:root{color-scheme:dark;background:#0b1220;color:#e8f0ff;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}*{box-sizing:border-box}body{margin:0;min-height:100vh;background:radial-gradient(circle at top,#223554,#0b1220 52%,#05090f)}.app-shell{min-height:100vh;padding:2rem;display:flex;flex-direction:column;align-items:center;gap:1.5rem}.hero{text-align:center;max-width:760px}.hero h1{margin:0;font-size:clamp(2rem,4vw,3.5rem);color:#f8fbff}.hero p{margin:.75rem auto 0;color:#a8b7d8;line-height:1.7;max-width:720px}.card{width:min(100%,720px);background:#0c1527f2;border:1px solid rgba(255,255,255,.08);border-radius:24px;padding:1.75rem;box-shadow:0 35px 90px #00000040;display:grid;gap:1rem}textarea{width:100%;resize:vertical;border:1px solid rgba(255,255,255,.15);border-radius:16px;background:#07101f;color:#f8fbff;padding:1rem;min-height:140px;font-size:1rem;line-height:1.6}button{border:none;background:linear-gradient(135deg,#4d8dff,#70c9ff);color:#07101f;font-weight:700;padding:1rem 1.25rem;border-radius:14px;cursor:pointer;transition:transform .18s ease,opacity .18s ease}button:hover{transform:translateY(-1px)}button:disabled{opacity:.6;cursor:not-allowed}.toast{border-radius:18px;padding:1rem;line-height:1.5;background:#0c1527e0;border:1px solid rgba(255,255,255,.08)}.toast.error{color:#ffd7d7;border-color:#ff747433}.toast.result{color:#d7f9ff}pre{margin:.75rem 0 0;white-space:pre-wrap;word-break:break-word;font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,Liberation Mono,Courier New,monospace}