:root{--navy:#071b34;--navy-2:#102a4d;--blue:#0d5fd3;--blue-2:#2b71e8;--sky:#eaf3ff;--mint:#2fcf9f;--ink:#101c2d;--muted:#617086;--line:#dbe4f0;--paper:#fff;--soft:#f5f8fc;--warning:#fff7e2;--danger:#d92d42;--shadow:0 22px 60px rgba(7,27,52,.12);--radius:28px}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;color:var(--ink);background:var(--paper);font-family:Inter,"Segoe UI",Arial,sans-serif;line-height:1.55}button,input,select,textarea{font:inherit}button,a{touch-action:manipulation}a{color:inherit;text-decoration:none}img{max-width:100%;display:block}.skip-link{position:fixed;left:12px;top:-80px;background:var(--navy);color:#fff;padding:12px 18px;z-index:100}.skip-link:focus{top:12px}.shell{width:min(1180px,calc(100% - 40px));margin:auto}.topbar{background:var(--navy);color:#d6e6fb;font-size:13px}.topbar-inner{height:42px;display:flex;align-items:center;justify-content:space-between}.topbar-inner>div{display:flex;align-items:center;gap:18px}.icon-btn{border:1px solid rgba(255,255,255,.2);background:rgba(255,255,255,.07);color:#fff;border-radius:50%;width:31px;height:31px;cursor:pointer}.site-header{position:sticky;top:0;z-index:40;background:var(--paper);box-shadow:0 1px 0 var(--line)}.nav-shell{height:92px;display:flex;align-items:center;gap:38px}.brand{position:relative;width:224px;flex:none}.brand img{width:190px}.brand-product{position:absolute;right:0;bottom:0;background:var(--blue);color:#fff;font-size:10px;font-weight:900;letter-spacing:.13em;padding:2px 7px;border-radius:4px}.desktop-nav{display:flex;gap:30px;align-items:center;flex:1}.desktop-nav a{font-weight:750}.desktop-nav a:hover,.desktop-nav a.active{color:var(--blue)}.nav-actions{display:flex;align-items:center;gap:18px}.text-btn{border:0;background:transparent;font-weight:800;cursor:pointer;color:var(--ink)}.button{border:0;border-radius:8px;padding:14px 20px;font-weight:850;display:inline-flex;align-items:center;justify-content:center;gap:9px;cursor:pointer;transition:.2s transform,.2s box-shadow}.button:hover{transform:translateY(-2px);box-shadow:0 10px 24px rgba(13,95,211,.2)}.button-primary{background:var(--blue);color:#fff}.button-secondary{background:#fff;color:var(--blue);border:2px solid var(--blue)}.button-dark{background:var(--navy);color:#fff}.button-light{background:#fff;color:var(--navy)}.button-success{background:#0c9c71;color:#fff}.mobile-menu-btn,.mobile-nav{display:none}
.hero{min-height:640px;background:linear-gradient(90deg,rgba(7,27,52,.58),rgba(7,27,52,.05)),url('assets/student-hero.jpg') center/cover;display:grid;align-items:center;padding:58px 0}.hero-card{width:min(660px,100%);background:rgba(255,255,255,.97);padding:54px;border-radius:38px;box-shadow:0 12px 0 rgba(13,95,211,.17)}.eyebrow{color:var(--blue);font-weight:900;text-transform:uppercase;letter-spacing:.13em;font-size:13px}.hero h1,.page-hero h1{font-size:clamp(42px,5vw,68px);line-height:1.02;letter-spacing:-.055em;margin:18px 0}.hero p,.page-hero p{color:var(--muted);font-size:19px;max-width:650px}.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin:28px 0}.trust-row{border-top:1px solid var(--line);display:flex;gap:24px;flex-wrap:wrap;padding-top:20px;font-size:14px;font-weight:750}.trust-row span::before{content:'✓';color:var(--blue);margin-right:7px}.section{padding:92px 0}.section-soft{background:var(--soft)}.section-dark{background:var(--navy);color:#fff}.section-heading{display:flex;justify-content:space-between;gap:30px;align-items:end;margin-bottom:34px}.section-heading h2{font-size:clamp(32px,4vw,50px);line-height:1.05;letter-spacing:-.04em;margin:8px 0}.section-heading p{max-width:570px;color:var(--muted);margin:0}.section-dark .section-heading p{color:#bdd0e7}.service-grid,.subject-grid,.teacher-grid,.plan-grid,.steps{display:grid;gap:20px}.service-grid{grid-template-columns:repeat(3,1fr)}.service-card{border:1px solid var(--line);border-radius:24px;padding:30px;background:var(--paper);position:relative;overflow:hidden}.service-card::after{content:'';position:absolute;width:90px;height:90px;background:var(--sky);right:-30px;top:-30px;border-radius:50%}.service-icon{width:52px;height:52px;border-radius:15px;background:var(--sky);color:var(--blue);display:grid;place-items:center;font-size:25px}.service-card h3{font-size:24px;margin:22px 0 8px}.service-card p{color:var(--muted)}.subject-grid{grid-template-columns:repeat(4,1fr)}.subject-card{padding:24px;border-radius:18px;background:#fff;border:1px solid var(--line);display:flex;gap:14px;align-items:center;font-weight:850}.subject-card span:first-child{font-size:27px}.tag{display:inline-flex;align-items:center;border-radius:999px;padding:7px 11px;background:var(--sky);color:var(--blue);font-size:12px;font-weight:850}.teacher-grid{grid-template-columns:repeat(3,1fr)}.teacher-card{border:1px solid var(--line);background:#fff;border-radius:22px;overflow:hidden;transition:.2s}.teacher-card:hover{transform:translateY(-4px);box-shadow:var(--shadow)}.teacher-photo{height:225px;background:linear-gradient(135deg,#cfe2fb,#eff6ff);position:relative;overflow:hidden}.teacher-photo img{width:100%;height:100%;object-fit:cover}.teacher-photo .verified{position:absolute;right:14px;top:14px;background:#fff;color:#087a5b;border-radius:999px;padding:7px 10px;font-weight:800;font-size:12px}.teacher-info{padding:23px}.teacher-info h3{margin:0;font-size:22px}.teacher-info p{color:var(--muted);margin:4px 0 13px}.rating{color:#ef9700;font-weight:850}.teacher-meta{display:flex;justify-content:space-between;margin-top:18px;border-top:1px solid var(--line);padding-top:16px}.teacher-meta strong{display:block}.teacher-meta span{font-size:12px;color:var(--muted)}.steps{grid-template-columns:repeat(4,1fr);counter-reset:step}.step{padding:28px;border-left:1px solid rgba(255,255,255,.18);counter-increment:step}.step::before{content:'0' counter(step);color:#61a1ff;font-weight:900}.step h3{font-size:20px}.step p{color:#b8c9de}.split-cta{display:grid;grid-template-columns:1fr 1fr;min-height:480px}.split-cta>div:first-child{background:url('assets/virtual-teacher-class.jpg') center/cover}.split-copy{background:var(--blue);color:#fff;padding:60px;display:flex;flex-direction:column;justify-content:center}.split-copy h2{font-size:44px;line-height:1.05;margin:12px 0}.split-copy p{color:#d9e9ff}.page-hero{padding:78px 0;background:linear-gradient(135deg,var(--sky),#fff)}.page-hero.compact h1{font-size:50px}.filter-bar{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:30px}.field{display:flex;flex-direction:column;gap:7px}.field label{font-size:13px;font-weight:850}.field input,.field select,.field textarea,.search-input{border:1px solid #cdd9e7;background:#fff;padding:14px 16px;border-radius:10px;color:var(--ink);outline:none}.field input:focus,.field select:focus,.field textarea:focus,.search-input:focus{border-color:var(--blue);box-shadow:0 0 0 3px rgba(13,95,211,.12)}.filter-bar .search-input{flex:1;min-width:240px}.empty-state{padding:50px;text-align:center;color:var(--muted)}
.study-layout{display:grid;grid-template-columns:250px 1fr 320px;min-height:690px;background:var(--soft)}.lesson-sidebar,.lesson-chat{background:#fff;padding:24px;border-right:1px solid var(--line)}.lesson-chat{border-left:1px solid var(--line);border-right:0;display:flex;flex-direction:column}.lesson-sidebar h3,.lesson-chat h3{margin-top:0}.lesson-list{display:flex;flex-direction:column;gap:8px}.lesson-item{padding:13px;border-radius:9px;color:var(--muted);cursor:pointer}.lesson-item.active{background:var(--sky);color:var(--blue);font-weight:850}.board-wrap{padding:28px;display:flex;flex-direction:column}.board-toolbar{display:flex;justify-content:space-between;align-items:center;margin-bottom:14px}.board{background:#fff;border:1px solid var(--line);border-radius:20px;min-height:530px;box-shadow:var(--shadow);position:relative;overflow:hidden}.board::before{content:'';position:absolute;inset:0;background-image:linear-gradient(#edf2f8 1px,transparent 1px),linear-gradient(90deg,#edf2f8 1px,transparent 1px);background-size:28px 28px}.board-content{position:relative;padding:50px;z-index:1}.board-content h2{font-size:38px;color:var(--blue);margin:0 0 24px}.equation{font-family:Georgia,serif;font-size:50px;margin:45px 0;text-align:center}.board-note{background:#fff8c8;border-left:5px solid #f1b800;padding:16px 18px;border-radius:8px}.chat-messages{flex:1;overflow:auto;display:flex;flex-direction:column;gap:12px;max-height:485px;padding-right:5px}.message{padding:13px 15px;border-radius:16px;font-size:14px}.message.ai{background:var(--soft);border-bottom-left-radius:3px}.message.user{background:var(--blue);color:#fff;align-self:flex-end;border-bottom-right-radius:3px}.chat-form{display:grid;grid-template-columns:1fr auto;gap:8px;margin-top:15px}.chat-form input{min-width:0;border:1px solid var(--line);border-radius:10px;padding:12px}.round-btn{width:45px;border:0;border-radius:10px;background:var(--blue);color:#fff;font-size:20px;cursor:pointer}.voice-bar{display:flex;align-items:center;gap:10px;background:var(--navy);color:#fff;border-radius:12px;padding:10px 13px;margin-top:10px}.voice-bar button{background:var(--blue);border:0;color:#fff;border-radius:50%;width:36px;height:36px;cursor:pointer}.voice-status{font-size:12px;color:#bcd1e9}.profile-grid{display:grid;grid-template-columns:1.35fr .65fr;gap:30px}.profile-card,.panel{background:#fff;border:1px solid var(--line);border-radius:24px;padding:30px}.profile-head{display:flex;gap:25px}.profile-avatar{width:130px;height:130px;border-radius:20px;object-fit:cover}.profile-head h1{font-size:40px;line-height:1.05;margin:7px 0}.profile-actions{display:flex;gap:10px;flex-wrap:wrap;margin:25px 0}.stat-list{display:grid;grid-template-columns:repeat(3,1fr);border-top:1px solid var(--line);margin-top:25px;padding-top:20px}.stat-list strong{font-size:24px;display:block}.stat-list span{font-size:12px;color:var(--muted)}.review{padding:22px 0;border-bottom:1px solid var(--line)}.review:last-child{border:0}.review-head{display:flex;justify-content:space-between}.verified-review{color:#087a5b;font-size:12px;font-weight:800}.schedule-list{display:flex;flex-direction:column;gap:9px}.schedule-slot{display:flex;justify-content:space-between;border:1px solid var(--line);padding:12px;border-radius:9px}.plan-grid{grid-template-columns:repeat(3,1fr)}.plan{padding:34px;border:1px solid var(--line);border-radius:24px;background:#fff}.plan.featured{border:2px solid var(--blue);position:relative;box-shadow:var(--shadow)}.plan.featured::before{content:'MOST POPULAR';position:absolute;right:20px;top:20px;font-size:10px;font-weight:900;color:var(--blue)}.price{font-size:42px;font-weight:900;letter-spacing:-.04em}.price small{font-size:13px;color:var(--muted)}.check-list{list-style:none;padding:0;display:grid;gap:11px;margin:25px 0}.check-list li::before{content:'✓';color:#0c9c71;font-weight:900;margin-right:9px}.form-shell{width:min(760px,calc(100% - 40px));margin:60px auto}.form-card{border:1px solid var(--line);border-radius:28px;padding:40px;box-shadow:var(--shadow)}.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}.field.full{grid-column:1/-1}.role-switch{display:grid;grid-template-columns:1fr 1fr;background:var(--soft);border-radius:12px;padding:5px;margin:20px 0}.role-switch button{border:0;background:transparent;padding:13px;border-radius:9px;font-weight:850;cursor:pointer}.role-switch button.active{background:#fff;color:var(--blue);box-shadow:0 4px 12px rgba(7,27,52,.08)}.dashboard{display:grid;grid-template-columns:240px 1fr;min-height:700px;background:var(--soft)}.dash-nav{background:var(--navy);color:#fff;padding:30px 20px}.dash-nav img{width:155px;margin-bottom:32px}.dash-nav a{display:block;padding:13px;border-radius:9px;color:#bcd1e9;margin:5px 0}.dash-nav a.active{background:var(--blue);color:#fff}.dash-main{padding:40px}.dash-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.dash-card{background:#fff;border:1px solid var(--line);padding:24px;border-radius:18px}.dash-card strong{font-size:28px}.modal-backdrop{position:fixed;inset:0;background:rgba(4,18,36,.72);backdrop-filter:blur(7px);z-index:100;display:grid;place-items:center;padding:20px}.modal-backdrop[hidden]{display:none}.modal{width:min(580px,100%);max-height:92vh;overflow:auto;background:#fff;border-radius:28px;padding:36px;position:relative}.modal-close{position:absolute;right:18px;top:16px;width:40px;height:40px;border-radius:50%;background:#fff;border:1px solid var(--line);font-size:25px;cursor:pointer}.modal h2{font-size:32px;margin:0 45px 8px 0}.modal .field{margin-top:14px}.toast{position:fixed;right:22px;bottom:22px;background:var(--navy);color:#fff;border-radius:10px;padding:14px 18px;z-index:120;opacity:0;transform:translateY(20px);pointer-events:none;transition:.2s}.toast.show{opacity:1;transform:none}.danger-link{color:var(--danger);border:0;background:none;cursor:pointer;font-weight:800}.notice{padding:16px;border-radius:12px;background:var(--warning);color:#78520b}.hidden{display:none!important}
body.dark{--ink:#eef5ff;--muted:#aec0d6;--line:#263c59;--paper:#0c1a2d;--soft:#101f33;--sky:#142f52;--shadow:0 22px 60px rgba(0,0,0,.3)}body.dark .brand img{filter:brightness(0) invert(1)}body.dark .teacher-card,body.dark .service-card,body.dark .subject-card,body.dark .plan,body.dark .panel,body.dark .profile-card,body.dark .form-card,body.dark .lesson-sidebar,body.dark .lesson-chat,body.dark .board{background:#0c1a2d}body.dark .board::before{opacity:.1}body.dark .modal{background:#0c1a2d}
@media(max-width:980px){.topbar{display:none}.nav-shell{height:72px}.brand{width:170px}.brand img{width:145px}.desktop-nav,.desktop-join{display:none}.mobile-menu-btn{display:block;border:1px solid var(--line);background:var(--paper);color:var(--ink);border-radius:8px;width:42px;height:42px;font-size:20px}.mobile-nav.open{display:flex;position:absolute;top:72px;left:0;right:0;background:var(--paper);padding:18px 22px;flex-direction:column;gap:4px;border-top:1px solid var(--line);box-shadow:var(--shadow)}.mobile-nav a{padding:12px;font-weight:800}.service-grid,.teacher-grid,.plan-grid{grid-template-columns:1fr 1fr}.subject-grid{grid-template-columns:repeat(2,1fr)}.steps{grid-template-columns:1fr 1fr}.study-layout{grid-template-columns:1fr}.lesson-sidebar{display:none}.lesson-chat{border:0}.board{min-height:420px}.profile-grid{grid-template-columns:1fr}.dashboard{grid-template-columns:1fr}.dash-nav{display:none}.dash-cards{grid-template-columns:1fr 1fr}}
@media(max-width:640px){.shell{width:min(100% - 28px,1180px)}.nav-actions{gap:8px}.text-btn{font-size:14px}.hero{min-height:auto;padding:270px 0 24px;background-position:63% center;align-items:end}.hero-card{padding:28px 22px;border-radius:28px}.hero h1,.page-hero h1{font-size:38px}.hero p,.page-hero p{font-size:16px}.hero-actions{display:grid}.hero-actions .button{width:100%}.trust-row{gap:8px 18px}.section{padding:62px 0}.section-heading{display:block}.service-grid,.teacher-grid,.plan-grid,.subject-grid,.steps{grid-template-columns:1fr}.split-cta{grid-template-columns:1fr}.split-cta>div:first-child{min-height:280px}.split-copy{padding:40px 25px}.split-copy h2{font-size:36px}.page-hero{padding:52px 0}.page-hero.compact h1{font-size:38px}.study-layout{display:flex;flex-direction:column}.board-wrap{padding:14px}.board-toolbar{align-items:flex-start;gap:8px}.board-content{padding:28px 22px}.board-content h2{font-size:29px}.equation{font-size:35px}.lesson-chat{min-height:500px}.profile-head{display:block}.profile-avatar{width:100%;height:260px}.profile-head h1{font-size:34px}.stat-list{gap:12px}.form-card{padding:28px 20px}.form-grid{grid-template-columns:1fr}.field.full{grid-column:auto}.dash-main{padding:25px 14px}.dash-cards{grid-template-columns:1fr}.modal{padding:30px 20px;border-radius:22px}.footer-grid{grid-template-columns:1fr!important}.footer-bottom{display:block!important}}
.site-footer{background:#06172c;color:#d9e6f6;padding:68px 0 24px}.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1.2fr;gap:50px}.footer-grid>div{display:flex;flex-direction:column;gap:10px}.footer-grid p{max-width:380px;color:#9eb3cc}.footer-grid strong{color:#fff;margin-bottom:8px}.footer-grid a:hover{color:#62a3ff}.footer-logo{width:190px}.footer-bottom{display:flex;justify-content:space-between;border-top:1px solid rgba(255,255,255,.13);padding-top:22px;margin-top:45px;color:#8fa6c1;font-size:13px}

/* Bright learning palette: playful enough for younger learners, structured for teens. */
:root{--sun:#ffb703;--coral:#ff6b6b;--violet:#7657e8;--green:#18a974;--aqua:#21b8c7}
.hero{min-height:640px;background-position:center;background-size:cover;background-repeat:no-repeat}
.hero-card{border:1px solid rgba(13,95,211,.09)}
.section-soft{background:linear-gradient(135deg,#f6f9ff 0%,#fff9ed 48%,#f2fbf7 100%)}
.service-card{transition:transform .2s ease,box-shadow .2s ease;border-top:5px solid var(--blue)}
.service-card:nth-child(3n+2){background:linear-gradient(145deg,#fff 55%,#fff6dc);border-top-color:var(--sun)}
.service-card:nth-child(3n+2)::after{background:#ffe8a7}.service-card:nth-child(3n+2) .service-icon{background:#fff0bf;color:#a86800}
.service-card:nth-child(3n+3){background:linear-gradient(145deg,#fff 55%,#eafaf4);border-top-color:var(--green)}
.service-card:nth-child(3n+3)::after{background:#c8f2e3}.service-card:nth-child(3n+3) .service-icon{background:#d9f7ed;color:#087b59}
.service-card:hover{transform:translateY(-5px);box-shadow:var(--shadow)}
.subject-card{--card-accent:var(--blue);--card-tint:#eef5ff;border-color:color-mix(in srgb,var(--card-accent) 24%,white);background:linear-gradient(135deg,#fff 42%,var(--card-tint));transition:transform .18s ease,box-shadow .18s ease}
.subject-card:nth-child(4n+2){--card-accent:var(--coral);--card-tint:#fff0ef}.subject-card:nth-child(4n+3){--card-accent:var(--green);--card-tint:#e9faf3}.subject-card:nth-child(4n+4){--card-accent:var(--violet);--card-tint:#f2efff}
.subject-card span:first-child{width:48px;height:48px;display:grid;place-items:center;border-radius:15px;background:var(--card-tint);box-shadow:inset 0 0 0 1px color-mix(in srgb,var(--card-accent) 18%,white)}
.subject-card:hover{transform:translateY(-4px) rotate(-.3deg);box-shadow:0 14px 30px color-mix(in srgb,var(--card-accent) 15%,transparent)}
.teacher-card:nth-child(3n+1){border-top:4px solid var(--blue)}.teacher-card:nth-child(3n+2){border-top:4px solid var(--sun)}.teacher-card:nth-child(3n+3){border-top:4px solid var(--green)}
.tag{background:linear-gradient(135deg,#eaf3ff,#f0edff)}
body.dark .service-card:nth-child(n),body.dark .subject-card:nth-child(n){background:var(--paper);border-color:var(--line)}
@media(max-width:640px){.hero{min-height:660px;padding:250px 0 18px;background-position:64% center}.hero-card{box-shadow:0 9px 0 rgba(13,95,211,.17)}}
/* Compact hero: 30% shorter with proportionally balanced content. */
@media(min-width:641px){.hero{height:484px;min-height:484px;padding:13px 0;background-position:center 20%}.hero-card{width:min(640px,100%);padding:27px 38px;border-radius:30px}.hero h1{font-size:clamp(38px,3.6vw,49px);margin:9px 0}.hero p{font-size:16px;line-height:1.48;margin:0}.hero-actions{margin:15px 0}.hero-actions .button{padding:12px 18px}.trust-row{padding-top:11px;gap:12px 20px;font-size:13px}}
@media(max-width:640px){.hero{min-height:auto;padding:190px 0 14px;background-position:63% center}.hero-card{padding:22px 20px;border-radius:24px}.hero h1{font-size:32px;margin:10px 0}.hero p{font-size:15px;line-height:1.48}.hero-actions{gap:8px;margin:16px 0}.hero-actions .button{padding:12px 16px}.trust-row{padding-top:12px;gap:6px 14px;font-size:12px}}

/* Color coded navigation icons make each learning route easier to scan. */
.desktop-nav a,.mobile-nav a{display:flex;align-items:center;gap:9px}
.desktop-nav{gap:12px}.desktop-nav a{font-size:12px;white-space:nowrap}.nav-shell{gap:24px}.nav-actions{gap:12px}.desktop-join{padding:12px 14px;font-size:13px;white-space:nowrap}
.text-btn{white-space:nowrap}
.nav-icon{width:27px;height:27px;flex:0 0 27px;display:inline-grid;place-items:center;border-radius:9px;color:#fff;font-size:13px;font-weight:950;box-shadow:0 5px 12px rgba(7,27,52,.13);transition:transform .22s ease,box-shadow .22s ease}
.icon-study{background:linear-gradient(135deg,#7657e8,#a06cff)}
.icon-teacher{background:linear-gradient(135deg,#12a979,#35d6a5)}
.icon-live{background:linear-gradient(135deg,#ff5964,#ff8a4c)}
.icon-plans{background:linear-gradient(135deg,#f2a900,#ffd34d);color:#573a00}
.desktop-nav a:hover .nav-icon,.desktop-nav a:focus-visible .nav-icon{animation:nav-icon-bob .58s ease;box-shadow:0 8px 18px rgba(13,95,211,.2)}
@keyframes nav-icon-bob{0%,100%{transform:translateY(0) rotate(0)}40%{transform:translateY(-4px) rotate(-5deg)}70%{transform:translateY(-1px) rotate(4deg)}}
@media(prefers-reduced-motion:reduce){.desktop-nav a:hover .nav-icon,.desktop-nav a:focus-visible .nav-icon{animation:none}}
@media(max-width:980px){.mobile-nav a{gap:12px}.mobile-nav .nav-icon{width:30px;height:30px;flex-basis:30px}}

/* Let the hero photograph show softly through the content panel. */
.hero-card{background:rgba(255,255,255,.88);-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}
body.dark .hero-card{background:rgba(12,26,45,.88)}

/* Guided study room: the board, question and conversation share one lesson state. */
.study-intro{background:linear-gradient(120deg,#edf5ff,#f8fbff 58%,#eefbf7);border-bottom:1px solid var(--line);padding:22px 0}
.study-intro-inner{display:flex;align-items:center;justify-content:space-between;gap:28px}
.study-intro h1{font-size:34px;line-height:1;margin:5px 0 7px;letter-spacing:-.035em}.study-intro p{margin:0;color:var(--muted)}
.study-context{display:flex;gap:10px}.study-context button{min-width:170px;text-align:left;border:1px solid var(--line);border-radius:13px;background:var(--paper);padding:10px 14px;color:var(--ink);cursor:pointer;box-shadow:0 7px 20px rgba(7,27,52,.06)}
.study-context button:hover{border-color:var(--blue)}.study-context span{display:block;color:var(--muted);font-size:10px;text-transform:uppercase;letter-spacing:.08em;font-weight:850}.study-context strong{display:block;color:var(--blue);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.study-layout{width:min(1600px,100%);margin:auto;display:grid;grid-template-columns:230px minmax(460px,1fr) 390px;align-items:start;background:var(--soft);min-height:760px}
.lesson-sidebar{padding:24px 18px;background:var(--paper);border-right:1px solid var(--line);position:sticky;top:134px;min-height:calc(100vh - 134px)}
.lesson-sidebar-title{display:block;margin-bottom:18px}.lesson-sidebar-title>strong{display:block;margin-top:2px;font-size:11px;color:var(--muted)}.lesson-kicker{font-size:16px;font-weight:900;color:var(--navy)}
.lesson-list{display:flex;flex-direction:column;gap:8px}.lesson-item{display:flex;align-items:center;gap:11px;padding:11px;border:1px solid transparent;border-radius:13px;color:var(--muted)}.lesson-item>span{width:30px;height:30px;display:grid;place-items:center;border-radius:50%;background:var(--soft);font-size:12px;font-weight:900}.lesson-item strong,.lesson-item small{display:block}.lesson-item strong{font-size:13px}.lesson-item small{font-size:10px;margin-top:1px}.lesson-item.active{background:var(--sky);border-color:#c9ddfb;color:var(--blue)}.lesson-item.active>span{background:var(--blue);color:#fff}.lesson-item.complete{color:#087a5b}.lesson-item.complete>span{background:#dff7ee;color:#087a5b}.lesson-item.complete>span::after{content:'✓'}.lesson-item.complete>span{font-size:0}.lesson-item.complete>span::after{font-size:13px}
.lesson-help{margin-top:22px;padding:15px;border-radius:14px;background:linear-gradient(135deg,#fff9e8,#fff);border:1px solid #f3dfaa}.lesson-help p{margin:5px 0 12px;font-size:11px;color:var(--muted)}.lesson-help .button{width:100%;padding:9px 10px;font-size:11px}
.board-wrap{padding:24px;min-width:0}.board-toolbar{display:flex;align-items:end;justify-content:space-between;gap:16px;margin-bottom:13px}.board-toolbar>div:first-child{display:flex;flex-direction:column}.board-toolbar strong{font-size:18px}.board-live{font-size:10px;color:#087a5b;text-transform:uppercase;letter-spacing:.08em;font-weight:900}.board-live i{display:inline-block;width:7px;height:7px;border-radius:50%;background:var(--mint);margin-right:5px}.board-actions{display:flex;gap:7px}.board-action{border:1px solid var(--line);background:var(--paper);color:var(--navy);padding:8px 11px;border-radius:9px;font-size:11px;font-weight:850;cursor:pointer}.board-action:hover{border-color:var(--blue);color:var(--blue)}
.board{position:relative;overflow:hidden;min-height:540px;border:1px solid var(--line);border-radius:22px;background:var(--paper);box-shadow:0 18px 48px rgba(7,27,52,.09)}.board::before{content:'';position:absolute;inset:0;background-image:linear-gradient(#e7eef8 1px,transparent 1px),linear-gradient(90deg,#e7eef8 1px,transparent 1px);background-size:28px 28px;opacity:.72}.board-content{position:relative;z-index:1;padding:34px 38px}.board-step{display:flex;align-items:center;justify-content:space-between;gap:16px}.board-step-count{font-size:11px;font-weight:850;color:var(--muted);background:var(--soft);border-radius:999px;padding:5px 9px}.board-content h2{max-width:760px;font-size:clamp(30px,3vw,42px);line-height:1.08;color:var(--blue);margin:14px 0}.board-content>p{max-width:760px;font-size:16px;color:#44566f}.equation{font-family:Georgia,serif;font-size:clamp(28px,3.5vw,46px);line-height:1.3;margin:22px 0;padding:18px;text-align:center;background:rgba(255,255,255,.82);border:1px solid #d9e5f5;border-radius:16px}.board-note{padding:13px 16px;border-left:5px solid var(--sun);border-radius:8px;background:#fff8d7;color:#59440a}.board-question{margin-top:18px;padding:14px 17px;border:2px solid var(--blue);border-radius:14px;background:#edf5ff}.board-question span,.board-question strong{display:block}.board-question span{font-size:10px;color:var(--blue);font-weight:900;text-transform:uppercase;letter-spacing:.09em;margin-bottom:4px}.board-question strong{font-size:16px}.board-empty{position:relative;z-index:1;min-height:540px;padding:35px;display:grid;align-content:center;justify-items:center;text-align:center}.board-empty[hidden]{display:none}.board-empty>span{font-size:46px;color:var(--blue)}.board-empty h2{margin:5px 0}.board-empty p{max-width:430px;color:var(--muted)}
.board-connection{display:flex;align-items:center;justify-content:center;gap:11px;margin-top:15px;color:var(--muted)}.board-connection>span{width:26px;height:26px;display:grid;place-items:center;border-radius:50%;background:var(--blue);color:#fff;font-size:11px;font-weight:900}.board-connection strong,.board-connection small{display:block}.board-connection strong{font-size:12px;color:var(--ink)}.board-connection small{font-size:10px}.board-connection>b{color:#8aa0bb;margin:0 8px}
.lesson-chat{height:calc(100vh - 286px);min-height:580px;max-height:680px;margin:16px 16px 16px 0;padding:0;overflow:hidden;position:sticky;top:142px;align-self:start;border:1px solid var(--line);border-radius:20px;background:var(--paper);box-shadow:0 18px 42px rgba(7,27,52,.11);display:flex;flex-direction:column}
.chat-heading{display:flex;align-items:flex-start;justify-content:space-between;gap:9px;padding:15px;border-bottom:1px solid var(--line);background:linear-gradient(135deg,#f8fbff,#edf5ff)}.chat-heading-main{display:flex;gap:9px;align-items:flex-start;min-width:0}.chat-heading h3{font-size:17px;line-height:1.15;margin:0}.chat-heading p{font-size:11px;color:var(--muted);margin:3px 0 0}.chat-status-dot{width:10px;height:10px;flex:0 0 10px;margin-top:5px;border-radius:50%;background:var(--mint);box-shadow:0 0 0 5px rgba(47,207,159,.14)}.chat-heading-actions{display:flex;gap:4px;flex-direction:column}.learner-level-btn,.change-subject-btn{border:1px solid #bfd4ef;background:#fff;color:var(--blue);border-radius:8px;padding:6px 8px;font-size:9px;font-weight:900;cursor:pointer;white-space:nowrap}.learner-level-btn{border-color:#b9e3d7;color:#087a5b;background:#effbf7}
.current-question{padding:13px 15px;background:#fff7d7;border-bottom:1px solid #ead58d}.current-question span,.current-question strong{display:block}.current-question span{font-size:9px;color:#8a6100;font-weight:950;text-transform:uppercase;letter-spacing:.1em}.current-question strong{font-size:14px;line-height:1.4;margin-top:3px;color:#3f3008}
.chat-messages{flex:1;min-height:120px;overflow-y:auto;overscroll-behavior:contain;scroll-behavior:smooth;padding:15px;display:flex;flex-direction:column;gap:11px;background:linear-gradient(#fff,#f7faff);scrollbar-color:#8bb5ef transparent;scrollbar-width:thin}.message{position:relative;max-width:94%;padding:12px 13px;border-radius:14px;font-size:13px;line-height:1.48;box-shadow:0 5px 14px rgba(7,27,52,.06)}.message.ai{align-self:flex-start;background:#eef3f9;border-bottom-left-radius:3px}.message.user{align-self:flex-end;margin-left:auto;background:var(--blue);color:#fff;border-bottom-right-radius:3px}.message-speaker,.message.user::before{display:block;font-size:9px;font-weight:950;text-transform:uppercase;letter-spacing:.1em;margin-bottom:4px}.message-speaker{color:var(--blue)}.message.user::before{content:'Your answer';color:#dceaff}.message-next{display:block;margin-top:8px;padding-top:8px;border-top:1px solid #cedaE8;font-weight:800;color:var(--navy)}.message-listen{margin-top:8px;border:0;background:transparent;color:var(--blue);padding:0;font-size:10px;font-weight:900;cursor:pointer}.thinking-dots{display:flex;gap:4px;padding:5px 0}.thinking-dots i{width:7px;height:7px;border-radius:50%;background:var(--blue);animation:study-thinking 1s infinite alternate}.thinking-dots i:nth-child(2){animation-delay:.2s}.thinking-dots i:nth-child(3){animation-delay:.4s}@keyframes study-thinking{to{opacity:.25;transform:translateY(-3px)}}
.reply-composer{flex:none;padding:12px 14px 14px;border-top:3px solid var(--blue);background:var(--paper);box-shadow:0 -10px 25px rgba(7,27,52,.08)}.reply-composer>label{display:block;font-size:14px;font-weight:950}.reply-prompt{font-size:10px;line-height:1.35;color:var(--muted);margin:2px 0 7px}.chat-form{display:grid;grid-template-columns:minmax(0,1fr) 94px;gap:6px;padding:5px;border:2px solid var(--blue);border-radius:13px;background:#f4f8ff;box-shadow:0 0 0 4px rgba(13,95,211,.09)}.chat-form:focus-within{box-shadow:0 0 0 5px rgba(13,95,211,.17)}.chat-form textarea{min-width:0;min-height:54px;max-height:105px;padding:7px;border:0;outline:0;resize:vertical;background:transparent;color:var(--ink);font-size:12px}.send-btn{border:0;border-radius:9px;background:var(--blue);color:#fff;font-size:11px;font-weight:900;cursor:pointer;display:flex;align-items:center;justify-content:center;gap:5px}.send-btn:disabled{opacity:.65;cursor:wait}.send-btn b{font-size:13px}.voice-bar{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-top:8px;padding:7px 9px;border-radius:10px;background:var(--navy);color:#fff}.voice-bar>button{width:30px;height:30px;flex:none;border:0;border-radius:50%;background:var(--blue);color:#fff;cursor:pointer}.voice-bar>button.listening{background:#d92d42;animation:voice-pulse 1s infinite}@keyframes voice-pulse{50%{box-shadow:0 0 0 7px rgba(217,45,66,.25)}}.voice-copy{min-width:100px;flex:1}.voice-copy strong{display:block;font-size:11px}.voice-status{font-size:9px;color:#bad0e8}.voice-choice{display:flex;flex-direction:column;color:#cfe0f3;font-size:8px;font-weight:800}.voice-choice select{width:125px;border:1px solid rgba(255,255,255,.25);border-radius:7px;background:#fff;color:var(--navy);padding:4px 5px;font-size:9px;outline:0}
.subject-picker{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:20px}.subject-picker button{display:flex;align-items:center;gap:12px;text-align:left;border:1px solid var(--line);background:var(--soft);color:var(--ink);border-radius:13px;padding:14px;cursor:pointer}.subject-picker button:hover{border-color:var(--blue);background:var(--sky);transform:translateY(-1px)}.subject-picker button span{font-size:23px}
body.dark .study-intro{background:linear-gradient(120deg,#10243e,#0d1d31)}body.dark .study-context button,body.dark .lesson-sidebar,body.dark .lesson-chat,body.dark .board,body.dark .reply-composer{background:var(--paper)}body.dark .chat-heading{background:#10243e}body.dark .chat-messages{background:var(--soft)}body.dark .chat-form{background:#14263d}body.dark .equation{background:rgba(7,27,52,.76)}body.dark .board-note{background:#4c3b08;color:#ffeeb0}body.dark .board-question{background:#102b50}body.dark .current-question{background:#493b12;border-color:#6c581a}body.dark .current-question strong{color:#fff2b8}body.dark .lesson-kicker,body.dark .board-action,body.dark .message-next{color:var(--ink)}
@media(max-width:1180px){.study-layout{grid-template-columns:205px minmax(0,1fr)}.lesson-chat{grid-column:1/-1;position:relative;top:auto;width:auto;height:650px;min-height:650px;max-height:650px;margin:18px;border-radius:20px}.lesson-sidebar{top:72px}.board{min-height:560px}.board-empty{min-height:560px}}
@media(max-width:760px){.study-intro{padding:18px 0}.study-intro-inner{display:block}.study-intro h1{font-size:29px}.study-intro p{font-size:13px}.study-context{margin-top:13px}.study-context button{min-width:0;flex:1;padding:8px 10px}.study-layout{display:flex;flex-direction:column}.lesson-sidebar{display:none}.board-wrap{order:1;width:100%;padding:14px}.board-toolbar{align-items:flex-start}.board-actions{flex-direction:column}.board-action{padding:7px 9px}.board{min-height:490px}.board-content{padding:27px 20px}.board-content h2{font-size:29px}.board-content>p{font-size:15px}.equation{font-size:29px;margin:25px 0;padding:17px 12px}.board-question strong{font-size:15px}.board-empty{min-height:490px}.board-connection{display:none}.lesson-chat{order:2;width:calc(100% - 28px);height:650px;min-height:650px;max-height:650px;margin:0 14px 18px}.chat-heading-actions{flex-direction:row}.chat-form{grid-template-columns:minmax(0,1fr) 88px}.voice-choice{width:100%;margin-left:38px}.voice-choice select{width:100%}}
@media(prefers-reduced-motion:reduce){.thinking-dots i,.voice-bar>button.listening{animation:none}}
/* Mobile home hero follows the Kachitech.net image-first composition. */
@media(max-width:640px){
  .hero{
    display:block;
    min-height:0;
    padding:238px 0 0;
    overflow:visible;
    background-color:#edf3fa;
    background-image:linear-gradient(180deg,rgba(7,27,52,.03),rgba(7,27,52,.13)),url('assets/student-hero.jpg');
    background-repeat:no-repeat;
    background-size:100% 238px,auto 238px;
    background-position:center top,58% top;
  }
  .hero>.shell{width:calc(100% - 28px);position:relative;z-index:1}
  .hero-card{
    width:100%;
    margin:0;
    padding:24px 20px 22px;
    border:1px solid rgba(255,255,255,.1);
    border-radius:28px;
    background:var(--navy);
    color:#fff;
    box-shadow:0 10px 0 rgba(13,95,211,.17);
    -webkit-backdrop-filter:none;
    backdrop-filter:none;
  }
  .hero .eyebrow{font-size:11px;color:#4f94f5}
  .hero h1{font-size:30px;line-height:1.08;letter-spacing:-.045em;margin:11px 0 12px}
  .hero p{margin:0;color:#c2d0e1;font-size:15px;line-height:1.52}
  .hero-actions{display:grid;grid-template-columns:1fr;gap:9px;margin:16px 0 12px}
  .hero-actions .button{width:100%;min-height:48px;padding:11px 14px}
  .hero .button-secondary{background:#fff;color:var(--blue)}
  .trust-row{padding-top:13px;gap:8px 14px;border-color:rgba(255,255,255,.25);color:#dce7f4;font-size:12px}
  body.dark .hero-card{background:var(--navy)}
}

.booking-honeypot{position:absolute!important;left:-10000px!important;width:1px!important;height:1px!important;opacity:0!important;pointer-events:none!important}

/* Mobile hand-off from the board to the answer area. */
.mobile-answer-jump{display:none}
@media(max-width:760px){
  .mobile-answer-jump{display:block;width:100%;margin-top:12px;padding:10px;border:0;border-radius:9px;background:var(--blue);color:#fff;font-weight:900;cursor:pointer}
}

.opening-voice{align-self:flex-start;border:1px solid rgba(146,91,0,.3);background:#fff;color:#744600;border-radius:999px;padding:9px 13px;font:800 12px/1 var(--font);cursor:pointer;box-shadow:0 5px 14px rgba(146,91,0,.1)}
.opening-voice:hover,.opening-voice:focus-visible{background:#fff5cf;border-color:#c78000;transform:translateY(-1px)}
body.dark .opening-voice{background:#17243a;color:#ffd974;border-color:#755a1d}
@media(max-width:700px){.opening-voice{width:100%;text-align:center;padding:11px 12px}}

.quick-replies{display:flex;flex-wrap:wrap;gap:7px;margin-top:4px}.quick-replies>span{flex-basis:100%;font-size:10px;font-weight:900;letter-spacing:.1em;text-transform:uppercase;color:#7a5a16}.quick-replies button{border:1px solid #edc55d;background:#fff9df;color:#493200;border-radius:10px;padding:9px 11px;font:800 12px/1.2 var(--font);cursor:pointer;text-align:left}.quick-replies button:hover,.quick-replies button:focus-visible{background:#ffeaa8;border-color:#ca9200;transform:translateY(-1px)}body.dark .quick-replies>span{color:#ffd974}body.dark .quick-replies button{background:#1c2a40;color:#fff1b9;border-color:#755a1d}@media(max-width:700px){.quick-replies button{flex:1 1 100%}}