:root{
  --bg: #f3f5f7;
  --card: #ffffff;
  --text: #0f172a;
  --muted: #475569;
  --border: #d7dde5;
  --shadow: 0 10px 25px rgba(15, 23, 42, 0.06);
  --primary: #2563eb;
  --primary-2: #1d4ed8;
  --danger: #dc2626;
  --danger-2: #b91c1c;

  --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, "Apple Color Emoji", "Segoe UI Emoji";
  background: var(--bg);
  color: var(--text);
}

.topbar{
  display:flex;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
  padding: 18px 18px;
  max-width: 1100px;
  margin: 0 auto;
}

.brand{
  display:flex;
  gap: 12px;
  align-items:center;
}

.logo{
  width: 70px;
  height: auto;
  border-radius: 90px;
  display: grid;
  place-items: center;
  display: block;
}

h1{
  margin:0;
  font-size: 20px;
  letter-spacing: 0.2px;
}

.subtitle{
  margin: 2px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.actions{
  display:flex;
  gap: 14px;
  align-items:flex-end;
  flex-wrap: wrap;
  justify-content:flex-end;
}

.layout{
  display:grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 16px;
  padding: 0 18px 24px;
  max-width: 1100px;
  margin: 0 auto;
}

.card{
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 16px;
}

h2{
  margin: 0 0 12px;
  font-size: 16px;
}

.field{
  display:flex;
  flex-direction: column;
  gap: 7px;
  margin-bottom: 12px;
}

.field-label{
  font-size: 13px;
  color: var(--muted);
  font-weight: 600;
}

.control{
  width: 100%;
  padding: 12px 12px;
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 15px;
  background: #fbfcfe;
  color: var(--text);
}

.form{
  margin-top: 10px;
}

.dynamic-grid{
  display:grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

@media (max-width: 920px){
  .layout{ grid-template-columns: 1fr; }
  .dynamic-grid{ grid-template-columns: 1fr; }
}

.form-row{
  display:flex;
  gap: 10px;
  margin-top: 12px;
  align-items:center;
}

.btn{
  appearance:none;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text);
  padding: 11px 14px;
  border-radius: 10px;
  font-size: 14px;
  cursor:pointer;
  transition: transform 0.05s ease, background 0.2s ease, border-color 0.2s ease;
}

.btn:hover{
  background: #f8fafc;
  border-color: #c7d2e3;
}

.btn:active{
  transform: translateY(1px);
}

.btn.primary{
  border-color: rgba(37,99,235,0.3);
  background: var(--primary);
  color: #fff;
}

.btn.primary:hover{
  background: var(--primary-2);
}

.btn.danger{
  border-color: rgba(220,38,38,0.3);
  background: #fff;
  color: var(--danger);
}

.btn.danger:hover{
  background: #fff5f5;
  border-color: rgba(220,38,38,0.45);
}

.result{
  margin-top: 14px;
  border: 1px dashed #cfd8e3;
  border-radius: 12px;
  padding: 12px;
  background: #fbfcff;
}

.result-line{
  display:flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 10px;
}

.result-label{
  color: var(--muted);
  font-weight: 700;
}

.result-value{
  font-size: 22px;
  font-weight: 800;
  letter-spacing: 0.2px;
}

.result-meta{
  margin-top: 6px;
  color: var(--muted);
  font-size: 13px;
}

.hint{
  margin: -4px 0 12px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.35;
}

.history{
  margin-top: 12px;
  display:flex;
  flex-direction: column;
  gap: 8px;
}

.history-item{
  border: 1px solid var(--border);
  background: #fff;
  border-radius: 12px;
  padding: 10px;
}

.history-title{
  font-weight: 800;
  font-size: 13px;
  margin-bottom: 4px;
}

.history-body{
  color: var(--muted);
  font-size: 13px;
  line-height: 1.35;
}

.bad-input{
  border-color: #fca5a5;
  background: #fff5f5;
}

.error{
  color: var(--danger);
  font-size: 13px;
  margin-top: 8px;
  font-weight: 700;
}

.footer{
  padding: 0 18px 18px;
  max-width: 1100px;
  margin: 0 auto;
  color: var(--muted);
}