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

:root {
  --bg:      #1a1a2e;
  --surface: #16213e;
  --border:  #0f3460;
  --text:    #e0e0e0;
  --muted:   #909090;
  --accent:  #e94560;

  --font-sans: system-ui, sans-serif;
  --font-mono: ui-monospace, "Cascadia Code", "Segoe UI Mono", Menlo, Consolas, monospace;
  --transition: opacity .15s, transform .15s;
}

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  height: 100dvh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* ── Header ── */
header {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 10px 20px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
  font-weight: 600;
  font-size: .85rem;
  color: #ff7091;
  text-transform: uppercase;
  letter-spacing: .05em;
}

.badge {
  background: rgba(233, 69, 96, .12);
  color: var(--accent);
  padding: .1rem .45rem;
  border-radius: 99px;
  font-size: .65rem;
  font-weight: 600;
  border: 1px solid rgba(233, 69, 96, .25);
}

.input-header-area {
  flex: 1;
  display: flex;
  align-items: center;
}

#input-area {
  flex: 1;
  padding: 10px 14px;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-family: var(--font-sans);
  font-size: .88rem;
  outline: none;
  height: 44px;
  overflow-y: auto;
  transition: border-color .15s;
}

#input-area:focus { border-color: var(--accent); }

#input-area[placeholder]:empty::before {
  content: attr(placeholder);
  color: var(--muted);
}

/* ── Main two-panel layout ── */
main.editor-container {
  flex: 1;
  display: flex;
  min-height: 0;
}

.panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  position: relative;
}

.panel.left  { background: var(--bg); border-right: 1px solid var(--border); }
.panel.right { background: #fff; color: #1e293b; }

.panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 1rem;
  height: 36px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.panel.right .panel-header {
  background: #f1f5f9;
  border-bottom: 1px solid #e2e8f0;
}

.panel-header h2 {
  font-size: .72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--muted);
}

.panel.right .panel-header h2 { color: #64748b; }

.stats {
  font-size: .75rem;
  color: var(--muted);
}

/* ── Left panel — code output ── */
.textarea-wrapper {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

#output-area {
  flex: 1;
  padding: 16px;
  background: transparent;
  color: #cbd5e1;
  font-family: var(--font-mono);
  font-size: .82rem;
  line-height: 1.6;
  border: none;
  outline: none;
  resize: none;
  overflow-y: auto;
  white-space: pre-wrap;
}

/* ── Right panel — preview ── */
.preview-content {
  flex: 1;
  padding: 2rem 2.5rem;
  overflow-y: auto;
  font-size: 1rem;
  line-height: 1.6;
  color: #334155;
}

.preview-content h2.title-level-2 {
  font-size: 1.6rem;
  font-weight: 600;
  color: #0f172a;
  margin: 1.5rem 0 .75rem;
}

.preview-content p           { margin-bottom: 1.1rem; }
.preview-content ul,
.preview-content ol          { margin-bottom: 1.1rem; padding-left: 1.5rem; }
.preview-content li          { margin-bottom: .4rem; }
.preview-content a           { color: #1155cc; text-decoration: underline; }

/* ── Copy button ── */
.copy-btn {
  position: absolute;
  bottom: 1.5rem;
  right: 1.5rem;
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 10px 23px;
  border-radius: 20px;
  font-family: var(--font-sans);
  font-size: .9rem;
  font-weight: 600;
  letter-spacing: .05em;
  text-transform: uppercase;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: .5rem;
  box-shadow: 0 4px 16px rgba(233, 69, 96, .4);
  transition: var(--transition);
  z-index: 20;
  overflow: hidden;
}

.copy-btn:hover  { transform: scale(1.02); }
.copy-btn:active { transform: scale(0.98); }
.copy-btn.copied { background: #2ea043; box-shadow: 0 4px 16px rgba(46, 160, 67, .4); }

.copy-btn .success-msg {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  transition: var(--transition);
}

.copy-btn.copied .btn-content {
  opacity: 0;
  transform: translateY(-20px);
}

.copy-btn.copied .success-msg {
  top: 50%;
  transform: translate(-50%, -50%);
}

.icon { width: 17px; height: 17px; }

/* ── Footer ── */
footer {
  padding: 8px 20px;
  background: var(--surface);
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: .75rem;
  flex-shrink: 0;
}

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

footer a:hover { color: var(--text); }

/* ── Scrollbars ── */
::-webkit-scrollbar       { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--muted); }

/* ── Responsive ── */
@media (max-width: 640px) {
  header {
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
    padding: 10px 14px;
  }

  #input-area { font-size: 1rem; }

  .copy-btn { font-size: .8rem; padding: 10px 18px; }
}