:root{--navy:#061d4a;--blue:#0758bb;--cyan:#16b4f5;--gold:#f4bc37;--gold2:#ffdf78;--white:#fff;--ink:#142c4c}*{box-sizing:border-box}body{margin:0;background:radial-gradient(circle at 30% 0%,#145fc3,#061e50 70%);font-family:Arial,Helvetica,sans-serif;color:#fff}button,select{font:inherit}button{cursor:pointer}button:disabled{cursor:not-allowed;opacity:.5}.app{min-height:100vh;display:flex;flex-direction:column;padding:12px;max-width:1900px;margin:auto}.topbar{display:flex;align-items:center;gap:16px;background:#061b46;border:1px solid #2873c8;box-shadow:0 3px 12px #0015;border-radius:11px;padding:7px 12px;min-height:65px}.brand img{height:46px;max-width:210px;object-fit:contain}.topbar nav{display:flex;flex:1;align-items:center;justify-content:center;gap:4px;flex-wrap:wrap}.nav{border:1px solid #3879bd;border-radius:8px;background:#103c7e;color:#fff;font-weight:bold;padding:10px 12px}.nav.active{background:linear-gradient(#ffe68c,#db9d1d);border-color:#f8d664;color:#092044}.top-status{display:flex;align-items:center;gap:8px;white-space:nowrap;font-size:12px}.top-meter{width:70px;height:9px;border:1px solid #8ac5ee;border-radius:9px;background:#092552;overflow:hidden}.top-meter i{display:block;width:0;height:100%;background:#f1c04b}.picker-bar{display:flex;align-items:center;gap:10px;flex-wrap:wrap;padding:11px 7px}.picker-bar label{font-weight:bold;color:#ffe38c}.picker-bar select{border:1px solid #efbd53;border-radius:8px;color:#fff;background:#0e448d;padding:9px}.picker-note{color:#d6e7ff;font-size:12px}.welcome{border:1px solid #d8ac4b;border-radius:12px;background:linear-gradient(110deg,#092d69,#0f4ca0);padding:10px 14px;margin-bottom:10px;display:flex;align-items:center;gap:13px}.welcome img{width:62px;height:62px;object-fit:cover;object-position:top;border:2px solid var(--gold);border-radius:50%}.welcome-copy{flex:1}.welcome strong{color:var(--gold2);font-size:18px}.welcome p{margin:4px 0 0;font-size:13px;line-height:1.4}.gold,.ava-actions button,#ask-ava{background:linear-gradient(#ffe783,#edae2a);border:1px solid #fff0a6;border-radius:8px;color:#142849;font-weight:800;padding:10px 14px;box-shadow:0 3px 0 #9f6614}.quiet{background:#164b94;border:1px solid #4a9bd9;border-radius:8px;color:white;padding:10px 14px}.tagline{display:block;font-weight:900;color:#ffe07b;letter-spacing:.05em}main{flex:1;min-height:0;display:flex}.view{width:100%;min-height:420px}.view[hidden]{display:none!important}.chrome{background:linear-gradient(155deg,#0e4d9e,#082d69);border:2px solid #0a9ded;border-radius:12px;overflow:hidden;box-shadow:0 8px 22px #0016}.lesson-grid{display:grid;grid-template-columns:minmax(180px,23%) minmax(0,1fr) minmax(215px,24%);gap:9px}.panel-title{padding:12px 14px;background:#071c49;border-bottom:1px solid #2a92e0;color:#fff;font-weight:800;display:flex;align-items:center;justify-content:space-between;gap:10px}.microtag{font-size:10px;letter-spacing:.08em;color:#ffe585}.notes-list{padding:10px;display:grid;gap:8px}.notes-list button,.contents-grid button{padding:12px;text-align:left;border:1px solid #478cdd;color:#fff;background:#164b91;border-radius:9px}.notes-list button.active{background:#f3bd3d;color:#092650;font-weight:bold}.note-tip{font-size:13px;padding:10px;color:#cbdfff}.lesson-inner{padding:16px;height:calc(100% - 50px);display:flex;flex-direction:column;gap:10px}.math-scene{flex:1;min-height:250px;background:#fff;color:#153153;border-radius:11px;display:grid;place-items:center;padding:25px}.math-visual{width:100%;text-align:center}.equation{font-size:clamp(32px,5vw,70px);font-weight:800;color:#0858ae}.visual-caption{font-size:20px;color:#25517d;margin-top:14px}.math-hint{padding:12px;border-radius:10px;background:#0b3878;color:#e5f4ff;font-size:14px}.step-list{padding:12px;display:grid;gap:9px}.step-list>div{border:1px solid #439bd6;background:#115197;border-radius:10px;padding:12px;line-height:1.4}.step-list b{color:#ffdf76}.whiteboard-layout{display:grid;grid-template-columns:minmax(180px,20%) minmax(0,1fr) 115px;gap:10px}.ava{padding:12px}.ava-profile{display:flex;gap:10px;align-items:center}.ava-profile img{width:74px;height:86px;object-fit:cover;object-position:top;border-radius:9px;border:2px solid var(--gold)}.ava-profile strong{font-size:24px;color:#ffe387}.ava-profile small{display:block;font-size:12px;color:#fff}.voice-note{line-height:1.45;font-size:13px}.ava-actions{display:grid;gap:8px;margin:16px 0}.ava-actions button{font-size:13px;padding:9px}.ava-footer{border-top:1px solid #48a5e5;padding-top:12px;font-size:12px}.ava-footer p{line-height:1.45}.board{position:relative;background:#fff;border-radius:10px;min-height:430px;color:#153156;padding:18px;overflow:hidden}.board-example{position:relative;z-index:1;pointer-events:none;max-width:90%;font-size:21px;font-weight:700}.board-example .step{padding:6px 8px;margin:8px 0;border-left:4px solid #e4ad24;background:#f5f9ff}.board-example .step:last-child{color:#0d6eb4}.board canvas{position:absolute;inset:0;width:100%;height:100%;z-index:2;touch-action:none}.board-feedback{position:absolute;bottom:4px;left:15px;z-index:3;background:#fff9e9;color:#23436d;font-size:12px;padding:4px}.tools{display:flex;flex-direction:column;gap:8px;padding:9px}.tools h3{font-size:14px;text-align:center;margin:4px}.tools button{background:#14559b;color:white;border:1px solid #58b3e9;border-radius:8px;padding:9px 3px;font-size:12px}.tools button.selected{background:#f5c04a;color:#10274a}.activity{background:#092c66;border:2px solid #10a3ec;border-radius:12px;display:flex;flex-direction:column;padding:17px 25px}.activity-top{display:flex;justify-content:space-between;align-items:center}.activity-top h2{margin:4px 0 14px;color:#ffe38c}.question-card{background:#fff;color:#12355b;border-radius:12px;border:3px solid #19a1ed;padding:25px;flex:1}.question-card h3{font-size:clamp(24px,3.5vw,42px);margin:12px 0 25px}.options{display:grid;grid-template-columns:1fr 1fr;gap:13px}.option{border:2px solid #83a9db;border-radius:10px;background:#edf5ff;padding:16px;text-align:left;font-size:19px;font-weight:700;color:#133966}.option.active{border-color:#dba632;background:#fff2c1}.feedback{margin-top:20px;padding:12px;border-radius:8px;background:#e6f2ff;color:#133c68}.feedback.correct{background:#dff9e9}.feedback.wrong{background:#fff0e4}.actions{display:flex;gap:12px;justify-content:space-between;margin-top:12px}.actions button{min-width:125px}.simple{padding:20px}.contents-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.simple h2{color:#ffe38c}.bottom{display:flex;justify-content:space-between;align-items:center;gap:10px;padding:10px 4px}.bottom-id{display:flex;gap:20px;align-items:center}.bottom-id span:last-child{color:#ffe38c}.bottom-controls{display:flex;gap:10px}.bottom button{padding:9px 14px}.voice-warning{color:#ffe292}.progress-tile{background:#124884;border:1px solid #36a9e8;padding:12px;border-radius:9px;margin:10px 0}.progress-tile strong{color:#ffe28d}@media(max-width:1000px){.topbar{flex-wrap:wrap}.topbar nav{order:3;flex-basis:100%}.top-status{margin-left:auto}.lesson-grid{grid-template-columns:190px minmax(0,1fr)}.steps{grid-column:1/-1}.whiteboard-layout{grid-template-columns:190px minmax(0,1fr)}.tools{grid-column:1/-1;flex-direction:row;flex-wrap:wrap}.tools h3{width:100%}.tools button{flex:1 0 75px}.board{min-height:460px}}@media(max-width:650px){.app{padding:6px}.topbar{gap:6px}.brand img{height:36px;max-width:150px}.nav{padding:8px;font-size:12px}.picker-bar{padding:8px 2px}.welcome{align-items:flex-start;padding:8px}.welcome img{width:46px;height:46px}.welcome p{font-size:12px}.welcome strong{font-size:15px}.lesson-grid,.whiteboard-layout{display:flex;flex-direction:column}.lesson-center{min-height:345px}.steps{min-height:120px}.math-scene{min-height:210px}.whiteboard-layout .board{min-height:400px;order:1}.whiteboard-layout .ava{order:2}.whiteboard-layout .tools{order:3}.ava-actions{grid-template-columns:1fr 1fr}.activity{padding:10px}.question-card{padding:15px}.options{grid-template-columns:1fr}.option{padding:12px}.contents-grid{grid-template-columns:1fr}.actions{gap:5px}.actions button{min-width:0;flex:1;padding:10px 3px;font-size:12px}.bottom{flex-wrap:wrap}.bottom-id{font-size:12px;gap:7px}.bottom-controls{margin-left:auto}}

.ava-written-work{position:relative;z-index:3;max-width:90%;pointer-events:none;font-size:clamp(18px,2.2vw,27px);line-height:1.4;font-weight:750;color:#135eaa;max-height:36vh;overflow:auto}.ava-written-work p{margin:7px 0;padding:6px 10px;background:#edf6ff;border-left:5px solid #e8ad2a;border-radius:5px}#voice-timer{display:block;color:#ffdf79;font-size:18px;margin-top:8px}#voice-timer[hidden]{display:none}#end-ava{margin:7px 0;background:#113b7a;color:white;border:1px solid #83b9ed;border-radius:6px;padding:7px 12px}#voice-status{font-weight:600}
/* Approved public entrance design - actual accessible HTML buttons, not an inert illustration. */
[hidden]{display:none!important}
.demo-intro{min-height:100vh;overflow:hidden;background:radial-gradient(ellipse at 50% 42%,#166ee2 0%,#073b9c 43%,#061f5d 72%,#040f31 100%);position:relative;color:#fff;font-family:Arial,Helvetica,sans-serif}
.demo-intro:before,.demo-intro:after{content:"";position:absolute;pointer-events:none;left:-10%;right:-10%;height:120px;border-top:9px solid #ffd362;border-radius:50%;box-shadow:0 -8px 22px #ffbc3e,0 -22px 26px #0078ff;transform:rotate(-5deg)}
.demo-intro:before{top:-106px}.demo-intro:after{bottom:-90px;transform:rotate(5deg)}
.intro-radiance{position:absolute;inset:0;background:repeating-linear-gradient(154deg,transparent 0 95px,#2e96ff0d 97px 98px,transparent 99px 150px);pointer-events:none}
.intro-shell{position:relative;isolation:isolate;max-width:1700px;min-height:min(920px,100vh);margin:auto;padding:22px 20px 35px;display:grid;grid-template-columns:24% minmax(0,1fr) 14%;grid-template-rows:1fr auto;align-items:center;gap:8px}
.intro-ava{align-self:stretch;display:flex;align-items:center;justify-content:flex-end;position:relative;min-height:560px;overflow:visible}
.intro-ava img{display:block;width:min(35vw,515px);max-width:none;aspect-ratio:1/1.45;object-fit:cover;object-position:54% center;filter:drop-shadow(8px 7px 18px #031540);border-radius:32% 32% 12% 12%;mask-image:linear-gradient(#000 0% 88%,transparent 100%);position:absolute;bottom:-10px;right:-20px}
.ava-nameplate{position:absolute;bottom:8%;left:0;border:2px solid #ffdb64;background:linear-gradient(110deg,#074ab4,#031b58);box-shadow:0 0 15px #ffc44e88;padding:7px 15px;border-radius:12px;font-size:24px;font-weight:900;color:#ffe272}.ava-nameplate span{display:block;font-size:9px;letter-spacing:.08em;color:white}
.intro-main{text-align:center;z-index:1;min-width:0}
.intro-welcome,.intro-choose h3{display:inline-block;background:linear-gradient(160deg,#ffeb91,#ffce4a 40%,#a8670e 100%);border:2px solid #ffeab1;border-radius:9px;box-shadow:0 4px 0 #764607,0 0 20px #ffc12988;padding:6px 30px;transform:skew(-5deg);font-size:clamp(21px,3vw,37px);line-height:1.1;font-weight:1000;color:#092354;text-shadow:0 1px #fff3a0}
.intro-main h1{margin:8px 0 0;font-size:clamp(37px,5.7vw,90px);line-height:.98;font-family:Georgia,'Times New Roman',serif;letter-spacing:-.04em;font-weight:900;background:linear-gradient(#fff7ce 0%,#ffd55a 23%,#fff4af 34%,#a56a16 58%,#fff3a0 82%,#ffb92e 100%);background-clip:text;color:transparent;-webkit-text-stroke:1px #ffe18a;filter:drop-shadow(3px 4px 2px #05132f)}
.intro-main h1 span{font-size:14px;vertical-align:top;letter-spacing:0}
.intro-main h2{font-size:clamp(17px,2.15vw,36px);font-weight:800;text-shadow:2px 3px 3px #02163c;margin:8px 0 16px;white-space:nowrap}.intro-main h2 em{color:#ffe073;font-family:Georgia,serif;font-size:1.17em}
.intro-quote{border:2px solid #f9c04d;background:linear-gradient(130deg,#092965 10%,#1453aa 50%,#092663 90%);box-shadow:0 0 19px #ffc65875,inset 0 0 12px #0181ff8a;border-radius:36px;padding:12px 18px;font-weight:650;line-height:1.35;font-size:clamp(13px,1.22vw,21px);text-shadow:0 1px 2px #001a4a}
.intro-motto{display:inline-block;background:linear-gradient(#fff2b3,#ffc63f 40%,#c17b16 76%,#ffdd68);border:3px solid #ffe68a;box-shadow:0 5px 0 #8a510b,0 0 26px #ffba27a8;border-radius:30px;color:#061c46;font-size:clamp(20px,2.4vw,38px);font-weight:1000;font-style:italic;text-shadow:1px 1px #fff4c4;margin:12px 0 18px;padding:8px 28px;line-height:1.1}
.intro-benefits{border:3px solid #ffe397;border-radius:30px;background:linear-gradient(125deg,#05317a,#031d5b 70%,#0a459b);box-shadow:0 0 22px #ffd36a9c,inset 0 0 16px #147dff69;display:grid;grid-template-columns:1fr 1fr;text-align:left;padding:16px 18px;gap:14px}
.intro-benefits ul{list-style:none;padding:0;margin:0;display:grid;gap:9px}.intro-benefits ul+ul{border-left:2px solid #ffd35a;padding-left:18px}.intro-benefits li{font-size:clamp(11px,1.18vw,18px);font-weight:800;line-height:1.3;display:flex;align-items:center;gap:10px;text-shadow:1px 2px #061b44;white-space:nowrap}.intro-benefits li:before{content:'✔';display:inline-grid;place-items:center;width:34px;height:34px;flex:0 0 34px;border-radius:50%;background:linear-gradient(#fff8b5,#ffbc24 56%,#c2750c);border:2px solid #ffefa7;box-shadow:0 2px 1px #915502,0 0 9px #ffd745a0;color:#061d43;font-size:20px;text-shadow:none}
.intro-books{align-self:start;margin-top:55px;display:grid;gap:3px;filter:drop-shadow(4px 5px 4px #001e55)}.intro-formula{border:1px solid #2fd2ff;background:#041f5b;border-radius:10px;color:#cdeaff;font:18px Georgia,serif;text-align:center;padding:16px 3px;margin-bottom:18px}.intro-book{border:2px solid #e9b44c;box-shadow:4px 4px 0 #503009,inset 4px 0 #ffce5d;background:linear-gradient(90deg,#031736,#0c285b 70%,#173766);border-radius:5px;color:#ffd56b;font:700 clamp(12px,1.3vw,19px) Georgia,serif;padding:11px 8px;text-align:center}
.intro-choose{grid-column:1/-1;text-align:center;z-index:2;margin-top:8px}.intro-choose h3{font-size:clamp(21px,2.8vw,42px);margin:0 0 18px;padding:7px 27px}.level-cards{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}.level-cards button{display:flex;gap:9px;align-items:center;justify-content:center;min-width:0;min-height:94px;border-radius:32px;border:4px solid #ffe58c;background:linear-gradient(#fffcdc 0%,#ffe7a0 27%,#ffd05a 46%,#ffa916 73%,#e39c10 100%);color:#041b49;text-shadow:0 1px #fff;box-shadow:0 5px 0 #804903,inset 0 0 0 2px #fff4c8,0 0 17px #ffdb6bb0;padding:10px 8px;font-size:clamp(15px,1.55vw,25px);font-weight:900;transition:transform .14s,filter .14s}.level-cards button:hover,.level-cards button:focus-visible{transform:translateY(-4px);filter:brightness(1.09);outline:3px solid #fff;outline-offset:2px}.level-cards small{display:block;font-size:.7em;margin-top:3px}.level-icon{font-size:clamp(22px,3vw,48px)}.level-arrow{margin-left:auto;font-size:16px}.intro-choose p{font-size:12px;color:#dbeaff;margin:16px 0 0}
.classroom-level-bar{display:flex;align-items:center;gap:16px;flex-wrap:wrap;padding:9px 3px}.classroom-level-bar strong{color:#fff}.classroom-level-bar span{margin-left:auto;color:#ffe079;font-weight:900}
@media(max-width:1150px){.intro-shell{grid-template-columns:22% minmax(0,1fr);padding:20px 14px}.intro-books{display:none}.intro-ava img{right:-24px;width:32vw}.intro-benefits li{white-space:normal}.intro-benefits li:before{width:27px;height:27px;flex-basis:27px;font-size:15px}.intro-main h2{white-space:normal}.level-cards button{border-radius:22px;min-height:80px}}
@media(max-width:730px){.intro-shell{display:flex;flex-direction:column;padding:16px 12px 22px;gap:6px}.intro-ava{min-height:0;height:190px;width:100%;order:0;justify-content:center;overflow:hidden}.intro-ava img{position:static;width:190px;height:220px;object-position:center 22%;mask-image:linear-gradient(#000 50%,transparent 100%);border-radius:30% 30% 0 0}.ava-nameplate{left:6px;bottom:10px;font-size:14px}.intro-main{order:1;width:100%}.intro-welcome{font-size:22px}.intro-main h1{font-size:clamp(37px,9vw,58px)}.intro-main h2{font-size:18px}.intro-quote{font-size:13px;padding:9px}.intro-quote br{display:none}.intro-motto{font-size:23px;margin:12px 0}.intro-benefits{padding:11px;gap:10px;border-radius:16px}.intro-benefits ul{gap:10px}.intro-benefits ul+ul{padding-left:9px}.intro-benefits li{font-size:11px;gap:5px;line-height:1.2}.intro-benefits li:before{width:20px;height:20px;flex-basis:20px;font-size:12px}.intro-choose{order:2;width:100%}.intro-choose h3{font-size:21px;margin:10px 0 14px}.level-cards{grid-template-columns:1fr 1fr;gap:11px}.level-cards button{min-height:70px;font-size:15px;padding:8px 5px;border-radius:16px;border-width:3px}.level-icon{font-size:24px}.level-arrow{font-size:10px}.intro-choose p{font-size:11px}.classroom-level-bar span{margin-left:0}}
@media(max-width:380px){.intro-benefits{grid-template-columns:1fr}.intro-benefits ul+ul{border:0;border-top:1px solid #ffdc75;padding:10px 0 0}.level-cards{gap:6px}.level-cards button{font-size:12px}.level-icon{font-size:18px}}

/* Compact, no-clipping welcome layout for Chromebooks with short browser viewports. */
@media (min-width:1100px) and (max-height:760px){
  .demo-intro{min-height:100dvh;overflow-x:hidden;overflow-y:auto}
  .intro-shell{min-height:100dvh;height:auto;grid-template-rows:minmax(0,1fr) auto;gap:4px;padding:8px 16px 12px;align-items:center}
  .intro-ava{min-height:0;height:100%;align-self:stretch}
  .intro-ava img{width:min(31vw,420px);height:calc(100dvh - 26px);aspect-ratio:auto;object-fit:cover;object-position:52% 20%;bottom:0;right:-14px}
  .ava-nameplate{bottom:4px}
  .intro-welcome{font-size:24px;padding:3px 24px}
  .intro-main h1{font-size:clamp(47px,4.1vw,62px);margin:5px 0 0;line-height:.93}
  .intro-main h2{font-size:clamp(18px,1.7vw,25px);margin:3px 0 7px}
  .intro-quote{font-size:clamp(12px,1.02vw,15px);line-height:1.2;padding:6px 10px;border-radius:20px}
  .intro-motto{font-size:clamp(19px,1.95vw,27px);margin:6px 0 8px;padding:4px 18px}
  .intro-benefits{padding:8px 10px;gap:9px;border-radius:20px;border-width:2px}
  .intro-benefits ul{gap:4px}.intro-benefits ul+ul{padding-left:10px}
  .intro-benefits li{font-size:clamp(11px,1.0vw,15px);line-height:1.14;gap:7px;white-space:normal}
  .intro-benefits li:before{width:23px;height:23px;flex:0 0 23px;font-size:14px}
  .intro-books{margin-top:16px;gap:2px}.intro-formula{padding:8px 2px;margin-bottom:9px;font-size:16px}.intro-book{padding:7px 5px}
  .intro-choose{margin-top:2px}.intro-choose h3{font-size:clamp(19px,2.0vw,29px);margin:0 0 6px;padding:3px 18px}
  .level-cards{gap:9px}.level-cards button{min-height:58px;border-width:3px;border-radius:19px;padding:4px 8px;font-size:clamp(14px,1.25vw,18px);box-shadow:0 3px 0 #804903,inset 0 0 0 2px #fff4c8,0 0 10px #ffdb6b88}
  .level-icon{font-size:clamp(21px,2.1vw,30px)}.intro-choose p{margin:7px 0 0;font-size:11px}
}
@media (min-width:1100px) and (max-height:610px){
  .intro-shell{padding:5px 13px 8px}.intro-welcome{font-size:20px}.intro-main h1{font-size:46px}.intro-main h2{font-size:19px}
  .intro-quote{font-size:12px;padding:4px 8px}.intro-motto{font-size:21px;margin:5px 0 6px}
  .intro-benefits{padding:5px 8px}.intro-benefits ul{gap:3px}.intro-benefits li{font-size:12px}.intro-benefits li:before{width:20px;height:20px;flex-basis:20px;font-size:12px}
  .intro-choose h3{font-size:21px}.level-cards button{min-height:51px}.intro-choose p{margin:5px 0 0}
}

/* v0.3.4: approved Chromebook welcome polish: readable type and unobstructed grade buttons */
.intro-logo-heading{margin:2px 0!important;background:none!important;filter:none!important;line-height:1!important}
.intro-brand-logo{display:block;width:min(100%,420px);height:auto;max-height:90px;object-fit:contain;margin:0 auto;filter:drop-shadow(1px 3px 3px #051844)}
.intro-choose{position:relative;z-index:12;isolation:isolate}
.level-cards{position:relative;z-index:13}
.level-cards button{position:relative;z-index:14}
/* Decorative curves must never cover the clickable grade cards. */
.demo-intro:after{display:none!important}
@media(min-width:1100px) and (max-height:780px){
 .demo-intro{overflow-x:hidden;overflow-y:auto;min-height:100dvh}
 .demo-intro:before{display:none!important}
 .intro-shell{min-height:100dvh;height:auto;padding:0 12px 7px;gap:0 8px;grid-template-columns:24% minmax(0,1fr) 14%;grid-template-rows:minmax(0,1fr) auto;align-items:start}
 .intro-ava{min-height:0;height:100%;align-self:stretch;overflow:hidden}
 .intro-ava img{height:100%;max-height:none;bottom:0;right:-7px;object-fit:cover;object-position:51% 15%;width:calc(100% + 30px);aspect-ratio:auto;mask-image:linear-gradient(#000 0% 90%,transparent 100%)}
 .ava-nameplate{bottom:9px;left:4px}
 .intro-main{padding-top:2px;align-self:start}
 .intro-welcome{font-size:24px;padding:3px 22px;margin:0;line-height:1.08}
 .intro-brand-logo{width:min(100%,350px);max-height:67px;margin:0 auto}
 .intro-main h2{font-size:clamp(20px,1.8vw,25px);margin:0 0 5px;line-height:1.12}
 .intro-quote{font-size:clamp(15px,1.18vw,18px);line-height:1.17;padding:6px 13px;border-radius:22px}
 .intro-motto{font-size:clamp(22px,2vw,27px);margin:6px 0 7px;padding:4px 19px}
 .intro-benefits{padding:8px 12px;gap:8px;border-radius:20px;border-width:2px}
 .intro-benefits ul{gap:4px}.intro-benefits ul+ul{padding-left:9px}
 .intro-benefits li{font-size:clamp(14px,1.14vw,18px);line-height:1.18;gap:7px;white-space:normal}
 .intro-benefits li:before{width:25px;height:25px;flex:0 0 25px;font-size:15px}
 .intro-books{margin-top:15px}.intro-formula{margin-bottom:7px}
 .intro-choose{margin-top:0;align-self:end}
 .intro-choose h3{font-size:clamp(19px,2vw,28px);margin:0 0 5px;padding:3px 18px}
 .level-cards{gap:8px}
 .level-cards button{min-height:59px;border-width:3px;border-radius:18px;padding:5px 9px;font-size:clamp(15px,1.28vw,19px);box-shadow:0 3px 0 #804903,inset 0 0 0 2px #fff4c8,0 0 10px #ffdb6b88}
 .level-icon{font-size:clamp(20px,2.0vw,29px)}
 .intro-choose p{margin:6px 0 0;font-size:10px}
}
@media(min-width:1100px) and (max-height:610px){
 .intro-shell{padding:0 12px 5px}
 .intro-welcome{font-size:21px;padding:2px 18px}
 .intro-brand-logo{max-height:56px;width:315px}
 .intro-main h2{font-size:20px;margin:0 0 4px}
 .intro-quote{font-size:15px;line-height:1.13;padding:5px 10px}
 .intro-motto{font-size:22px;margin:5px 0 6px;padding:3px 16px}
 .intro-benefits{padding:6px 10px}
 .intro-benefits ul{gap:3px}
 .intro-benefits li{font-size:14px;line-height:1.15;gap:6px}
 .intro-benefits li:before{width:23px;height:23px;flex:0 0 23px;font-size:14px}
 .intro-choose h3{font-size:20px;padding:2px 16px;margin-bottom:4px}
 .level-cards button{min-height:53px;padding:2px 8px;font-size:15px}
 .level-icon{font-size:22px}
 .intro-choose p{margin:3px 0 0}
}
@media(max-width:1099px){.intro-brand-logo{max-height:90px;width:min(100%,380px)}}
@media(max-width:730px){.intro-quote{font-size:15px;line-height:1.3}.intro-benefits li{font-size:13px;line-height:1.22}.intro-brand-logo{max-height:75px}}

/* v0.4.0: actual responsive HTML reconstruction of the approved gold reference.
   Priority at 1366 x 600: all four controls visible and readable, without art overlays. */
.intro-corner-brand{position:absolute;top:4px;left:14px;width:clamp(185px,22vw,330px);height:61px;z-index:8;display:flex;align-items:center}
.intro-corner-brand img{display:block;width:100%;height:100%;object-fit:contain;object-position:left center;filter:drop-shadow(0 2px 4px #001841)}
.intro-main .intro-title{font-family:Georgia,'Times New Roman',serif;font-weight:900;font-size:clamp(42px,4.65vw,78px);letter-spacing:-.045em;line-height:.98;white-space:nowrap;display:block;margin:3px 0 0;color:#ffd875;-webkit-text-stroke:.7px #fff2a8;background:linear-gradient(180deg,#fff8d2 0%,#ffe18a 22%,#d58b17 48%,#fff1a8 76%,#ca7d0a 100%);background-clip:text;-webkit-background-clip:text;-webkit-text-fill-color:transparent;filter:drop-shadow(2px 4px 2px #00102e)}
.intro-main .intro-title sup{-webkit-text-fill-color:#fff5c5;font:700 12px Arial,sans-serif;vertical-align:top;margin-left:2px}
/* The four grade buttons are genuine HTML controls, not part of a background image. */
@media (min-width:1100px){
  .demo-intro{min-height:100dvh;overflow:hidden}
  .demo-intro:before,.demo-intro:after{display:none!important}
  .intro-shell{max-width:1700px;width:100%;height:100dvh;min-height:600px;display:block;padding:0;position:relative;overflow:hidden}
  .intro-radiance{background:repeating-linear-gradient(160deg,transparent 0 150px,#168bff16 151px 153px,transparent 155px 260px)}
  .intro-ava{position:absolute;left:0;top:64px;bottom:70px;width:28.8%;height:auto;min-height:0;overflow:hidden;display:block;z-index:2;align-self:auto;background:radial-gradient(ellipse at 30% 45%,#0a60c5a0,transparent 70%)}
  .intro-ava img{position:absolute;top:0;bottom:auto;right:-3%;width:110%;height:100%;max-height:none;aspect-ratio:auto;object-fit:cover;object-position:54% 30%;border-radius:0;mask-image:linear-gradient(90deg,#000 0% 83%,#0000 100%);filter:drop-shadow(5px 3px 9px #041337)}
  .ava-nameplate{left:12px;bottom:8px;padding:5px 12px;font-size:22px;z-index:3}
  .intro-main{position:absolute;left:27.7%;right:14.5%;top:7px;width:auto;display:block;z-index:3;text-align:center;padding:0}
  .intro-welcome{font-size:clamp(24px,2.35vw,37px);padding:5px 22px;line-height:1.08;margin:0;transform:skew(-4deg)}
  .intro-main h2{font-size:clamp(20px,1.85vw,32px);margin:3px 0 9px;line-height:1.15;white-space:nowrap}
  .intro-quote{font-size:clamp(15px,1.33vw,22px);line-height:1.24;padding:8px 15px;border-radius:24px;font-weight:750;min-height:0}
  .intro-motto{font-size:clamp(22px,2.27vw,36px);margin:8px 0 12px;padding:5px 22px;border-radius:22px;line-height:1.06}
  .intro-benefits{position:relative;left:0;width:calc((100vw - 40px) * .715);max-width:1160px;padding:10px 12px;gap:10px;border:3px solid #ffe18f;border-radius:23px;grid-template-columns:1fr 1fr}
  .intro-benefits ul{gap:5px;min-width:0}
  .intro-benefits ul+ul{padding-left:13px}
  .intro-benefits li{font-size:clamp(15px,1.24vw,22px);line-height:1.13;gap:9px;white-space:nowrap;font-weight:850;letter-spacing:-.025em}
  .intro-benefits li:before{width:28px;height:28px;flex:0 0 28px;font-size:18px}
  .intro-books{position:absolute;right:12px;top:27px;width:13.2%;margin:0;display:grid;gap:4px;z-index:4;align-self:auto}
  .intro-formula{font-size:clamp(13px,1.25vw,19px);padding:8px 2px;margin-bottom:8px}
  .intro-book{font-size:clamp(14px,1.5vw,21px);padding:8px 2px}
  .intro-choose{position:absolute;left:10px;right:10px;bottom:5px;z-index:12;width:auto;margin:0;grid-column:auto}
  .intro-choose h3{font-size:clamp(21px,2.5vw,37px);padding:4px 25px;margin:0 0 9px;line-height:1.08}
  .level-cards{gap:10px;grid-template-columns:repeat(4,minmax(0,1fr))}
  .level-cards button{min-height:64px;padding:4px 8px;border-radius:24px;border-width:3px;font-size:clamp(17px,1.55vw,25px);line-height:1.05;box-shadow:0 4px 0 #805008,inset 0 0 0 2px #fff5c2,0 0 14px #ffc7368a}
  .level-cards small{margin-top:3px;font-size:.7em}
  .level-icon{font-size:clamp(25px,2.7vw,40px)}
  .level-arrow{font-size:18px}
  .intro-choose p{display:none}
}
@media(min-width:1100px) and (max-height:760px){
  .intro-shell{height:100dvh;min-height:570px;padding:0}
  .intro-main{top:2px}
  .intro-welcome{font-size:27px;padding:3px 22px}
  .intro-main .intro-title{font-size:clamp(48px,4.25vw,66px);margin:2px 0 0}
  .intro-main h2{font-size:clamp(19px,1.65vw,25px);margin:1px 0 5px}
  .intro-quote{font-size:clamp(15px,1.15vw,18px);line-height:1.17;padding:6px 9px}
  .intro-motto{font-size:clamp(22px,2.15vw,30px);margin:5px 0 8px;padding:3px 22px}
  .intro-benefits{padding:8px 12px;gap:9px}
  .intro-benefits ul{gap:4px}
  .intro-benefits li{font-size:clamp(15px,1.13vw,17px);line-height:1.12;gap:7px}
  .intro-benefits li:before{width:26px;height:26px;flex:0 0 26px;font-size:17px}
  .intro-choose h3{font-size:clamp(22px,2.25vw,30px);padding:3px 22px;margin-bottom:6px}
  .level-cards button{min-height:57px;font-size:clamp(16px,1.38vw,20px);padding:3px 8px}
  .level-icon{font-size:28px}
  .intro-books{top:20px}
}
@media(min-width:1100px) and (max-height:620px){
  .intro-welcome{font-size:24px}
  .intro-main .intro-title{font-size:clamp(43px,3.9vw,56px)}
  .intro-main h2{font-size:20px}
  .intro-quote{font-size:15px;line-height:1.14;padding:5px 8px}
  .intro-motto{font-size:23px;margin:5px 0 7px;padding:3px 15px}
  .intro-benefits{padding:7px 9px}
  .intro-benefits ul{gap:3px}
  .intro-benefits li{font-size:15px;line-height:1.1}
  .intro-benefits li:before{width:25px;height:25px;flex:0 0 25px;font-size:16px}
  .intro-choose h3{font-size:22px;margin-bottom:6px}
  .level-cards button{min-height:54px}
  .intro-ava{top:54px;bottom:60px}
}
@media(max-width:1099px){
  .intro-corner-brand{position:relative;top:auto;left:auto;display:block;width:min(300px,80%);height:58px;margin:0 auto 4px}
  .intro-main .intro-title{font-size:clamp(32px,5vw,55px)}
  .intro-shell{height:auto;min-height:100dvh}
}
@media(max-width:730px){
 .intro-corner-brand{height:52px}
 .intro-main .intro-title{font-size:clamp(31px,8vw,45px);letter-spacing:-.055em}
 .intro-main h2{white-space:normal}
 .intro-benefits li{font-size:13px}
 .intro-choose p{display:block}
}
/* Final reference-alignment tuning: legible selling points on a 1366px Chromebook. */
@media(min-width:1100px) and (max-height:620px){
 .intro-corner-brand{width:360px;height:65px}
 .intro-main{left:26.4%;right:14%}
 .intro-welcome{font-size:27px;padding:4px 24px}
 .intro-main .intro-title{font-size:62px;letter-spacing:-.05em;margin:1px 0 0}
 .intro-main h2{font-size:23px;margin:3px 0 6px}
 .intro-quote{font-size:16px;line-height:1.17;padding:7px 8px}
 .intro-motto{font-size:26px;margin:7px 0 9px;padding:4px 20px}
 .intro-benefits{width:calc((100vw - 30px) * .725);padding:10px 12px}
 .intro-benefits ul{gap:5px}
 .intro-benefits li{font-size:16px;gap:8px;line-height:1.15;letter-spacing:-.032em}
 .intro-benefits li:before{width:27px;height:27px;flex:0 0 27px;font-size:17px}
 .intro-books{top:14px}
 .intro-books .intro-formula{padding:7px 1px;margin-bottom:5px;font-size:15px}
 .intro-books .intro-book{padding:5px 1px;font-size:16px}
}