:root{
  --bg:#0b0f14;
  --card:#111823;
  --text:#e8eef7;
  --muted:#a8b3c2;
  --line:#223046;
  --btn:#2c75ff;
  --btn2:#172132;
  --shadow: 0 10px 30px rgba(0,0,0,.35);
  --radius: 14px;
}

*{ box-sizing:border-box; }
html,body{ height:100%; }

body{
  margin:0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial;
  background: var(--bg); /* flat dark background */
  color:var(--text);
  line-height:1.45;
}

a{ color:inherit; text-decoration:none; }
.container{ width:min(980px, 92vw); margin:0 auto; }

.topbar{
  padding:18px 0;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:14px;
}

.brand{
  font-weight:950;
  letter-spacing:.2px;
}
.brand.small{ font-size:14px; opacity:.95; }

.nav{
  display:flex;
  gap:14px;
  color:var(--muted);
  font-size:14px;
}
.nav a{ padding:8px 10px; border-radius:10px; }
.nav a:hover{ background:rgba(255,255,255,.06); color:var(--text); }

.hero{ padding:18px 0 8px; }
h1{ margin:0 0 8px; font-size:34px; }
h2{ margin:0 0 10px; font-size:22px; }
h3{ margin:0 0 6px; font-size:16px; }

.lede{ color:var(--muted); margin:0 0 12px; }

.card{
  margin:18px 0;
  background:linear-gradient(180deg, rgba(255,255,255,.05), rgba(255,255,255,.03));
  border:1px solid rgba(255,255,255,.08);
  border-radius:var(--radius);
  box-shadow:var(--shadow);
  padding:16px;
}

.card-head{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  margin-bottom:6px;
}

.right-controls{ display:flex; align-items:center; gap:10px; }

.toggle{
  display:flex;
  border:1px solid rgba(255,255,255,.12);
  border-radius:999px;
  overflow:hidden;
  background:rgba(0,0,0,.18);
}
.toggle-btn{
  border:0;
  background:transparent;
  color:var(--muted);
  padding:8px 12px;
  cursor:pointer;
  font-weight:950;
  font-size:13px;
}
.toggle-btn.is-on{
  background:rgba(44,117,255,.18);
  color:var(--text);
}

.segmented{
  display:flex;
  gap:8px;
  margin:10px 0 4px;
}
.seg-btn{
  border:1px solid rgba(255,255,255,.12);
  background:rgba(0,0,0,.18);
  color:var(--muted);
  padding:8px 12px;
  border-radius:999px;
  cursor:pointer;
  font-weight:950;
  font-size:13px;
}
.seg-btn.is-on{
  background:rgba(44,117,255,.18);
  color:var(--text);
  border-color:rgba(44,117,255,.35);
}

.grid{
  display:grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap:14px;
  margin:12px 0 14px;
}

.field label{
  display:block;
  font-size:13px;
  color:var(--muted);
  margin:0 0 6px;
}

.field input, .field select{
  width:100%;
  padding:10px 12px;
  border-radius:12px;
  border:1px solid rgba(255,255,255,.10);
  background:rgba(10,14,20,.6);
  color:var(--text);
  outline:none;
}

.field input:focus, .field select:focus{
  border-color: rgba(44,117,255,.6);
  box-shadow: 0 0 0 3px rgba(44,117,255,.15);
}

.row{ display:flex; align-items:center; gap:10px; }
.unit{ color:var(--muted); font-size:13px; white-space:nowrap; }
.hint{ margin:6px 0 0; font-size:12px; color:var(--muted); }

.full{ grid-column: 1 / -1; }
.actions{ display:flex; gap:10px; }

.btn{
  padding:10px 14px;
  border-radius:12px;
  border:1px solid rgba(255,255,255,.10);
  background:var(--btn);
  color:white;
  font-weight:950;
  cursor:pointer;
}
.btn:hover{ filter:brightness(1.05); }
.btn.ghost{
  background:transparent;
  color:var(--text);
  border:1px solid rgba(255,255,255,.14);
}

.results{
  display:grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap:12px;
  margin-top:10px;
}

.result{
  background:rgba(0,0,0,.18);
  border:1px solid rgba(255,255,255,.08);
  border-radius:14px;
  padding:12px;
}
.k{ color:var(--muted); font-size:13px; }
.v{ font-size:26px; font-weight:950; margin-top:4px; }
.s{ color:var(--muted); font-size:12px; margin-top:2px; }

.tools{
  display:grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap:12px;
  margin-top:12px;
}
.tool{
  background:rgba(0,0,0,.18);
  border:1px solid rgba(255,255,255,.08);
  border-radius:14px;
  padding:12px;
}
.tool:hover{ border-color: rgba(44,117,255,.45); }
.tool p{ margin:0 0 10px; color:var(--muted); font-size:13px; }
.cta{ font-weight:950; font-size:13px; color:#cfe0ff; }

.fineprint{ color:var(--muted); font-size:12px; margin-top:10px; }

.footer{
  margin-top:20px;
  padding:22px 0;
  border-top:1px solid rgba(255,255,255,.08);
  color:var(--muted);
}
.footer-grid{
  display:flex;
  justify-content:space-between;
  gap:16px;
  align-items:flex-start;
}
.footer-links{ display:flex; gap:12px; font-size:14px; }
.muted{ color:var(--muted); }

.hidden{ display:none !important; }

@media (max-width: 720px){
  .grid{ grid-template-columns: 1fr; }
  .results{ grid-template-columns: 1fr; }
  .tools{ grid-template-columns: 1fr; }
  .topbar{ flex-direction:column; align-items:flex-start; }
  .actions{ flex-direction:column; }
  .segmented{ flex-wrap:wrap; }
}