.scroll-top-btn{position:fixed;right:1.5rem;bottom:105px;z-index:700;width:56px;height:56px;padding:0;border-radius:50%;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:1px;background:rgba(18,24,38,0.85);border:none;color:#38bdf8;cursor:pointer;backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);box-shadow:0 4px 18px rgba(0,0,0,0.45);opacity:0;visibility:hidden;pointer-events:none;transform:translateY(12px) scale(0.9);transition:opacity 0.25s ease,transform 0.25s cubic-bezier(0.16,1,0.3,1),box-shadow 0.25s ease,background 0.25s ease;}.scroll-top-btn.show{opacity:1;visibility:visible;pointer-events:auto;transform:translateY(0) scale(1);}.scroll-top-btn:hover{background:rgba(21,27,43,0.92);box-shadow:0 4px 22px rgba(0,0,0,0.5),0 0 20px rgba(56,189,248,0.2);transform:translateY(-2px) scale(1.03);}.scroll-top-btn.show:hover{transform:translateY(-2px) scale(1.03);}.scroll-top-btn:active{transform:translateY(0) scale(0.96);}.stt-progress-ring{position:absolute;inset:0;width:56px;height:56px;pointer-events:none;}.stt-ring-track{stroke:rgba(255,255,255,0.08);stroke-width:2.5;fill:none;}.stt-ring-fill{stroke:url(#sttGrad);stroke-width:2.5;stroke-linecap:round;fill:none;transition:stroke-dashoffset 0.1s linear;}.stt-icon{position:relative;z-index:1;display:flex;align-items:center;justify-content:center;width:16px;height:16px;color:#f1f5f9;margin-top:2px;}.stt-icon svg{width:100%;height:100%;}.stt-label{position:relative;z-index:1;font-family:var(--fc-display),sans-serif;font-size:0.5rem;font-weight:700;letter-spacing:0.08em;color:#94bfd8;margin-bottom:1px;}.scroll-top-btn:hover .stt-icon{color:#38bdf8;}@media (max-width:600px){.scroll-top-btn{right:1rem;bottom:95px;width:48px;height:48px;}.stt-progress-ring{width:48px;height:48px;}.stt-label{font-size:0.44rem;}}:root{--fc-green:#00d68f;--fc-green-bg:rgba(0,214,143,0.08);--fc-green-border:rgba(0,214,143,0.18);--fc-red:#ff4d6d;--fc-red-bg:rgba(255,77,109,0.08);--fc-red-border:rgba(255,77,109,0.18);--fc-amber:#f59e0b;--fc-amber-bg:rgba(245,158,11,0.08);--fc-blue:#38b2f0;--fc-blue-bg:rgba(56,178,240,0.08);--fc-blue-border:rgba(56,178,240,0.18);}.header h1{font-family:'Outfit',sans-serif;font-size:2.0rem;font-weight:800;letter-spacing:-0.75px;text-transform:uppercase;background:linear-gradient(135deg,#fff,#94a3b8);-webkit-background-clip:text;-webkit-text-fill-color:transparent;}@media (max-width:1024px){.header h1{font-size:1.6rem;}}.subtitle{font-size:0.83rem;color:#64748b;letter-spacing:0.03em;margin-top:0.15rem;font-family:'Outfit',sans-serif;}.disclaimer-banner{background:rgba(245,158,11,0.1);border-top:1px solid rgba(245,158,11,0.2);border-bottom:1px solid rgba(245,158,11,0.2);padding:1rem 4rem;text-align:center;font-size:0.85rem;color:#fbbf24;display:flex;align-items:center;justify-content:center;gap:0.75rem;}.sm-switch{width:36px;height:19px;background:rgba(255,255,255,0.08);border-radius:99px;position:relative;transition:background 0.25s ease,box-shadow 0.25s ease;flex-shrink:0;border:1px solid rgba(255,255,255,0.1);}.sm-switch::after{content:'';position:absolute;top:2px;left:2px;width:13px;height:13px;background:#64748b;border-radius:50%;transition:transform 0.25s cubic-bezier(0.4,0,0.2,1),background 0.25s ease;}.student-mode-active .sm-switch{background:rgba(139,92,246,0.65);border-color:rgba(167,139,250,0.5);box-shadow:0 0 10px rgba(139,92,246,0.45);}.student-mode-active .sm-switch::after{transform:translateX(17px);background:#e9d5ff;}body.student-mode-active #mobileStudentModeBtn .mobile-sm-label{color:#e9d5ff;}.sidebar.mobile-open{transform:translateX(0);}