:root{
  --bg:#0e1b2e;          /* dark blue */
  --bg-2:#11233d;
  --primary:#ff7a00;     /* orange */
  --primary-2:#ff9f3d;
  --text:#e9eef7;
  --muted:#a5b0c0;
  --ok:#2ecc71;
  --warn:#ffcc00;
  --danger:#ff4d4f;
  --card:#0f213a;
  --border:#1d3255;
  --shadow: 0 10px 25px rgba(0,0,0,.35);
}
*{box-sizing:border-box}
html,body{
  margin:0;
  padding:0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji","Segoe UI Emoji";
  background: linear-gradient(180deg,var(--bg), var(--bg-2));
  color:var(--text);
}
.container{
  max-width: 1100px;
  margin: 0 auto;
  padding: 24px;
}
.header{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
}
.brand{
  display:flex; gap:12px; align-items:center;
}
.brand .dot{
  width:14px; height:14px; border-radius:50%;
  background: linear-gradient(135deg,var(--primary), var(--primary-2));
  box-shadow: 0 0 0 4px rgba(255, 122, 0, .08), 0 0 30px rgba(255,122,0,.25);
}
.title{
  font-weight:800; letter-spacing:.4px; font-size:24px
}
.sub{
  color:var(--muted); font-size:14px
}
.btn{
  border:1px solid var(--border);
  background: linear-gradient(135deg, #142a4d, #0f213a);
  color:var(--text);
  padding: 10px 14px; border-radius:14px;
  cursor:pointer;
  box-shadow: var(--shadow);
  transition:.2s ease all;
  text-decoration:none; display:inline-flex; align-items:center; gap:8px;
}
.btn:hover{
  transform: translateY(-1px);
  border-color: var(--primary-2);
  box-shadow: 0 12px 30px rgba(255,122,0,.12);
}
.btn.primary{
  background: linear-gradient(135deg, var(--primary), var(--primary-2));
  color:#0c1426; font-weight:700; border-color:transparent;
}
.grid{
  display:grid; gap:18px;
  grid-template-columns: repeat(12, minmax(0, 1fr));
}
.card{
  background: linear-gradient(180deg, rgba(255,255,255,.02), transparent);
  border:1px solid var(--border); border-radius:18px; padding:16px;
  box-shadow: var(--shadow);
}
.section h2{
  margin:0 0 8px 0; font-size:20px
}
.option-row{
  display:flex; flex-wrap:wrap; gap:10px
}
.option-pill{
  border:1px solid var(--border);
  background:#0e1f37; border-radius:100px; padding:8px 12px; cursor:pointer;
}
.option-pill input{ margin-right:8px; accent-color: var(--primary); }
.select{
  width:100%; padding:12px 14px; border-radius:12px; border:1px solid var(--border);
  background:#0e1f37; color:var(--text);
}
.field{
  display:flex; flex-direction:column; gap:6px; margin-bottom:12px;
}
.qty{
  display:flex; align-items:center; gap:10px
}
.qty button{
  width:38px; height:38px; border-radius:12px; border:1px solid var(--border); background:#0e1f37; color:var(--text);
  cursor:pointer; font-size:20px
}
.price{
  font-size:28px; font-weight:800; letter-spacing:.5px
}
.footer{
  margin-top:24px; display:flex; align-items:center; justify-content:space-between; gap:12px; flex-wrap:wrap
}
.cylinders{
  display:grid; grid-template-columns: repeat(4, minmax(0,1fr)); gap:14px
}
.cylinder{
  text-align:center; padding:14px; border:1px dashed var(--border); border-radius:16px;
}
.cylinder img{ width:80px; height:auto; }
.cylinder .label{ margin-top:8px; font-weight:700; color:var(--muted) }
.note{ color:var(--muted); font-size:13px }
.form-row{
  display:grid; grid-template-columns: repeat(12, minmax(0,1fr)); gap:12px; width:100%;
}
.col-6{ grid-column: span 6 / span 6 }
.col-12{ grid-column: span 12 / span 12 }
.input{
  width:100%; padding:12px 14px; border-radius:12px; border:1px solid var(--border); background:#0e1f37; color:var(--text);
}
.badge{
  background: rgba(255,122,0,.15); color:var(--primary-2); padding:4px 8px; border-radius:999px; font-size:12px; font-weight:700
}
.success{ color: var(--ok) }
.error{ color: var(--danger) }
hr{ border:0; border-top:1px solid var(--border); margin:12px 0 }
@media (max-width: 900px){
  .grid{ grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .cylinders{ grid-template-columns: repeat(2, minmax(0,1fr)); }
  .col-6{ grid-column: span 6 / span 6 }
}