/* TCX responsive portal and single original-image previews. */
*{box-sizing:border-box}img,video,audio{max-width:100%}main,.card,.welcome,.intro,.topbar,.question,.exam-layout{min-width:0}p,h1,h2,h3,strong,small{overflow-wrap:anywhere}
main{width:min(1230px,100%);padding:28px 20px 40px}.welcome{min-height:0;gap:32px;grid-template-columns:minmax(0,1fr) minmax(280px,.85fr);align-items:start}.intro{padding:18px 0 18px 18px}.intro h1{font-size:26px;line-height:1.4;letter-spacing:-.5px}.intro p{font-size:14px;line-height:1.7}.topbar{gap:14px}.brand{display:flex;align-items:center;gap:10px;min-width:0}.brand span{min-width:0}.brand-logo{flex:0 0 44px}.topbar .row{min-width:0}.tabs{width:100%;min-width:0;overscroll-behavior-x:contain}.tabs button{flex:0 0 auto;min-height:44px}.auth-card{width:100%;max-width:100%;padding:26px}.auth-card>.row{justify-content:space-between}.hanzi{font-size:23px;line-height:1.55}.exam-layout{grid-template-columns:220px minmax(0,1fr)}.exam-bar{top:105px;flex-wrap:wrap}.exam-bar strong{flex:1;min-width:90px}.question-nav{grid-template-columns:repeat(auto-fit,minmax(32px,1fr))}.options,.option{min-width:0}.option>span:last-child{min-width:0;overflow-wrap:anywhere}.table-scroll{width:100%;max-width:100%;overflow:auto}#audio-preview{display:block;width:100%;max-width:100%;height:auto;max-height:65dvh;object-fit:contain}#audio-preview[hidden]{display:none}#audio-player{width:100%;max-width:100%}.audio-languages{display:flex;flex-wrap:wrap;gap:8px;margin:12px 0}.audio-languages button{min-height:44px;padding:9px 12px}.learning-preview{padding:16px;border:1px solid #cce0d3;border-radius:16px;background:linear-gradient(135deg,#fff,#edf8f0);box-shadow:0 4px 0 #d4e5d9;margin-top:20px}.preview-row{display:grid;grid-template-columns:112px minmax(0,1fr) 48px;gap:12px;align-items:start}.preview-row .lesson-image{padding:0;border:1px solid #cce0d3;background:#e9f6ee;border-radius:12px;overflow:hidden;cursor:zoom-in}.preview-row img{display:block;width:100%;height:auto;object-fit:contain;max-height:220px}.preview-row h2{font-size:20px;line-height:1.5}.preview-row p{font-size:13px;line-height:1.6}.preview-row em{display:block;font-size:12px;line-height:1.6;color:#0a7169;margin-bottom:8px}.lesson-audio{display:flex;flex-direction:column;gap:8px}.lesson-audio button{display:flex;flex-direction:column;align-items:center;justify-content:center;min-width:44px;min-height:54px;padding:6px 3px;border:1px solid #bad7c6;border-radius:12px;background:linear-gradient(135deg,#fff,#dcefe3);box-shadow:0 3px 0 #b4ccbe;font-size:10px;line-height:1.4;color:#064a46}.lesson-audio b{font-size:18px}.lesson-audio button[aria-pressed=true]{background:#f2c66d}.image-zoom{width:min(1000px,calc(100% - 20px));max-width:calc(100% - 20px);max-height:92dvh;padding:12px;border-radius:16px;background:#f5faf7}.image-zoom-tools{display:flex;gap:8px;justify-content:space-between;margin-bottom:10px}.image-zoom-tools button{min-width:44px;min-height:44px}.image-zoom-scroll{width:100%;height:65dvh;overflow:auto;overscroll-behavior:contain;background:#e7f1eb}.image-zoom-scroll img{width:100%;max-width:none;height:100%;object-fit:contain;transform:none}.image-zoom>p{font-size:12px;margin-top:10px}
@media(max-width:850px){.welcome{grid-template-columns:minmax(0,1fr) minmax(260px,1fr);gap:24px}.exam-layout{grid-template-columns:minmax(0,1fr)}}
@media(max-width:680px){main{padding:20px 12px 36px}.topbar{position:relative;top:auto;width:calc(100% - 20px);margin:10px auto 0;padding:10px;flex-wrap:wrap;align-items:start}.topbar .brand{flex:1 1 180px;font-size:12px}.topbar .row{margin-left:auto;flex-wrap:wrap;max-width:100%}.brand-logo{width:36px;height:36px;flex-basis:36px}.brand small{font-size:10px}.welcome{grid-template-columns:minmax(0,1fr);gap:20px}.intro{padding:12px 0 12px 12px}.intro h1{font-size:23px;margin:8px 0 12px}.intro p{font-size:14px}.auth-card{padding:22px}.auth-card::before{left:22px}.card{padding:18px}.section-head{flex-direction:column;align-items:stretch}.exam-bar{top:0;gap:8px;padding:12px}.exam-bar strong{flex-basis:calc(100% - 100px)}.exam-layout{grid-template-columns:minmax(0,1fr);gap:16px}.question{padding:18px}.hanzi{font-size:21px}.form-grid,.grid,.admin-grid{grid-template-columns:minmax(0,1fr)}.preview-row{grid-template-columns:82px minmax(0,1fr) 44px;gap:8px}.learning-preview{padding:12px}.preview-row h2{font-size:18px}.preview-row p{font-size:12px}.preview-row img{max-height:220px}dialog{padding:18px}input,select,textarea{font-size:16px!important;max-width:100%}.word{align-items:start;min-width:0}.word>div{min-width:0}.score strong{font-size:42px}}
@media(max-width:360px){.preview-row{grid-template-columns:65px minmax(0,1fr) 44px;gap:6px}.learning-preview{padding:10px}.preview-row h2{font-size:17px}.auth-card{padding:18px}}

.account-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.account-identity{display:flex;align-items:center;gap:20px;flex-wrap:wrap}.account-identity>div:last-child{flex:1;min-width:160px}.account-field{display:flex;justify-content:space-between;align-items:start;gap:14px;margin:12px 0;min-width:0}.account-field small{color:#5a6a64}.account-field strong{text-align:right}.account-avatar{width:100%;height:100%;object-fit:cover;border-radius:50%;z-index:1;position:relative}.account-identity .avatar-frame,.plain-avatar{width:80px;height:80px;flex:0 0 80px;margin:0;border-radius:50%;background:#dcf1e4;display:grid;place-items:center;font-size:30px;overflow:visible}.account-identity .avatar-frame .account-avatar{width:68px;height:68px}.plain-avatar{overflow:hidden}.account-identity .avatar-frame:has(.account-avatar)::before{inset:2px}#google-login,#google-link{max-width:100%;min-width:0}.social-stack{min-width:0}.social-stack iframe{max-width:100%}@media(max-width:680px){.account-grid{grid-template-columns:minmax(0,1fr)}.account-field{gap:10px}.account-identity{gap:14px}.account-identity .avatar-frame,.plain-avatar{width:64px;height:64px;flex-basis:64px}.account-identity .avatar-frame .account-avatar{width:54px;height:54px}}