:root {
  --bg-a: #0f172a;
  --bg-b: #1f2937;
  --panel: #0b1220cc;
  --panel-border: #334155;
  --text: #e5e7eb;
  --muted: #9ca3af;
  --accent: #22d3ee;
  --shadow: 0 18px 45px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: "Segoe UI", "Trebuchet MS", Verdana, sans-serif;
  background:
    radial-gradient(1000px 500px at 15% -10%, #0ea5e966, transparent 60%),
    radial-gradient(900px 520px at 100% 0%, #14b8a655, transparent 50%),
    linear-gradient(145deg, var(--bg-a), var(--bg-b));
  display: grid;
  place-items: center;
  padding: 22px;
}

.card {
  width: min(900px, 100%);
  border: 1px solid var(--panel-border);
  border-radius: 18px;
  background: var(--panel);
  backdrop-filter: blur(6px);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.header {
  padding: 24px;
  border-bottom: 1px solid #1f2a3b;
  background: linear-gradient(90deg, #0f172a88, #082f49aa);
}

h1 {
  margin: 0;
  font-size: clamp(1.35rem, 2vw, 1.9rem);
  letter-spacing: 0.02em;
}

.subtitle {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 0.96rem;
}

.top-links {
  margin-top: 12px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tool-link {
  display: inline-block;
  text-decoration: none;
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: #dbeafe;
  border: 1px solid #2f4661;
  border-radius: 999px;
  padding: 6px 10px;
  background: #0b1322;
}

.tool-link.active {
  color: #05202a;
  border-color: #67e8f9;
  background: linear-gradient(90deg, #67e8f9, #2dd4bf);
}

.tool-grid {
  padding: 22px 24px 24px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.tool-card {
  display: block;
  text-decoration: none;
  border: 1px solid #2f4661;
  border-radius: 14px;
  padding: 16px;
  background: #0b1322;
  color: var(--text);
  transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}

.tool-card:hover {
  transform: translateY(-2px);
  border-color: #67e8f9;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.28);
}

.tool-card-title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 6px;
  color: #e2e8f0;
}

.tool-card-desc {
  font-size: 0.86rem;
  color: #94a3b8;
  line-height: 1.35;
}

form {
  padding: 20px 24px 10px;
  display: grid;
  gap: 14px;
}

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

label {
  display: block;
  margin-bottom: 6px;
  font-size: 0.9rem;
  color: #cbd5e1;
}

input[type="text"] {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid #2f3f55;
  border-radius: 10px;
  background: #0b1322;
  color: var(--text);
  outline: none;
  font-size: 1rem;
}

input[type="text"]:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px #22d3ee33;
}

select {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid #2f3f55;
  border-radius: 10px;
  background: #0b1322;
  color: var(--text);
  outline: none;
  font-size: 1rem;
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2322d3ee' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 10px center;
  background-size: 20px;
  padding-right: 40px;
}

select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px #22d3ee33;
}

select option {
  background: #0b1322;
  color: var(--text);
  padding: 8px;
}

.hint {
  color: var(--muted);
  font-size: 0.83rem;
  margin-top: 2px;
}

button {
  width: fit-content;
  border: none;
  border-radius: 10px;
  padding: 11px 18px;
  font-weight: 700;
  color: #05202a;
  background: linear-gradient(90deg, #67e8f9, #2dd4bf);
  cursor: pointer;
}

button:hover { filter: brightness(1.04); }

.errors {
  margin: 0 24px 0;
  padding: 12px 14px;
  border-radius: 10px;
  border: 1px solid #7f1d1d;
  background: #450a0aaa;
  color: #fecaca;
  display: none;
}

.result {
  margin: 18px 24px 24px;
  padding: 16px;
  border: 1px solid #334155;
  border-radius: 12px;
  background: #0b1322cc;
  display: none;
}

.badge {
  display: inline-block;
  padding: 4px 8px;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  margin-bottom: 10px;
}

.add { background: #14532d; color: #bbf7d0; }
.cut { background: #7c2d12; color: #fed7aa; }
.match { background: #1f2937; color: #d1d5db; }

.main-line {
  font-size: 1.2rem;
  margin: 4px 0 12px;
  font-weight: 700;
}

.detail-results {
  margin: 8px 0 14px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.detail-card {
  border: 1px solid #263346;
  border-radius: 10px;
  padding: 10px;
  background: #0b1322;
}

.detail-title {
  font-size: 0.86rem;
  color: #cbd5e1;
  margin-bottom: 6px;
  font-weight: 600;
}

.detail-value {
  font-size: 1.02rem;
  font-weight: 700;
  color: #e2e8f0;
  margin-bottom: 5px;
}

.detail-note {
  font-size: 0.78rem;
  color: #94a3b8;
  line-height: 1.35;
}

.sizing-results {
  margin: 8px 0 14px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.sizing-card {
  border: 1px solid #263346;
  border-radius: 10px;
  padding: 10px;
  background: #0b1322;
}

.sizing-label {
  font-size: 0.84rem;
  color: #cbd5e1;
  margin-bottom: 6px;
  font-weight: 600;
}

.sizing-value {
  font-size: 1.02rem;
  font-weight: 700;
  color: #e2e8f0;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}

th, td {
  text-align: left;
  padding: 8px 6px;
  border-bottom: 1px solid #1f2a3b;
}

th { color: #cbd5e1; font-weight: 600; }

.foot {
  margin-top: 10px;
  color: var(--muted);
  font-size: 0.84rem;
}

@media (max-width: 680px) {
  .grid { grid-template-columns: 1fr; }
  .detail-results { grid-template-columns: 1fr; }
  .sizing-results { grid-template-columns: 1fr; }
  .tool-grid { grid-template-columns: 1fr; padding-left: 16px; padding-right: 16px; }
  .card { border-radius: 14px; }
  .header, form { padding-left: 16px; padding-right: 16px; }
  .result, .errors { margin-left: 16px; margin-right: 16px; }
}