body{min-width:0}
.platform{width:min(100% - 32px,680px);margin:clamp(30px,8vh,82px) auto}
.platform-card,.platform-notice{background:var(--paper);border:1px solid var(--line);border-radius:18px;box-shadow:0 16px 48px #34446824}
.platform-card{padding:clamp(20px,5vw,40px);border-top:4px solid #6d42d8}
.platform h1,.platform-notice h2{margin:4px 0 8px;line-height:1.2}
.platform h1{font:700 clamp(28px,6vw,38px)/1.2 Georgia,serif}
.platform p{margin:0 0 20px;color:var(--muted)}
.platform form label{display:block;font-weight:700;margin:14px 0 5px}
.platform input{display:block;width:100%;min-height:44px;padding-inline:12px}
.primary{background:linear-gradient(135deg,#6d42d8,#167bd8);border:0;color:white;font-weight:700;min-height:44px;padding:0 20px}
#login-form .primary{width:100%}
.text-action{border:0;background:transparent;color:var(--blue);padding-left:0;text-decoration:underline}
.platform .login-error{color:var(--red);margin:8px 0}
.login-error:empty{display:none}
.level-heading{display:flex;justify-content:space-between;align-items:center;gap:8px}
.level-list{display:grid;gap:10px}
.level-card{display:flex;align-items:center;justify-content:space-between;gap:14px;border:1px solid var(--line);border-left:4px solid #16a89e;border-radius:9px;padding:13px 14px}
.level-card small{display:block;color:var(--muted)}
.level-card a,.level-card button{flex-shrink:0}
.level-card a{color:var(--blue);font-weight:700}
.platform-notice{width:min(100% - 32px,510px);padding:24px;color:var(--ink)}
.platform-notice::backdrop{background:#17202a85}
.platform-notice ul{padding-left:22px}
.platform-notice li+li{margin-top:8px}
.platform-notice label:not([hidden]){display:block;margin:14px 0}
.platform-notice input[type=checkbox]{vertical-align:middle}
.platform-notice .primary{display:block;margin-left:auto}
[hidden]{display:none!important}

#login-form .primary{margin-top:14px;display:flex;align-items:center;justify-content:center;gap:9px}
button.primary:hover:not(:disabled){background:linear-gradient(135deg,#5230b0,#105fae);color:#fff}
button.primary:disabled{background:linear-gradient(135deg,#6245a4,#386da7);color:#fff;cursor:wait}
.platform .login-wait{margin:6px 0 0;font-size:13px}
.login-wait:empty{display:none}
.login-spinner{width:16px;height:16px;border:2px solid #ffffff70;border-top-color:#fff;border-radius:50%;animation:login-spin .8s linear infinite}
@keyframes login-spin{to{transform:rotate(360deg)}}
@media(prefers-reduced-motion:reduce){.login-spinner{animation:none}}
.challenge:not([hidden]){margin-top:14px;padding:0 12px 12px;border:1px solid #c8d8ed;border-radius:8px;background:#f0f7ff}
.level-upcoming{flex-shrink:0;color:var(--muted);background:var(--soft);padding:5px 10px;border-radius:5px}
.study{display:flex;flex-direction:column;height:100dvh}
body:has(.study:not([hidden]))>.app-header,body:has(.study:not([hidden]))>.platform{display:none}
.study-bar{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:8px 16px;padding:8px clamp(12px,3vw,28px);background:#fffdf8;border-bottom:3px solid #ffd83d}
.study-actions{display:flex;flex-wrap:wrap;gap:8px}
.study iframe{width:100%;min-height:0;flex:1;border:0;background:#fff}