:root{color-scheme:dark;--bg:#151c2b;--bg-strong:#1a2637;--fg:#f3f5f7;--card:#1c2737;--card-alt:#222f41;--bd:#354255;--ac:#a4e82f;--ac2:#244b83;--mut:#aab4c4;--ok:#a4e82f;--danger:#ff8585;--shadow:rgba(0,0,0,.24);--lux-link-bg:#111713;--lux-link-fg:#f1f7ef;--lux-link-accent:#a4e82f;--lux-link-border:#3c503a;--lux-link-hover:#1b2920}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{min-height:100vh;margin:0;background:radial-gradient(circle at top,#1d2b40 0%,var(--bg) 42%,#101622 100%);color:var(--fg);font:16px/1.65 system-ui,-apple-system,Segoe UI,Roboto,sans-serif}
.skip-link{position:fixed;top:8px;left:8px;z-index:100;transform:translateY(-160%);padding:9px 12px;border-radius:8px;background:var(--ac);color:#172113;font-weight:800;text-decoration:none}
.skip-link:focus{transform:translateY(0)}
a:focus-visible,button:focus-visible,input:focus-visible,textarea:focus-visible,summary:focus-visible{outline:2px solid var(--ac);outline-offset:3px}
.hero{position:relative;isolation:isolate;overflow:hidden;padding:42px 20px 26px;background:radial-gradient(ellipse at 78% 18%,rgba(164,232,47,.16),transparent 34%),radial-gradient(ellipse at 12% 100%,rgba(36,75,131,.46),transparent 48%),linear-gradient(128deg,#101925 0%,#14283a 48%,#10271f 100%);color:var(--fg);box-shadow:inset 0 -30px 80px rgba(0,0,0,.2)}
.hero::before{position:absolute;z-index:-1;inset:0;background-image:linear-gradient(rgba(196,226,233,.055) 1px,transparent 1px),linear-gradient(90deg,rgba(196,226,233,.055) 1px,transparent 1px),radial-gradient(circle,rgba(164,232,47,.32) 1px,transparent 1.5px);background-size:42px 42px,42px 42px,42px 42px;background-position:center center;content:"";mask-image:linear-gradient(90deg,#000 0%,rgba(0,0,0,.72) 65%,transparent 100%);pointer-events:none}
.hero::after{position:absolute;z-index:-1;top:50%;right:max(3vw,calc((100vw - 1180px)/2));color:rgba(226,245,229,.075);content:"\2211 \222B \03C0 \221A \221E";font-size:clamp(2rem,6vw,5.5rem);font-weight:800;letter-spacing:.12em;line-height:1;white-space:nowrap;transform:translateY(-50%) rotate(-8deg);pointer-events:none}
.hero-shell{position:relative;max-width:1080px;margin:0 auto;display:grid;grid-template-columns:1fr;gap:28px;align-items:center}
.eyebrow{display:inline-block;padding:6px 12px;border-radius:999px;background:rgba(255,255,255,.15);border:1px solid rgba(255,255,255,.25);font-weight:700;letter-spacing:.08em;text-transform:uppercase;font-size:.72rem}
.hero-copy h1{margin:16px 0 12px;font-size:clamp(2.2rem,5vw,4rem);line-height:1.02;letter-spacing:-.04em}
.hero p{max-width:620px;margin:0 0 20px;opacity:.95;font-size:1.08rem}
.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:18px}
.gcse-entry,.secondary-link,#today,#rnd,.rev,.check-answer{display:inline-flex;align-items:center;justify-content:center;border-radius:12px;padding:11px 18px;font-weight:700;text-decoration:none;transition:transform .15s ease,box-shadow .15s ease}
.gcse-entry,.secondary-link{border:1px solid rgba(164,232,47,.55);background:rgba(164,232,47,.08);color:var(--fg)}
.secondary-link{background:transparent}
.gcse-entry:hover,.secondary-link:hover,#today:hover,#rnd:hover,.rev:hover,.check-answer:hover{transform:translateY(-1px);box-shadow:0 8px 20px rgba(17,24,39,.12)}
.stats{display:flex;gap:14px;justify-content:flex-start;align-items:center;flex-wrap:wrap}
.hero-progress-line{margin:0;color:var(--mut);font-size:.9rem}
.hero-progress-line b{color:var(--fg)}
.stats div{background:rgba(255,255,255,.16);backdrop-filter:blur(8px);border:1px solid rgba(255,255,255,.2);border-radius:14px;padding:10px 16px;min-width:120px}
.stats b{display:block;font-size:1.5rem;line-height:1.2}.stats small{opacity:.9}
#today,#rnd,.rev,.check-answer{background:var(--ac);color:#172113;border:0}
.hero #today{background:var(--ac);color:#172113}
.hero-panel{display:grid;gap:14px}
.mini-card{display:flex;flex-direction:column;gap:6px;background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.2);backdrop-filter:blur(8px);padding:16px 18px;border-radius:18px}
.mini-card span{font-size:1.8rem}
.mini-card strong{font-size:1.1rem}
.mini-card small{opacity:.9}
.bar{max-width:980px;margin:22px auto 0;height:12px;background:rgba(255,255,255,.25);border-radius:999px;overflow:hidden}
.bar div{height:100%;width:0;background:#fff;transition:width .4s}
main{max-width:1080px;margin:0 auto;padding:8px 20px 48px}
section{margin-top:26px}
h2{margin:0 0 12px;font-size:clamp(1.45rem,3vw,2rem);letter-spacing:-.03em}
.mut{color:var(--mut);margin:4px 0 14px}
.feature-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px;margin-top:24px}
.feature-card{background:linear-gradient(180deg,var(--card),var(--card-alt));border:1px solid var(--bd);border-radius:18px;padding:22px 18px;box-shadow:0 12px 25px var(--shadow)}
.feature-card .icon{display:inline-flex;align-items:center;justify-content:center;width:44px;height:44px;border-radius:12px;background:rgba(164,232,47,.12);font-size:1.5rem}
.feature-card h3{margin:14px 0 8px;font-size:1.1rem}
.feature-card p{margin:0;color:var(--mut)}
.roadmap-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:16px;margin-top:16px}
.roadmap-card{background:linear-gradient(180deg,var(--card),var(--card-alt));border:1px solid var(--bd);border-radius:18px;padding:18px 18px 16px;box-shadow:0 10px 22px rgba(0,0,0,.16)}
.step-tag{display:inline-block;margin-bottom:10px;padding:5px 10px;border-radius:999px;background:rgba(164,232,47,.12);color:var(--ac);font-size:.78rem;font-weight:700;letter-spacing:.05em;text-transform:uppercase}
.roadmap-card h3{margin:0 0 10px;font-size:1.08rem}
.roadmap-card ul{margin:0;padding-left:18px;color:var(--mut);display:grid;gap:8px}
.roadmap-card li{line-height:1.5}
.notes-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;margin-top:12px}
.note-card{background:linear-gradient(180deg,var(--card),var(--card-alt));border:1px solid var(--bd);border-radius:16px;padding:16px;box-shadow:0 8px 20px rgba(0,0,0,.16)}
.note-card .note-kind{display:inline-block;margin-bottom:8px;padding:5px 8px;border-radius:999px;background:rgba(164,232,47,.1);color:var(--ac);font-size:.7rem;font-weight:700;text-transform:uppercase;letter-spacing:.06em}
.note-card h3{margin:0 0 8px;font-size:1.02rem}
.note-card p{margin:0;color:var(--mut);line-height:1.55}
.note-card ul{margin:8px 0 0;padding-left:18px;color:var(--mut);display:grid;gap:6px}
.study-flow{display:grid;grid-template-columns:1.3fr .9fr;gap:18px;align-items:stretch;margin-top:22px}
.study-queue,.study-summary{background:linear-gradient(180deg,var(--card),var(--card-alt));border:1px solid var(--bd);border-radius:20px;padding:20px 18px;box-shadow:0 12px 25px var(--shadow)}
.study-queue h2{margin:12px 0 10px;font-size:clamp(1.5rem,3vw,2.2rem)}
.study-queue p{margin:0 0 18px;color:var(--mut);}
.dark{background:rgba(164,232,47,.12);color:var(--ac)}
.dark-link{color:var(--ac);border-color:var(--ac)}
.study-summary{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;align-items:center;align-self:start}
.summary-item{display:flex;flex-direction:column;gap:6px;padding:12px 10px;border-radius:14px;background:rgba(164,232,47,.05);border:1px solid var(--bd)}
.summary-item strong{font-size:1.15rem}
.summary-item small{color:var(--mut)}
.course-badge{display:inline-block;margin:0 0 10px;padding:4px 9px;border-radius:999px;background:rgba(22,163,74,.1);color:var(--ok);font-size:.72rem;font-weight:700;letter-spacing:.05em;text-transform:uppercase}
.roadmap-card.done{border-color:var(--ok);box-shadow:0 10px 22px rgba(22,163,74,.08)}
.roadmap-card.done .course-badge{background:rgba(22,163,74,.12);color:var(--ok)}
.roadmap-card.current{border-color:var(--ac);box-shadow:0 10px 22px rgba(164,232,47,.12)}
.roadmap-card.current .course-badge{background:rgba(164,232,47,.12);color:var(--ac)}
.course-actions{margin-top:12px}
.course-progress-wrap{margin-bottom:20px}
.resource-groups{display:grid;gap:10px;margin:12px 0}
.resource-group{overflow:hidden;border:1px solid var(--bd);border-radius:12px;background:var(--card)}
.resource-group>summary{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:12px 14px;color:var(--fg);font-weight:750;cursor:pointer;list-style:none}
.resource-group>summary::-webkit-details-marker{display:none}
.resource-group>summary::after{content:"+";color:var(--ac);font-size:1.2rem}
.resource-group[open]>summary::after{content:"−"}
.resource-group>summary span{margin-left:auto;padding:2px 8px;border-radius:999px;background:rgba(164,232,47,.12);color:var(--ac);font-size:.78rem}
.resource-group ul{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:10px;margin:0;padding:0 12px 12px;list-style:none}
.resource-group li{min-width:0;padding:11px;border:1px solid var(--bd);border-radius:10px;background:var(--card-alt)}
.resource-group li>a{color:var(--ac);font-weight:750;text-decoration:none}
.resource-group li>a[href*="wolframalpha.com"]{color:#60a5fa}
.resource-group li>a:hover{text-decoration:underline}
.resource-group li>p{margin:4px 0 0;color:var(--mut);font-size:.9rem;line-height:1.45}
button{font:inherit;cursor:pointer}
.check-result{margin-top:8px;padding:8px 12px;border-radius:10px;background:rgba(22,163,74,.08);color:var(--ok);font-weight:600;display:block}
.check-result[style*="color: rgb(180, 35, 24)"]{background:rgba(180,35,24,.08);color:var(--danger)}
.tools{display:flex;gap:12px;flex-wrap:wrap;align-items:center}
input[type=search]{flex:1;min-width:200px;padding:10px 14px;border-radius:10px;border:1px solid var(--bd);background:var(--card);color:var(--fg);font:inherit}
.chip-group{display:flex;gap:8px;flex-wrap:wrap;align-items:center}
.chip{background:var(--card);color:var(--fg);border:1px solid var(--bd);border-radius:20px;padding:6px 14px;transition:all .15s ease}
.chip.on{background:var(--ac);color:#172113;border-color:var(--ac)}
.small-hero{padding-bottom:18px}
#grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:14px}
.card{display:flex;flex-direction:column;gap:8px;align-items:stretch;text-align:left;background:linear-gradient(180deg,var(--card),var(--card-alt));color:var(--fg);border:1px solid var(--bd);border-radius:16px;padding:14px;transition:transform .15s ease, box-shadow .15s ease, opacity .15s ease, border-color .15s ease}
.card:hover{transform:translateY(-3px);box-shadow:0 10px 22px rgba(164,232,47,.12)}
.topic-lock-settings{margin:10px 0 16px;padding:12px 14px;border:1px solid var(--bd);border-radius:12px;background:var(--card)}
.topic-lock-settings>label{display:flex;align-items:center;gap:9px;font-weight:750}
.topic-practice-banner{margin:10px 0 0;padding:9px 12px;border:1px solid var(--ac);border-radius:9px;background:rgba(164,232,47,.1);color:var(--ac);font-weight:800}
.topic-lock-settings .mut{margin:6px 0 0;font-size:.86rem}
.locked-card{justify-content:flex-start;border-color:#596579;background:linear-gradient(180deg,#202938,#171f2c);cursor:default}
.locked-card:hover{transform:none;box-shadow:none}
.topic-lock-icon{font-size:1rem}
.locked-topic-placeholder{display:grid;gap:7px;overflow:hidden;padding:12px;border:1px solid var(--bd);border-radius:10px;background:rgba(7,12,20,.42)}
.locked-topic-placeholder span{display:block;height:9px;border-radius:9px;background:linear-gradient(90deg,#778294,#3d4859);filter:blur(3px)}
.locked-topic-placeholder span:nth-child(2){width:78%}
.locked-topic-placeholder span:nth-child(3){width:56%}
.topic-lock-message{margin:0;color:var(--mut);font-size:.86rem;line-height:1.5}
.topic-lock-message strong{color:var(--fg)}
.topic-quiz-question{display:block;margin:12px 0;padding:12px;border:1px solid var(--bd);border-radius:10px;background:var(--card)}
.topic-quiz-question input{display:block;width:100%;min-height:44px;margin-top:8px;padding:9px 11px;border:1px solid var(--bd);border-radius:8px;background:var(--bg);color:var(--fg);font:inherit}
.wolfram-question-link{display:inline-flex;align-items:center;gap:5px;margin:4px 0 10px;color:#60a5fa!important;font-size:.88rem;font-weight:750;text-decoration:underline;text-underline-offset:3px}
.wolfram-question-link:hover,.wolfram-question-link:focus-visible{color:#93c5fd!important}
.topic-quiz-result{margin:16px 0;padding:12px;border:1px solid var(--bd);border-radius:10px;background:var(--card)}
.topic-quiz-review-list{padding-left:22px}
.topic-quiz-review{margin:12px 0;padding:12px;border:1px solid var(--bd);border-radius:10px;background:var(--card)}
.topic-quiz-review.correct{border-color:var(--ok)}
.topic-quiz-review.incorrect{border-color:var(--danger)}
.topic-quiz-review p{margin:5px 0}
.topic-open{display:inline-flex;align-items:center;justify-content:center;width:100%;min-height:44px;padding:9px 13px;border:1px solid rgba(164,232,47,.55);border-radius:10px;background:rgba(164,232,47,.1);color:var(--fg);font-weight:750;text-align:center}
.topic-open:focus-visible{outline:2px solid var(--ac);outline-offset:4px;border-radius:8px}
.topic-detail{width:100%;margin:4px 0 0;padding:8px 10px;background:var(--card);border:1px solid var(--bd);border-radius:10px}
.topic-detail summary{color:var(--ac);font-size:.9rem}
.topic-note p{margin:8px 0;color:var(--mut);font-size:.9rem;line-height:1.5}
.topic-note strong{font-size:.86rem}
.topic-note ul{margin:4px 0 0;padding-left:18px;color:var(--mut);font-size:.86rem}
.topic-content{margin-top:10px}
.worked-example{margin:8px 0;padding:9px 11px;background:var(--bg);border:1px solid var(--bd);border-radius:9px}
.worked-example summary{color:var(--fg);font-size:.88rem}
.worked-example p,.topic-practice p{margin:8px 0 0;font-size:.86rem;line-height:1.5}
.worked-example .example-answer{color:var(--ok)}
.topic-practice{padding:8px 0;border-bottom:1px solid var(--bd)}
.topic-practice:last-child{border-bottom:0}
.topic-practice p{margin:0 0 6px}
.course-links{gap:7px;margin:10px 0 2px}
.course-links a{padding:6px 9px;font-size:.78rem}
.university-course-links{display:block;width:100%;margin:5px 0;padding:5px 8px;background:var(--lux-link-bg);border:1px solid var(--lux-link-border);border-radius:9px;font-size:.78rem}
.university-course-links[open]{display:grid;gap:8px;padding:12px}
.university-course-links>summary{display:flex;align-items:center;justify-content:space-between;gap:8px;min-height:24px;color:var(--lux-link-accent);font-weight:750;line-height:1.25;cursor:pointer;list-style:none}
.university-course-links>summary::-webkit-details-marker{display:none}
.university-course-links>summary::before{content:"+";display:inline-flex;flex:0 0 18px;align-items:center;justify-content:center;width:18px;height:18px;border:1px solid var(--lux-link-border);border-radius:5px;color:var(--lux-link-accent);font-size:.9rem;line-height:1}
.university-course-links[open]>summary::before{content:"−"}
.university-course-links .resource-count{flex:0 0 auto;padding:2px 7px;border:1px solid var(--lux-link-border);border-radius:999px;color:var(--lux-link-fg);font-size:.7rem}
.university-course-links strong{margin-top:2px;padding-bottom:4px;border-bottom:1px solid var(--lux-link-border);color:var(--lux-link-accent);line-height:1.4}
.university-course-links strong:not(:first-child){margin-top:8px}
.course-note{display:grid;gap:3px;margin:8px 0;padding:11px 12px;border:1px solid var(--bd);border-radius:9px;background:var(--bg);font-size:.82rem}
.course-note strong{color:var(--fg)}
.course-note span{color:var(--mut)}
.university-course-links a{display:block;padding:8px 10px;border:1px solid var(--lux-link-border);border-left:3px solid var(--lux-link-accent);border-radius:9px;background:var(--lux-link-bg);color:var(--lux-link-fg);font-weight:700;line-height:1.4;text-decoration:none;overflow-wrap:anywhere;transition:border-color .15s ease,background .15s ease,transform .15s ease}
.university-course-links a:hover{transform:translateY(-1px);border-color:var(--lux-link-accent);background:var(--lux-link-hover)}
.university-course-links a:focus-visible{outline:2px solid var(--lux-link-accent);outline-offset:2px}
.university-course-links span{color:var(--mut)}
.exam-detail{border-color:rgba(180,35,24,.28)}
.exam-detail summary{color:var(--danger);font-weight:750}
.exam-instructions{margin:8px 0;color:var(--mut);font-size:.84rem}
.exam-question{display:grid;gap:5px;margin:10px 0;padding:9px 10px;border:1px solid var(--bd);border-radius:9px;background:var(--bg);font-size:.84rem}
.exam-question input{width:100%;padding:8px 10px;border:1px solid var(--bd);border-radius:8px;background:var(--card);color:var(--fg);font:inherit}
.exam-question input:focus{outline:2px solid var(--ac);outline-offset:1px}
.exam-result{margin:10px 0 0}
.topic-roadmap{display:grid;gap:8px;margin:10px 0 2px;padding:0;list-style:none}
.topic-roadmap li{display:grid;gap:2px;padding:8px 10px;border-left:3px solid var(--bd);border-radius:0 8px 8px 0;background:var(--bg);font-size:.84rem}
.topic-roadmap li.roadmap-current{border-left-color:var(--ac);background:rgba(164,232,47,.08)}
.topic-roadmap span{color:var(--mut);font-size:.72rem;font-weight:700;text-transform:uppercase;letter-spacing:.04em}
.topic-roadmap small{color:var(--mut);font-size:.78rem}
.card.done{border-color:var(--ok);box-shadow:0 10px 22px rgba(164,232,47,.12)}
.card h3{margin:0;font-size:1rem;line-height:1.4}
.card:not(.done){border-color:rgba(164,232,47,.24);box-shadow:0 10px 22px rgba(164,232,47,.06)}
.card-topline{display:flex;align-items:center;justify-content:space-between;gap:8px;width:100%}
.em{font-size:1.8rem}
.topic-badges{display:flex;flex-wrap:wrap;justify-content:flex-end;gap:5px}
.level-badge,.key-badge{display:inline-flex;align-items:center;padding:4px 7px;border:1px solid var(--bd);border-radius:999px;background:var(--bg);color:var(--mut);font-size:.64rem;font-weight:800;line-height:1.25}
.key-badge{display:inline-flex;align-items:center;justify-content:center;padding:4px 8px;border-radius:999px;background:rgba(164,232,47,.12);color:var(--ac);font-size:.7rem;font-weight:800;letter-spacing:.04em;text-transform:uppercase}
.card-progress-copy,.card-meta{display:flex;align-items:center;justify-content:space-between;gap:8px;color:var(--mut);font-size:.74rem}
.card-progress{height:6px;overflow:hidden;border-radius:999px;background:var(--bd)}
.card-progress span{display:block;height:100%;border-radius:inherit;background:var(--ac);transition:width .2s ease}
.lesson-label{color:var(--ac);font-weight:800}
.recommended-badge{align-self:flex-start;padding:3px 8px;border:1px solid var(--lux-link-border);border-radius:999px;background:var(--lux-link-hover);color:var(--lux-link-accent);font-size:.68rem;font-weight:800}
.completed-badge{align-self:flex-start;padding:4px 9px;border:1px solid var(--ok);border-radius:999px;background:rgba(164,232,47,.12);color:var(--ok);font-size:.72rem;font-weight:850}
.today-panel{margin-top:24px;padding:clamp(16px,3vw,26px);border:1px solid var(--bd);border-radius:20px;background:linear-gradient(145deg,var(--card),var(--bg-strong));box-shadow:0 14px 30px var(--shadow)}
.today-heading-row{display:flex;align-items:center;justify-content:space-between;gap:16px}
.today-heading-row h2{margin:8px 0 2px}
.today-heading-row p{margin:0}
.today-stats{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;margin:18px 0}
.today-stats>div{display:grid;gap:2px;padding:12px;border:1px solid var(--bd);border-radius:12px;background:rgba(164,232,47,.04)}
.today-stats strong{font-size:1.35rem;color:var(--ac);line-height:1.2}
.today-stats small{color:var(--mut);font-size:.78rem}
.today-panel h3{margin:16px 0 8px;font-size:1rem}
.today-questions{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}
.today-question{min-width:0;padding:10px 12px;border:1px solid var(--bd);border-radius:12px;background:var(--bg)}
.today-question>small{color:var(--ac);font-size:.7rem;font-weight:750}
.today-question .q{padding:5px 0;border:0;font-size:.84rem}
.today-question .answer-label{font-size:.76rem}
.today-question .answer-input{min-height:42px}
.today-question .btns button{padding:7px 10px;font-size:.75rem}
.room-content{padding:22px clamp(14px,3vw,32px) 32px}
.room-tabs{display:flex;gap:8px;margin:0 0 16px;padding-bottom:8px;overflow-x:auto;border-bottom:1px solid var(--bd)}
.room-tab{flex:0 0 auto;padding:9px 14px;border:1px solid var(--bd);border-radius:10px;background:var(--card);color:var(--mut);font-size:.84rem;font-weight:750}
.room-tab:hover,.room-tab.active{border-color:var(--lux-link-border);background:var(--lux-link-hover);color:var(--lux-link-accent)}
.room-tab:focus-visible{outline:2px solid var(--ac);outline-offset:2px}
.room-panel{min-width:0;margin:0;padding:clamp(14px,3vw,26px);border:1px solid var(--bd);border-radius:14px;background:var(--card)}
.room-panel[hidden]{display:none}
.room-panel h3{margin:20px 0 8px;color:var(--ac);font-size:1.05rem}
.room-panel>h4{margin-top:22px}
.practice-set-heading{display:flex;align-items:center;justify-content:space-between;gap:14px;margin:0 0 12px;padding:12px 14px;border:1px solid var(--bd);border-radius:12px;background:linear-gradient(135deg,var(--card-alt),var(--card))}
.practice-set-heading h3{margin:0;color:var(--fg)}
.practice-set-heading p{margin:4px 0 0;color:var(--mut);font-size:.82rem}
.practice-set-heading button{flex:0 0 auto}
.practice-set-heading button:disabled{opacity:.55;cursor:not-allowed}
.room-briefing{margin-bottom:18px;padding:14px 16px;border-left:3px solid var(--ac);border-radius:0 10px 10px 0;background:rgba(164,232,47,.05)}
.room-briefing p{margin-top:0}
.room-briefing h3{margin-top:10px}
.mastery-routine{margin:18px 0 24px;padding:18px;border:1px solid var(--bd);border-radius:14px;background:linear-gradient(145deg,var(--card-alt),var(--card))}
.mastery-routine-heading .room-kicker{margin-bottom:6px}
.mastery-routine-heading h3{margin:0 0 6px;color:var(--fg)}
.mastery-routine-heading p{margin:0;color:var(--mut);font-size:.9rem}
.mastery-steps{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin:14px 0 0;padding:0;list-style:none;counter-reset:mastery}
.mastery-steps li{min-width:0;padding:13px;border:1px solid var(--bd);border-radius:11px;background:var(--bg);counter-increment:mastery}
.mastery-steps li::before{content:counter(mastery);display:inline-grid;width:23px;height:23px;margin-right:7px;place-items:center;border-radius:50%;background:var(--ac);color:#172113;font-size:.75rem;font-weight:850}
.mastery-step-time{font-size:.8rem;font-weight:800}
.mastery-steps li p{margin:8px 0;color:var(--mut);font-size:.84rem;line-height:1.5}
.mastery-action{min-height:40px;padding:8px 11px;border:1px solid var(--lux-link-border);border-radius:9px;background:var(--lux-link-hover);color:var(--lux-link-accent);font-size:.8rem;font-weight:750}
.mastery-action:hover{filter:brightness(1.12)}
.mastery-action:focus-visible{outline:2px solid var(--ac);outline-offset:2px}
.mastery-review{margin:12px 0 0;padding:11px 13px;border-left:3px solid var(--ac);border-radius:0 8px 8px 0;background:rgba(164,232,47,.05);font-size:.84rem;line-height:1.5}
.finish-topic{display:inline-flex;gap:7px;align-items:center;margin-top:14px;padding:9px 12px;border:1px solid var(--bd);border-radius:10px;background:var(--bg)}
.card-status{display:inline-flex;align-items:center;justify-content:center;padding:4px 8px;border-radius:999px;background:var(--bd);color:var(--mut);font-size:.7rem;font-weight:800;text-transform:uppercase}
.status-current{background:var(--ac);color:#172113}
.status-next{background:rgba(164,232,47,.12);color:var(--ok)}
.status-passed{background:rgba(164,232,47,.12);color:var(--ok)}
.tag{padding:2px 10px;border-radius:12px;background:var(--bd);color:var(--mut)}
.tag.core{background:var(--ac);color:#172113}
.box{background:var(--card);border:1px solid var(--bd);border-radius:14px;padding:14px 16px;margin-top:12px;min-height:60px;box-shadow:0 8px 18px rgba(0,0,0,.02)}
.video-section{margin-top:26px}
.video-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}
.video-grid a{display:flex;flex-direction:column;gap:8px;padding:18px 16px;border-radius:18px;background:linear-gradient(135deg,var(--card),var(--card-alt));border:1px solid var(--bd);text-decoration:none;color:var(--fg);box-shadow:0 10px 18px rgba(0,0,0,.03)}
.video-grid a span{font-size:1.8rem}
.video-grid a strong{font-size:1.02rem}
.video-grid a small{color:var(--mut)}
.syms{display:flex;flex-wrap:wrap;gap:8px;margin:8px 0}
.syms span{background:var(--card);border:1px solid var(--bd);border-radius:10px;padding:4px 10px}
.syms b{color:var(--ac);font-size:1.1rem;margin-right:6px}
dialog{width:min(1180px,96vw);max-height:92vh;overflow:auto;border:1px solid var(--bd);border-radius:18px;padding:0;background:var(--bg);color:var(--fg);box-shadow:0 20px 60px rgba(0,0,0,.5);scroll-behavior:smooth}
dialog::backdrop{background:rgba(5,5,20,.78);backdrop-filter:blur(5px)}
dialog h3{margin:0 0 6px;font-size:1.4rem}
.x{display:inline-flex;align-items:center;justify-content:center;float:right;background:var(--bd);color:var(--fg);border:1px solid var(--bd);border-radius:50%;width:36px;height:36px}
.room-shell{min-height:100%;background:var(--bg)}
.room-header{position:relative;padding:30px clamp(18px,4vw,46px) 24px;background:linear-gradient(120deg,#151c2b,#1b3152);border-bottom:1px solid var(--bd)}
.room-close{float:right;margin:0 0 12px 16px}
.room-kicker{display:block;margin:0 0 10px;color:var(--ac);font-size:.72rem;font-weight:800;letter-spacing:.12em}
.room-kicker span{padding:0 5px;color:var(--mut)}
.room-header h2{max-width:850px;margin:0 0 9px;font-size:clamp(1.5rem,3vw,2.25rem);line-height:1.18}
.room-header>p{max-width:900px;margin:0;color:var(--mut);font-size:.96rem}
.room-meta{display:flex;flex-wrap:wrap;gap:8px;margin-top:16px}
.room-meta span{padding:4px 10px;border:1px solid var(--bd);border-radius:999px;background:rgba(255,255,255,.04);color:var(--fg);font-size:.76rem;font-weight:700}
.room-meta span.room-completed{border-color:var(--ok);background:rgba(164,232,47,.12);color:var(--ok)}
.room-progress{max-width:500px;margin-top:18px}
.room-progress-copy{display:flex;justify-content:space-between;gap:12px;margin-bottom:6px;color:var(--mut);font-size:.78rem}
.room-progress-copy strong{color:var(--fg)}
.room-progress-track{height:7px;overflow:hidden;border-radius:999px;background:var(--bd)}
.room-progress-track span{display:block;height:100%;border-radius:inherit;background:var(--ac);transition:width .2s ease}
.room-layout{display:grid;grid-template-columns:220px minmax(0,1fr);gap:22px;align-items:start;padding:24px clamp(14px,3vw,32px) 32px}
.room-sidebar{position:sticky;top:12px;display:grid;gap:5px;padding:12px;border:1px solid var(--bd);border-radius:14px;background:var(--card)}
.room-sidebar-title{padding:3px 8px 9px;color:var(--mut);font-size:.68rem;letter-spacing:.1em}
.room-nav-item{display:flex;align-items:center;gap:9px;width:100%;padding:9px 8px;border:1px solid transparent;border-radius:8px;background:transparent;color:var(--mut);text-align:left;font-size:.8rem}
.room-nav-item>span{color:var(--mut);font-size:.7rem;font-weight:800}
.room-nav-item:hover,.room-nav-item.active{border-color:var(--lux-link-border);background:var(--lux-link-hover);color:var(--lux-link-accent)}
.room-nav-item.active>span{color:var(--lux-link-accent)}
.room-sidebar-tip{display:grid;gap:4px;margin-top:10px;padding:10px;border-top:1px solid var(--bd);font-size:.76rem}
.room-sidebar-tip strong{color:var(--ac)}
.room-sidebar-tip span{font-weight:700}
.room-sidebar-tip small{color:var(--mut)}
.room-tasks{display:grid;gap:12px;min-width:0}
.room-task{scroll-margin-top:14px;margin:0;padding:0;overflow:hidden;border:1px solid var(--bd);border-radius:12px;background:var(--card)}
.room-task>summary{display:flex;align-items:center;gap:12px;min-height:58px;padding:12px 16px;list-style:none;cursor:pointer}
.room-task>summary::-webkit-details-marker{display:none}
.room-task-number{flex:0 0 auto;color:var(--ac);font-size:.68rem;font-weight:850;letter-spacing:.08em}
.room-task-title{flex:1;color:var(--fg);font-size:.94rem;font-weight:750}
.room-task-chevron{width:9px;height:9px;border-right:2px solid var(--mut);border-bottom:2px solid var(--mut);transform:rotate(45deg);transition:transform .15s}
.room-task[open]>summary{border-bottom:1px solid var(--bd);background:rgba(164,232,47,.04)}
.room-task[open] .room-task-chevron{transform:rotate(225deg)}
.room-task-content{padding:18px clamp(14px,3vw,28px) 22px}
.room-task-content>p:first-child,.room-task-intro{margin-top:0}
.room-task-content h4{margin:18px 0 7px;color:var(--ac)}
.room-task-content ul,.room-task-content ol{padding-left:22px}
.room-goal{margin:16px 0 0;padding:12px 14px;border-left:3px solid var(--ac);border-radius:0 8px 8px 0;background:rgba(164,232,47,.06);color:var(--fg)}
.room-roadmap{display:grid;gap:7px;padding:0!important;list-style:none}
.room-roadmap li{display:grid;gap:2px;padding:9px 12px;border:1px solid var(--bd);border-radius:8px;background:var(--bg);font-size:.86rem}
.room-roadmap li.current{border-color:var(--lux-link-border);background:var(--lux-link-hover)}
.room-roadmap li span{color:var(--mut);font-size:.65rem;font-weight:800;letter-spacing:.07em;text-transform:uppercase}
.room-task-content .q{border-top:1px solid var(--bd)}
.room-task-content .topic-detail{background:var(--bg)}
.room-task-content .university-course-links{margin-top:12px}
.room-task-content .course-links{margin-top:14px}
.room-task-content .topic-content{margin-top:12px}
.room-task-content .exam-question{font-size:.82rem}
.room-task-content .submit-exam{margin-top:8px}
.list{display:flex;flex-wrap:wrap;gap:6px;margin:8px 0 14px}
.list span{background:var(--bd);border-radius:8px;padding:2px 10px;font-size:.9rem}
.q{border-top:1px solid var(--bd);padding:10px 0}
.a{color:var(--ok);font-weight:600;margin-top:6px}
footer{text-align:center;color:var(--mut);padding:24px;font-size:.9rem}.meta{color:var(--mut);font-size:.82rem}
.links{display:flex;flex-wrap:wrap;gap:10px;margin:10px 0}
.links a{background:var(--ac);color:#172113;text-decoration:none;border-radius:10px;padding:8px 14px;font-weight:600;font-size:.95rem}
.links a:last-child{background:transparent;color:var(--ac);border:1px solid var(--ac)}
dialog h4{margin:22px 0 6px;color:var(--ac)}
dialog ul{padding-left:22px}
details{background:var(--bd);border-radius:10px;padding:8px 14px;margin:8px 0}
summary{cursor:pointer;font-weight:600}
.sol{padding:8px 0}
.btns{margin-top:6px;display:flex;flex-wrap:wrap;gap:8px;align-items:flex-start}
.btns .a{flex-basis:100%;margin:0}
.rev.alt{background:transparent;color:var(--ac);border:1px solid var(--ac)}
.explain-answer{min-height:44px;padding:9px 13px;border:1px solid var(--ac);border-radius:10px;background:rgba(164,232,47,.08);color:var(--fg);font-weight:700}
.explain-answer:disabled{opacity:.55;cursor:not-allowed}
.hint{color:var(--mut);font-weight:400}
.ck{display:block;padding:3px 0}
.answer-label{display:block;margin:10px 0 4px;color:var(--mut);font-size:.9rem;font-weight:600}
.answer-input{display:block;width:100%;min-height:54px;margin-top:4px;padding:10px 12px;resize:vertical;border:1px solid var(--bd);border-radius:10px;background:var(--bg);color:var(--fg);font:inherit}
.answer-input:focus{outline:2px solid var(--ac);outline-offset:1px}
.site-menu{position:sticky;top:0;z-index:20;display:flex;justify-content:center;gap:8px;flex-wrap:wrap;padding:8px 12px;background:rgba(21,28,43,.94);backdrop-filter:blur(12px);border-bottom:1px solid var(--bd);box-shadow:0 3px 12px rgba(0,0,0,.2)}
.site-menu a{display:inline-block;padding:7px 12px;border:1px solid var(--bd);border-radius:10px;background:var(--bg);color:var(--fg);font-size:.92rem;font-weight:650;text-decoration:none;white-space:nowrap}
.site-menu a:hover,.site-menu a:focus-visible{background:var(--ac);border-color:var(--ac);color:#172113}
.site-menu a[aria-current=page]{background:var(--ac);border-color:var(--ac);color:#172113}
.site-menu a{transition:background .15s ease,border-color .15s ease,color .15s ease}
@media(max-width:760px){
  .site-menu{justify-content:flex-start;flex-wrap:nowrap;overflow-x:auto;scrollbar-width:thin;mask-image:linear-gradient(to right,transparent,#000 14px,#000 calc(100% - 14px),transparent)}
  .site-menu a{flex:0 0 auto;min-height:44px;display:inline-flex;align-items:center}
  .room-layout{grid-template-columns:1fr;gap:14px;padding-top:14px}
  .room-sidebar{position:static;grid-template-columns:repeat(2,minmax(0,1fr))}
  .room-sidebar-title,.room-sidebar-tip{grid-column:1/-1}
  .room-nav-item{min-height:42px}
  .today-heading-row{align-items:flex-start;flex-direction:column}
  .today-questions{grid-template-columns:1fr}
  .today-stats{gap:7px}
  .today-stats>div{padding:9px}
  .today-stats small{font-size:.7rem}
}
@media(max-width:600px){
  #grid{grid-template-columns:minmax(0,1fr)}
  .tools{align-items:stretch}
  input[type=search]{width:100%;min-width:0}
  .chip-group{justify-content:flex-start}
  .chip{min-height:40px;padding:7px 12px}
  dialog{width:100vw;max-width:100vw;height:100dvh;max-height:100dvh;margin:0;border-radius:0}
  .room-header{padding:18px 16px}
  .room-header>p{font-size:.9rem}
  .room-content{padding:14px 12px 20px}
  .room-tabs{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));overflow:visible}
  .room-tab{min-height:44px;padding:7px 6px;white-space:normal;line-height:1.25}
  .room-tab:last-child{grid-column:1/-1}
  .room-panel{padding:14px 12px}
  .mastery-routine{padding:13px}
  .mastery-steps{grid-template-columns:1fr}
  .room-panel,.room-header,.card{overflow-wrap:anywhere}
  .practice-set-heading{align-items:stretch;flex-direction:column}
  .card{padding:13px}
  .card-topline{align-items:flex-start}
  .topic-badges{max-width:75%}
  .answer-input{font-size:16px}
}
@media(min-width:601px) and (max-width:900px){
  #grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (max-width: 900px) {
  .hero-shell,
  .feature-grid,
  .video-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 660px) {
  .hero-shell,
  .feature-grid,
  .video-grid {
    grid-template-columns: 1fr;
  }

  .study-flow {
    grid-template-columns: 1fr;
  }
  main{padding-right:14px;padding-left:14px}

  .hero {
    padding-top: 28px;
  }
  .hero::after{top:16%;right:10px;font-size:2rem;opacity:.7}

  .stats {
    justify-content: center;
  }

}

@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{scroll-behavior:auto!important;animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}
}

a,
a:visited,
a:hover,
a:focus,
a:focus-visible,
a:active{
  color:#60a5fa!important;
}