:root{--bg:#091825;--panel:#122738;--panel2:#172d3c;--panel3:#1c3646;--text:#eef8f8;--muted:#a5bbc2;--faint:#78919a;--line:rgba(196,239,230,.12);--accent:#66e4b0;--accent-dark:#143c3c;--blue:#89aefd;--orange:#ffc38b;--danger:#ffaaaa;--shadow:0 24px 72px rgba(2,10,18,.28);--radius:23px;--font-scale:1;--sidebar-width:258px;color-scheme:dark}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:90px;font-size:calc(16px*var(--font-scale))}body{margin:0;background:var(--bg);color:var(--text);font-family:system-ui,-apple-system,"Segoe UI",Arial,sans-serif;line-height:1.6;min-height:100vh}button,input,textarea,select{font:inherit}button{cursor:pointer}a{color:inherit;text-decoration:none}img,svg{max-width:100%}input,textarea,select{color:var(--text);background:#0c2331;border:1px solid #365260;border-radius:12px;padding:12px 14px;outline:none}input:focus,textarea:focus,select:focus{border-color:var(--accent);box-shadow:0 0 0 3px rgba(102,228,176,.11)}textarea{width:100%;resize:vertical;min-height:156px}button:focus-visible,a:focus-visible{outline:3px solid var(--accent);outline-offset:4px}::selection{background:#368b79;color:#fff}.skip-link{position:absolute;top:-60px;z-index:1001;padding:12px 20px;background:var(--accent);color:#071a22}.skip-link:focus{top:8px;left:8px}.ambient{position:fixed;pointer-events:none;z-index:-1;filter:blur(75px);opacity:.3}.ambient-one{width:460px;height:460px;top:-250px;right:12%;background:#28615b;border-radius:50%}.ambient-two{width:420px;height:420px;bottom:-190px;left:30%;background:#192f74;border-radius:50%}
.app-shell{display:grid;grid-template-columns:var(--sidebar-width) minmax(0,1fr);min-height:100vh;max-width:2200px;margin:auto}.sidebar{background:#0b1c2b;display:flex;flex-direction:column;position:sticky;top:0;height:100vh;min-height:750px;padding:25px 17px 22px;border-right:1px solid var(--line);z-index:11}.brand{display:flex;gap:11px;align-items:center;padding:4px 5px;margin-bottom:39px}.brand-mark{width:42px;height:42px;background:linear-gradient(140deg,#183b3c,#143a3a);border:1px solid rgba(111,235,178,.25);border-radius:13px;padding:7px;display:grid;place-items:center;color:var(--accent);flex-shrink:0}.brand strong{display:block;font-size:1rem;letter-spacing:-.035em;line-height:1.3}.brand small{display:block;color:var(--muted);font-size:.68rem;letter-spacing:.05em}.nav-section-title{font-size:.67rem;color:#79939d;letter-spacing:.16em;font-weight:800;text-transform:uppercase;padding:8px 13px;margin:10px 0 8px}.nav-item{display:flex;align-items:center;gap:13px;font-size:.87rem;font-weight:640;padding:10px 14px;border-radius:13px;color:#aebec7;margin-bottom:4px;transition:background .15s,color .15s}.nav-item:hover{color:var(--text);background:#193346}.nav-item.active{background:#173f40;color:#8bf5c6;box-shadow:inset 3px 0 0 #5edfa9}.nav-icon{font-weight:700;font-size:1.16rem;line-height:1;min-width:22px;text-align:center}.sidebar-bottom{margin-top:auto}.daily-card{position:relative;overflow:hidden;background:radial-gradient(circle at top right,#2c6157 0,transparent 58%),linear-gradient(135deg,#123b3d,#142b38);border:1px solid #33695e;border-radius:18px;padding:17px}.daily-card .eyebrow{font-size:.62rem;letter-spacing:.14em;color:#97f1cb;font-weight:800}.daily-icon{position:absolute;right:16px;top:18px;color:#a1f5ce;font-size:1.6rem}.daily-card strong{font-family:Georgia,serif;font-size:1.09rem;display:block;max-width:160px;line-height:1.3;margin:12px 0 6px}.daily-card p{color:#c5d9d9;font-size:.74rem;line-height:1.5;margin:0 0 12px}.daily-card a{font-size:.76rem;font-weight:800;color:#a1f5ce}.sidebar-links{display:flex;justify-content:space-between;margin:21px 6px 0;flex-wrap:wrap;gap:4px}.sidebar-links a{font-size:.69rem;color:#8ca5ad}.sidebar-links a:hover{text-decoration:underline;color:var(--text)}
.main-column{min-width:0;display:flex;flex-direction:column}.topbar{display:flex;align-items:center;justify-content:space-between;padding:17px 37px;min-height:81px;border-bottom:1px solid var(--line);background:rgba(8,24,37,.86);backdrop-filter:blur(18px);position:sticky;top:0;z-index:8;gap:16px}.topbar-left,.top-actions{display:flex;align-items:center;gap:12px}.topbar-breadcrumb{font-size:.83rem;color:var(--muted);font-weight:620}.topbar-breadcrumb span{color:#597782;margin:0 7px}.icon-button{border:1px solid rgba(185,219,226,.15);color:var(--muted);background:#132a39;border-radius:11px;width:39px;height:39px;display:inline-grid;place-items:center;font-size:.83rem;font-weight:800}.icon-button:hover{color:var(--accent);border-color:rgba(102,228,176,.4)}.mobile-menu{display:none}.tutor-link{display:flex;align-items:center;gap:6px;font-size:.8rem;font-weight:750;color:var(--accent);padding:8px 12px;border:1px solid rgba(102,228,176,.21);border-radius:12px;background:rgba(102,228,176,.06)}.tutor-link:hover{background:#1d4940}.tutor-link span:first-child{font-size:1.3rem}.btn{border:1px solid transparent;border-radius:12px;padding:11px 16px;display:inline-flex;justify-content:center;align-items:center;gap:9px;font-size:.82rem;font-weight:800;line-height:1.2;min-height:42px;white-space:normal;text-align:center}.btn-primary{background:var(--accent);color:#082823;box-shadow:0 8px 28px rgba(102,228,176,.12)}.btn-primary:hover{background:#9af2ce}.btn-ghost{background:#1a3442;border-color:#37505b;color:var(--text)}.btn-ghost:hover{background:#274655}.btn-outline{background:transparent;border-color:rgba(146,206,195,.42);color:#9aecce}.btn-outline:hover{background:#1b4640}.btn-small{font-size:.74rem;padding:8px 11px;min-height:34px}.btn-muted{background:transparent;color:var(--muted);border:1px solid var(--line)}.btn-danger{background:#543036;color:#ffd9d9}.btn:disabled{opacity:.48;cursor:not-allowed}.main-content{width:100%;max-width:1480px;margin:0 auto;flex:1;padding:33px 39px 67px}.footer{padding:24px 37px;border-top:1px solid var(--line);font-size:.7rem;color:#7295a0;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}
.eyebrow{font-size:.72rem;font-weight:850;letter-spacing:.13em;text-transform:uppercase;color:var(--accent)}.page-title{font-family:Georgia,"Times New Roman",serif;letter-spacing:-.047em;line-height:1.08;font-size:clamp(2.15rem,4vw,3.7rem);margin:10px 0 12px;font-weight:500}.page-subtitle{color:var(--muted);max-width:790px;line-height:1.68;font-size:.99rem}.section-heading{display:flex;justify-content:space-between;align-items:end;gap:20px;margin:38px 0 18px}.section-heading h2{font-size:1.4rem;letter-spacing:-.03em;margin:0}.section-heading p{font-size:.82rem;color:var(--muted);margin:5px 0 0}.link-inline{color:var(--accent);font-weight:800;font-size:.8rem}.link-inline:hover{text-decoration:underline}.panel{border:1px solid var(--line);background:linear-gradient(160deg,rgba(25,49,63,.93),rgba(16,35,49,.96));border-radius:var(--radius);box-shadow:0 12px 36px rgba(2,10,15,.09)}.panel-pad{padding:25px}.muted{color:var(--muted)}.small{font-size:.79rem}.very-small{font-size:.72rem}.tag{display:inline-block;font-size:.7rem;font-weight:780;padding:5px 10px;border-radius:9px;color:#99ead0;background:#193f40;border:1px solid rgba(107,222,188,.15)}.tag.blue{background:#213954;color:#b7c9ff}.tag.orange{background:#553e37;color:#ffe0bb}.tag.neutral{background:#1f3845;color:#adcad2}.flex{display:flex;gap:12px;align-items:center}.flex-wrap{display:flex;align-items:center;gap:10px;flex-wrap:wrap}.grow{flex:1}.divider{height:1px;background:var(--line);margin:24px 0}.loader{min-height:100px}.loading-screen{min-height:65vh;display:grid;place-content:center;gap:15px;color:var(--muted);text-align:center}.load-orbit{height:70px;width:70px;border:3px solid #234648;border-top-color:var(--accent);border-radius:50%;margin:0 auto;animation:spin 1s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}
.hero{min-height:332px;border-radius:28px;position:relative;overflow:hidden;border:1px solid rgba(115,218,177,.29);background:radial-gradient(ellipse at 80% 27%,rgba(65,186,130,.22),transparent 37%),radial-gradient(ellipse at 90% 90%,rgba(44,100,149,.25),transparent 47%),linear-gradient(125deg,#153842 3%,#143b3e 36%,#122635 100%);display:grid;grid-template-columns:minmax(0,1.1fr) minmax(270px,.9fr);gap:12px;align-items:center;padding:38px 45px}.hero h1{font-family:Georgia,serif;font-size:clamp(2.4rem,4.2vw,4.35rem);font-weight:400;letter-spacing:-.06em;line-height:1.07;margin:13px 0 14px;max-width:610px}.hero h1 em{font-style:normal;color:#94f3c7}.hero .hero-desc{color:#c1dbda;font-size:.92rem;line-height:1.72;max-width:510px;margin:0 0 23px}.hero .hero-actions{display:flex;gap:10px;flex-wrap:wrap}.hero-art{height:285px;position:relative;isolation:isolate;display:grid;place-items:center}.orbit-ring{position:absolute;inset:9% 9%;border:1px solid rgba(163,239,203,.15);border-radius:50%;transform:rotate(-22deg) scaleY(.75)}.orbit-ring.two{inset:3% 3%;transform:rotate(50deg) scaleY(.68)}.orbit-ring.three{inset:15% 15%;transform:rotate(-65deg) scaleY(.8)}.planet{position:relative;width:196px;height:196px;border-radius:50%;background:radial-gradient(circle at 24% 22%,#a2f6ce -8%,#61b7a5 20%,#1a6c78 50%,#0c3454 74%,#062338 100%);box-shadow:0 0 80px rgba(100,236,176,.16),inset -22px -20px 34px rgba(1,19,30,.54);overflow:hidden;animation:bob 7s ease-in-out infinite}.planet:before{content:"";position:absolute;inset:15% -20%;border-radius:45%;border:24px solid transparent;border-top-color:rgba(17,84,76,.5);transform:rotate(45deg)}.planet:after{content:"";position:absolute;top:39%;left:9%;height:36%;width:51%;background:rgba(89,205,156,.32);border-radius:62% 21% 60% 18%;transform:rotate(-19deg)}.orbit-dot{position:absolute;border-radius:50%;box-shadow:0 0 14px currentColor}.orbit-dot.a{top:7%;right:27%;width:19px;height:19px;background:#f2d08a;color:#f2d08a}.orbit-dot.b{left:11%;bottom:26%;width:13px;height:13px;background:#86d9d8;color:#86d9d8}.orbit-dot.c{right:17%;bottom:16%;width:10px;height:10px;background:#d9b7fd;color:#d9b7fd}.hero-art .spark{position:absolute;font-size:2rem;color:#e5f9d8;top:18%;left:16%}.floating-symbol{position:absolute;border:1px solid rgba(153,233,189,.23);background:rgba(25,61,59,.72);backdrop-filter:blur(5px);border-radius:14px;padding:9px;font-size:1.25rem;left:11%;top:14%;transform:rotate(-12deg)}.floating-symbol.bottom{left:auto;right:5%;top:auto;bottom:17%;transform:rotate(12deg)}@keyframes bob{0%,100%{transform:translateY(0)}50%{transform:translateY(-10px)}}
.stats-strip{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;margin-top:20px}.stat{padding:19px 20px;border:1px solid var(--line);background:#132a3a;border-radius:16px;display:flex;align-items:center;gap:15px}.stat-icon{height:46px;width:46px;background:#1c4446;border-radius:13px;display:grid;place-items:center;color:#9cecc8;font-size:1.32rem;flex-shrink:0}.stat-number{font-weight:860;font-size:1.54rem;line-height:1.2;letter-spacing:-.04em}.stat-label{font-size:.71rem;color:var(--muted);margin-top:2px}.book-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.book-card{min-height:280px;display:flex;flex-direction:column;position:relative;overflow:hidden;padding:23px;background:linear-gradient(138deg,#193443,#112733);border:1px solid var(--line);border-radius:22px;transition:transform .2s,border-color .2s}.book-card:hover,.lab-card:hover,.chapter-row:hover{transform:translateY(-3px);border-color:rgba(128,232,188,.45)}.book-card:before{content:"";position:absolute;height:160px;width:210px;right:-55px;top:-35px;background:var(--book-color);opacity:.1;filter:blur(20px);border-radius:50%;pointer-events:none}.book-top{display:flex;align-items:start;justify-content:space-between;gap:10px}.book-grade{font-size:.72rem;letter-spacing:.03em;color:var(--muted);font-weight:740}.book-icon{height:61px;width:61px;border:1px solid rgba(224,254,231,.12);border-radius:19px;background:#233c46;display:grid;place-items:center;font-size:2.2rem}.book-card h3{font-family:Georgia,serif;font-size:1.63rem;line-height:1.2;letter-spacing:-.035em;font-weight:500;margin:19px 0 6px}.book-card p{color:var(--muted);font-size:.78rem;line-height:1.62;margin:0 0 20px;flex:1}.bar{height:7px;width:100%;background:#29424e;border-radius:50px;overflow:hidden}.bar>span{display:block;height:100%;background:linear-gradient(90deg,var(--accent),#9df3ca);border-radius:inherit;max-width:100%;transition:width .2s}.book-bottom{margin-top:10px;display:flex;justify-content:space-between;font-size:.72rem;align-items:center}.book-bottom span:first-child{color:var(--muted)}.book-bottom strong{color:var(--accent)}.feature-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.feature-card{padding:20px;display:flex;align-items:center;gap:14px}.feature-emoji{font-size:1.9rem;background:#183b42;height:50px;width:50px;display:grid;place-items:center;border-radius:16px;flex-shrink:0}.feature-card h3{margin:0 0 3px;font-size:.95rem;line-height:1.3}.feature-card p{font-size:.73rem;color:var(--muted);line-height:1.45;margin:0}.feature-card .more{margin-left:auto;color:var(--accent)}
.page-head{margin-bottom:25px}.filter-bar{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin:24px 0}.chip{padding:10px 14px;border-radius:12px;background:#142a38;border:1px solid var(--line);color:var(--muted);font-weight:750;font-size:.82rem;display:inline-block}.chip.active,.chip:hover{background:#1a4b43;color:#a6f6d5;border-color:#3e9479}.search-field{display:flex;align-items:center;gap:10px;padding:5px 10px;background:#122b39;border-radius:13px;border:1px solid var(--line);flex:1;max-width:340px}.search-field input{width:100%;background:transparent;border:0;box-shadow:none!important;outline:0;padding:7px 5px}.chapter-stack{display:grid;gap:11px}.chapter-row{display:flex;align-items:center;gap:16px;padding:17px 19px;background:#132a3a;border-radius:17px;border:1px solid var(--line);transition:transform .15s,border-color .15s}.chapter-count{height:53px;width:53px;display:grid;place-items:center;border-radius:14px;background:#224043;color:var(--accent);font-family:Georgia,serif;font-size:1.4rem;flex-shrink:0}.chapter-content{flex:1;min-width:0}.chapter-content h3{font-size:1rem;margin:0 0 2px;letter-spacing:-.015em}.chapter-content p{margin:0;font-size:.75rem;color:var(--muted);max-width:780px}.chapter-meta{text-align:right;min-width:130px;display:grid;gap:7px}.chapter-meta .mini-bar{height:5px;width:100px;justify-self:end;background:#2a4651;border-radius:9px;overflow:hidden}.mini-bar span{display:block;background:var(--accent);height:100%}.chapter-meta small{font-size:.67rem;color:var(--muted)}.chapter-arrow{color:var(--accent);font-size:1.5rem;margin-left:7px}.empty-state{text-align:center;padding:48px 28px}.empty-state .symbol{font-size:3rem}.empty-state h3{font-size:1.24rem}
.lesson-hero{padding:26px 31px;border-radius:24px;background:radial-gradient(circle at right top,rgba(89,220,169,.13),transparent 45%),linear-gradient(120deg,#183f43,#172d3e);border:1px solid #326558}.back-link{display:inline-block;color:var(--accent);font-size:.78rem;font-weight:850;margin-bottom:16px}.lesson-hero h1{font-family:Georgia,serif;font-size:clamp(2rem,4vw,3.3rem);letter-spacing:-.05em;line-height:1.14;margin:12px 0}.lesson-hero p{color:#c4dcdb;max-width:800px;margin:0 0 20px}.lesson-tools{display:flex;align-items:center;flex-wrap:wrap;gap:10px}.lesson-grid{display:grid;grid-template-columns:minmax(0,1fr) 265px;gap:17px;margin-top:17px}.lesson-main{min-width:0;display:grid;gap:18px}.lesson-side{min-width:0;display:grid;gap:17px;align-content:start}.lesson-side .panel{padding:20px;position:relative}.lesson-side h3,.lesson-main h2{margin:0 0 12px;font-size:1.25rem;letter-spacing:-.035em}.lesson-side h3{font-size:1.06rem}.reading-copy p{color:#c1d2d8;line-height:1.86;margin:12px 0}.reading-copy p:first-child{margin-top:0}.goal-list{list-style:none;margin:0;padding:0;display:grid;gap:12px}.goal-list li{display:flex;gap:10px;font-size:.82rem;color:#d0e3de}.goal-check{flex-shrink:0;color:var(--accent);font-size:1.1rem}.word-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.word-card{border:1px solid #34515a;background:#173342;border-radius:13px;padding:15px;display:flex;flex-direction:column;gap:5px;text-align:left;color:var(--text);transition:background .14s}.word-card strong{font-size:.88rem;color:#9feacb}.word-card small{font-size:.74rem;color:var(--muted);line-height:1.55}.word-card:hover{background:#244754}.quiz-shell{display:grid;gap:17px}.question-card{border:1px solid #284a56;border-radius:18px;padding:19px;background:#102b39}.question-heading{display:flex;gap:14px;align-items:start}.question-n{flex-shrink:0;color:var(--accent);font-size:.72rem;font-weight:900;letter-spacing:.08em;padding-top:5px}.question-heading h3{margin:0;font-size:1rem;line-height:1.52}.options{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px;margin-top:16px}.option{display:flex;align-items:center;gap:9px;text-align:left;background:#1d3a48;border:1px solid #36525c;border-radius:12px;padding:10px 13px;color:#e5f2f1;font-size:.78rem;min-height:55px}.option:hover:not(:disabled){border-color:#8ef1c4}.option:disabled{cursor:default}.option.checked{border-color:#6decac;background:#1b4e40;color:#c5ffe1}.option.incorrect{border-color:#ce8181;background:#503238;color:#ffdfdf}.option-letter{font-size:.7rem;font-weight:850;display:grid;place-items:center;width:23px;height:23px;background:rgba(255,255,255,.06);border-radius:6px;flex-shrink:0}.feedback{padding:11px 14px;border-radius:11px;background:#1b4d41;color:#d1ffe7;font-size:.78rem;margin-top:12px}.feedback.bad{background:#483337;color:#ffe3df}.task-stack{display:grid;gap:12px}.task-box{border:1px solid #2f4b57;border-radius:16px;padding:18px;background:#112e3c}.task-box-header{display:flex;align-items:start;justify-content:space-between;gap:12px;margin-bottom:13px}.task-box h3{margin:0 0 4px;font-size:1rem}.task-box p{color:var(--muted);font-size:.83rem;margin:0 0 12px;line-height:1.7}.task-box textarea{background:#0a2432;min-height:125px;font-size:.88rem}.task-box .saved{font-size:.72rem;color:var(--accent)}.quiz-summary{padding:15px 18px;border-radius:14px;background:#183d3d;border:1px solid #316b59;color:#c4f6e2;margin-bottom:12px}.confidence-group{display:grid;gap:8px}.confidence{display:flex;gap:8px;flex-wrap:wrap}.confidence label{display:flex;align-items:center;gap:6px;padding:8px 10px;border-radius:10px;background:#15313f;border:1px solid var(--line);font-size:.77rem}.confidence input{width:auto;accent-color:#69ecb6;box-shadow:none}.step-list{display:grid;gap:10px;font-size:.81rem;color:var(--muted)}.step-list div{display:flex;align-items:start;gap:9px}.side-progress{text-align:center;font-size:2.6rem;letter-spacing:-.04em;font-weight:800;color:var(--accent)}.stat-note{text-align:center;font-size:.73rem;color:var(--muted)}
.lab-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.lab-card{padding:24px;border-radius:20px;background:linear-gradient(155deg,#1b3b45,#132836);border:1px solid var(--line);display:flex;flex-direction:column;min-height:235px;transition:transform .18s,border-color .18s}.lab-card .lab-icon{font-size:2.2rem;margin-bottom:12px}.lab-card h3{font-size:1.07rem;margin:0 0 7px}.lab-card p{font-size:.78rem;color:var(--muted);margin:0 0 20px;flex:1}.lab-frame{padding:25px;margin-top:15px}.lab-controls{display:grid;grid-template-columns:repeat(3,1fr);gap:13px}.range-field{background:#112f3a;border-radius:13px;padding:18px;border:1px solid var(--line)}.range-field label{display:block;font-size:.8rem;font-weight:770;margin-bottom:15px}.range-field label span{float:right;color:var(--accent)}input[type=range]{width:100%;padding:0;border:0;accent-color:#7eebba;box-shadow:none;background:transparent}.sim-meter{margin:25px 0;padding:21px;border-radius:15px;background:#123d3c;text-align:center}.sim-meter strong{font-size:2.3rem;color:#a0f7cf;letter-spacing:-.05em}.sim-meter p{font-size:.78rem;margin:0;color:#bfd7d1}.sequence{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:11px;margin:25px 0}.seq-node{display:flex;flex-direction:column;align-items:center;gap:8px;background:#193b46;border:1px solid #37616b;padding:18px 8px;border-radius:14px;text-align:center;position:relative}.seq-node:not(:last-child):after{content:'→';position:absolute;right:-18px;top:38%;color:var(--accent);font-size:1.6rem;z-index:2}.seq-node span{font-size:1.9rem}.seq-node select{width:100%;max-width:170px;padding:9px;font-size:.8rem}.lab-action-row{display:flex;align-items:center;gap:12px;flex-wrap:wrap}.punnett{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));max-width:410px;gap:6px;margin:20px auto}.punnett div{background:#20414b;border:1px solid #45717b;border-radius:10px;padding:20px 8px;text-align:center;font-size:1.35rem;font-weight:800}.punnett .headcell{background:#224d42;color:#adf6cd}.punnett .blank{background:transparent;border-color:transparent}.pulse-bars{display:grid;gap:11px;margin:24px 0}.pulse-bar{display:grid;grid-template-columns:110px 1fr 70px;align-items:center;gap:14px;font-size:.79rem}.pulse-bar .bar{height:15px}.pulse-bar .bar span{background:var(--blue)}.pulse-bar.after .bar span{background:var(--orange)}.match-list{display:grid;gap:9px}.match-row{display:grid;grid-template-columns:minmax(160px,1fr) minmax(200px,1.5fr);gap:12px;align-items:center;padding:12px 13px;border:1px solid var(--line);border-radius:12px;background:#13313f}.match-row select{width:100%;font-size:.8rem}.field-grid{display:grid;grid-template-columns:1fr 1fr;gap:15px}.field label{display:block;font-size:.77rem;color:#d2e5e6;font-weight:800;margin-bottom:8px}.field input,.field select{width:100%}.notice{border:1px solid #3b7561;background:#173b3d;border-radius:13px;padding:15px 18px;font-size:.79rem;color:#c9eadf;line-height:1.7}.warning{border:1px solid #86694c;background:#41362e;color:#ffdfb2}.infobox{padding:16px;border-radius:13px;background:#142e3b;border:1px solid var(--line);color:#bed2d5;font-size:.81rem}.glossary-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.gloss-item{padding:18px}.gloss-item h3{color:#a0f3cd;margin:0 0 6px;font-size:.97rem}.gloss-item p{color:#c0d1d6;font-size:.79rem;margin:0 0 13px}.gloss-item small{color:#8099a4}.work-summary{display:grid;grid-template-columns:repeat(3,1fr);gap:15px;margin:20px 0}.work-stat{padding:22px}.work-stat .big{font-size:1.9rem;font-weight:800;color:var(--accent)}.work-stat p{margin:0;font-size:.78rem;color:var(--muted)}.work-entry{display:flex;gap:15px;align-items:center;padding:19px;border:1px solid var(--line);border-radius:15px;background:#142d3c;margin:12px 0}.work-entry strong{display:block}.work-entry small{color:var(--muted)}.work-entry .actions{margin-left:auto;display:flex;gap:8px;flex-wrap:wrap}.teacher-steps{counter-reset:instructions;display:grid;gap:13px}.teacher-steps li{list-style:none;position:relative;padding:17px 17px 17px 62px;border-radius:14px;border:1px solid var(--line);background:#142c3b}.teacher-steps li:before{counter-increment:instructions;content:counter(instructions);display:grid;place-items:center;position:absolute;left:14px;top:15px;height:33px;width:33px;border-radius:10px;background:#1e5a4c;color:var(--accent);font-weight:850}.teacher-steps li strong{display:block;font-size:.91rem}.teacher-steps li p{margin:5px 0 0;color:var(--muted);font-size:.79rem}.bookshelf{display:grid;gap:14px}.shelf-row{display:flex;align-items:center;gap:18px;padding:22px}.shelf-cover{width:88px;height:112px;border-radius:5px 13px 13px 5px;display:grid;place-items:center;font-size:2rem;background:linear-gradient(115deg,#244f5b,#17413f);border-left:7px solid #377d69;box-shadow:8px 9px 18px rgba(0,0,0,.15);flex-shrink:0}.shelf-row h3{margin:0}.shelf-row p{font-size:.77rem;color:var(--muted);margin:6px 0}.shelf-actions{margin-left:auto;display:flex;align-items:center;gap:9px;flex-wrap:wrap}.page-marks{display:grid;gap:5px;grid-template-columns:repeat(2,1fr);margin:12px 0}.page-marks a{font-size:.76rem;color:var(--muted);padding:7px;border-radius:8px;background:#12313d}.page-marks a:hover{color:var(--accent)}.dialog-inner{max-height:84vh;overflow:auto;padding:25px}.dialog-header{display:flex;justify-content:space-between;gap:18px;align-items:start;margin-bottom:12px}.dialog-header h2{font-family:Georgia,serif;font-size:1.7rem;margin:0;letter-spacing:-.04em}.dialog-close{color:var(--text);background:#26414e;border:0;border-radius:10px;width:35px;height:35px;flex-shrink:0}.app-dialog{background:#102a39;color:var(--text);border:1px solid #4c7777;border-radius:20px;width:min(720px,calc(100vw - 24px));padding:0;box-shadow:0 30px 150px rgba(0,0,0,.7);max-height:90vh}.app-dialog::backdrop{background:rgba(2,13,23,.78);backdrop-filter:blur(6px)}.app-dialog.pdf-viewer{width:min(1000px,calc(100vw - 24px))}.pdf-embed{width:100%;height:62vh;border:1px solid #345764;border-radius:10px;background:white}.toast-area{position:fixed;z-index:101;bottom:22px;right:22px;display:grid;gap:9px;max-width:360px}.toast{background:#225246;border:1px solid #70c8a6;color:#edfff5;border-radius:12px;padding:13px 17px;font-size:.83rem;font-weight:700;box-shadow:var(--shadow);animation:slide-in .2s}.toast.error{background:#663b3c;border-color:#d99e9e}@keyframes slide-in{from{transform:translateY(15px);opacity:0}to{transform:translateY(0);opacity:1}}.reader-actions{display:flex;gap:9px;flex-wrap:wrap}.doc-note{font-size:.75rem;color:var(--muted)}.hidden{display:none!important}
@media(min-width:1500px){.main-content{padding:42px 62px 78px}.topbar{padding-left:62px;padding-right:62px}}@media(max-width:1180px){.stats-strip{grid-template-columns:repeat(2,minmax(0,1fr))}.feature-grid{grid-template-columns:1fr}.book-grid{gap:10px}.book-card{padding:18px}.lesson-grid{grid-template-columns:minmax(0,1fr) 225px}.hero{padding:31px}.main-content{padding:28px}}@media(max-width:950px){:root{--sidebar-width:225px}.sidebar{padding:20px 11px}.main-content{padding:25px}.topbar{padding:12px 23px}.hero{grid-template-columns:1fr;min-height:290px}.hero-art{display:none}.book-grid{grid-template-columns:1fr}.book-card{min-height:210px}.book-card h3{margin:10px 0 6px}.lab-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.word-grid{grid-template-columns:1fr}.top-submit{padding:10px}.top-actions{gap:6px}.tutor-link{font-size:.73rem}}@media(max-width:720px){.app-shell{display:block}.sidebar{position:fixed;top:0;left:0;width:min(280px,85vw);height:100dvh;min-height:0;transform:translateX(-103%);transition:transform .2s;z-index:30;overflow-y:auto}.app-shell.menu-open .sidebar{transform:translateX(0)}.screen-shade:not([hidden]){position:fixed;inset:0;background:rgba(0,0,0,.65);z-index:25;display:block}.mobile-menu{display:inline-grid}.topbar{gap:7px;padding:10px 15px;min-height:66px}.topbar-breadcrumb{display:none}.tutor-link{font-size:.75rem;padding:7px 9px}.tutor-link span:not(:first-child){display:none}.top-submit{font-size:.73rem;padding:8px}.tool-icon{display:none}.main-content{padding:18px 14px 52px}.hero{padding:27px 21px;min-height:0}.hero h1{font-size:2.55rem}.hero .hero-desc{font-size:.86rem}.stats-strip{gap:8px}.stat{padding:14px 11px;gap:9px}.stat-icon{width:36px;height:36px;font-size:1rem}.stat-number{font-size:1.2rem}.stat-label{font-size:.66rem}.section-heading{margin-top:29px}.section-heading h2{font-size:1.25rem}.feature-grid,.lab-grid,.work-summary{grid-template-columns:1fr}.feature-card{padding:16px}.lesson-hero{padding:22px}.lesson-grid{grid-template-columns:1fr}.lesson-side{grid-row:1}.lesson-side .panel{padding:16px}.options{grid-template-columns:1fr}.panel-pad{padding:17px}.lab-controls,.sequence{grid-template-columns:1fr 1fr}.seq-node:nth-child(2):after{content:''}.chapter-row{gap:9px;padding:14px}.chapter-count{width:38px;height:43px;font-size:1.13rem}.chapter-meta{min-width:62px}.chapter-meta .mini-bar{width:55px}.chapter-arrow{display:none}.chapter-content p{display:-webkit-box;-webkit-box-orient:vertical;-webkit-line-clamp:2;overflow:hidden}.shelf-row{flex-wrap:wrap}.shelf-actions{margin-left:0;width:100%}.field-grid{grid-template-columns:1fr}.pulse-bar{grid-template-columns:65px 1fr 56px}.match-row{grid-template-columns:1fr}.footer{padding:17px}.app-dialog{width:calc(100vw - 15px)}.dialog-inner{padding:17px}}@media(max-width:390px){.topbar .tutor-link{display:none}.hero h1{font-size:2.18rem}.stats-strip{grid-template-columns:1fr 1fr}.stat-icon{display:none}.stats-strip .stat{padding:12px}.lesson-hero h1{font-size:2rem}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
body.light-mode{--bg:#f2f6f2;--panel:#fff;--panel2:#fff;--panel3:#f3f8f5;--text:#18313a;--muted:#566d74;--faint:#657780;--line:rgba(38,84,76,.19);--accent:#168c62;--shadow:0 20px 60px rgba(26,68,57,.12);color-scheme:light;background:#eff4f1}body.light-mode .main-column .panel,body.light-mode .book-card,body.light-mode .chapter-row,body.light-mode .lab-card,body.light-mode .work-entry,body.light-mode .task-box,body.light-mode .question-card,body.light-mode .word-card,body.light-mode .gloss-item,body.light-mode .stat,body.light-mode .feature-card,body.light-mode .work-stat,body.light-mode .teacher-steps li,body.light-mode .range-field,body.light-mode .match-row{background:#fff}body.light-mode .topbar{background:rgba(242,247,244,.94)}body.light-mode .sidebar,body.light-mode .hero,body.light-mode .lesson-hero{color:#eef8f8}body.light-mode .sidebar .nav-item,body.light-mode .sidebar .brand{color:#eef8f8}body.light-mode .sidebar .nav-item.active{color:#a6f5cf}body.light-mode .sidebar .nav-item:hover{color:#fff}body.light-mode .hero *,body.light-mode .lesson-hero *{color:inherit}body.light-mode .hero em{color:#a0f4cd}body.light-mode input,body.light-mode textarea,body.light-mode select,body.light-mode .chip,body.light-mode .icon-button,body.light-mode .option,body.light-mode .search-field,body.light-mode .quiz-summary,body.light-mode .sim-meter,body.light-mode .infobox,body.light-mode .confidence label{background:#f0f6f3;color:#18313a;border-color:#cbd9d4}body.light-mode .reading-copy p,body.light-mode .gloss-item p,body.light-mode .task-box p,body.light-mode .book-card p,body.light-mode .feature-card p,body.light-mode .chapter-content p{color:#566d74}body.light-mode .tag{color:#126843;background:#e6f9ee}body.light-mode .btn-ghost{color:#18313a;background:#e4f0eb;border-color:#9db9ac}body.light-mode .btn-primary{background:#1c9c6c;color:#fff}body.light-mode .app-dialog{background:#fff;color:#18313a}body.light-mode .dialog-close{color:#18313a;background:#e6f0ec}body.light-mode .option.checked{background:#e0fae7;border-color:#25a56c}body.light-mode .option.incorrect{background:#ffe5e5;border-color:#cc8585}body.light-mode .feedback{background:#d5f1df;color:#185e3a}body.light-mode .feedback.bad{background:#ffe1e1;color:#773c3c}body.light-mode .goal-list li{color:#385d5d}body.light-mode .notice{background:#e0f4e9;color:#276046}body.light-mode .warning{background:#fff0d8;color:#805418}
/* V2: livandi forsíða, efnafræði og námsleikur */
.hero-art .planet{animation:planet-breathe 6s ease-in-out infinite;box-shadow:inset -20px -14px 40px #123b62,0 0 52px #48ddb040}
.hero-art .orbit-ring{animation:orbit-turn 34s linear infinite;transform-origin:center}
.hero-art .orbit-ring.two{animation-duration:24s;animation-direction:reverse}.hero-art .orbit-ring.three{animation-duration:47s}
.hero-art .floating-symbol{animation:floaty 4s ease-in-out infinite alternate}.hero-art .floating-symbol.bottom{animation-delay:-2s}
@keyframes planet-breathe{50%{filter:brightness(1.28);transform:scale(1.055)}}@keyframes orbit-turn{to{transform:rotate(360deg)}}@keyframes floaty{to{transform:translateY(-17px) rotate(7deg)}}
.v2-showcase{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:17px;margin:27px 0}.v2-tile{min-height:170px;display:flex;align-items:center;gap:19px;background:linear-gradient(120deg,#15494c,#15354c);border:1px solid #42796f;padding:23px;border-radius:23px;transition:transform .2s,box-shadow .2s}.v2-tile:hover{transform:translateY(-4px);box-shadow:0 20px 30px #0003}.v2-tile.game-tile{background:linear-gradient(110deg,#403656,#1b4252);border-color:#68618b}.v2-emoji{font-size:3rem}.v2-tile small{color:#90e9cd;font-weight:800;letter-spacing:.13em}.v2-tile h3{font-size:1.45rem;margin:5px 0 4px;color:#fff}.v2-tile p{font-size:.78rem;color:#d0dce4;margin:0}.v2-tile>span:last-child{margin-left:auto;font-size:1.7rem;color:#c7fce0}
.periodic-controls{display:flex;gap:12px;align-items:center;flex-wrap:wrap;margin:23px 0}.periodic-controls .search-field{min-width:min(350px,100%)}.periodic-scroll{overflow:auto;max-width:100%;border-radius:21px;background:#091b2b;border:1px solid #2c4c59;padding:16px}.periodic-grid{display:grid;grid-template-columns:repeat(18,minmax(48px,1fr));gap:5px;min-width:980px}.element-cell{position:relative;min-height:69px;padding:4px 2px 3px;border-radius:8px;border:1px solid #ffffff36;color:#f5fff9;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:0;transition:transform .12s,filter .12s;background:#235567}.element-cell small{font-size:10px;align-self:flex-start;margin-left:4px}.element-cell strong{font-size:22px;line-height:1.15}.element-cell span{max-width:100%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:9px}.element-cell:hover,.element-cell.chosen{transform:scale(1.08);z-index:2;box-shadow:0 0 0 2px #fff9,0 8px 17px #0007}.element-cell.dimmed{opacity:.18;filter:grayscale(1)}.g0{background:#8b4155!important}.g1{background:#9c6639!important}.g2{background:#315ca2!important}.g3{background:#526c9b!important}.g4{background:#307a78!important}.g5{background:#237d64!important}.g6{background:#777031!important}.g7{background:#66538f!important}.g8{background:#98628b!important}.g9{background:#686789!important}.period-label{grid-column:span 3;display:flex;align-items:center;font-size:12px;color:#bcd4de}.periodic-key{display:flex;gap:7px;flex-wrap:wrap;margin:16px 0 20px}.key-chip{color:#fff;border-radius:16px;border:1px solid #fff3;padding:7px 12px;font-size:12px}.element-focus{display:flex;gap:25px;align-items:center}.element-big{width:130px;height:150px;flex-shrink:0;display:flex;flex-direction:column;justify-content:center;align-items:center;border-radius:19px;border:1px solid #fff4;color:#fff}.element-big small{font-size:19px}.element-big strong{font-size:4rem}.element-focus h2{margin:4px 0}.element-focus p{font-size:.87rem}.element-focus .flex-wrap{margin-top:12px}
.game-stats{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}.game-stats>.panel{padding:19px;text-align:center}.game-stats span{font-size:.75rem;color:var(--muted);display:block}.game-stats strong{font-size:1.7rem;color:var(--accent)}.game-menu{display:flex;gap:14px;align-items:center;flex-wrap:wrap;margin:20px 0}.game-menu label{font-weight:750;font-size:.85rem}.game-question{max-width:970px;margin:auto}.game-question h2{font-size:clamp(1.25rem,3vw,2rem);line-height:1.4;margin:14px 0 23px}.game-top{display:flex;gap:12px;align-items:center}.game-pulse{text-align:center;font-size:2.9rem;color:#70e4b7;animation:floaty 3s ease-in-out infinite alternate}.game-pulse span{font-size:4.5rem}.game-options{display:grid;grid-template-columns:1fr 1fr;gap:12px}.game-option{min-height:82px;border:1px solid #507086;border-radius:15px;background:#183747;color:#f0f8f7;text-align:left;padding:14px;font-weight:650;display:flex;align-items:center;gap:14px}.game-option span{background:#385d69;color:#fff;display:grid;place-items:center;min-width:35px;height:35px;border-radius:11px}.game-option:hover:not(:disabled){background:#265063;border-color:#7acfb4}.game-option.correct{background:#1d5c44;border:2px solid #79edb0}.game-option.wrong{background:#673441;border:2px solid #e69898}.game-option:disabled{cursor:default}.game-feedback{margin-top:20px;padding:18px;background:#1e4d41;border-radius:14px;border:1px solid #3db28b}.game-feedback.oops{background:#473c40;border-color:#b78b89}.game-feedback p{line-height:1.7}.game-feedback .btn{margin:4px 8px 4px 0}
@media(max-width:880px){.v2-showcase{grid-template-columns:1fr}.game-options{grid-template-columns:1fr}.game-stats{grid-template-columns:repeat(2,1fr)}.element-focus{align-items:flex-start}}
@media(max-width:540px){.element-focus{flex-wrap:wrap}.element-big{width:94px;height:110px}.element-big strong{font-size:3rem}.v2-tile{padding:18px;min-height:140px}.v2-emoji{font-size:2.1rem}}
@media(prefers-reduced-motion:reduce){.hero-art .planet,.hero-art .orbit-ring,.hero-art .floating-symbol,.game-pulse{animation:none!important}}

/* Viðbót v4: skýr kennslumynd – frumeind (atóm) er ekki aktíníð. */
.atom-intro{margin:17px 0 23px;display:grid;grid-template-columns:minmax(225px,0.8fr) minmax(0,1.55fr);gap:20px;align-items:center;padding:20px 25px;border:1px solid #488a81;border-radius:22px;background:radial-gradient(circle at 13% 54%,#2a777346,transparent 40%),linear-gradient(125deg,#102e3d,#153346);color:#f0fff9}
.atom-intro-art{display:flex;flex-direction:column;align-items:center;justify-content:center;min-width:0}
.atom-intro-art svg{display:block;width:100%;max-width:286px;height:auto}
.atom-orbit{fill:none;stroke:#84c7c1;stroke-width:1.6;stroke-dasharray:5 7;opacity:.65}
.atom-core-glow{fill:#d1e1f8;opacity:.09}
.atom-particle.proton,.atom-legend i.proton{fill:#fb947a;background:#fb947a}
.atom-particle.neutron,.atom-legend i.neutron{fill:#b0c8eb;background:#b0c8eb}
.atom-particle.electron,.atom-legend i.electron{fill:#72ebc5;background:#72ebc5}
.atom-particle{stroke:#17374a;stroke-width:1.8}
.atom-legend{display:flex;flex-wrap:wrap;gap:12px;justify-content:center;color:#d8f7ed;font-size:.68rem}
.atom-legend span{display:flex;align-items:center;gap:5px;white-space:nowrap}
.atom-legend i{display:inline-block;width:9px;height:9px;border-radius:50%}
.atom-intro-copy h2{margin:8px 0 12px;font-size:clamp(1.3rem,2vw,1.8rem);color:#f7fffc}
.atom-intro-copy p{font-size:.88rem;line-height:1.68;color:#deefe9;margin:0 0 10px}
.atom-intro-copy .eyebrow{color:#95f3cc}
.atom-intro-copy strong{color:#ffffff}
.atom-intro-copy .atom-intro-note{padding:9px 12px;border:1px solid #5d8980;border-radius:11px;background:#122d35}
.atom-intro-copy small{display:block;color:#b7d9d5;line-height:1.5;font-size:.72rem}
body.light-mode .atom-intro{background:linear-gradient(130deg,#e5f6ef,#f1f8fc);border-color:#74b39c;color:#194b46}
body.light-mode .atom-intro-copy h2,body.light-mode .atom-intro-copy strong{color:#133e3a}
body.light-mode .atom-intro-copy p{color:#23514e}
body.light-mode .atom-intro-copy .atom-intro-note{background:#d4eee2;border-color:#a6d9c1}
body.light-mode .atom-intro-copy small,body.light-mode .atom-legend{color:#325854}
body.light-mode .atom-intro-copy .eyebrow{color:#267456}
@media(max-width:680px){.atom-intro{grid-template-columns:1fr;padding:15px;gap:4px}.atom-intro-art svg{max-width:235px}.atom-intro-copy h2{font-size:1.36rem}}