:root {
  --bg:           #0f1117;
  --surface:      #1a1d2e;
  --surface2:     #21263d;
  --border:       #2d3561;
  --accent:       #4a90d9;
  --accent-light: #6aabf0;
  --text:         #e8eaf6;
  --muted:        #8892b0;
  --locked-bg:    rgba(64,145,108,.14);
  --locked-bdr:   #40916c;
  --output-bg:    rgba(74,144,217,.06);
  --output-bdr:   #4a90d9;
  --warn-bg:      rgba(244,162,97,.1);
  --warn:         #f4a261;
  --err-bg:       rgba(230,57,70,.1);
  --err:          #e63946;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  font-size: 15px;
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding: 0;
}

/* ── Header ─────────────────────────────────────── */
header {
  text-align: center;
  padding: 36px 20px 32px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 40px;
}

.site-logo {
  width: 56px;
  height: 56px;
  border-radius: 12px;
  display: block;
  margin: 0 auto 14px;
}

h1 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -.02em;
  margin-bottom: 6px;
}

header p { color: var(--muted); font-size: .95rem; }

/* ── Layout ──────────────────────────────────────── */
main {
  max-width: 980px;
  margin: 0 auto;
  flex: 1;
  width: 100%;
  padding: 0 20px 60px;
}

/* ── Cards ───────────────────────────────────────── */
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 24px;
}

@media (max-width: 700px) {
  .cards { grid-template-columns: 1fr; }
  h1 { font-size: 1.55rem; }
}

.card {
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  transition: border-color .2s, background .2s;
}

.card.output {
  background: var(--output-bg);
  border-color: var(--output-bdr);
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 11px 14px;
  background: var(--surface2);
  border-bottom: 1px solid var(--border);
}

.card-header h2 {
  font-size: .75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--muted);
}

.lock-btn {
  background: transparent;
  border: 1.5px solid var(--border);
  border-radius: 6px;
  width: 30px;
  height: 30px;
  cursor: pointer;
  font-size: 13px;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background .15s, border-color .15s;
  user-select: none;
}

.lock-btn.locked {
  background: var(--locked-bg);
  border-color: var(--locked-bdr);
}

.lock-btn:not(.locked) {
  cursor: default;
  opacity: .45;
}

.lock-btn.locked:hover { filter: brightness(1.2); }

.card-body {
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

/* ── Form elements ───────────────────────────────── */
label {
  display: flex;
  flex-direction: column;
  gap: 5px;
  font-size: .78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--muted);
}

.input-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

input[type=number], select {
  background: rgba(0,0,0,.28);
  border: 1.5px solid var(--border);
  border-radius: 7px;
  color: var(--text);
  font-size: 1.05rem;
  padding: 9px 11px;
  width: 100%;
  transition: border-color .15s;
  appearance: none;
  -moz-appearance: textfield;
}

input[type=number]::-webkit-outer-spin-button,
input[type=number]::-webkit-inner-spin-button { -webkit-appearance: none; }

input[type=number]:focus, select:focus {
  outline: none;
  border-color: var(--accent);
}

.output-field {
  color: var(--accent-light) !important;
  border-style: dashed;
}

input[readonly].output-field { cursor: default; }

select:disabled {
  opacity: 1;
  cursor: default;
}

.unit {
  color: var(--muted);
  font-size: .85rem;
  white-space: nowrap;
  flex-shrink: 0;
}

/* ── Actions ─────────────────────────────────────── */
.actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 20px;
}

.btn-primary, .btn-secondary {
  padding: 11px 26px;
  border-radius: 8px;
  font-size: .95rem;
  font-weight: 600;
  letter-spacing: .02em;
  cursor: pointer;
  transition: all .15s;
  border: none;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

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

.btn-secondary {
  background: var(--surface2);
  color: var(--text);
  border: 1.5px solid var(--border);
}

.btn-secondary:not(:disabled):hover {
  border-color: var(--accent);
  color: var(--accent);
}

.btn-secondary:disabled { opacity: .35; cursor: not-allowed; }

/* ── Messages ────────────────────────────────────── */
.msg-warn, .msg-error {
  border-radius: 8px;
  padding: 10px 16px;
  margin-bottom: 16px;
  font-size: .9rem;
  line-height: 1.55;
}

.msg-warn  { background: var(--warn-bg); border: 1px solid var(--warn);  color: var(--warn); }
.msg-error { background: var(--err-bg);  border: 1px solid var(--err);   color: var(--err); }

.hidden { display: none !important; }

/* ── Result summary ──────────────────────────────── */
.result-summary {
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: 10px;
  padding: 16px 20px;
  margin-bottom: 24px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 16px;
}

.sl {
  font-size: .72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .07em;
  color: var(--muted);
  margin-bottom: 3px;
}

.sv {
  font-size: .98rem;
  font-weight: 600;
  color: var(--text);
}

/* ── SVG Preview ─────────────────────────────────── */
.svg-container {
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 180px;
}

.svg-container svg { max-width: 100%; height: auto; display: block; }

.placeholder { color: var(--muted); font-size: .9rem; }

/* ── Orient hint ─────────────────────────────────── */
.orient-hint {
  font-size: .78rem;
  color: var(--muted);
  font-style: italic;
  margin-top: -4px;
  line-height: 1.4;
}

/* ── Footer ──────────────────────────────────────── */
footer {
  margin-top: auto;
  border-top: 1px solid var(--border);
  padding: 24px 20px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.footer-logo {
  width: 32px;
  height: 32px;
  border-radius: 7px;
  opacity: .7;
}

footer p {
  font-size: .82rem;
  color: var(--muted);
}