:root{--bg:#f5f6f7;--panel:#fff;--panel-2:#f1f3f5;--text:#1f2328;--muted:#667085;--border:#d9dde3;--accent:#2463eb;--accent-hover:#1d4ed8;--danger:#b42318;--shadow:0 1px 3px rgba(0,0,0,.08);color-scheme:light}
:root[data-theme="dark"]{--bg:#111214;--panel:#191b1f;--panel-2:#23262b;--text:#f5f7fa;--muted:#aeb4be;--border:#343942;--accent:#5b8cff;--accent-hover:#78a0ff;--danger:#ff8078;--shadow:none;color-scheme:dark}
*{box-sizing:border-box}body{margin:0;font-family:Arial,Helvetica,sans-serif;background:var(--bg);color:var(--text)}button,input,textarea{font:inherit}.hidden{display:none!important}.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}.subtle{color:var(--muted)}.small{font-size:.84rem}.fine-print{font-size:.82rem;color:var(--muted);line-height:1.45}
.site-header{height:62px;background:var(--panel);border-bottom:1px solid var(--border);display:flex;align-items:center;justify-content:space-between;padding:0 22px;position:sticky;top:0;z-index:20}.brand{display:flex;align-items:center;gap:10px;border:0;background:none;color:var(--text);font-weight:700;font-size:1.06rem;cursor:pointer}.brand-mark,.calculator-icon{font-size:1.45rem}.header-actions{display:flex;gap:8px}.icon-btn,.small-btn,.secondary,.primary,.tab,.sidebar-icon,.sidebar-action,.sidebar-brand{border:1px solid var(--border);background:var(--panel);color:var(--text);border-radius:8px;cursor:pointer}.icon-btn{padding:8px 11px}.primary{background:var(--accent);color:#fff;border-color:var(--accent);padding:10px 15px;font-weight:600}.primary:hover{background:var(--accent-hover)}.secondary{padding:9px 13px}.small-btn{padding:6px 9px}.danger{color:var(--danger)!important}.settings-menu{position:fixed;right:18px;top:58px;width:220px;background:var(--panel);border:1px solid var(--border);border-radius:10px;box-shadow:var(--shadow);padding:8px;z-index:30}.settings-menu>button,.menu-row{width:100%;border:0;background:none;color:var(--text);padding:10px;border-radius:7px;text-align:left}.settings-menu>button{cursor:pointer}.settings-menu>button:hover{background:var(--panel-2)}.menu-row{display:flex;justify-content:space-between;align-items:center}
.page{padding:32px 20px}.calculator-layout{max-width:1240px;margin:0 auto;display:grid;grid-template-columns:180px minmax(0,720px) 180px;gap:24px;align-items:start;justify-content:center}.ad-slot{min-width:0}.ad-label{display:block;text-align:center;color:var(--muted);font-size:.68rem;margin-bottom:7px;letter-spacing:.08em}.ad-placeholder{height:560px;border:1px solid var(--border);background:var(--panel);display:flex;align-items:center;justify-content:center;color:var(--muted);overflow:hidden}.ad-placeholder img{width:100%;height:100%;object-fit:cover}.calculator-card{background:var(--panel);border:1px solid var(--border);border-radius:12px;padding:24px;box-shadow:var(--shadow)}.calculator-card h1{margin:8px 0}.calc-tabs,.staff-tabs{display:flex;gap:8px}.tab{padding:8px 11px}.tab.active{background:var(--panel-2);font-weight:700}.calculator-card label,.modal-card label{display:grid;gap:6px;font-weight:600;margin-top:14px}.display-row{display:grid;grid-template-columns:1fr auto;gap:8px}.display-row input,input,textarea{width:100%;border:1px solid var(--border);border-radius:8px;background:var(--panel);color:var(--text);padding:11px 12px;outline:none}.display-row input:focus,input:focus,textarea:focus{border-color:var(--accent);box-shadow:0 0 0 2px color-mix(in srgb,var(--accent) 20%,transparent)}.result-box{margin-top:12px;border:1px solid var(--border);background:var(--panel-2);border-radius:8px;padding:16px;font-size:1.5rem;font-weight:700;text-align:right;overflow-wrap:anywhere}.status-text{min-height:18px;margin:7px 0;color:var(--danger);font-size:.86rem}.keypad{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}.keypad button{min-height:48px;border:1px solid var(--border);border-radius:8px;background:var(--panel);color:var(--text);cursor:pointer}.keypad button:hover{background:var(--panel-2)}.algebra-panel{border-top:1px solid var(--border);margin-top:22px;padding-top:18px}.algebra-form{display:grid;grid-template-columns:repeat(3,1fr) auto;gap:10px;align-items:end}.ai-entry-wrap{max-width:720px;margin:20px auto;text-align:center}
.ai-shell{display:grid;grid-template-columns:270px minmax(0,1fr);min-height:calc(100vh - 62px);background:var(--panel)}.ai-sidebar{border-right:1px solid var(--border);background:var(--bg);padding:12px;display:flex;flex-direction:column;min-width:0}.sidebar-top{display:flex;gap:8px;align-items:center}.sidebar-brand{border:0;background:none;display:flex;gap:8px;align-items:center;padding:9px;flex:1;text-align:left;font-weight:700}.sidebar-icon{width:40px;height:40px}.sidebar-action{margin-top:10px;padding:11px;text-align:left}.sidebar-search input{margin-top:10px;background:var(--panel)}.sidebar-section-title{color:var(--muted);font-size:.75rem;font-weight:700;text-transform:uppercase;margin:16px 8px 8px}.chat-list{display:flex;flex-direction:column;gap:3px;min-height:0;overflow:auto}.chat-list button{border:0;background:none;color:var(--text);padding:10px;text-align:left;border-radius:8px;cursor:pointer;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.chat-list button.active,.chat-list button:hover{background:var(--panel-2)}.sidebar-account{margin-top:auto;border-top:1px solid var(--border);padding:12px 8px;color:var(--muted)}.chat-main{display:grid;grid-template-rows:auto 1fr auto;min-width:0}.chat-header{min-height:70px;border-bottom:1px solid var(--border);display:flex;justify-content:space-between;align-items:center;padding:12px 20px}.chat-header h1{font-size:1rem;margin:0 0 3px}.message-list{padding:24px max(20px,calc((100% - 760px)/2));overflow:auto;display:flex;flex-direction:column;gap:16px}.message{max-width:82%;line-height:1.55;white-space:pre-wrap}.message.user{align-self:flex-end;background:var(--panel-2);padding:11px 14px;border-radius:14px}.message.ai{align-self:flex-start}.message .who{font-size:.72rem;color:var(--muted);margin-bottom:4px}.composer{max-width:800px;width:calc(100% - 36px);margin:0 auto 18px;border:1px solid var(--border);border-radius:12px;background:var(--panel);padding:10px;display:grid;grid-template-columns:1fr auto;gap:8px;align-items:end}.composer textarea{border:0;resize:none;box-shadow:none!important;padding:8px}.composer textarea:focus{border:0}
.staff-wrap{max-width:1100px;margin:0 auto}.staff-header{display:flex;justify-content:space-between;align-items:flex-start;gap:15px}.staff-panel{margin-top:18px;background:var(--panel);border:1px solid var(--border);border-radius:10px;padding:18px}.table-wrap{overflow:auto}table{width:100%;border-collapse:collapse}th,td{text-align:left;padding:10px;border-bottom:1px solid var(--border);font-size:.9rem}.staff-form{display:grid;gap:12px;max-width:620px}.ad-admin-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}.ad-preview{height:300px;background:var(--panel-2);border:1px dashed var(--border);display:flex;align-items:center;justify-content:center;overflow:hidden}.ad-preview img{width:100%;height:100%;object-fit:contain}
.modal{border:0;padding:0;background:transparent}.modal::backdrop{background:rgba(0,0,0,.45)}.modal-card{width:min(94vw,500px);background:var(--panel);color:var(--text);border:1px solid var(--border);border-radius:12px;padding:24px;position:relative;box-shadow:0 14px 40px rgba(0,0,0,.2)}.modal-card.wide{width:min(94vw,700px)}.modal-close{position:absolute;right:12px;top:10px;border:0;background:none;color:var(--muted);font-size:1.5rem;cursor:pointer}.calculator-icon{margin-bottom:10px}.auth-actions{display:flex;gap:8px;margin-top:16px;flex-wrap:wrap}.password-rules{font-size:.84rem;color:var(--muted);line-height:1.55;margin:8px 0}.password-rules .ok{color:#15803d}.password-row{display:grid;grid-template-columns:auto 1fr auto;gap:10px;align-items:center;margin:18px 0;padding:12px;background:var(--panel-2);border-radius:8px}.search-results,.members-list{display:grid;gap:8px;margin-top:10px}.search-result,.member-row{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:10px;border:1px solid var(--border);border-radius:8px}.pricing-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px}.price-card{border:1px solid var(--border);border-radius:10px;padding:18px;display:grid;gap:8px}.price-card strong{font-size:2rem}.toast{position:fixed;left:50%;bottom:24px;transform:translateX(-50%);background:#1f2937;color:#fff;padding:10px 14px;border-radius:8px;z-index:100}.notification-bar{background:#fff8db;border-bottom:1px solid #ead88c;padding:10px 18px;color:#554700}
@media(max-width:980px){.calculator-layout{grid-template-columns:minmax(0,720px)}.ad-slot{display:none}.ai-shell{grid-template-columns:230px minmax(0,1fr)}}
@media(max-width:720px){.page{padding:18px 12px}.site-header{padding:0 12px}.calculator-card{padding:16px}.algebra-form{grid-template-columns:1fr 1fr}.algebra-form .primary{grid-column:1/-1}.ai-shell{grid-template-columns:1fr}.ai-sidebar{display:none}.chat-header{padding:10px 12px}.composer{width:calc(100% - 20px)}.pricing-grid,.ad-admin-grid{grid-template-columns:1fr}.staff-header{flex-direction:column}.password-row{grid-template-columns:1fr}.message{max-width:94%}}