/* ===== Reset & Base ===== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #0f172a;
  --surface: #1e293b;
  --surface-2: #273449;
  --border: #334155;
  --text: #e2e8f0;
  --text-muted: #94a3b8;
  --accent-blue: #38bdf8;
  --accent-green: #4ade80;
  --accent-orange: #fb923c;
  --accent-red: #f87171;
  --radius: 12px;

  /* Harmonize Pico with the existing palette */
  --pico-background-color: var(--bg);
  --pico-color: var(--text);
  --pico-muted-color: var(--text-muted);
  --pico-h1-color: var(--text);
  --pico-h2-color: var(--text);
  --pico-h3-color: var(--text);
  --pico-primary: var(--accent-blue);
  --pico-primary-hover: var(--accent-blue);
  --pico-primary-focus: rgba(56, 189, 248, 0.25);
  --pico-card-background-color: var(--surface);
  --pico-card-border-color: var(--border);
  --pico-border-color: var(--border);
  --pico-border-radius: var(--radius);
  --pico-form-element-background-color: var(--surface);
  --pico-form-element-border-color: var(--border);
  --pico-form-element-color: var(--text);
  --pico-form-element-focus-color: var(--accent-blue);
}

html { font-size: 16px; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  text-align: center;
  padding: 2rem 1rem 1rem;
}

header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.subtitle {
  color: var(--text-muted);
  margin-top: 0.25rem;
  font-size: 0.9rem;
}

main {
  flex: 1;
  max-width: 960px;
  width: 100%;
  margin: 0 auto;
  padding: 0 1rem 2rem;
}

/* ===== Layout ===== */
.layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
  align-items: start;
}

/* ===== Input panel ===== */
.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  margin: 0;
}

.field__label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  font-weight: 600;
}

.field__hint {
  text-transform: none;
  letter-spacing: 0;
  color: var(--text);
  font-weight: 600;
  margin-left: 0.25rem;
}

.field__input {
  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.55rem 0.7rem;
  font-size: 0.95rem;
  font-family: inherit;
  width: 100%;
  margin: 0;
}

textarea.field__input {
  resize: vertical;
  min-height: 3rem;
}

.field__input:focus {
  outline: none;
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.2);
}

.field__range {
  width: 100%;
  accent-color: var(--accent-blue);
  margin: 0.25rem 0;
}

.hint {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin: 0;
}

.hint strong {
  color: var(--text);
  font-weight: 600;
}

/* Grouped sub-sections (logo, ring text, 3D print) */
.sub-group {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.75rem 0.85rem 0.85rem;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.sub-group > legend {
  padding: 0 0.4rem;
  margin-left: -0.4rem;
}

.sub-group.is-disabled {
  opacity: 0.45;
}

.field-row--three {
  grid-template-columns: 1fr 1fr 1fr;
}

.field__input--file {
  padding: 0.35rem 0.5rem;
  font-size: 0.8rem;
}

.field__input--file::file-selector-button {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.25rem 0.6rem;
  margin-right: 0.6rem;
  font-size: 0.8rem;
  cursor: pointer;
}

.btn--inline {
  align-self: end;
}

.hint--tight {
  font-size: 0.75rem;
}

.preview__warn {
  color: var(--accent-orange);
  font-size: 0.85rem;
  text-align: center;
  margin: 0;
}

input:disabled {
  cursor: not-allowed;
}

.field--check input:disabled + .field__label {
  opacity: 0.5;
}

.field-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.field--color input[type="color"] {
  width: 100%;
  height: 40px;
  padding: 2px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
}

.field--check {
  grid-column: 1 / -1;
  flex-direction: row;
  align-items: center;
  gap: 0.5rem;
}

.field--check input[type="checkbox"] {
  width: 1.1rem;
  height: 1.1rem;
  accent-color: var(--accent-blue);
  cursor: pointer;
  margin: 0;
}

.field--check .field__label {
  text-transform: none;
  letter-spacing: 0;
  font-weight: 500;
  color: var(--text);
}

/* ===== Preview ===== */
.preview {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.preview__frame {
  width: 100%;
  min-height: 240px;
  display: flex;
  align-items: center;
  justify-content: center;
  /* Checkerboard so transparent backgrounds are visible. */
  background-color: var(--surface-2);
  background-image:
    linear-gradient(45deg, #2f3e57 25%, transparent 25%),
    linear-gradient(-45deg, #2f3e57 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #2f3e57 75%),
    linear-gradient(-45deg, transparent 75%, #2f3e57 75%);
  background-size: 20px 20px;
  background-position: 0 0, 0 10px, 10px -10px, -10px 0;
  border-radius: 8px;
  padding: 1rem;
  overflow: hidden;
}

.preview__frame svg {
  max-width: 100%;
  height: auto;
  border-radius: 4px;
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.4);
}

.preview__empty {
  color: var(--text-muted);
  font-size: 0.9rem;
  font-style: italic;
  text-align: center;
}

.preview__error {
  color: var(--accent-red);
  font-size: 0.85rem;
  text-align: center;
  margin: 0;
}

.preview__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  justify-content: center;
  width: 100%;
}

.btn {
  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.55rem 1rem;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, color 0.15s, opacity 0.15s;
  width: auto;
  margin: 0;
}

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

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn--ghost {
  background: transparent;
}

.btn--copied {
  border-color: var(--accent-green) !important;
  color: var(--accent-green) !important;
}

/* ===== Footer ===== */
footer {
  text-align: center;
  padding: 1.5rem 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
}

footer a {
  color: var(--accent-blue);
  text-decoration: none;
}

footer a:hover { text-decoration: underline; }

/* ===== Responsive ===== */
@media (max-width: 720px) {
  .layout { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  header h1 { font-size: 1.35rem; }
  .field-row { grid-template-columns: 1fr; }
}