/* Student DZ — Smart Calculator */
.calculator-page{padding:1.5rem 0 3rem}.calculator-shell{max-width:1050px;margin:0 auto}.calculator-intro{text-align:center;margin:0 auto 1.5rem;color:var(--text-muted);max-width:720px}.calculator-layout{display:grid;grid-template-columns:minmax(0,1.05fr) minmax(320px,.95fr);gap:1.25rem;align-items:start}.calculator-card,.history-card{background:var(--bg-card);border:1px solid var(--border-color);border-radius:var(--radius-lg);box-shadow:0 4px 12px rgba(0,0,0,.05)}.calculator-card{padding:1rem}.display{border:1px solid var(--border-color);background:var(--bg-main);border-radius:var(--radius-md);padding:1rem;margin-bottom:1rem;min-height:126px;display:flex;flex-direction:column;justify-content:flex-end}.display-expression{min-height:28px;color:var(--text-muted);font-size:1rem;overflow-wrap:anywhere;text-align:left;direction:ltr}.display-result{font-size:2.25rem;font-weight:800;line-height:1.2;overflow-wrap:anywhere;text-align:left;direction:ltr;color:var(--text-main)}.display-result.error{color:#d93025;font-size:1.15rem}.keypad{display:grid;grid-template-columns:repeat(4,1fr);gap:.55rem}.calc-key{min-height:58px;border:1px solid var(--border-color);border-radius:var(--radius-md);background:var(--bg-card);color:var(--text-main);font:700 1.15rem var(--font-family);cursor:pointer;transition:transform .12s,background .12s}.calc-key:hover{background:var(--bg-main)}.calc-key:active{transform:scale(.97)}.calc-key.operator{background:var(--primary-light);color:#fff;border-color:transparent}.calc-key.utility{background:var(--bg-main);color:var(--text-muted)}.calc-key.equals{grid-column:1 / -1;background:var(--primary-color);color:#fff;border-color:transparent}.calculator-actions{display:grid;grid-template-columns:1fr 1fr;gap:.6rem;margin-top:.75rem}.calculator-actions .btn{width:100%;min-height:46px}.save-panel{margin-top:.75rem;padding:.85rem;border-radius:var(--radius-md);background:var(--bg-main);border:1px solid var(--border-color)}.save-fields{display:grid;grid-template-columns:1fr auto;gap:.6rem}.save-fields input{width:100%;min-height:44px;padding:.65rem .8rem;border:1px solid var(--border-color);border-radius:var(--radius-md);background:var(--bg-card);color:var(--text-main);font:500 .95rem var(--font-family)}.save-fields input:focus{outline:2px solid var(--primary-light);border-color:var(--primary-color)}.history-card{padding:1rem}.history-head{display:flex;justify-content:space-between;align-items:center;gap:.75rem;margin-bottom:.8rem}.history-head h2{font-size:1.2rem;margin:0}.history-count{font-size:.82rem;color:var(--text-muted)}.history-list{display:flex;flex-direction:column;gap:.65rem;max-height:650px;overflow:auto}.history-empty{text-align:center;color:var(--text-muted);padding:2rem 1rem;border:1px dashed var(--border-color);border-radius:var(--radius-md)}.history-item{border:1px solid var(--border-color);border-radius:var(--radius-md);padding:.8rem;background:var(--bg-main)}.history-title{font-weight:700;margin-bottom:.35rem;overflow-wrap:anywhere}.history-expression{direction:ltr;text-align:left;font-size:.95rem;color:var(--text-muted);overflow-wrap:anywhere}.history-result{direction:ltr;text-align:left;font-weight:800;font-size:1.2rem;margin-top:.2rem}.history-meta{font-size:.75rem;color:var(--text-muted);margin-top:.4rem}.history-actions{display:flex;flex-wrap:wrap;gap:.4rem;margin-top:.65rem}.history-btn{border:1px solid var(--border-color);background:var(--bg-card);color:var(--text-main);border-radius:var(--radius-md);padding:.45rem .65rem;font:500 .82rem var(--font-family);cursor:pointer}.history-btn:hover{border-color:var(--primary-color)}.history-btn.delete{color:#c62828}.edit-mode{display:inline-flex;align-items:center;gap:.4rem;margin-bottom:.7rem;color:var(--primary-color);font-size:.85rem;font-weight:700}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.calculator-note{margin-top:1rem;text-align:center;font-size:.8rem;color:var(--text-muted)}@media(max-width:800px){.calculator-layout{grid-template-columns:1fr}.history-list{max-height:none}}@media(max-width:520px){.calculator-page{padding:.8rem 0 2rem}.calculator-card,.history-card{border-radius:var(--radius-md);padding:.75rem}.display{min-height:112px;padding:.8rem}.display-result{font-size:1.85rem}.keypad{gap:.45rem}.calc-key{min-height:52px;font-size:1.05rem}.calculator-actions{grid-template-columns:1fr}.save-fields{grid-template-columns:1fr}.save-fields .btn{width:100%}.history-head{align-items:flex-start;flex-direction:column}}