2.2rem,6vw,4.4rem);line-height:.98;font-weight:800;letter-spacing:-.03em;margin:1.2rem 0 1rem}
.join-lede{max-width:36rem;color:#c8cede;font-weight:300;font-size:1.1rem}
.join-form{display:flex;flex-wrap:wrap;gap:.8rem;margin-top:2rem;align-items:center}
.join-form input{
  flex:1 1 200px;min-width:0;background:var(--void);border:1px solid var(--line);
  border-radius:100px;padding:.9rem 1.3rem;color:var(--white);font-family:var(--mono);font-size:.85rem;
}
.join-form input::placeholder{color:var(--muted-2)}
.join-form input:focus{outline:none;border-color:var(--gold)}
.form-msg{flex:1 1 100%;font-family:var(--mono);font-size:.78rem;color:var(--plasma);min-height:1.1rem;margin-top:.2rem}

/* ---------- FOOTER ---------- */
.foot{max-width:var(--maxw);margin:0 auto;padding:4rem clamp(1.1rem,5vw,2rem) 3rem;border-top:1px solid var(--line)}
.foot-top{display:flex;align-items:center;gap:.6rem;margin-bottom:2.4rem}
.foot-brand{font-weight:800;letter-spacing:.22em}
.foot-cols{display:grid;grid-template-columns:repeat(3,1fr);gap:2rem;margin-bottom:3rem}
.foot-h{font-family:var(--mono);font-size:.66rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);margin-bottom:1rem}
.foot-cols a{display:block;color:#aab1c4;font-size:.9rem;padding:.3rem 0;transition:color .25s}
.foot-cols a:hover{color:var(--gold)}
.foot-bottom{display:flex;flex-wrap:wrap;justify-content:space-between;gap:1rem;padding-top:2rem;border-top:1px solid var(--line);
  font-family:var(--mono);font-size:.72rem;color:var(--muted)}
.foot-coord{color:var(--gold)}
@media (max-width:620px){.foot-cols{grid-template-columns:1fr 1fr}}