/* ===== ValveDyn Pro Web Analysis — styled to match the Kaydani brand ===== */
:root{
  --ink:#13212e; --ink-soft:#455563; --muted:#6b7c8c;
  --navy:#0b2540; --navy-2:#0e2c4d;
  --brand:#1a8fd1; --brand-dark:#1466c0; --brand-ink:#0d4c86;
  --bg:#ffffff; --bg-soft:#f4f7fa; --bg-softer:#eef3f8;
  --border:#e2e8f0; --border-strong:#cfd9e4;
  --ok:#1f9d6b; --warn:#d98a1f; --bad:#d1495b;
  --radius:12px; --radius-sm:8px;
  --shadow:0 1px 2px rgba(16,40,66,.06), 0 8px 24px rgba(16,40,66,.06);
  --shadow-lg:0 12px 40px rgba(11,37,64,.16);
  --maxw:1240px;
  --font:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;
}
*{box-sizing:border-box}
body{margin:0;font-family:var(--font);color:var(--ink);background:var(--bg-soft);
  line-height:1.55;font-size:16px;-webkit-font-smoothing:antialiased}
img{max-width:100%;display:block}
a{color:var(--brand-dark);text-decoration:none}
a:hover{text-decoration:underline}
h1,h3{line-height:1.2;color:var(--ink);font-weight:700;margin:0 0 .5em}
h1{font-size:clamp(1.7rem,3.6vw,2.5rem);letter-spacing:-.02em}
h3{font-size:1.15rem;margin-bottom:1rem}
p{margin:0 0 1rem}
.container{max-width:var(--maxw);margin:0 auto;padding:0 24px}
.section{padding:34px 0 70px}
.eyebrow{color:var(--brand-dark);font-weight:700;text-transform:uppercase;
  letter-spacing:.14em;font-size:.76rem;margin-bottom:.5rem}
.muted{color:var(--muted)}
code{background:var(--bg-softer);padding:.1rem .4rem;border-radius:4px;font-size:.9em}

/* buttons */
.btn{display:inline-flex;align-items:center;gap:.5rem;font-weight:600;
  padding:.8rem 1.4rem;border-radius:var(--radius-sm);border:1px solid transparent;
  cursor:pointer;transition:.15s;font-size:.98rem;text-decoration:none;background:none}
.btn:hover{text-decoration:none}
.btn--primary{background:var(--brand);color:#fff;box-shadow:0 6px 16px rgba(26,143,209,.28);width:100%;justify-content:center}
.btn--primary:hover{background:var(--brand-dark)}
.btn--primary:disabled{opacity:.6;cursor:default;transform:none}
.btn--outline{background:#fff;color:var(--brand-dark);border-color:var(--border-strong)}
.btn--outline:hover{border-color:var(--brand)}
.btn--ghost{background:transparent;color:#fff;border-color:rgba(255,255,255,.4)}
.btn--ghost:hover{background:rgba(255,255,255,.1)}
.btn--sm{padding:.5rem .85rem;font-size:.85rem}
.btn--lg{padding:1rem 1.7rem;font-size:1.05rem;margin-top:6px}

/* header */
.site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.96);
  backdrop-filter:saturate(180%) blur(8px);border-bottom:1px solid var(--border)}
.nav{display:flex;align-items:center;gap:16px;height:72px}
.brand{display:flex;align-items:center;gap:11px;font-weight:800;color:var(--ink);white-space:nowrap}
.brand__logo{width:38px;height:38px;flex:none;object-fit:contain}
.brand__name{display:flex;flex-direction:column;line-height:1.05}
.brand__name b{font-size:1.04rem}
.brand__name span{font-size:.66rem;letter-spacing:.1em;text-transform:uppercase;color:var(--muted);font-weight:600}
.nav__links{display:flex;gap:4px}
.nav__links a{color:var(--ink-soft);font-weight:600;font-size:.9rem;padding:.5rem .3rem}
.nav__links a:hover{color:var(--brand-dark)}
.nav__right{margin-left:auto;display:flex;align-items:center;gap:10px}

/* page hero (secondary pages) */
.page-hero{background:linear-gradient(160deg,#0b2540,#0a1e33);color:#fff;padding:44px 0 40px}
.page-hero h1{color:#fff;margin-bottom:.3rem}
.page-hero p{color:#c3d4e6;max-width:70ch;margin:0}
.breadcrumb{color:#8fb0cf;font-size:.85rem;margin-bottom:14px}
.breadcrumb a{color:#a9c6e0}

/* hero (landing) */
.hero{position:relative;color:#eaf2fb;background:
   radial-gradient(900px 500px at 82% -10%, rgba(26,143,209,.35), transparent 60%),
   linear-gradient(160deg,#0b2540 0%,#0a1e35 60%,#081726 100%);overflow:hidden}
.hero::after{content:"";position:absolute;inset:0;
  background-image:linear-gradient(rgba(255,255,255,.05) 1px,transparent 1px),
  linear-gradient(90deg,rgba(255,255,255,.05) 1px,transparent 1px);
  background-size:44px 44px;mask-image:radial-gradient(700px 400px at 75% 0%,#000,transparent 75%);opacity:.5}
.hero__inner{position:relative;z-index:1;padding:64px 0 48px}
.hero h1{color:#fff;max-width:20ch;margin-bottom:.5rem}
.hero .lead{color:#c3d4e6;font-size:1.14rem;max-width:66ch;margin-bottom:0}
.hero__tags{display:flex;gap:10px;flex-wrap:wrap;margin-top:26px}
.tag{border:1px solid rgba(255,255,255,.22);color:#d5e3f2;border-radius:999px;
  padding:.4rem .9rem;font-size:.83rem;font-weight:600;background:rgba(255,255,255,.04)}

/* how it works */
.how{background:#fff;border-bottom:1px solid var(--border)}
.how__grid{display:grid;grid-template-columns:repeat(3,1fr);gap:28px;padding:34px 0}
.how__step h3{margin-bottom:.3rem;font-size:1.05rem}
.how__step p{color:var(--ink-soft);font-size:.92rem;margin-bottom:0}
.how__num{display:inline-flex;align-items:center;justify-content:center;width:30px;height:30px;
  border-radius:999px;background:var(--brand);color:#fff;font-weight:800;font-size:.9rem;margin-bottom:10px}

/* app layout */
.app-grid{display:grid;grid-template-columns:.95fr 1.15fr;gap:24px;align-items:start;margin-top:0}
.app-panel{background:#fff;border:1px solid var(--border);border-radius:14px;
  padding:28px;box-shadow:var(--shadow)}

/* dropzone */
.dropzone{border:2px dashed var(--border-strong);border-radius:12px;padding:34px 20px;
  text-align:center;cursor:pointer;transition:.15s;outline-offset:4px}
.dropzone:hover,.dropzone:focus-visible{border-color:var(--brand);background:var(--bg-soft)}
.dropzone.dragover{border-color:var(--brand);background:#eaf5fc}
.dropzone__idle .ic{width:48px;height:48px;border-radius:12px;background:var(--bg-soft);
  color:var(--brand);display:flex;align-items:center;justify-content:center;margin:0 auto 14px}
.dropzone__idle .ic svg{width:24px;height:24px}
.dropzone__idle p{margin:0;color:var(--ink-soft);font-size:.94rem}
.dropzone__file{display:flex;align-items:center;gap:12px;text-align:left}
.dropzone__file .ic{width:38px;height:38px;border-radius:10px;flex:none;
  display:flex;align-items:center;justify-content:center;background:#e6f5ee;color:var(--ok)}
.dropzone__file .ic svg{width:20px;height:20px}
.file-meta{flex:1;min-width:0;display:flex;flex-direction:column}
.file-meta b{font-size:.94rem;color:var(--ink);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.file-meta span{font-size:.8rem}

.project-meta{margin-top:20px;padding-top:18px;border-top:1px solid var(--border)}

/* CTA band */
.cta-band{background:linear-gradient(150deg,#0b2540,#0a2036);color:#fff;border-radius:16px;
  padding:44px;display:flex;align-items:center;justify-content:space-between;gap:28px;flex-wrap:wrap}
.cta-band h2{color:#fff;margin:0;font-size:1.4rem}
.cta-band p{color:#c3d4e6;margin:.5rem 0 0;max-width:56ch}

/* form */
.form-card > .btn--lg{margin-top:4px}
.fieldset{margin-bottom:18px;padding-bottom:18px;border-bottom:1px solid var(--border)}
.fieldset:last-of-type{border-bottom:0}
.fieldset__title{font-weight:700;font-size:.86rem;letter-spacing:.03em;text-transform:uppercase;
  color:var(--brand-dark);margin-bottom:12px}
details.fieldset summary::-webkit-details-marker{display:none}
.row3{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-bottom:14px}
.field{display:flex;flex-direction:column;gap:5px}
.field label{font-weight:600;font-size:.82rem;color:var(--ink-soft)}
.field input,.field select{border:1px solid var(--border-strong);border-radius:8px;
  padding:.6rem .7rem;font:inherit;font-size:.94rem;color:var(--ink);background:#fff;width:100%}
.field input:focus,.field select:focus{outline:2px solid rgba(26,143,209,.35);border-color:var(--brand)}
.form-error{color:var(--bad);font-weight:600;font-size:.9rem;margin-top:10px}

/* gas mixture editor */
.mix-head{display:flex;justify-content:space-between;align-items:baseline}
.mix-total{font-weight:700;font-size:.86rem;color:var(--muted)}
.mix-total.ok{color:var(--ok)}
.mix-rows{display:grid;gap:8px;margin:10px 0}
.mix-row{display:grid;grid-template-columns:1fr 90px auto;gap:8px;align-items:center}
.mix-row select,.mix-row input{border:1px solid var(--border-strong);border-radius:8px;
  padding:.55rem .65rem;font:inherit;font-size:.9rem;background:#fff;width:100%}
.mix-row__remove{background:none;border:0;color:var(--muted);cursor:pointer;padding:.4rem;
  border-radius:6px;line-height:0}
.mix-row__remove:hover{color:var(--bad);background:var(--bg-soft)}

/* results */
.results-empty{display:flex;flex-direction:column;align-items:center;justify-content:center;
  text-align:center;padding:70px 20px;color:var(--muted);min-height:340px}
.results-empty .ic{width:56px;height:56px;border-radius:14px;background:var(--bg-soft);
  display:flex;align-items:center;justify-content:center;color:var(--brand);margin-bottom:18px}
.results-empty .ic svg{width:28px;height:28px}
.results-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px}
.results-head h3{margin:0}

.headline-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin-bottom:20px}
.stat-card{background:var(--bg-soft);border:1px solid var(--border);border-radius:12px;
  padding:16px;text-align:center}
.stat-card__label{display:block;font-size:.78rem;color:var(--muted);font-weight:600;margin-bottom:6px}
.stat-card b{display:block;font-size:1.55rem;color:var(--navy);letter-spacing:-.02em}
.stat-card__unit{display:block;font-size:.74rem;color:var(--muted);margin-top:2px}

.health-card{background:var(--bg-soft);border:1px solid var(--border);border-radius:12px;
  padding:20px;margin-bottom:20px}
.health-card__head{display:flex;justify-content:space-between;align-items:flex-start;margin-bottom:16px}
.health-total{display:flex;align-items:baseline;gap:6px}
.health-total b{font-size:2.4rem;color:var(--navy);letter-spacing:-.02em}
.health-total span{color:var(--muted);font-weight:600}
.grade-chip{display:inline-block;margin-left:10px;padding:.2rem .65rem;border-radius:999px;
  font-weight:700;font-size:.82rem;background:var(--ok);color:#fff;vertical-align:middle}
.grade-chip.warn{background:var(--warn)}
.grade-chip.bad{background:var(--bad)}
.discharge-temp{text-align:right;font-size:.82rem;color:var(--muted)}
.discharge-temp b{color:var(--ink);font-size:1.1rem}
.health-bars{display:grid;gap:8px}
.health-bar{display:grid;grid-template-columns:130px 1fr 46px;align-items:center;gap:10px;font-size:.82rem}
.health-bar__track{height:8px;border-radius:6px;background:var(--border);overflow:hidden}
.health-bar__fill{height:100%;background:var(--brand);border-radius:6px}
.health-bar__val{text-align:right;color:var(--muted);font-weight:600}

.chart-card{background:#fff;border:1px solid var(--border);border-radius:12px;padding:20px;margin-bottom:20px}

.checks-card{background:#fff;border:1px solid var(--border);border-radius:12px;padding:20px}
.checks-list{list-style:none;margin:0;padding:0;display:grid;gap:10px}
.checks-list li{display:flex;gap:10px;align-items:flex-start;font-size:.9rem;color:var(--ink-soft)}
.chip{flex:none;width:20px;height:20px;border-radius:999px;display:flex;align-items:center;
  justify-content:center;color:#fff;font-size:.7rem;font-weight:800;margin-top:1px}
.chip.pass{background:var(--ok)}
.chip.fail{background:var(--bad)}
.checks-list b{color:var(--ink)}

/* footer */
.mini-footer{padding:26px 0 50px;color:var(--muted);font-size:.86rem;text-align:center}

/* settings modal */
.modal{position:fixed;inset:0;background:rgba(11,37,64,.45);display:none;
  align-items:center;justify-content:center;z-index:100;padding:20px}
.modal.open{display:flex}
.modal__card{background:#fff;border-radius:14px;padding:26px;max-width:420px;width:100%;box-shadow:var(--shadow-lg)}
.modal__actions{display:flex;justify-content:flex-end;gap:10px;margin-top:16px}

/* responsive */
@media(max-width:900px){
  .app-grid{grid-template-columns:1fr;margin-top:0}
  .row3{grid-template-columns:1fr 1fr}
  .headline-grid{grid-template-columns:1fr 1fr}
  .how__grid{grid-template-columns:1fr;gap:20px}
  .nav__links{display:none}
  .cta-band{padding:30px}
}

/* print — one clean page for "Download PDF" */
@media print{
  .site-header,.page-hero,.hero,.how,.app-panel--input,.mini-footer,.cta-band,
  #pdfBtn,.results-head .btn{display:none !important}
  body{background:#fff}
  .app-grid{display:block;margin-top:0}
  .app-panel{box-shadow:none;border:0;padding:0}
  .chart-card,.checks-card,.health-card,.stat-card{break-inside:avoid;border:1px solid #ccc}
}