:root{
  --bg:#f4f6f8; --card:#ffffff; --ink:#1f2933; --muted:#6b7785;
  --line:#e1e6ea; --brand:#1f6feb; --brand-d:#1550b8; --sky:#0b3d66;
  --accent:#17a398; --shadow:0 1px 3px rgba(16,24,40,.08),0 8px 24px rgba(16,24,40,.06);
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  font-family:Inter,"Segoe UI",system-ui,sans-serif;color:var(--ink);
  background:var(--bg);line-height:1.5;-webkit-font-smoothing:antialiased;
}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
h1,h2{margin:0 0 .4em;line-height:1.15}
small{font-size:.8em}

/* hero -------------------------------------------------------------------*/
.hero{
  position:relative;color:#fff;overflow:hidden;
  background:linear-gradient(120deg,#0a2c4d 0%,#11578f 48%,#1f7a8c 100%);
}
.hero::after{ /* subtle sky glow, top-right */
  content:"";position:absolute;top:-30%;right:-10%;width:55%;height:160%;
  background:radial-gradient(closest-side,rgba(255,255,255,.18),rgba(255,255,255,0) 70%);
  pointer-events:none;
}
.hero-inner{
  position:relative;max-width:1080px;margin:0 auto;padding:54px 24px 60px;
  display:grid;grid-template-columns:1.2fr .85fr;gap:38px;align-items:center;
}
.badge{
  display:inline-block;font-size:.74rem;letter-spacing:.12em;text-transform:uppercase;
  font-weight:600;background:rgba(255,255,255,.16);border:1px solid rgba(255,255,255,.28);
  padding:5px 12px;border-radius:999px;backdrop-filter:blur(4px)
}
.hero h1{font-size:2.45rem;font-weight:700;margin-top:.5em;text-shadow:0 2px 18px rgba(0,0,0,.22)}
.lede{font-size:1.05rem;color:#eaf1f7}
.hero-links{margin-top:22px;display:flex;gap:12px;flex-wrap:wrap}
.hero-figure{
  margin:0;border-radius:16px;overflow:hidden;position:relative;
  border:1px solid rgba(255,255,255,.22);
  box-shadow:0 18px 40px rgba(5,20,38,.4);
  background:
    linear-gradient(rgba(255,255,255,.05) 1px, transparent 1px) 0 0/26px 26px,
    linear-gradient(90deg, rgba(255,255,255,.05) 1px, transparent 1px) 0 0/26px 26px,
    radial-gradient(120% 100% at 70% 30%, rgba(31,122,140,.35), rgba(6,26,46,.55));
}
.hero-figure img{
  display:block;width:100%;height:300px;object-fit:contain;padding:14px;
  filter:drop-shadow(0 1px 6px rgba(120,200,255,.25));
}

/* layout -----------------------------------------------------------------*/
main{max-width:1080px;margin:0 auto;padding:26px 24px 60px}
.card{
  background:var(--card);border:1px solid var(--line);border-radius:14px;
  box-shadow:var(--shadow);padding:24px 26px;margin:-46px 0 26px;position:relative
}
.card+.card{margin-top:26px}
.card h2{font-size:1.3rem;display:flex;align-items:center;gap:.5em}
.step{
  display:inline-grid;place-items:center;width:1.5em;height:1.5em;border-radius:50%;
  background:var(--brand);color:#fff;font-size:.85rem;font-weight:700
}

/* buttons ----------------------------------------------------------------*/
.btn{
  display:inline-flex;align-items:center;gap:.4em;cursor:pointer;font:inherit;font-weight:600;
  border-radius:9px;padding:10px 16px;border:1px solid var(--line);background:#fff;color:var(--ink);
  transition:.15s;white-space:nowrap
}
.btn:hover{border-color:#c4ccd4;text-decoration:none}
.btn.primary{background:var(--brand);border-color:var(--brand);color:#fff}
.btn.primary:hover{background:var(--brand-d)}
.btn.ghost{background:rgba(255,255,255,.12);border-color:rgba(255,255,255,.5);color:#fff}
.btn.ghost:hover{background:rgba(255,255,255,.22)}
.btn.small{padding:7px 12px;font-size:.85rem}
.btn.tiny{padding:5px 10px;font-size:.78rem;font-weight:500}

/* load -------------------------------------------------------------------*/
.load-grid{display:grid;grid-template-columns:1.4fr 1fr;gap:20px}
.dropzone{
  border:2px dashed #c4d0db;border-radius:12px;padding:30px 20px;text-align:center;
  color:var(--muted);cursor:pointer;transition:.15s;background:#fafcfe
}
.dropzone:hover,.dropzone.drag{border-color:var(--brand);background:#f0f6ff;color:var(--brand)}
.dropzone p{margin:.5em 0 .2em;color:var(--ink)}
.load-side{display:flex;flex-direction:column;gap:10px;justify-content:center}
.muted{color:var(--muted);font-size:.92rem;margin:.2em 0}
.status{font-size:.9rem;color:var(--sky);background:#eef5ff;border:1px solid #d6e6ff;
  padding:9px 12px;border-radius:8px}
.status.err{color:#9b2226;background:#fdecec;border-color:#f6c9c9}

/* flight row + summary ---------------------------------------------------*/
.flight-row{display:flex;gap:18px;align-items:end;flex-wrap:wrap;margin-bottom:14px}
.flight-row label{display:flex;flex-direction:column;font-size:.82rem;color:var(--muted);gap:4px;font-weight:600}
.flight-row select,.flight-row input,.opts select,.opts input,.map-controls input,.map-controls select{
  font:inherit;padding:8px 10px;border:1px solid var(--line);border-radius:8px;background:#fff;color:var(--ink)
}
.flight-row .hint{font-size:.8rem;color:var(--muted);max-width:280px}
.summary{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:10px;
  background:#f7f9fb;border:1px solid var(--line);border-radius:10px;padding:14px 16px;margin-bottom:18px
}
.summary div{display:flex;flex-direction:column}
.summary span{font-size:.72rem;text-transform:uppercase;letter-spacing:.05em;color:var(--muted)}
.summary b{font-size:1rem}

/* tabs -------------------------------------------------------------------*/
.tabs{display:flex;gap:4px;border-bottom:2px solid var(--line);margin-bottom:18px;flex-wrap:wrap}
.tab{
  border:none;background:none;font:inherit;font-weight:600;color:var(--muted);cursor:pointer;
  padding:10px 16px;border-bottom:3px solid transparent;margin-bottom:-2px;border-radius:6px 6px 0 0
}
.tab:hover{color:var(--ink);background:#f5f7f9}
.tab.active{color:var(--brand);border-bottom-color:var(--brand)}

/* controls + chips -------------------------------------------------------*/
.controls{display:flex;justify-content:space-between;gap:16px;align-items:flex-start;
  flex-wrap:wrap;margin-bottom:10px}
.chips{display:flex;flex-wrap:wrap;gap:7px;flex:1;min-width:240px}
.chip{
  display:inline-flex;align-items:center;gap:6px;font:inherit;font-size:.84rem;cursor:pointer;
  border:1px solid var(--line);background:#fff;border-radius:999px;padding:5px 11px;color:var(--muted);transition:.12s
}
.chip i{width:9px;height:9px;border-radius:50%;display:inline-block;opacity:.45}
.chip small{opacity:.7}
.chip:hover{border-color:#b9c2cc}
.chip.on{background:#eef5ff;border-color:var(--brand);color:var(--sky);font-weight:600}
.chip.on i{opacity:1}
.opts{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.opts label{display:flex;flex-direction:column;font-size:.72rem;color:var(--muted);gap:3px;font-weight:600}
.presets{display:flex;gap:6px}

/* plots ------------------------------------------------------------------*/
.plot{width:100%;height:460px}
.plot.tall{height:560px}
.caption{font-size:.85rem;color:var(--muted);margin:10px 2px 0}

/* map --------------------------------------------------------------------*/
.map-controls{align-items:end}
.map-controls label{display:flex;flex-direction:column;font-size:.72rem;color:var(--muted);gap:3px;font-weight:600}
.map-controls input[type=number]{width:110px}
.map-controls .lean{min-width:160px}
.map-controls .lean input{width:120px}
.map-wrap{position:relative;border-radius:12px;overflow:hidden;border:1px solid var(--line)}
.map{width:100%;height:560px;background:#0b1622}
.map-fallback{display:grid;place-items:center;height:100%;color:#cfd8e3;text-align:center;padding:24px;font-size:.95rem}
.map-legend{
  position:absolute;left:14px;bottom:14px;background:rgba(12,22,34,.82);color:#fff;
  padding:8px 12px;border-radius:8px;font-size:.76rem;display:flex;align-items:center;gap:8px;backdrop-filter:blur(4px)
}
.map-legend .lbl{position:absolute;top:-20px;left:0;white-space:nowrap;font-weight:600}
.map-legend .bar{width:150px;height:10px;border-radius:5px}
.maplibregl-ctrl-attrib{font-size:10px}

/* about ------------------------------------------------------------------*/
.about-grid{display:grid;grid-template-columns:1.3fr 1fr;gap:26px;align-items:start}
.about p{margin:.4em 0}
.derived{font-size:.86rem;color:var(--muted);background:#f7f9fb;border:1px solid var(--line);
  border-radius:8px;padding:10px 12px}
.gallery{margin:0}
.gallery img{width:100%;height:300px;object-fit:cover;object-position:50% 48%;
  border-radius:10px;border:1px solid var(--line);display:block}
.gallery figcaption{margin-top:8px;font-size:.82rem;color:var(--muted);text-align:center}

footer{text-align:center;color:var(--muted);font-size:.85rem;padding:20px 0 0}

.hidden{display:none!important}

@media(max-width:760px){
  .hero h1{font-size:1.9rem}
  .hero-inner{grid-template-columns:1fr;gap:24px}
  .hero-figure img{height:230px}
  .load-grid,.about-grid{grid-template-columns:1fr}
  .controls{flex-direction:column}
  .plot{height:380px}.plot.tall{height:460px}
}