/* ========================
   DESIGN TOKENS
   ======================== */
:root{
  --bg:#1b123f;
  --bg-2:#28185d;
  --bg-3:#211750;
  --panel:#2a1c61;
  --panel-2:#352475;
  --panel-3:#3e2a83;
  --text:#fbfaff;
  --muted:#c9c3e6;
  --muted-2:#aaa3cd;
  --line:rgba(255,255,255,.11);
  --gold:#ffd34d;
  --blue:#60bdff;
  --green:#70e4a8;
  --purple:#aa8cff;
  --orange:#ff9a38;
  --red:#ff6a7a;
  --shadow:0 20px 58px rgba(5,3,24,.28);
  --safe-bottom:env(safe-area-inset-bottom,0px);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  color:var(--text);
  font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif;
  background:
    radial-gradient(900px 650px at 50% -160px,#6943bd 0%,transparent 58%),
    radial-gradient(520px 420px at 108% 25%,#1b4a96 0%,transparent 58%),
    linear-gradient(180deg,var(--bg-2),var(--bg));
}
button,a,input,select{font:inherit}
a{color:inherit;text-decoration:none}
button{cursor:pointer;color:inherit}
img{max-width:100%}
[hidden]{display:none!important}
.container{width:min(100% - 28px,480px);margin-inline:auto}
main{overflow:hidden}

/* ========================
   HEADER
   ======================== */
.topbar{
  position:sticky;top:0;z-index:100;
  height:60px;
  background:rgba(20,13,55,.91);
  border-bottom:1px solid rgba(255,255,255,.07);
  backdrop-filter:blur(14px);
  -webkit-backdrop-filter:blur(14px);
}
.topbar-inner{height:100%;display:flex;align-items:center;justify-content:space-between;gap:10px}
.brand{display:flex;align-items:center}
.brand-logo{width:144px;height:auto;display:block}
.header-cta{
  flex:0 0 auto;
  padding:9px 12px;border-radius:999px;
  border:1px solid rgba(255,211,77,.43);
  background:rgba(255,211,77,.13);
  color:var(--gold);font-size:11px;font-weight:950;
}

/* ========================
   HERO
   ======================== */
.hero{padding:0 0 25px;text-align:center}
.hero-art{margin-inline:-14px;line-height:0;position:relative}
.hero-art:after{content:"";position:absolute;inset:auto 0 0;height:33%;background:linear-gradient(180deg,transparent,var(--bg-2))}
.hero-art img{display:block;width:100%;height:auto}
.hero-copy{position:relative;margin-top:-22px;text-align:left;padding-inline:2px}
.eyebrow{margin:0;color:var(--gold);font-size:10.5px;font-weight:900;letter-spacing:1.15px;text-transform:uppercase}
.hero h1{margin:9px 0 10px;font-size:31px;line-height:1.04;letter-spacing:-1.05px}
.hero h1 span{color:#94d2ff}
.hero h1 em{font-style:normal;color:#ffda71}
.hero-desc{margin:0;color:#e7e5f7;font-size:14px;line-height:1.55}
.hero-actions{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:17px}
.role-cta{
  min-height:64px;border-radius:18px;
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  padding:9px 7px;border:1px solid var(--line);
  box-shadow:0 14px 34px rgba(0,0,0,.17);
  transition:transform .15s ease,filter .15s ease;
}
.role-cta:active{transform:scale(.985)}
.role-cta strong{font-size:13.5px;letter-spacing:.08px}
.role-cta small{margin-top:4px;font-size:9.5px;opacity:.92}
.role-cta-student{background:linear-gradient(135deg,#267dff,#5bb9ff);border-color:rgba(148,210,255,.32);color:#fff}
.role-cta-teacher{background:linear-gradient(135deg,#f29a30,#ffc34f);border-color:rgba(255,226,137,.42);color:#4e2500}
.no-account{margin:12px 0 0;color:#d6d2e9;font-size:10.5px;line-height:1.45;display:flex;align-items:center;justify-content:center;gap:6px}
.no-account span{width:18px;height:18px;border-radius:50%;display:grid;place-items:center;background:rgba(112,228,168,.15);color:var(--green);font-weight:950}
.trust-strip{margin-top:13px;display:flex;flex-wrap:wrap;justify-content:center;gap:7px}
.trust-strip span{padding:7px 9px;border-radius:999px;background:rgba(255,255,255,.055);border:1px solid rgba(255,255,255,.075);color:var(--muted);font-size:9.5px;font-weight:700}

/* ========================
   ROLE GUIDE + DOCK
   ======================== */
.role-guide{padding:22px 0 8px;background:linear-gradient(180deg,rgba(255,255,255,.018),transparent)}
.role-guide p{margin:0;color:var(--muted);font-size:12px;line-height:1.55}
.role-guide strong{color:var(--text);font-size:13px}
.role-dock-wrap{position:relative;padding:8px 0;background:linear-gradient(180deg,rgba(27,18,63,.97),rgba(27,18,63,.88));border-block:1px solid rgba(255,255,255,.055)}
.role-dock{display:block}
.role-switch{display:grid;grid-template-columns:1fr 1fr;gap:4px;padding:4px;border-radius:14px;background:rgba(255,255,255,.06);border:1px solid var(--line);width:100%}
.role-tab{min-height:34px;border:0;border-radius:10px;background:transparent;color:var(--muted);font-size:11px;font-weight:950;display:flex;align-items:center;justify-content:center;gap:6px}
.role-tab span{width:8px;height:8px;border-radius:50%}
.role-tab.student span{background:#50a8ff}.role-tab.teacher span{background:#ff9a38}
.role-tab.active.student{color:#fff;background:rgba(80,168,255,.22);box-shadow:inset 0 0 0 1px rgba(96,189,255,.24)}
.role-tab.active.teacher{color:#ffd5ae;background:rgba(255,154,56,.18);box-shadow:inset 0 0 0 1px rgba(255,154,56,.24)}

/* Thanh chuyển vai trò rút gọn: chỉ hiện khi bộ chọn gốc đã cuộn khỏi màn hình */
.quick-role-bar{
  position:fixed;
  left:0;
  right:0;
  top:60px;
  z-index:90;
  padding:7px 0;
  background:linear-gradient(180deg,rgba(23,15,58,.98),rgba(27,18,63,.94));
  border-bottom:1px solid rgba(255,255,255,.08);
  box-shadow:0 13px 28px rgba(5,3,24,.24);
  backdrop-filter:blur(14px);
  -webkit-backdrop-filter:blur(14px);
  opacity:0;
  visibility:hidden;
  pointer-events:none;
  transform:translateY(calc(-100% - 3px));
  transition:transform .18s ease,opacity .18s ease,visibility .18s ease;
}
.quick-role-bar.is-visible{
  opacity:1;
  visibility:visible;
  pointer-events:auto;
  transform:translateY(0);
}
.quick-role-switch{
  min-height:42px;
  padding:4px;
  background:rgba(255,255,255,.065);
  box-shadow:0 7px 20px rgba(0,0,0,.12);
}
.quick-role-switch .role-tab{min-height:34px}
html{scroll-padding-top:116px}
.section[id],.role-guide[id]{scroll-margin-top:116px}

/* ========================
   SECTIONS
   ======================== */
.section{padding:34px 0 5px}
.section-head h2{margin:5px 0 8px;font-size:25px;line-height:1.16;letter-spacing:-.55px}
.section-desc{margin:0 0 16px;color:var(--muted);font-size:12.5px;line-height:1.55}
.benefits-section{background:linear-gradient(180deg,rgba(255,255,255,.015),transparent)}
.benefit-grid{display:grid;gap:10px}
.benefit-card{display:grid;grid-template-columns:48px 1fr;gap:12px;align-items:start;padding:14px;border-radius:18px;border:1px solid var(--line);background:linear-gradient(145deg,rgba(255,255,255,.085),rgba(255,255,255,.035));box-shadow:0 12px 30px rgba(0,0,0,.15)}
.benefit-icon{width:48px;height:48px;border-radius:16px;display:grid;place-items:center;background:rgba(255,211,77,.12);font-size:23px}
.benefit-card h3{margin:1px 0 4px;font-size:15px}.benefit-card p{margin:0;color:var(--muted);font-size:11.5px;line-height:1.48}

/* ========================
   THREE FEATURE ACCORDIONS
   ======================== */
.features-section{background:linear-gradient(180deg,transparent,rgba(42,28,97,.22),transparent)}
.feature-accordion-list{display:grid;gap:11px;margin-top:13px}
.feature-accordion{position:relative}
.mode-tab{width:100%;min-height:103px;padding:17px 17px;border-radius:23px;border:1px solid var(--line);display:grid;grid-template-columns:42px 1fr 22px;align-items:center;gap:10px;text-align:left;color:#fff;position:relative;z-index:2;overflow:hidden;box-shadow:var(--shadow);transition:transform .16s ease,filter .16s ease,border-color .16s ease,border-radius .16s ease}
.mode-tab:after{content:"";position:absolute;right:-34px;bottom:-62px;width:150px;height:150px;border-radius:50%;background:rgba(255,255,255,.08)}
.feature-accordion.open .mode-tab{transform:translateY(-1px);border-color:rgba(255,211,77,.43);filter:saturate(1.06) brightness(1.04);border-radius:23px 23px 15px 15px}
.mode-tab.arena{background:linear-gradient(135deg,#b55a14,#92296e)}
.mode-tab.practice{background:linear-gradient(135deg,#0a73b4,#2b45a4)}
.mode-tab.assignment{background:linear-gradient(135deg,#1f8054,#317449)}
.mode-icon{font-size:30px;position:relative;z-index:1}
.mode-copy{position:relative;z-index:1}
.mode-copy strong{display:block;font-size:18px;font-weight:950}
.mode-copy small{display:block;margin-top:6px;color:rgba(255,255,255,.84);font-size:11px;line-height:1.35}
.mode-arrow{position:relative;z-index:1;font-size:31px;opacity:.52;transition:transform .16s ease,opacity .16s ease}
.feature-accordion.open .mode-arrow{transform:rotate(90deg);opacity:1;color:var(--gold)}
.feature-detail{position:relative;z-index:1;margin:-7px 8px 0;padding:24px 17px 17px;border-radius:0 0 22px 22px;border:1px solid var(--line);border-top:0;background:linear-gradient(145deg,rgba(255,255,255,.095),rgba(255,255,255,.038));box-shadow:0 18px 48px rgba(5,3,24,.22);animation:featureExpand .18s ease}
@keyframes featureExpand{from{opacity:.15;transform:translateY(-5px)}to{opacity:1;transform:none}}
.feature-detail-head{display:grid;grid-template-columns:52px 1fr;gap:12px;align-items:start}
.feature-detail-icon{width:52px;height:52px;border-radius:18px;display:grid;place-items:center;font-size:27px;background:linear-gradient(135deg,rgba(96,189,255,.19),rgba(170,140,255,.16));border:1px solid rgba(96,189,255,.18)}
.feature-role{margin:0 0 3px!important;color:var(--gold)!important;font-size:9.5px!important;font-weight:900!important;letter-spacing:.9px!important}
.feature-detail h3{margin:0;font-size:19px}
.feature-detail-head p{margin:4px 0 0;color:var(--muted);font-size:11px;line-height:1.45}
.feature-list{list-style:none;margin:15px 0 0;padding:0;display:grid;gap:10px}
.feature-list li{position:relative;padding-left:29px;color:#f1eeff;font-size:12.5px;line-height:1.5}
.feature-list li:before{content:"✓";position:absolute;left:0;top:0;width:20px;height:20px;border-radius:50%;display:grid;place-items:center;background:rgba(112,228,168,.13);color:var(--green);font-size:11px;font-weight:950}
.feature-benefit{margin-top:14px;padding:11px 12px;border-radius:14px;border:1px solid rgba(96,189,255,.18);background:rgba(96,189,255,.09);color:#d8ecff;font-size:11.5px;line-height:1.52}
.feature-benefit b{color:var(--gold)}
.context-cta{margin-top:13px;min-height:45px;border-radius:14px;display:flex;align-items:center;justify-content:center;gap:7px;background:rgba(255,211,77,.13);border:1px solid rgba(255,211,77,.31);color:var(--gold);font-size:11.5px;font-weight:950}
.context-cta span{font-size:17px}

/* ========================
   EXPERIENCE: STUDENT DEMO
   ======================== */
.experience-section{padding-top:37px;background:linear-gradient(180deg,transparent,rgba(42,28,97,.34),transparent)}
.demo-app,.teacher-demo{width:100%;max-width:390px;margin:0 auto;border-radius:24px;border:1px solid var(--line);background:var(--panel);box-shadow:var(--shadow);overflow:hidden}
.demo-screen{display:none;min-height:520px;padding:16px 14px 18px;flex-direction:column}.demo-screen.active{display:flex}
.demo-top{text-align:center;margin-bottom:16px}.demo-brand{font-size:11px;font-weight:850;color:var(--gold);letter-spacing:.4px}
.demo-title{text-align:center;margin:0 0 4px;font-size:20px}.demo-sub{text-align:center;margin:0 0 22px;color:var(--muted);font-size:12px;line-height:1.45}
.class-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-bottom:16px}.class-btn{aspect-ratio:1;min-height:74px;border-radius:18px;border:1px solid var(--line);background:linear-gradient(145deg,rgba(255,255,255,.1),rgba(255,255,255,.03));color:var(--gold);font-size:31px;font-weight:950;box-shadow:var(--shadow)}.class-btn:active{transform:scale(.97);border-color:var(--gold)}
.demo-note{text-align:center;margin:0;color:var(--muted);font-size:10.5px;line-height:1.45}
.demo-hud{display:flex;align-items:center;justify-content:space-between;margin-bottom:12px}.hud-item{text-align:center;min-width:52px}.hud-label{display:block;color:var(--muted);font-size:9.5px;text-transform:uppercase;letter-spacing:.05em}.hud-value{font-size:20px;font-weight:900;color:var(--gold)}
.hud-timer{position:relative;width:58px;height:58px}.timer-svg{width:100%;height:100%;transform:rotate(-90deg)}.timer-bg{fill:none;stroke:rgba(255,255,255,.1);stroke-width:3}.timer-fg{fill:none;stroke:var(--gold);stroke-width:3;stroke-linecap:round;transition:stroke-dasharray .3s linear}.timer-text{position:absolute;inset:0;display:grid;place-items:center;font-size:16px;font-weight:900}
.question-card{flex:1;display:flex;flex-direction:column;justify-content:center;text-align:center;margin-bottom:12px;padding:16px 12px;border-radius:20px;border:1px solid rgba(170,140,255,.26);background:rgba(255,255,255,.05)}
.topic-pill{align-self:center;margin-bottom:10px;padding:4px 9px;border-radius:999px;background:rgba(255,211,77,.12);color:var(--gold);font-size:9.5px;font-weight:750}.question-text{margin-bottom:12px;font-size:28px;font-weight:900}.answer-input{width:100%;max-width:160px;margin:0 auto;padding:8px;border:2px solid rgba(255,211,77,.35);border-radius:12px;outline:0;background:rgba(12,8,34,.6);color:var(--text);font-size:26px;font-weight:900;text-align:center;caret-color:transparent}
.keypad{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}.key{height:49px;border-radius:14px;border:1px solid var(--line);background:rgba(255,255,255,.08);font-size:20px;font-weight:800}.key:active{background:rgba(255,255,255,.16);transform:scale(.97)}.key-empty{visibility:hidden}.key-del{font-size:18px}.key-ok{grid-column:span 3;height:53px;margin-top:2px;background:linear-gradient(135deg,#ffe066,#ffb631);color:#2f2244;font-weight:950}.demo-end{margin-top:8px;border:0;background:transparent;color:var(--muted);font-size:10.5px;text-decoration:underline;text-underline-offset:3px}
.question-card.correct{border-color:var(--green);box-shadow:0 0 0 2px rgba(112,228,168,.22)}.question-card.wrong{border-color:var(--red);box-shadow:0 0 0 2px rgba(255,106,122,.23);animation:shake .35s ease}@keyframes shake{25%{transform:translateX(-5px)}75%{transform:translateX(5px)}}
.result-screen{align-items:center;justify-content:center;text-align:center;gap:6px}.result-icon{font-size:45px}.result-title{margin:0;font-size:21px}.result-score{font-size:54px;font-weight:950;line-height:1;color:var(--gold)}.result-label{margin:0 0 14px;color:var(--muted);font-size:12px}.result-stats{display:flex;gap:21px;margin-bottom:24px}.result-stats div{text-align:center}.result-stats strong{display:block;font-size:20px}.result-stats span{color:var(--muted);font-size:10px}.result-actions{display:grid;gap:9px;width:100%;max-width:270px}
.button{min-height:47px;padding:10px 13px;border-radius:14px;border:1px solid var(--line);display:flex;align-items:center;justify-content:center;color:#fff;font-size:12px;font-weight:950}.button-primary{background:linear-gradient(135deg,#d8a92a,#f4c638);border-color:rgba(255,231,146,.48);color:#211513}.button-secondary{background:rgba(255,255,255,.07)}.button-full{width:100%}
.experience-note{max-width:390px;margin:12px auto 0;color:var(--muted);font-size:10.5px;line-height:1.48}.experience-note strong{color:#eeeaff}

/* ========================
   EXPERIENCE: TEACHER DEMO
   ======================== */
.teacher-demo{min-height:520px;padding:15px 14px 18px}
.teacher-progress{display:grid;grid-template-columns:auto 1fr auto 1fr auto;align-items:center;margin-bottom:18px}.teacher-progress>span{width:35px;height:35px;border-radius:50%;display:grid;place-items:center;background:rgba(255,255,255,.08);border:1px solid var(--line);color:var(--muted);font-size:11px;font-weight:950;position:relative}.teacher-progress>span span{position:absolute;top:40px;left:50%;transform:translateX(-50%);white-space:nowrap;font-size:8px;font-weight:700;color:var(--muted)}.teacher-progress>span.active{background:rgba(255,211,77,.14);color:var(--gold);border-color:rgba(255,211,77,.28)}.teacher-progress>i{height:1px;background:rgba(255,255,255,.12)}
.teacher-screen{display:none;padding-top:20px}.teacher-screen.active{display:block}.teacher-screen-title{margin-bottom:14px}.teacher-screen-title strong{display:block;font-size:16px}.teacher-screen-title small{display:block;margin-top:4px;color:var(--muted);font-size:10.5px;line-height:1.4}
.mock-form{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-bottom:14px}.mock-form label{display:grid;gap:5px;color:var(--muted);font-size:9.5px;font-weight:800}.mock-form select{width:100%;height:42px;padding:0 9px;border-radius:12px;border:1px solid var(--line);background:#21164f;color:#fff;outline:none;font-size:10.5px}
.review-toolbar{display:flex;align-items:center;justify-content:space-between;gap:8px;margin-bottom:10px}.review-toolbar button{padding:8px 9px;border-radius:10px;border:1px solid rgba(255,211,77,.28);background:rgba(255,211,77,.11);color:var(--gold);font-size:8.5px;font-weight:950}.review-toolbar span{color:var(--muted);font-size:9px;text-align:right}
.mock-questions{display:grid;gap:9px;margin-bottom:12px}.mock-question{padding:11px;border-radius:14px;border:1px solid var(--line);background:rgba(255,255,255,.045)}.mock-question-top{display:flex;justify-content:space-between;gap:8px}.mock-question-title{font-size:9px;color:var(--muted)}.mock-expression{margin-top:5px;font-size:17px;font-weight:900;outline:none;border-radius:6px}.mock-answer{margin-top:3px;color:#d7d2eb;font-size:10px;outline:none;border-radius:5px}.mock-question.editing .mock-expression,.mock-question.editing .mock-answer{background:rgba(255,211,77,.10);box-shadow:0 0 0 1px rgba(255,211,77,.23);padding:2px 4px}.mock-actions{display:flex;gap:6px}.mock-actions button{padding:6px 7px;border-radius:8px;border:1px solid var(--line);background:rgba(255,255,255,.07);font-size:8px;font-weight:900}.mock-actions button:first-child{color:var(--gold)}
.text-button{display:block;margin:9px auto 0;border:0;background:transparent;color:var(--muted);font-size:10px;text-decoration:underline;text-underline-offset:3px}.publish-icon{width:60px;height:60px;margin:15px auto 10px;border-radius:50%;display:grid;place-items:center;background:rgba(112,228,168,.15);color:var(--green);font-size:29px;font-weight:950}.teacher-screen[data-teacher-screen="2"]{text-align:center}.teacher-screen[data-teacher-screen="2"] h3{margin:0 0 7px;font-size:19px}.teacher-screen[data-teacher-screen="2"]>p{margin:0 0 13px;color:var(--muted);font-size:10.5px;line-height:1.45}.mock-link{display:flex;align-items:center;gap:7px;padding:8px 8px 8px 11px;margin-bottom:12px;border-radius:13px;background:rgba(255,255,255,.055);border:1px solid var(--line)}.mock-link span{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;color:#e7e3f5;font-size:9px}.mock-link button{margin-left:auto;padding:7px 8px;border-radius:9px;border:1px solid rgba(255,211,77,.28);background:rgba(255,211,77,.11);color:var(--gold);font-size:8px;font-weight:950}.publish-points{display:flex;flex-wrap:wrap;justify-content:center;gap:6px;margin-bottom:14px}.publish-points span{padding:7px 8px;border-radius:999px;background:rgba(255,255,255,.055);color:var(--muted);font-size:8.5px}

/* ========================
   HOW TO USE
   ======================== */
.steps{display:grid;gap:9px}.step{display:grid;grid-template-columns:38px 1fr;gap:11px;align-items:center;padding:12px;border-radius:16px;background:rgba(255,255,255,.05);border:1px solid rgba(255,255,255,.075)}.step-num{width:38px;height:38px;border-radius:14px;display:grid;place-items:center;background:rgba(255,211,77,.13);color:var(--gold);font-weight:950}.step h3{margin:0;font-size:12.5px}.step p{margin:3px 0 0;color:var(--muted);font-size:10.5px;line-height:1.45}

/* ========================
   GALLERY
   ======================== */
.gallery{display:flex;align-items:flex-start;gap:12px;overflow-x:auto;scroll-snap-type:x mandatory;overscroll-behavior-inline:contain;padding:2px 14px 12px 0;margin-right:-14px;scrollbar-width:none}.gallery::-webkit-scrollbar{display:none}.gallery-card{flex:0 0 78%;align-self:flex-start;scroll-snap-align:start;overflow:hidden;border-radius:19px;border:1px solid var(--line);background:linear-gradient(145deg,rgba(255,255,255,.085),rgba(255,255,255,.035));box-shadow:var(--shadow)}.gallery-media{display:block;width:100%;aspect-ratio:3/4;overflow:hidden;border:0;padding:0;margin:0;background:#140d35;cursor:zoom-in;touch-action:pan-x}.gallery-media img{display:block;width:100%;height:100%;object-fit:cover;object-position:top center}.gallery-meta{padding:10px 11px 12px}.gallery-meta h3{margin:0;font-size:12px;line-height:1.35}.gallery-meta p{margin:4px 0 0;color:var(--muted);font-size:10px;line-height:1.42}

/* ========================
   FAQ
   ======================== */
.faq-list{display:grid;gap:9px}.faq-list details{border:1px solid var(--line);border-radius:16px;background:rgba(255,255,255,.045);overflow:hidden}.faq-list summary{list-style:none;padding:14px 40px 14px 14px;position:relative;font-size:12px;font-weight:850;cursor:pointer}.faq-list summary::-webkit-details-marker{display:none}.faq-list summary:after{content:"+";position:absolute;right:14px;top:50%;transform:translateY(-50%);color:var(--gold);font-size:20px}.faq-list details[open] summary:after{content:"−"}.faq-list details p{margin:0;padding:0 14px 14px;color:var(--muted);font-size:10.5px;line-height:1.5}

/* ========================
   FINAL CTA + FOOTER
   ======================== */
.final-cta{padding:36px 0 31px}.final-box{padding:23px 17px;border-radius:24px;text-align:center;background:linear-gradient(135deg,#6240aa,#2948aa);border:1px solid rgba(255,255,255,.12);box-shadow:var(--shadow)}.final-box h2{margin:5px 0 7px;font-size:23px}.final-box>p{margin:0;color:#dfdaf5;font-size:11.5px;line-height:1.52}
.footer{padding:26px 0 calc(98px + var(--safe-bottom));border-top:1px solid rgba(255,255,255,.07);background:rgba(8,5,25,.24)}.footer-inner{text-align:center}.footer-brand{display:flex;align-items:center;justify-content:center}.footer-brand img{width:152px;height:auto}.footer-desc{max-width:360px;margin:12px auto;color:var(--muted);font-size:10.5px;line-height:1.52}.footer-links{display:flex;flex-wrap:wrap;justify-content:center;gap:14px;color:#d8d3ed;font-size:10.5px;font-weight:750}.copyright{margin:14px 0 0;color:#8f88b3;font-size:9.5px}

/* ========================
   ROLE-AWARE STICKY CTA
   ======================== */
.sticky-cta{position:fixed;left:0;right:0;bottom:0;z-index:110;padding:9px 14px calc(9px + var(--safe-bottom));background:rgba(17,11,43,.94);backdrop-filter:blur(14px);border-top:1px solid var(--line)}.sticky-cta a{width:min(100%,452px);margin:auto;min-height:47px;border-radius:15px;display:flex;align-items:center;justify-content:center;font-size:12.5px;font-weight:950}.sticky-cta.student a{background:linear-gradient(135deg,#267dff,#5bb9ff);color:#fff}.sticky-cta.teacher a{background:linear-gradient(135deg,#f29a30,#ffc34f);color:#4e2500}

@media (min-width:600px){
  body{padding:20px 0 calc(20px + 64px)}
  .topbar{width:100%;max-width:508px;margin:auto;border-radius:22px 22px 0 0}
  main,.footer{width:100%;max-width:508px;margin:auto}
  main{border-inline:1px solid rgba(255,255,255,.07);background:rgba(15,9,41,.12)}
  .footer{border-radius:0 0 26px 26px;border-inline:1px solid rgba(255,255,255,.07)}
  .sticky-cta{left:50%;right:auto;transform:translateX(-50%);width:508px;bottom:20px;border-radius:0 0 26px 26px}
  .quick-role-bar{
    left:50%;
    right:auto;
    width:508px;
    transform:translate(-50%,calc(-100% - 3px));
    border-inline:1px solid rgba(255,255,255,.07);
  }
  .quick-role-bar.is-visible{transform:translate(-50%,0)}
}
@media (prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;animation-duration:.01ms!important;transition-duration:.01ms!important}}

/* Final UX refinements */
.role-dock{display:block}
.role-switch{width:100%;min-width:0}
#screenSelect{min-height:360px}
#screenResult{min-height:430px}


/* ========================
   GALLERY FULL IMAGE VIEWER
   ======================== */
.image-viewer[hidden]{display:none!important}
.image-viewer{position:fixed;inset:0;z-index:300;display:flex;align-items:center;justify-content:center;padding:18px;background:rgba(5,3,22,.94);backdrop-filter:blur(10px)}
.image-viewer-inner{position:relative;width:min(100%,520px);height:min(94dvh,1000px);display:flex;align-items:center;justify-content:center}
.image-viewer img{display:block;max-width:100%;max-height:100%;width:auto;height:auto;object-fit:contain;border-radius:18px;box-shadow:0 24px 80px rgba(0,0,0,.5)}
.image-viewer-close{position:absolute;top:8px;right:8px;z-index:2;width:42px;height:42px;border-radius:50%;border:1px solid rgba(255,255,255,.18);background:rgba(18,12,45,.88);color:#fff;font-size:25px;line-height:1;display:grid;place-items:center;box-shadow:0 10px 28px rgba(0,0,0,.32)}
.image-viewer-caption{position:absolute;left:12px;right:60px;bottom:12px;margin:0;padding:9px 11px;border-radius:12px;background:rgba(18,12,45,.84);color:#fff;font-size:11px;line-height:1.4;backdrop-filter:blur(8px)}
body.viewer-open{overflow:hidden}