*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: #0d1117; color: #c9d1d9;
  min-height: 100vh; padding: 2rem;
}
h1 { color: #58a6ff; margin-bottom: 0.25rem; font-size: 1.6rem; }
h2 { color: #79c0ff; margin: 1.5rem 0 0.75rem; font-size: 1.15rem; }
h3 { color: #79c0ff; margin: 1rem 0 0.5rem; font-size: 1rem; }
.subtitle { color: #8b949e; margin-bottom: 1.5rem; font-size: 0.9rem; }
.container { max-width: 720px; margin: 0 auto; }
.card {
  background: #161b22; border: 1px solid #30363d; border-radius: 8px;
  padding: 1.25rem; margin-bottom: 1rem;
}
.grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.75rem; }
@media (max-width: 500px) { .grid { grid-template-columns: 1fr; } }
label { display: block; color: #8b949e; font-size: 0.8rem; margin-bottom: 0.25rem; }
input, select {
  width: 100%; padding: 0.5rem 0.65rem; background: #0d1117;
  border: 1px solid #30363d; border-radius: 6px; color: #c9d1d9;
  font-size: 0.9rem;
}
input:focus, select:focus { outline: none; border-color: #58a6ff; }
/* ── Themed buttons ── */
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  border: none; border-radius: 8px; cursor: pointer;
  padding: 0.7rem 1.4rem; font-size: 0.95rem; font-weight: 600;
  color: #fff; margin-top: 1rem;
  position: relative; overflow: hidden;
  transition: transform 0.2s, box-shadow 0.3s;
}
.btn::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(circle at 30% 40%, rgba(255,255,255,0.12) 0%, transparent 60%);
  pointer-events: none;
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }


/* Location button — deep space blue */
.btn-location {
  background: linear-gradient(135deg, #1a3a5c 0%, #0e2a47 100%);
  border: 1px solid #264d73;
  box-shadow: 0 0 8px rgba(88,166,255,0.15);
}
.btn-location:hover {
  box-shadow: 0 0 18px rgba(88,166,255,0.35), 0 4px 12px rgba(0,0,0,0.4);
  border-color: #58a6ff;
}

/* Calculate button */
.btn-calculate {
  background: #238636;
  border: 1px solid #2ea043;
  box-shadow: 0 0 8px rgba(35,134,54,0.15);
  font-size: 1rem; padding: 0.75rem 1.8rem;
}
.btn-calculate:hover {
  background: #2ea043;
  box-shadow: 0 0 16px rgba(46,160,67,0.35), 0 4px 12px rgba(0,0,0,0.3);
  border-color: #3fb950;
}
#result {
  background: #161b22; border: 1px solid #30363d; border-radius: 8px;
  padding: 1.25rem; margin-top: 1.25rem; display: none;
}
#result.visible { display: block; }
.result-row { display: flex; justify-content: space-between; padding: 0.4rem 0;
  border-bottom: 1px solid #21262d; font-size: 0.9rem; }
.result-row:last-child { border-bottom: none; }
.result-label { color: #8b949e; }
.result-value { color: #58a6ff; font-family: 'Consolas', monospace; }
.phase-table { width: 100%; border-collapse: collapse; margin: 0.5rem 0; font-size: 0.85rem; }
.phase-table th { color: #8b949e; text-align: left; padding: 0.35rem 0.5rem; border-bottom: 1px solid #30363d; }
.phase-table td { padding: 0.35rem 0.5rem; border-bottom: 1px solid #21262d; font-family: 'Consolas', monospace; color: #c9d1d9; }
.phase-table .highlight { color: #58a6ff; font-weight: 600; }
.skipped { margin-top: 1rem; }
.skipped summary { cursor: pointer; color: #8b949e; font-size: 0.85rem; }
.skipped-item { font-size: 0.8rem; color: #6e7681; padding: 0.15rem 0; font-family: monospace; }
.error { color: #f85149; }
.success { color: #3fb950; }
.loading { color: #d29922; }
.hint { color: #6e7681; font-size: 0.75rem; margin-top: 0.15rem; }

/* ── Mobile optimizations ── */
@media (max-width: 600px) {
  body { padding: 1rem 0.75rem; }
  h1 { font-size: 1.3rem; }
  h2 { font-size: 1.05rem; margin: 1.25rem 0 0.6rem; }
  .subtitle { font-size: 0.82rem; margin-bottom: 1rem; }

  .card { padding: 1rem; }

  /* Larger tap targets for inputs */
  input, select {
    padding: 0.65rem 0.75rem;
    font-size: 1rem;
  }

  /* Full-width buttons */
  .btn { width: 100%; justify-content: center; }
  .btn-calculate { font-size: 1rem; padding: 0.85rem; }

  /* Horizontally scroll phase table */
  .table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; margin: 0 -1rem; padding: 0 1rem; }
  .phase-table { font-size: 0.78rem; min-width: 480px; }
  .phase-table th, .phase-table td { padding: 0.4rem 0.35rem; white-space: nowrap; }

  /* Stack result rows vertically */
  .result-row { flex-direction: column; gap: 0.15rem; }
  .result-value { font-size: 0.85rem; }

  /* Skipped section */
  .skipped-item { font-size: 0.72rem; word-break: break-word; }

  /* Results card padding */
  #result { padding: 1rem; margin-top: 1rem; }
}

/* Prevent iOS zoom on input focus (font-size >= 16px) */
@media (max-width: 600px) and (hover: none) {
  input, select { font-size: 16px; }
}

/* Safe area insets for notched devices */
@supports (padding: env(safe-area-inset-bottom)) {
  body {
    padding-left: max(env(safe-area-inset-left), 0.75rem);
    padding-right: max(env(safe-area-inset-right), 0.75rem);
    padding-bottom: env(safe-area-inset-bottom);
  }
}