:root{--primary-bg:#6366f1;--primary-hover:#4f46e5;--display-bg:#1e293b;--display-text:#4ade80}#history-list{scrollbar-width:thin;scrollbar-color:rgba(156,163,175,0.5) transparent;max-height:540px;overflow-y:auto;padding:.5rem}.dark #history-list::-webkit-scrollbar-thumb{background-color:rgba(75,85,99,.5)}.dark #history-list::-webkit-scrollbar-thumb:hover{background-color:rgba(75,85,99,.7)}body{font-family:"Noto Sans SC",ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;background:#f8fafc}.display-area{background:var(--display-bg);padding:1rem;border-radius:.5rem;margin-bottom:1rem}#display-exp{min-height:1.5rem;color:#94a3b8;text-align:right;font-size:.875rem;margin-bottom:.25rem}#display{color:var(--display-text);text-align:right;font-size:2rem;font-weight:600;line-height:1.2}button{border-radius:.5rem;transition:150ms ease-in-out;font-weight:500}button[data-number]{background:#fff;color:#374151;border:1px solid #e5e7eb}button[data-number]:hover{background:#f9fafb}button[data-number]:active{background:#f3f4f6}button[data-function],button[data-operation]{background:#8b5cf6;color:#fff}button[data-function]:hover,button[data-operation]:hover{background:#7c3aed}button[data-operation]:active{background:#6d28d9}button[data-action=clear-entry],button[data-action=clear]{background:#dc2626;color:#fff}button[data-action=clear]:hover{background:#dc2626}button[data-action=clear-entry]:hover{background:#ea580c}button[data-action=equals]{background:#22c55e;color:#fff;grid-row:span 2}button[data-action=equals]:hover{background:#16a34a}button[data-constant]{background:#ec4899;color:#fff}button[data-constant]:hover{background:#db2777}button[data-function=cos],button[data-function=sin],button[data-function=tan]{background:#6366f1;color:#fff}button[data-function=cos]:hover,button[data-function=sin]:hover,button[data-function=tan]:hover{background:#4f46e5}button[data-function=inv].active{background:#f97316;color:#fff;box-shadow:inset 0 2px 4px 0 rgba(0,0,0,.1)}button[data-function=inv].active:hover{background:#ea580c}.angle-unit{font-size:.875rem;font-weight:500;padding:.5rem;transition:150ms ease-in-out}.angle-unit.active{background:#8b5cf6;color:#fff}.angle-unit:not(.active){color:#374151}.angle-unit:not(.active):hover{background:#f3f4f6}@media (max-width:640px){button{min-height:2.25rem;font-size:.875rem}#display{font-size:1.5rem}}button:active{transform:scale(.95)}.history-item{padding:.5rem;border-radius:.375rem;margin-bottom:.5rem;background:#f9fafb;cursor:pointer;transition:background-color 150ms}.history-item:hover{background:#f3f4f6}.history-exp{color:#6b7280;font-size:.875rem}.history-result{color:#1f2937;font-weight:500}#history-list::-webkit-scrollbar{width:4px}#history-list::-webkit-scrollbar-track{background:#f1f1f1}#history-list::-webkit-scrollbar-thumb{background:#94a3b8;border-radius:2px}#history-list::-webkit-scrollbar-thumb:hover{background:#64748b}.shadow-inner{box-shadow:inset 0 2px 4px 0 rgba(0,0,0,.05)}.shadow-sm{box-shadow:0 1px 2px 0 rgba(0,0,0,.05)}.shadow{box-shadow:0 1px 3px 0 rgba(0,0,0,.1),0 1px 2px -1px rgba(0,0,0,.1)}