:root{font-family:Segoe UI,Arial,sans-serif;color-scheme:dark;--bg:#111315;--panel:#1b1e22;--key:#292d32;--muted:#9aa0a6;--accent:#8ab4f8}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:#f1f3f4;min-height:100vh}
.app{display:grid;grid-template-columns:minmax(360px,520px) minmax(360px,1fr);min-height:100vh}
.calculator{padding:28px;display:flex;flex-direction:column;border-right:1px solid #30343a}
.brand{font-weight:700;font-size:20px}.brand span{display:block;color:var(--muted);font-size:12px;font-weight:400;margin-top:4px}
.display{min-height:180px;display:flex;flex-direction:column;justify-content:flex-end;text-align:right;padding:25px 4px}
.expression{min-height:30px;color:var(--muted);font-size:20px;word-break:break-all}.result{font-size:48px;word-break:break-all}
.keys{display:grid;grid-template-columns:repeat(4,1fr);gap:10px}
button{border:0;border-radius:12px;background:var(--key);color:#fff;font-size:20px;padding:18px;cursor:pointer}button:hover{filter:brightness(1.15)}
.operator{color:var(--accent)}.utility{color:#c7d8f7}.equals{grid-column:1/-1;background:var(--accent);color:#111;font-weight:700}.danger{font-size:13px;padding:10px 12px;color:#ffb4ab}.primary{background:var(--accent);color:#111}
.history-panel{padding:28px;overflow:auto;max-height:100vh}.history-head{display:flex;justify-content:space-between;align-items:center;gap:12px}.history-head h1{margin:0}.history-head p{color:var(--muted);margin:5px 0 20px}
#search,#noteInput{width:100%;background:#24272c;border:1px solid #3c4043;color:#fff;border-radius:10px;padding:13px;font-size:15px;outline:none}
.group-title{color:var(--muted);font-size:13px;margin:24px 0 8px;text-transform:uppercase;letter-spacing:.08em}
.item{background:var(--panel);border:1px solid #30343a;border-radius:12px;padding:14px;margin-bottom:9px}
.calc{font-size:18px;cursor:pointer}.note{color:var(--accent);margin-top:8px}.meta{display:flex;justify-content:space-between;align-items:center;color:var(--muted);font-size:12px;margin-top:10px}.item-actions button{font-size:12px;padding:6px 8px;margin-left:5px}
.empty{color:var(--muted);text-align:center;margin-top:50px}
dialog{border:1px solid #3c4043;border-radius:14px;background:#1b1e22;color:#fff;width:min(440px,90vw)}dialog::backdrop{background:#0009}.dialog-actions{display:flex;justify-content:flex-end;gap:8px;margin-top:16px}.dialog-actions button{font-size:14px;padding:10px 16px}
@media(max-width:800px){.app{grid-template-columns:1fr}.calculator{border-right:0;border-bottom:1px solid #30343a}.history-panel{max-height:none}.display{min-height:140px}}

.backup-actions{display:flex;gap:7px;flex-wrap:wrap;justify-content:flex-end}.backup-actions button{font-size:13px;padding:10px 12px}
@media(max-width:1050px){.history-head{align-items:flex-start;flex-direction:column}.backup-actions{justify-content:flex-start;margin-bottom:14px}}