/* OpenType Feature Explorer */

:root {
  --font-body: 'Space Grotesk', system-ui, sans-serif;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  background: var(--slate);
  color: var(--cloud);
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
}

/* ── SKIP + HEADER ───────────────────────────────────────── */

.skip-link {
  position: absolute; top: -4rem; left: 1rem;
  background: var(--violet); color: var(--cloud);
  padding: 0.5rem 1rem; border-radius: 0 0 0.5rem 0.5rem;
  font-size: 0.875rem; text-decoration: none; z-index: 200;
  transition: top 0.15s;
}
.skip-link:focus { top: 0; }

.site-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 1rem 2rem;
  border-bottom: 1px solid var(--slate-raised);
  gap: 1rem;
}

.brand { display: flex; align-items: center; gap: 0.6rem; font-size: 0.8rem; }
.back-link { color: var(--violet-muted); text-decoration: none; transition: color 0.15s; }
.back-link:hover { color: var(--cloud); }
.brand-sep { color: var(--slate-raised); }
.brand-name { color: var(--violet-bright); font-weight: 600; }

.btn-ghost {
  background: transparent;
  border: 1px solid var(--slate-raised);
  color: var(--violet-muted);
  padding: 0.4rem 0.85rem;
  border-radius: 0.5rem;
  font: 500 0.78rem var(--font-body);
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}
.btn-ghost:hover { border-color: var(--violet); color: var(--cloud); }

/* ── LAYOUT ──────────────────────────────────────────────── */

.layout {
  flex: 1;
  display: grid;
  grid-template-columns: 300px 1fr;
  min-height: 0;
}

/* ── FEATURES PANEL ──────────────────────────────────────── */

.features-panel {
  background: var(--slate-panel);
  border-right: 1px solid var(--slate-raised);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  overflow-y: auto;
}

.panel-label {
  display: block;
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--violet-muted);
  margin-bottom: 0.45rem;
}

.font-select {
  background: var(--slate-raised);
  border: 1px solid var(--slate-raised);
  color: var(--cloud);
  font: 500 0.875rem var(--font-body);
  padding: 0.5rem 0.75rem;
  border-radius: 0.5rem;
  width: 100%;
  cursor: pointer;
  transition: border-color 0.15s;
}
.font-select:hover { border-color: var(--violet-deep); }
.font-select:focus { outline: 2px solid var(--cyan); outline-offset: 2px; }

.custom-input {
  background: var(--slate-raised);
  border: 1px solid var(--slate-raised);
  color: var(--cloud);
  font: 400 0.875rem var(--font-body);
  padding: 0.5rem 0.75rem;
  border-radius: 0.5rem;
  width: 100%;
  transition: border-color 0.15s;
}
.custom-input:hover { border-color: var(--violet-deep); }
.custom-input:focus { outline: 2px solid var(--cyan); outline-offset: 2px; border-color: transparent; }

/* Feature rows */
.features-list {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.feature-section-label {
  font-size: 0.58rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--violet-deep);
  padding: 0.6rem 0 0.2rem;
  margin-top: 0.25rem;
}

.feature-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.55rem 0.75rem;
  border-radius: 0.5rem;
  border: 1px solid transparent;
  gap: 0.75rem;
  transition: background 0.15s, border-color 0.15s;
  cursor: pointer;
}
.feature-row:hover { background: var(--slate-raised); }
.feature-row.is-on {
  background: rgba(139, 92, 246, 0.12);
  border-color: var(--violet-deep);
}

.feature-info { flex: 1; min-width: 0; }

.feature-name {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--cloud);
  display: block;
}

.feature-tag {
  font-size: 0.62rem;
  font-family: 'Space Mono', monospace;
  color: var(--violet-muted);
  letter-spacing: 0.06em;
}

/* Custom toggle switch */
.toggle-wrap {
  flex-shrink: 0;
}

.feature-toggle {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0);
  white-space: nowrap; border: 0;
}

.toggle-track {
  display: block;
  width: 32px; height: 18px;
  background: var(--slate-raised);
  border-radius: 999px;
  position: relative;
  transition: background 0.2s;
  cursor: pointer;
  flex-shrink: 0;
}
.toggle-track::after {
  content: '';
  position: absolute;
  top: 2px; left: 2px;
  width: 14px; height: 14px;
  border-radius: 50%;
  background: var(--violet-muted);
  transition: transform 0.2s, background 0.2s;
}

.feature-toggle:checked + .toggle-track { background: var(--violet); }
.feature-toggle:checked + .toggle-track::after {
  transform: translateX(14px);
  background: var(--cloud);
}
.feature-toggle:focus-visible + .toggle-track {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

/* ── PREVIEW PANEL ───────────────────────────────────────── */

.preview-panel {
  padding: 2.5rem;
  display: flex;
  flex-direction: column;
  gap: 2rem;
  overflow-y: auto;
}

.preview-large {
  font-size: clamp(3rem, 8vw, 7rem);
  line-height: 1.1;
  color: var(--cloud);
  /* font-family + font-feature-settings set by JS */
}

.preview-text {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  font-size: clamp(1rem, 2vw, 1.25rem);
  line-height: 1.65;
  color: var(--violet-muted);
  /* font-family + font-feature-settings set by JS */
}
.preview-text p { margin: 0; }

.active-features {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  flex-wrap: wrap;
  font-size: 0.75rem;
  padding-top: 1rem;
  border-top: 1px solid var(--slate-raised);
}

.feat-label {
  color: var(--violet-muted);
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-size: 0.62rem;
}

.feat-list { color: var(--violet-bright); font-family: 'Space Mono', monospace; }

/* ── FOOTER ──────────────────────────────────────────────── */

.site-footer {
  padding: 1rem 2rem;
  border-top: 1px solid var(--slate-raised);
  font-size: 0.75rem;
}
.site-footer a { color: var(--violet-muted); text-decoration: none; transition: color 0.15s; }
.site-footer a:hover { color: var(--cloud); }

/* ── RESPONSIVE ──────────────────────────────────────────── */

@media (max-width: 768px) {
  .layout { grid-template-columns: 1fr; }
  .features-panel { border-right: none; border-bottom: 1px solid var(--slate-raised); }
  .preview-panel { padding: 1.5rem; }
}