/* DT Classroom accounts: header chip, join / sign-in dialog, avatar customiser. Self-contained, prefixed .dtu-
   Look: dark navy panels, warm amber accents (same family as the Revision films). */
.dtu-chip,.dtu-overlay,.dtu-menu,.dtu-toast{--dtu-navy:#0f1a33;--dtu-panel:#172646;--dtu-panel2:#1e3059;--dtu-line:#2d4272;--dtu-text:#eaf2fb;--dtu-mute:#a9b9d6;--dtu-amber:#ffb703;--dtu-orange:#ff7a3d;--dtu-red:#ff7b7b}
.dtu-chip{display:inline-flex;align-items:center;gap:8px;font:600 13px/1.1 system-ui,-apple-system,Segoe UI,sans-serif;color:#eaf2fb;background:rgba(255,255,255,.08);border:1px solid rgba(255,255,255,.22);border-radius:999px;padding:3px 14px 3px 3px;cursor:pointer;min-height:40px;white-space:nowrap;flex:none;text-align:left}
.dtu-chip.dtu-light{color:#16202e;background:#fff;border-color:#d6cfbf}.dtu-chip.dtu-light:hover{background:#f3efe6}
.dtu-chip.dtu-inline{margin-left:8px}
.dtu-chip:hover{background:rgba(255,255,255,.16)}
.dtu-chip:focus-visible,.dtu-btn:focus-visible,.dtu-opt:focus-visible,.dtu-sw:focus-visible,.dtu-x:focus-visible,.dtu-menu button:focus-visible,.dtu-menu a:focus-visible,.dtu-tabs button:focus-visible,.dtu-overlay a:focus-visible,.dtu-overlay input:focus-visible{outline:3px solid #ffb703;outline-offset:2px}
.dtu-float{position:fixed;top:10px;right:10px;z-index:900;background:#14243b;box-shadow:0 4px 14px rgba(0,0,0,.3)}
.dtu-ava{position:relative;width:34px;height:34px;border-radius:50%;display:inline-flex;align-items:center;justify-content:center;flex:none;background:#1b2a4a}
.dtu-ava svg{display:block;border-radius:50%}
.dtu-badge{position:absolute;right:-4px;bottom:-4px;min-width:16px;height:16px;padding:0 3px;box-sizing:border-box;border-radius:9px;background:#ffb703;color:#1a1200;font:800 10px/16px system-ui,sans-serif;text-align:center;border:2px solid #0f1a33;box-sizing:content-box;min-width:12px;height:12px;line-height:12px}
.dtu-chip.dtu-light .dtu-badge{border-color:#fff}
.dtu-who{display:flex;flex-direction:column;gap:2px;min-width:0}
.dtu-name{max-width:120px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:13px}
.dtu-lvl{font-size:11px;font-weight:700;white-space:nowrap}
.dtu-chip.dtu-light .dtu-lvl{color:#b25a00}
.dtu-chip:not(.dtu-light) .dtu-lvl{color:#ffcf70}
.dtu-menu{position:fixed;z-index:1000;min-width:250px;background:var(--dtu-navy);color:var(--dtu-text);border:1px solid var(--dtu-line);border-radius:14px;box-shadow:0 14px 40px rgba(0,0,0,.5);padding:8px;font:500 14px system-ui,sans-serif}
.dtu-menu-head{display:flex;gap:12px;align-items:center;padding:6px 8px 12px;border-bottom:1px solid var(--dtu-line);margin-bottom:6px}
.dtu-menu-head svg{border-radius:50%;flex:none}
.dtu-menu-head small{display:block;color:var(--dtu-mute);font-weight:500;font-size:12px}
.dtu-menu-head small:first-of-type{color:#ffcf70;font-weight:700}
.dtu-menu button,.dtu-menu a{display:block;width:100%;text-align:left;background:none;border:0;padding:10px 10px;border-radius:8px;font:inherit;color:inherit;cursor:pointer;text-decoration:none;box-sizing:border-box}
.dtu-menu button:hover,.dtu-menu a:hover{background:var(--dtu-panel2)}
.dtu-menu .dtu-danger{color:var(--dtu-red)}
.dtu-overlay{position:fixed;inset:0;z-index:1100;background:rgba(6,11,24,.78);display:flex;align-items:center;justify-content:center;padding:14px;font:15px/1.45 system-ui,-apple-system,Segoe UI,sans-serif}
.dtu-card{background:var(--dtu-navy);color:var(--dtu-text);width:min(440px,100%);max-height:calc(100vh - 28px);max-height:calc(100dvh - 28px);overflow:auto;border-radius:18px;border:1px solid var(--dtu-line);box-shadow:0 24px 70px rgba(0,0,0,.6)}
.dtu-card.dtu-wide{width:min(900px,100%)}
.dtu-head{display:flex;justify-content:space-between;align-items:center;padding:16px 20px 6px}
.dtu-head h2{margin:0;font-size:21px;letter-spacing:.2px;color:var(--dtu-text)}
.dtu-x{background:none;border:0;font-size:18px;cursor:pointer;color:var(--dtu-mute);padding:8px 10px;border-radius:8px}
.dtu-x:hover{background:var(--dtu-panel2);color:#fff}
.dtu-body{padding:6px 20px 20px}
.dtu-body p{margin:.6em 0}
.dtu-tabs{display:flex;gap:6px;margin:6px 0 12px}
.dtu-tabs button{flex:1;padding:10px 8px;border-radius:10px;border:1px solid var(--dtu-line);background:var(--dtu-panel);font:600 14px system-ui,sans-serif;cursor:pointer;color:var(--dtu-text);min-height:42px}
.dtu-tabs button:hover{background:var(--dtu-panel2)}
.dtu-tabs button[aria-selected=true]{background:var(--dtu-amber);color:#1a1200;border-color:var(--dtu-amber)}
.dtu-form label{display:block;font-weight:600;font-size:13px;margin:12px 0 0;color:var(--dtu-mute)}
.dtu-form input{display:block;width:100%;box-sizing:border-box;margin-top:5px;padding:12px;font:16px system-ui,sans-serif;border:1.5px solid var(--dtu-line);border-radius:10px;color:var(--dtu-text);background:var(--dtu-panel)}
.dtu-form input::placeholder{color:#7487ad}
.dtu-form input:focus{border-color:var(--dtu-amber)}
.dtu-note{font-size:13px;color:#ffe3a3;background:rgba(255,183,3,.1);border:1px solid rgba(255,183,3,.3);border-radius:10px;padding:9px 11px;margin:12px 0 0}
.dtu-fieldhint{display:block;font-size:11.5px;color:var(--dtu-mute);margin:4px 2px 0}
.dtu-test{font-size:13px;color:#ffd0b8;background:rgba(255,122,61,.12);border:1px solid rgba(255,122,61,.45);border-radius:10px;padding:8px 11px;margin:0 0 6px}
.dtu-err{color:var(--dtu-red);font-weight:600;min-height:1.3em;margin:8px 0 0}
.dtu-hint{color:var(--dtu-mute);min-height:1.3em;margin:6px 0 0;font-size:13px}
.dtu-btn{margin-top:8px;padding:12px 20px;border-radius:10px;border:0;background:var(--dtu-amber);color:#1a1200;font:800 15px system-ui,sans-serif;cursor:pointer;min-height:44px}
.dtu-btn:hover{filter:brightness(1.08)}
.dtu-btn:disabled{opacity:.6;cursor:wait}
.dtu-btn-ghost{background:var(--dtu-panel2);color:var(--dtu-text);border:1px solid var(--dtu-line);font-weight:700}
.dtu-btn-danger{background:#e0463d;color:#fff}
.dtu-actions{display:flex;gap:8px;flex-wrap:wrap}
.dtu-foot{font-size:12.5px;color:var(--dtu-mute);margin:14px 0 0}
.dtu-foot a,.dtu-body a{color:#ffcf70}
.dtu-builder{display:flex;gap:20px;align-items:flex-start}
.dtu-side{flex:none;width:210px;text-align:center}
.dtu-preview{width:200px;height:200px;margin:0 auto;border-radius:20px;overflow:hidden;box-shadow:0 10px 26px rgba(0,0,0,.45);line-height:0}
.dtu-preview svg{display:block}
.dtu-sizes{display:flex;gap:10px;justify-content:center;align-items:flex-end;margin-top:12px}
.dtu-sizes span{display:block;line-height:0;border-radius:50%;overflow:hidden}
.dtu-lv{margin:12px 0 0;font-size:13px;color:var(--dtu-text);line-height:1.35}
.dtu-lv small{color:var(--dtu-mute)}
.dtu-side-actions{justify-content:center}
.dtu-main{flex:1;min-width:0}
.dtu-ctabs{margin-top:0}
.dtu-ctabs button{padding:9px 4px;font-size:13.5px}
.dtu-opts{max-height:min(54vh,440px);overflow:auto;padding:2px 4px 2px 0;scrollbar-color:var(--dtu-line) transparent}
.dtu-row{margin-bottom:14px}
.dtu-rl{display:block;font-weight:800;font-size:11.5px;text-transform:uppercase;letter-spacing:.07em;color:var(--dtu-mute);margin-bottom:6px}
.dtu-grid{display:flex;flex-wrap:wrap;gap:6px}
.dtu-parts{display:grid;grid-template-columns:repeat(auto-fill,minmax(74px,1fr));gap:8px}
.dtu-opt{position:relative;display:flex;flex-direction:column;align-items:center;gap:3px;padding:5px 3px 6px;border-radius:12px;border:2px solid var(--dtu-line);background:var(--dtu-panel);font:600 11.5px/1.15 system-ui,sans-serif;cursor:pointer;color:var(--dtu-text);min-height:44px}
.dtu-opt:hover{background:var(--dtu-panel2)}
.dtu-opt[aria-pressed=true]{border-color:var(--dtu-amber);background:#2a3d6b;box-shadow:0 0 0 1px var(--dtu-amber)}
.dtu-th{display:block;line-height:0;border-radius:50%;overflow:hidden;width:52px;height:52px}
.dtu-on{display:block;text-align:center;max-width:100%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;color:var(--dtu-mute)}
.dtu-opt[aria-pressed=true] .dtu-on{color:#fff}
.dtu-sw{position:relative;width:34px;height:34px;border-radius:50%;border:2px solid #0f1a33;box-shadow:0 0 0 1.5px var(--dtu-line);cursor:pointer;padding:0}
.dtu-sw[aria-pressed=true]{box-shadow:0 0 0 3px var(--dtu-amber)}
.dtu-locked{opacity:.5;cursor:not-allowed}
.dtu-opt.dtu-locked .dtu-th{filter:grayscale(.85) brightness(.75)}
.dtu-opt i{position:absolute;top:3px;right:4px;font-size:12px;font-style:normal}
.dtu-sw i{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;font-size:13px;font-style:normal;background:rgba(15,26,51,.5);border-radius:50%}
.dtu-opt[data-rarity]:not([data-rarity=common])::before{content:'';position:absolute;top:3px;left:4px;width:8px;height:8px;border-radius:50%;background:var(--rc);box-shadow:0 0 0 1px rgba(0,0,0,.45)}
.dtu-sw[data-rarity]:not([data-rarity=common])::after{content:'';position:absolute;bottom:-3px;right:-3px;width:10px;height:10px;border-radius:50%;background:var(--rc);box-shadow:0 0 0 2px var(--dtu-navy)}
.dtu-rarity-key{display:flex;flex-wrap:wrap;gap:10px;margin-top:8px;font-size:11px;color:var(--dtu-mute)}
.dtu-rarity-key span{display:inline-flex;align-items:center;gap:4px}
.dtu-rarity-key i{width:8px;height:8px;border-radius:50%;display:inline-block}
.dtu-save{margin-top:8px}
.dtu-toast{position:fixed;left:50%;bottom:22px;transform:translateX(-50%);z-index:1200;background:var(--dtu-navy);color:var(--dtu-text);border:1px solid var(--dtu-amber);padding:11px 16px;border-radius:12px;font:600 14px system-ui,sans-serif;box-shadow:0 8px 24px rgba(0,0,0,.4);max-width:calc(100vw - 28px);transition:opacity .4s}
.dtu-toast-out{opacity:0}
@media(max-width:700px){
  .dtu-overlay{padding:0;align-items:flex-end}
  .dtu-card,.dtu-card.dtu-wide{width:100%;max-height:96vh;max-height:96dvh;border-radius:18px 18px 0 0}
  .dtu-body{padding:4px 14px 16px}
  .dtu-builder{flex-direction:column;align-items:stretch;gap:10px}
  .dtu-side{width:auto;display:grid;grid-template-columns:120px 1fr;grid-template-areas:"p s" "p l" "p a";gap:4px 14px;align-items:center;text-align:left}
  .dtu-preview{grid-area:p;width:120px;height:120px;margin:0;border-radius:16px}.dtu-preview svg{width:120px;height:120px}
  .dtu-sizes{grid-area:s;justify-content:flex-start;margin:0}
  .dtu-lv{grid-area:l;margin:0}
  .dtu-side-actions{grid-area:a;justify-content:flex-start}
  .dtu-side-actions .dtu-btn{margin-top:0;padding:9px 14px}
  .dtu-ctabs{overflow-x:auto;flex-wrap:nowrap}.dtu-ctabs button{flex:1 0 auto;padding:9px 12px}
  .dtu-opts{max-height:38vh}
  .dtu-parts{grid-template-columns:repeat(auto-fill,minmax(66px,1fr))}
  .dtu-save{position:sticky;bottom:0;background:var(--dtu-navy);padding-top:6px}
  .dtu-save .dtu-btn{flex:1}
  .dtu-name{max-width:84px}
}
@media(prefers-reduced-motion:reduce){.dtu-toast{transition:none}}
@media(max-width:1560px){.dtu-inline .dtu-who{display:none}.dtu-inline{padding-right:3px}}
@media(min-width:1561px){.dtu-inline .dtu-badge{display:none}}
@media(max-width:700px){.dtu-chip.dtu-inline{margin-left:4px}}
/* signed-out chooser: "I'm a student" / "I'm a teacher" */
.dtu-chooser{width:min(300px,calc(100vw - 16px));min-width:0;box-sizing:border-box}
.dtu-chooser .dtu-sec{padding:6px 10px 4px;font:700 11px/1.3 system-ui,sans-serif;letter-spacing:.08em;text-transform:uppercase;color:var(--dtu-mute)}
.dtu-chooser .dtu-sec small{display:block;text-transform:none;letter-spacing:0;font-size:12px;font-weight:600;color:#ffcf70;margin-top:2px;overflow-wrap:anywhere}
.dtu-opt2{display:block;width:100%;box-sizing:border-box;text-align:left;background:none;border:0;padding:10px;border-radius:10px;font:600 14px system-ui,sans-serif;color:inherit;cursor:pointer;text-decoration:none;min-height:44px}
.dtu-opt2:hover{background:var(--dtu-panel2)}
.dtu-opt2.dtu-big{background:var(--dtu-panel);border:1px solid var(--dtu-line);margin:6px 0}
.dtu-opt2.dtu-big:hover{background:var(--dtu-panel2);border-color:var(--dtu-amber)}
.dtu-opt2.dtu-big b{display:block;font-size:15px}
.dtu-opt2.dtu-big small{display:block;margin-top:2px;font-size:12px;font-weight:500;color:var(--dtu-mute)}
.dtu-opt2:focus-visible{outline:3px solid var(--dtu-amber);outline-offset:2px}
.dtu-hr{height:1px;background:var(--dtu-line);margin:6px 4px}
.dtu-fine{margin:6px 10px 4px;font-size:12px;color:var(--dtu-mute)}
/* signed out: a plain "Sign in" button so teachers and students can find it */
.dtu-chip.dtu-out .dtu-ava{display:none}
.dtu-inline.dtu-out .dtu-who{display:flex}
.dtu-chip.dtu-out{padding:9px 14px;min-height:38px}
.dtu-chip.dtu-out .dtu-name{font-weight:800;max-width:none}

/* Google / Microsoft sign-in (a linked shortcut for an existing class-code+nickname account) */
.dtu-oauth{margin-top:14px}
.dtu-or{display:flex;align-items:center;gap:10px;color:var(--dtu-mute);font-size:12px;margin:0 0 10px}
.dtu-or::before,.dtu-or::after{content:'';flex:1;height:1px;background:var(--dtu-line)}
.dtu-oauth-btns{display:flex;flex-direction:column;align-items:center;gap:8px}
.dtu-g-wrap{min-height:40px;display:flex;justify-content:center;width:100%}
.dtu-g-wrap iframe{margin:0 auto}
.dtu-btn-ms{width:100%;box-sizing:border-box}