:root{--bg-main: #0f172a;--bg-card: #1e293b;--bg-input: #090d16;--text-primary: #f8fafc;--text-muted: #94a3b8;--accent: #38bdf8;--accent-hover: #0284c7;--operator-bg: #334155;--operator-hover: #475569;--btn-bg: #1e293b;--btn-hover: #334155;--border: #334155;--danger: #ef4444;--success: #10b981;--radius: 12px;--glass-bg: rgba(30, 41, 59, .65);--glass-border: rgba(255, 255, 255, .1)}[data-theme=light]{--bg-main: #f8fafc;--bg-card: #ffffff;--bg-input: #f1f5f9;--text-primary: #0f172a;--text-muted: #64748b;--accent: #0284c7;--accent-hover: #0369a1;--operator-bg: #e2e8f0;--operator-hover: #cbd5e1;--btn-bg: #ffffff;--btn-hover: #f1f5f9;--border: #e2e8f0;--danger: #dc2626;--success: #16a34a;--glass-bg: rgba(255, 255, 255, .75);--glass-border: rgba(0, 0, 0, .08)}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--bg-main);color:var(--text-primary);font-family:Inter,system-ui,-apple-system,sans-serif;min-height:100vh;display:flex;justify-content:center;align-items:center;padding:16px;position:relative;transition:background-color .25s ease,color .25s ease}.fixed-theme-toggle{position:fixed;top:18px;right:22px;display:inline-flex;align-items:center;gap:7px;background:var(--glass-bg);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border:1px solid var(--glass-border);color:var(--text-primary);border-radius:20px;padding:7px 14px;font-size:.82rem;font-weight:500;font-family:Inter,sans-serif;cursor:pointer;box-shadow:0 4px 12px #0000001a;transition:all .2s ease;z-index:999}.fixed-theme-toggle:hover{background:var(--operator-bg);border-color:var(--accent);transform:translateY(-1px)}.fixed-theme-toggle svg{width:14px;height:14px;stroke-width:2;stroke:currentColor;fill:none}.fixed-theme-toggle .mode-dot{width:6px;height:6px;border-radius:50%;background:var(--accent)}#root{width:100%;max-width:1000px}.app-container{display:grid;grid-template-columns:1fr 340px;gap:20px;background:var(--bg-card);border:1px solid var(--border);border-radius:16px;box-shadow:0 20px 25px -5px #00000026,0 8px 10px -6px #00000026;overflow:hidden;transition:background .2s ease,border-color .2s ease}@media (max-width: 768px){.app-container{grid-template-columns:1fr}.fixed-theme-toggle{top:12px;right:12px;padding:5px 10px;font-size:.75rem}}.main-calc{padding:24px;display:flex;flex-direction:column;gap:16px}.top-bar{display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid var(--border);padding-bottom:12px}.nav-tabs{display:flex;gap:8px}.nav-tab{background:none;border:none;color:var(--text-muted);font-weight:600;padding:6px 12px;border-radius:6px;cursor:pointer;font-size:.9rem;transition:background .15s ease,color .15s ease}.nav-tab:hover{color:var(--text-primary)}.nav-tab.active{background:var(--operator-bg);color:var(--text-primary)}.display-panel{background:var(--bg-input);border:1px solid var(--border);border-radius:var(--radius);padding:18px;display:flex;flex-direction:column;align-items:flex-end;min-height:110px;justify-content:space-between}.expression-input{width:100%;background:transparent;border:none;outline:none;box-shadow:none;color:var(--text-primary);font-family:JetBrains Mono,monospace;font-size:1.4rem;text-align:right;cursor:text;-webkit-user-select:text;user-select:text}.expression-input:focus,.expression-input:focus-visible{outline:none;border:none;box-shadow:none}.result-view{font-family:JetBrains Mono,monospace;font-size:2rem;font-weight:700;color:var(--accent);word-break:break-all}.error-view{color:var(--danger);font-size:.85rem;font-family:JetBrains Mono,monospace}.keypad-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:10px}.keypad-grid.basic{grid-template-columns:repeat(4,1fr)}.keypad-grid.scientific{grid-template-columns:repeat(5,1fr)}button.key-btn{background:var(--btn-bg);border:1px solid var(--border);border-radius:8px;color:var(--text-primary);font-size:1.1rem;font-weight:500;padding:14px;cursor:pointer;transition:background .15s ease,transform .05s ease;font-family:JetBrains Mono,monospace}button.key-btn:hover{background:var(--btn-hover)}button.key-btn:focus-visible{outline:2px solid var(--accent);outline-offset:2px}button.key-btn:active{transform:scale(.98)}button.key-btn.op{background:var(--operator-bg);color:var(--accent);font-weight:700}button.key-btn.eq{background:var(--accent);color:#0f172a;font-weight:700}[data-theme=light] button.key-btn.eq{color:#fff}button.key-btn.eq:hover{background:var(--accent-hover)}button.key-btn.fn{background:var(--btn-bg);color:#a5b4fc;font-size:.95rem}[data-theme=light] button.key-btn.fn{color:#4f46e5}.sidebar-panel{border-left:1px solid var(--border);background:var(--bg-card);padding:20px;display:flex;flex-direction:column;gap:16px;max-height:600px}.sidebar-header{display:flex;justify-content:space-between;align-items:center;font-size:1rem;font-weight:600}.history-list{display:flex;flex-direction:column;gap:10px;overflow-y:auto;flex:1}.history-item{background:var(--bg-input);border:1px solid var(--border);border-radius:8px;padding:10px 12px;cursor:pointer;transition:border-color .15s ease}.history-item:hover,.history-item:focus-visible{border-color:var(--accent);outline:none}.history-exp{font-size:.85rem;color:var(--text-muted);font-family:JetBrains Mono,monospace}.history-res{font-size:1.1rem;font-weight:600;color:var(--text-primary);font-family:JetBrains Mono,monospace}.practical-form{display:flex;flex-direction:column;gap:12px}.form-group{display:flex;flex-direction:column;gap:4px}.form-group label{font-size:.85rem;color:var(--text-muted)}.form-group input,.form-group select{background:var(--bg-input);border:1px solid var(--border);border-radius:6px;padding:8px 12px;color:var(--text-primary);font-family:JetBrains Mono,monospace}.form-result-box{background:var(--bg-input);border:1px solid var(--accent);border-radius:8px;padding:12px;margin-top:8px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border-width:0}