:root {
  --bg: #09090b; --bg2: #18181b; --bg3: #27272a;
  --accent: #6366f1; --accent2: #8b5cf6; --accent3: #ec4899;
  --ds: #6366f1; --os: #06b6d4; --coa: #f59e0b; --dbms: #10b981; --flat: #f43f5e;
  --green: #10b981; --amber: #f59e0b; --red: #ef4444; --cyan: #06b6d4;
  --t1: #f8fafc; --t2: #94a3b8; --t3: #64748b;
  --border: rgba(255, 255, 255, 0.06); --glass: rgba(255, 255, 255, 0.02);
  --shadow: 0 10px 40px -10px rgba(0,0,0,0.5);
  --r: 16px; --r2: 24px; --tr: 300ms cubic-bezier(0.4, 0, 0.2, 1);
}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;font-size:16px}
body{background:var(--bg);color:var(--t1);font-family:'Inter',system-ui,sans-serif;min-height:100vh;overflow-x:hidden}
a{color:inherit;text-decoration:none}
button{cursor:pointer;border:none;outline:none;background:none;font-family:inherit}
input,select,textarea{font-family:inherit;outline:none}
img{max-width:100%;display:block}

/* TYPOGRAPHY */
.display{font-family:'Outfit',sans-serif;font-weight:800;line-height:1.1;background:linear-gradient(135deg,#ffffff 0%,#a1a1aa 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;letter-spacing:-0.02em}
.display-xl{font-size:clamp(2.5rem,6vw,5rem)}
.display-lg{font-size:clamp(2rem,4vw,3.5rem)}
.display-md{font-size:clamp(1.5rem,3vw,2.5rem)}
h1,h2,h3,h4{font-family:'Outfit',sans-serif;font-weight:700;line-height:1.2;letter-spacing:-0.01em}
.text-sm{font-size:.875rem} .text-xs{font-size:.75rem} .text-lg{font-size:1.125rem} .text-xl{font-size:1.25rem}
.muted{color:var(--t2)} .faint{color:var(--t3)}
.mono{font-family:'JetBrains Mono',monospace}

/* LAYOUT */
.container{max-width:1280px;margin:0 auto;padding:0 1.5rem}
.section{padding:5rem 0}
.grid{display:grid} .flex{display:flex} .flex-col{flex-direction:column}
.items-center{align-items:center} .justify-center{justify-content:center}
.justify-between{justify-content:space-between} .gap-1{gap:.5rem} .gap-2{gap:1rem}
.gap-3{gap:1.5rem} .gap-4{gap:2rem} .gap-6{gap:3rem}
.grid-2{grid-template-columns:repeat(2,1fr)} .grid-3{grid-template-columns:repeat(3,1fr)}
.grid-4{grid-template-columns:repeat(4,1fr)} .grid-5{grid-template-columns:repeat(5,1fr)}

/* GLASS CARD */
.card{background:linear-gradient(145deg, rgba(255,255,255,0.03) 0%, rgba(255,255,255,0.01) 100%);border:1px solid var(--border);border-radius:var(--r);backdrop-filter:blur(24px);-webkit-backdrop-filter:blur(24px);transition:var(--tr);box-shadow:inset 0 1px 1px rgba(255,255,255,0.05)}
.card:hover{border-color:rgba(255,255,255,0.12);transform:translateY(-3px);box-shadow:0 20px 40px -15px rgba(0,0,0,0.5), inset 0 1px 1px rgba(255,255,255,0.08)}
.card-p{padding:1.5rem} .card-p2{padding:2rem}

/* BUTTONS */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:.5rem;padding:.75rem 1.5rem;border-radius:99px;font-weight:600;font-size:.95rem;transition:var(--tr);cursor:pointer;letter-spacing:0.01em}
.btn-primary{background:linear-gradient(135deg, var(--accent), var(--accent2));color:#fff;border:1px solid rgba(255,255,255,0.1);box-shadow:0 4px 15px rgba(99,102,241,0.2)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 8px 25px rgba(99,102,241,0.4);border-color:rgba(255,255,255,0.2)}
.btn-ghost{background:var(--glass);border:1px solid var(--border);color:var(--t1)}
.btn-ghost:hover{background:rgba(255,255,255,.06);border-color:rgba(255,255,255,.18)}
.btn-danger{background:#EF4444;color:#fff}
.btn-danger:hover{background:#DC2626}
.btn-sm{padding:.5rem 1rem;font-size:.85rem}
.btn-lg{padding:1rem 2rem;font-size:1.05rem}
.btn-icon{width:2.5rem;height:2.5rem;padding:0;border-radius:50%;justify-content:center}

/* BADGES */
.badge{display:inline-flex;align-items:center;padding:.25rem .75rem;border-radius:99px;font-size:.75rem;font-weight:600}
.badge-ds{background:rgba(99,102,241,.15);color:var(--ds)}
.badge-os{background:rgba(6,182,212,.15);color:var(--os)}
.badge-coa{background:rgba(245,158,11,.15);color:var(--coa)}
.badge-dbms{background:rgba(16,185,129,.15);color:var(--dbms)}
.badge-flat{background:rgba(244,63,94,.15);color:var(--flat)}
.badge-easy{background:rgba(16,185,129,.15);color:#10B981}
.badge-medium{background:rgba(245,158,11,.15);color:#F59E0B}
.badge-hard{background:rgba(239,68,68,.15);color:#EF4444}

/* PROGRESS */
.progress-bar{background:rgba(255,255,255,.04);border-radius:99px;overflow:hidden;height:6px;box-shadow:inset 0 1px 2px rgba(0,0,0,0.2)}
.progress-fill{height:100%;border-radius:99px;transition:width .6s cubic-bezier(0.4, 0, 0.2, 1);background:linear-gradient(90deg,var(--accent),var(--accent3))}
.progress-ring{transform:rotate(-90deg)}
.progress-ring circle{transition:stroke-dashoffset .6s ease;stroke-linecap:round}

/* SUBJECT INDICATORS */
.subject-dot{width:10px;height:10px;border-radius:50%;flex-shrink:0}
.dot-ds{background:var(--ds)} .dot-os{background:var(--os)} .dot-coa{background:var(--coa)}
.dot-dbms{background:var(--dbms)} .dot-flat{background:var(--flat)}

/* NAV */
.nav{position:fixed;top:0;left:0;right:0;z-index:100;padding:1rem 1.5rem;display:flex;align-items:center;justify-content:space-between;background:rgba(7,12,20,.85);backdrop-filter:blur(20px);border-bottom:1px solid var(--border)}
.nav-logo{font-family:'Outfit',sans-serif;font-weight:800;font-size:1.25rem;background:linear-gradient(135deg,var(--accent),var(--accent2));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.nav-links{display:flex;gap:2rem;align-items:center}
.nav-link{color:var(--t2);font-size:.9rem;font-weight:500;transition:color .2s}
.nav-link:hover,.nav-link.active{color:var(--t1)}
.nav-actions{display:flex;gap:.75rem;align-items:center}

/* SIDEBAR */
.sidebar{position:fixed;top:0;left:0;bottom:0;width:260px;background:var(--bg2);border-right:1px solid var(--border);padding:1.5rem 1rem;display:flex;flex-direction:column;z-index:90;transition:transform .3s ease}
.sidebar-logo{padding:.5rem .75rem 1.5rem;border-bottom:1px solid var(--border);margin-bottom:1rem;display:flex;align-items:center;gap:.75rem}
.logo{height:32px;width:auto;object-fit:contain}
.logo-lg{height:48px;width:auto}
.logo-xl{height:80px;width:auto}
.sidebar-item{display:flex;align-items:center;gap:.75rem;padding:.75rem .875rem;border-radius:var(--r);color:var(--t2);font-size:.9rem;font-weight:500;transition:all .2s;cursor:pointer}
.sidebar-item:hover{background:var(--glass);color:var(--t1)}
.sidebar-item.active{background:rgba(99,102,241,.12);color:var(--accent);border:1px solid rgba(99,102,241,.2)}
.sidebar-icon{font-size:1.1rem;width:1.25rem;text-align:center}
.main-content{margin-left:260px;min-height:100vh;padding:2rem}

/* STAT CARDS */
.stat-card{background:linear-gradient(145deg, rgba(255,255,255,0.03) 0%, rgba(255,255,255,0.01) 100%);border:1px solid var(--border);border-radius:var(--r);padding:1.25rem 1.5rem;display:flex;flex-direction:column;gap:.5rem;box-shadow:inset 0 1px 1px rgba(255,255,255,0.05);transition:var(--tr)}
.stat-card:hover{border-color:rgba(255,255,255,0.1);transform:translateY(-2px)}
.stat-value{font-size:2.25rem;font-weight:800;font-family:'Outfit',sans-serif;line-height:1;letter-spacing:-0.02em;background:linear-gradient(135deg,#fff,#a1a1aa);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.stat-label{font-size:.75rem;color:var(--t2);text-transform:uppercase;letter-spacing:.08em;font-weight:700}

/* SUBJECT CARDS */
.subject-card{border-radius:var(--r2);padding:1.75rem;cursor:pointer;transition:all .3s;position:relative;overflow:hidden;border:1px solid transparent}
.subject-card::before{content:'';position:absolute;inset:0;opacity:.06;background:currentColor;pointer-events:none}
.subject-card:hover{transform:translateY(-4px);border-color:currentColor}
.subject-card .icon{font-size:2.5rem;margin-bottom:1rem}
.subject-card .name{font-weight:700;font-size:1.05rem;margin-bottom:.25rem}
.subject-card .count{font-size:.8rem;color:var(--t2)}
.sc-ds{color:var(--ds)} .sc-os{color:var(--os)} .sc-coa{color:var(--coa)} .sc-dbms{color:var(--dbms)} .sc-flat{color:var(--flat)}

/* QUESTION PALETTE */
.q-palette{display:grid;grid-template-columns:repeat(10,1fr);gap:.35rem}
.q-bubble{width:100%;aspect-ratio:1;border-radius:6px;font-size:.7rem;font-weight:700;display:flex;align-items:center;justify-content:center;cursor:pointer;transition:all .15s;border:1.5px solid transparent;background:var(--glass)}
.q-bubble.answered{background:rgba(16,185,129,.2);border-color:var(--green);color:var(--green)}
.q-bubble.current{background:rgba(99,102,241,.3);border-color:var(--accent);color:var(--accent)}
.q-bubble.marked{background:rgba(245,158,11,.2);border-color:var(--amber);color:var(--amber)}
.q-bubble.answered.marked{background:rgba(245,158,11,.2);border-color:var(--amber)}
.q-bubble:hover{border-color:rgba(255,255,255,.3)}

/* OPTIONS */
.option-btn{display:flex;align-items:flex-start;gap:1rem;padding:1rem 1.25rem;border-radius:var(--r);border:1.5px solid var(--border);background:var(--glass);cursor:pointer;transition:all .2s;text-align:left;width:100%;color:var(--t1)}
.option-btn:hover{border-color:rgba(99,102,241,.5);background:rgba(99,102,241,.05)}
.option-btn.selected{border-color:var(--accent);background:rgba(99,102,241,.12);color:#fff}
.option-btn.correct{border-color:var(--green);background:rgba(16,185,129,.12)}
.option-btn.wrong{border-color:var(--red);background:rgba(239,68,68,.12)}
.option-label{width:28px;height:28px;border-radius:6px;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.85rem;flex-shrink:0;background:rgba(255,255,255,.06);border:1px solid var(--border)}
.option-btn.selected .option-label{background:var(--accent);border-color:var(--accent);color:#fff}
.option-btn.correct .option-label{background:var(--green);border-color:var(--green);color:#fff}
.option-btn.wrong .option-label{background:var(--red);border-color:var(--red);color:#fff}

/* TIMER */
.timer-display{font-family:'JetBrains Mono',monospace;font-size:2.5rem;font-weight:700;letter-spacing:.05em}
.timer-display.warning{color:var(--amber);animation:pulse 1s infinite}
.timer-display.danger{color:var(--red);animation:pulse .5s infinite}

/* TOAST */
.toast-container{position:fixed;bottom:1.5rem;right:1.5rem;z-index:999;display:flex;flex-direction:column;gap:.75rem}
.toast{background:var(--bg3);border:1px solid var(--border);border-radius:var(--r);padding:.875rem 1.25rem;display:flex;align-items:center;gap:.75rem;box-shadow:var(--shadow);animation:slideIn .3s ease;max-width:320px}
.toast.success{border-color:rgba(16,185,129,.4)} .toast.error{border-color:rgba(239,68,68,.4)} .toast.info{border-color:rgba(99,102,241,.4)}

/* MODAL */
.modal-overlay{position:fixed;inset:0;background:rgba(0,0,0,.6);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);z-index:200;display:flex;align-items:center;justify-content:center;padding:1rem;animation:fadeIn .2s ease}
.modal{background:#18181b;border:1px solid rgba(255,255,255,0.1);border-radius:var(--r2);padding:2.5rem;max-width:520px;width:100%;box-shadow:0 25px 50px -12px rgba(0,0,0,0.5);animation:scaleIn .3s cubic-bezier(0.175, 0.885, 0.32, 1.275)}

/* TOGGLE */
.theme-toggle{width:48px;height:26px;background:var(--glass);border:1px solid var(--border);border-radius:99px;position:relative;cursor:pointer;transition:.3s}
.theme-toggle::after{content:'';position:absolute;top:3px;left:3px;width:18px;height:18px;border-radius:50%;background:var(--t2);transition:.3s}
.theme-toggle.light::after{transform:translateX(22px);background:var(--accent)}

/* SCORE RINGS */
.score-ring-wrap{display:flex;flex-direction:column;align-items:center;gap:.5rem}
.score-ring-val{position:absolute;font-family:'Outfit',sans-serif;font-weight:800;font-size:1.8rem}
.score-ring-lbl{font-size:.8rem;color:var(--t2);font-weight:600;text-align:center}

/* UTILITIES */
.hidden{display:none!important} .sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}
.rounded{border-radius:var(--r)} .rounded-lg{border-radius:var(--r2)} .rounded-full{border-radius:99px}
.w-full{width:100%} .h-full{height:100%} .relative{position:relative} .absolute{position:absolute}
.overflow-hidden{overflow:hidden} .truncate{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.p-1{padding:.5rem} .p-2{padding:1rem} .p-3{padding:1.5rem} .p-4{padding:2rem}
.mt-1{margin-top:.5rem} .mt-2{margin-top:1rem} .mt-3{margin-top:1.5rem} .mt-4{margin-top:2rem}
.mb-1{margin-bottom:.5rem} .mb-2{margin-bottom:1rem} .mb-3{margin-bottom:1.5rem}
.text-center{text-align:center} .text-right{text-align:right}
.border-top{border-top:1px solid var(--border)}
.glow{box-shadow:0 0 30px rgba(99,102,241,.25)}

/* SPLASH */
#splash{position:fixed;inset:0;background:var(--bg);z-index:1000;display:flex;align-items:center;justify-content:center;flex-direction:column;gap:2rem}
#splash canvas{position:absolute;inset:0;pointer-events:none}
.splash-logo{font-family:'Outfit',sans-serif;font-weight:800;font-size:3.5rem;background:linear-gradient(135deg,#fff 0%,var(--accent) 50%,var(--accent2) 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;animation:fadeUp 1s ease .5s both}
.splash-sub{color:var(--t2);font-size:1rem;letter-spacing:.15em;text-transform:uppercase;text-align:center;line-height:1.6;animation:fadeUp 1s ease .8s both}
.splash-loader{width:200px;height:2px;background:rgba(255,255,255,.08);border-radius:99px;overflow:hidden;animation:fadeUp 1s ease 1s both}
.splash-loader-fill{height:100%;width:0;background:linear-gradient(90deg,var(--accent),var(--accent2));border-radius:99px;transition:width .1s linear}

/* LIGHT MODE */
body.light{--bg:#F8FAFC;--bg2:#F1F5F9;--bg3:#E2E8F0;--t1:#0F172A;--t2:#475569;--t3:#94A3B8;--border:rgba(0,0,0,.08);--glass:rgba(0,0,0,.02)}
body.light .nav{background:rgba(248,250,252,.9)}
body.light .sidebar{background:var(--bg2)}

/* SCROLLBAR */
::-webkit-scrollbar{width:5px;height:5px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:rgba(255,255,255,.12);border-radius:99px}

/* ANIMATIONS */
@keyframes fadeUp{from{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}
@keyframes fadeIn{from{opacity:0}to{opacity:1}}
@keyframes slideIn{from{opacity:0;transform:translateX(20px)}to{opacity:1;transform:translateX(0)}}
@keyframes scaleIn{from{opacity:0;transform:scale(.9)}to{opacity:1;transform:scale(1)}}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:.6}}
@keyframes spin{to{transform:rotate(360deg)}}
@keyframes shimmer{0%{background-position:-200% 0}100%{background-position:200% 0}}
@keyframes gradientShift{0%{background-position:0% 50%}50%{background-position:100% 50%}100%{background-position:0% 50%}}

.animate-fade-up{animation:fadeUp .6s ease both}
.animate-fade-in{animation:fadeIn .4s ease both}
.animate-delay-1{animation-delay:.1s} .animate-delay-2{animation-delay:.2s}
.animate-delay-3{animation-delay:.3s} .animate-delay-4{animation-delay:.4s}
.animate-delay-5{animation-delay:.5s}

/* SKELETON */
.skeleton{background:linear-gradient(90deg,rgba(255,255,255,.04) 25%,rgba(255,255,255,.08) 50%,rgba(255,255,255,.04) 75%);background-size:200% 100%;animation:shimmer 1.5s infinite;border-radius:6px}

/* OMR SHEET */
.omr-sheet{background:#fff;color:#111;border-radius:var(--r);padding:2rem;font-family:'Times New Roman',serif}
.omr-row{display:flex;align-items:center;gap:1rem;padding:.4rem 0;border-bottom:1px solid #eee}
.omr-qnum{width:2rem;font-weight:700;font-size:.9rem;text-align:right}
.omr-bubble{width:24px;height:24px;border:2px solid #333;display:flex;align-items:center;justify-content:center;font-size:.7rem;font-weight:700;cursor:pointer;transition:.15s;border-radius:3px;position:relative}
.omr-bubble.filled{background:#111;color:#111}
.omr-bubble.filled::after{content:'';position:absolute;inset:2px;background:#111;border-radius:1px}
.omr-bubbles{display:flex;gap:.75rem}

/* RESPONSIVE */
@media(max-width:1024px){.sidebar{transform:translateX(-100%)}.main-content{margin-left:0}}
@media(max-width:768px){.grid-2,.grid-3,.grid-4,.grid-5{grid-template-columns:1fr}
.container{padding:0 1rem}.display-xl{font-size:2.5rem}}