.castudy-study{height:100dvh;display:flex;flex-direction:column;overflow:hidden}
.castudy-study .site-header{flex:none;flex-wrap:wrap;gap:.5rem 1rem;min-height:4rem;padding:.65rem 1.5rem}
.castudy-study .brand{flex:1 1 18rem;min-width:0}
.course-login{flex:none;font-size:.875rem}
.course-login summary{cursor:pointer;font-weight:600;list-style:none}
.course-login summary::-webkit-details-marker{display:none}
.course-login[open]{flex-basis:100%;display:flex;flex-direction:column;gap:.5rem}
.course-login form{margin:.5rem 0 0;max-width:36rem}
.course-login label{display:block;margin-bottom:.35rem;color:#cbd5e1}
.login-controls{display:flex;gap:.5rem}
.login-controls input{min-width:0;flex:1;padding:.5rem .7rem;border:1px solid #94a3b8;border-radius:.3rem;font:inherit}
.course-login button{flex:none;padding:.5rem .8rem;border:0;border-radius:.3rem;background:#e2e8f0;color:#0f172a;font:inherit;font-weight:600;cursor:pointer}
.logout-controls{margin-top:.5rem}
.course-login [hidden]{display:none}
.course-login button:disabled{opacity:.5;cursor:wait}
#login-error{margin:.5rem 0 0;color:#fecaca}
.study-stage{flex:1;min-height:0;width:100%;display:flex}
.study-stage iframe{display:block;flex:1;min-height:0;width:100%;border:0;background:#fff}
@media(max-width:40rem){.castudy-study .site-header{padding:.5rem .75rem}.castudy-study .brand{font-size:.95rem;line-height:1.4;flex-basis:14rem}.course-login{font-size:.8rem}}