:root {
  --bg: #0b0f1a;
  --surface: rgba(22, 28, 45, 0.7);
  --border: rgba(255, 255, 255, 0.1);
  --accent: #6366f1;
  --text: #f1f5f9;
  --muted: #94a3b8;
  --error: #fb7185;
  --success: #22c55e;
}

* {
  box-sizing: border-box;
  transition: all 0.2s ease;
}

body {
  margin: 0;
  background: radial-gradient(circle at top right, #1e1b4b, #0b0f1a);
  color: var(--text);
  font-family: "Plus Jakarta Sans", sans-serif;
  height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* Header */
header {
  padding: 0.8rem 1.5rem;
  background: rgba(11, 15, 26, 0.8);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-weight: 700;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo span {
  color: var(--accent);
}

/* Container & Panels */
.main-container {
  flex: 1;
  display: flex;
  overflow: hidden;
  background: var(--border);
  gap: 1px;
}

.panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  background: var(--surface);
  min-width: 0;
  position: relative;
}

.panel-header {
  padding: 12px 20px;
  font-size: 11px;
  font-weight: 700;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(0, 0, 0, 0.2);
}

/* Scrollable Content Areas */
textarea,
.preview,
#transformed {
  flex: 1;
  padding: 25px;
  overflow-y: auto !important;
  line-height: 1.7;
  outline: none;
  border: none;
  background: transparent;
  color: var(--text);
}

textarea {
  font-family: "JetBrains Mono", monospace;
  font-size: 14px;
  resize: none;
}

#transformed {
  font-family: "JetBrains Mono", monospace;
  font-size: 13px;
  color: var(--muted);
  white-space: pre-wrap;
}

.preview {
  font-size: 15px;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 10px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--muted);
}

/* Buttons */
.btn {
  background: var(--accent);
  color: white;
  border: none;
  padding: 6px 12px;
  border-radius: 5px;
  font-size: 11px;
  font-weight: 600;
  cursor: pointer;
}

.btn:hover {
  opacity: 0.8;
  transform: translateY(-1px);
}

/* Tab System for Mobile */
.tabs {
  display: none;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.tab {
  flex: 1;
  padding: 12px;
  text-align: center;
  font-size: 12px;
  color: var(--muted);
  cursor: pointer;
}

.tab.active {
  color: var(--accent);
  border-bottom: 2px solid var(--accent);
}

@media (max-width: 850px) {
  .tabs {
    display: flex;
  }

  .panel {
    display: none;
  }

  .panel.active {
    display: flex;
  }
}

/* LaTeX Preview Styling */
.preview h1 {
  font-size: 1.5rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 5px;
}

.preview .katex-display {
  margin: 1.5em 0;
  padding: 10px;
  background: rgba(255, 255, 255, 0.03);
  border-radius: 8px;
}