.operation-nav{display:flex;flex-wrap:wrap;gap:8px;margin:0 0 18px}.operation-nav a{padding:10px 14px;border-radius:9px;background:#e7f1ec;color:#174b46;font-weight:700;text-decoration:none}.operation-nav a[aria-current="page"]{background:#197c73;color:#fff}.student-list{max-height:62vh;overflow:auto;border:1px solid #d8e5df;border-radius:10px}.student-link-row{padding:10px 12px}.student-link-row .registration-state{color:#627c78;font-size:13px}.student-link-row button{flex:0 0 auto}.classroom-screen{text-align:center}.classroom-screen .round-buttons{justify-content:center}.classroom-screen .round-buttons button.active{background:#075850}.classroom-qr{min-height:310px;display:flex;align-items:center;justify-content:center}.classroom-qr[hidden]{display:none}.classroom-qr svg{display:block;width:min(72vw,520px);height:auto;max-height:60vh}.countdown{font-size:clamp(24px,5vw,40px);font-weight:800;color:#116d63;margin:12px 0}.screen-actions{justify-content:center}.classroom-screen:fullscreen{overflow:auto;background:#fff;padding:24px;display:flex;flex-direction:column;align-items:center;justify-content:center}.classroom-screen:fullscreen .classroom-qr svg{width:min(72vw,660px);max-height:65vh}.classroom-screen:fullscreen .round-buttons{margin:0}.classroom-screen:fullscreen h1{font-size:clamp(28px,4vw,46px)}@media(max-width:600px){.student-link-row{align-items:flex-start}.classroom-qr{min-height:250px}}
.student-qr-instruction{max-width:1000px;margin:16px auto;font-size:clamp(28px,4.6vw,52px);font-weight:900;line-height:1.3;color:#116d63}.classroom-screen:fullscreen .teacher-explanation{display:none}.classroom-screen:fullscreen .student-qr-instruction{font-size:clamp(32px,5vw,60px)}.classroom-screen:fullscreen .classroom-qr svg{max-height:54vh}