:root {
  --primary: #6366F1; --primary-hover: #4F46E5; --secondary: #8B5CF6;
  --accent: #22D3EE; --success: #10B981; --error: #EF4444; --warning: #F59E0B;
  --bg: #0F172A; --bg-elevated: #1E293B; --bg-card: #243044;
  --bg-input: #0F172A; --text: #E2E8F0; --text-muted: #94A3B8; --text-dim: #475569;
  --border: #1E293B; --border-hover: #334155; --radius: 12px; --radius-sm: 8px;
  --font: 'Inter', system-ui, sans-serif; --mono: monospace; --transition: 200ms ease;
}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
body{font-family:var(--font);background:var(--bg);color:var(--text);min-height:100vh;overflow:hidden}
.app{display:flex;flex-direction:column;height:100vh}

.header{display:flex;align-items:center;justify-content:space-between;padding:12px 20px;background:var(--bg-elevated);border-bottom:1px solid var(--border);gap:12px;flex-shrink:0}
.header-left{display:flex;align-items:center;gap:12px}
.logo{font-size:1.3rem}
.header-title{font-size:1.05rem;font-weight:700;background:linear-gradient(135deg,var(--primary),var(--accent));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}

.btn{display:inline-flex;align-items:center;gap:6px;padding:8px 14px;font-size:.8rem;font-weight:500;font-family:var(--font);border:none;border-radius:var(--radius-sm);cursor:pointer;transition:all var(--transition);white-space:nowrap}
.btn:disabled{opacity:.4;cursor:not-allowed}
.btn-primary{background:linear-gradient(135deg,var(--primary),var(--primary-hover));color:#fff;box-shadow:0 2px 8px rgba(99,102,241,.3)}
.btn-primary:hover{transform:translateY(-1px);box-shadow:0 4px 16px rgba(99,102,241,.4)}
.btn-ghost{background:transparent;color:var(--text-muted);border:1px solid var(--border)}
.btn-ghost:hover:not(:disabled){background:var(--bg-card);color:var(--text);border-color:var(--border-hover)}
.btn-sm{padding:5px 10px;font-size:.72rem}

.main{display:grid;grid-template-columns:1fr 1fr;flex:1;overflow:hidden;gap:1px;background:var(--border)}
.panel{display:flex;flex-direction:column;background:var(--bg);overflow:hidden;padding:12px;gap:8px}
.panel-title{font-size:.82rem;font-weight:600}
.code-editor{flex:1;padding:14px;font-family:var(--mono);font-size:.78rem;line-height:1.6;background:var(--bg-input);border:1px solid var(--border);border-radius:var(--radius-sm);color:var(--accent);resize:none;outline:none;tab-size:2}
.code-editor:focus{border-color:var(--primary)}
.code-editor::placeholder{color:var(--text-dim)}
.output-area{flex:1;overflow-y:auto;font-size:.78rem;display:flex;flex-direction:column;gap:4px}
.dim{font-size:.72rem;color:var(--text-dim);font-style:italic}

.class-row{display:flex;align-items:center;gap:8px;padding:6px 10px;border-radius:6px;font-family:var(--mono);font-size:.72rem}
.class-row.changed{background:rgba(34,211,238,.04);border-left:3px solid var(--accent)}
.class-row.breaking{background:rgba(239,68,68,.04);border-left:3px solid var(--error)}
.class-row.unchanged{background:rgba(148,163,184,.04);border-left:3px solid var(--text-dim)}
.class-old{color:var(--text-dim);text-decoration:line-through;min-width:160px}
.class-arrow{color:var(--text-dim)}
.class-new{color:var(--accent);font-weight:600}
.class-note{font-size:.6rem;color:var(--text-muted);font-family:var(--font);margin-left:auto}
.class-tag{font-size:.55rem;padding:1px 5px;border-radius:3px;font-weight:600;margin-left:4px}
.tag-breaking{background:rgba(239,68,68,.15);color:var(--error)}
.tag-changed{background:rgba(34,211,238,.15);color:var(--accent)}

.stats-bar{display:flex;gap:16px;padding:8px 20px;background:var(--bg-elevated);border-top:1px solid var(--border);font-size:.68rem;color:var(--text-dim);flex-shrink:0}
.stat{display:flex;align-items:center;gap:4px}
.stat-val{font-weight:700;color:var(--text)}

.toast{position:fixed;bottom:60px;left:50%;transform:translateX(-50%);padding:10px 20px;background:var(--bg-card);border:1px solid var(--primary);border-radius:var(--radius-sm);color:var(--accent);font-size:.8rem;font-weight:500;z-index:200;animation:toast-in .3s ease}
@keyframes toast-in{from{opacity:0;transform:translateX(-50%) translateY(10px)}to{opacity:1;transform:translateX(-50%) translateY(0)}}
::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:var(--border);border-radius:3px}
@media(max-width:768px){.main{grid-template-columns:1fr;grid-template-rows:1fr 1fr}}