:root{--font-sans:'Inter',-apple-system,sans-serif;--font-mono:'JetBrains Mono',monospace;--radius:12px;--transition:0.25s ease}
[data-theme="dark"]{--bg:#0F172A;--bg2:#1E293B;--bg-card:rgba(30,41,59,0.85);--bg-input:rgba(99,102,241,0.05);--border:rgba(99,102,241,0.12);--text:#F1F5F9;--text2:#94A3B8;--text3:#64748B;--primary:#6366F1;--accent:#10B981;--gradient:linear-gradient(135deg,#6366F1,#8B5CF6)}
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}body{font-family:var(--font-sans);background:var(--bg);color:var(--text);min-height:100vh}
.app{max-width:640px;margin:0 auto}.header{padding:16px 24px;border-bottom:1px solid var(--border)}
.logo{display:flex;align-items:center;gap:10px}.logo h1{font-size:1rem;font-weight:700;background:var(--gradient);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.btn{display:inline-flex;align-items:center;gap:6px;font-family:var(--font-sans);font-size:.82rem;font-weight:500;padding:8px 16px;border-radius:8px;border:none;cursor:pointer;transition:all var(--transition)}
.btn-primary{background:var(--gradient);color:#fff}.btn-primary:hover{transform:translateY(-1px)}
.btn-ghost{background:transparent;color:var(--text2)}.btn-ghost:hover{background:var(--bg-input);color:var(--text)}.btn-ghost.active{color:var(--primary)}
.main{padding:24px;display:flex;flex-direction:column;gap:20px}
.label{font-size:.78rem;font-weight:600;color:var(--text2);margin-bottom:6px;display:block}
.field{margin-bottom:12px}
input[type="text"],textarea{width:100%;padding:10px;background:var(--bg-input);color:var(--text);border:1px solid var(--border);border-radius:8px;font-family:var(--font-sans);font-size:.85rem;outline:none;resize:vertical}
input:focus,textarea:focus{border-color:var(--primary)}
.form-actions{display:flex;gap:8px;flex-wrap:wrap}
.preview-section{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:16px}
.preview-section h3{font-size:.85rem;font-weight:600;margin-bottom:8px;color:var(--text2)}
.preview-box{background:var(--bg-input);border-radius:8px;padding:14px;font-family:var(--font-mono);font-size:.82rem;color:var(--text);white-space:pre-wrap;line-height:1.5;margin-bottom:10px}
.format-toggle{display:flex;gap:6px}
.history-section h3{font-size:.85rem;font-weight:600;margin-bottom:10px;color:var(--text2)}
.history-item{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:12px;margin-bottom:8px;cursor:pointer;transition:all var(--transition)}
.history-item:hover{border-color:var(--primary)}.history-item .hi-date{font-size:.72rem;font-weight:600;color:var(--primary);font-family:var(--font-mono)}
.history-item .hi-preview{font-size:.78rem;color:var(--text3);margin-top:4px}
@media(max-width:500px){.form-actions{flex-direction:column}}