:root{--blue:#174e73;--deep:#0e3855;--orange:#e88a18;--ink:#20313d;--muted:#667784;--paper:#fff;--wash:#edf5f8;--line:#d8e4e9;--ok:#25734b;--danger:#a84032;--shadow:0 16px 42px rgba(25,65,87,.12);--green:var(--blue);--jade:var(--blue);--gold:var(--orange);--soft:var(--wash);--warn:#fff7ea}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:128px}body{margin:0;background:linear-gradient(180deg,#e9f3f7,#fbfcfd 34rem,#fff);color:var(--ink);font:16px/1.5 "Lora",serif}button,input,select,textarea{font:inherit}button{cursor:pointer}button:disabled{cursor:not-allowed;opacity:.58}a{color:inherit}.site-head,.shell,.site-footer{width:min(1080px,100%);margin:auto;padding-left:15px;padding-right:15px}.site-head{padding-top:10px}.brand{text-align:center;padding:0 0 14px}.brand img{width:96px;height:96px;border-radius:50%;object-fit:cover;background:#fff;box-shadow:var(--shadow)}.brand p{margin:8px 0 3px;color:var(--blue);font-size:.78rem;font-weight:800;letter-spacing:.05em}.brand h1{margin:0;color:var(--deep);font-size:clamp(1.15rem,4.3vw,1.85rem);line-height:1.18}.app-switch{display:flex;gap:7px;justify-content:center;overflow:auto;padding:3px 0 14px}.app-switch button{white-space:nowrap;border:1px solid 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@media(min-width:720px){.brand img{width:118px;height:118px}.card-grid{grid-template-columns:repeat(3,1fr)}.account-card{padding:15px 19px}}
@media(max-width:720px){html{scroll-padding-top:170px}.four-grid,.lesson-layout,.split{grid-template-columns:1fr}.four-grid>.door:last-child:nth-child(odd){grid-column:auto}.account-card,.offline-note{align-items:flex-start;flex-direction:column}.account-card .btn{width:100%}.panel{padding:16px}.library-tabs{top:0}.library-grid{grid-template-columns:1fr}.library-side{display:block;overflow:visible;padding:9px}.side-item{min-width:0;border-bottom:1px solid var(--line);padding:10px}.library-content{min-height:400px;scroll-margin-top:86px}.floating-actions{bottom:12px}.floating-actions>*{padding:10px 13px;font-size:.86rem}}
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.small{min-height:36px;padding:7px 11px;font-size:.82rem}.offline-note>div{display:flex;align-items:center;gap:10px;min-width:0}.offline-note .btn{margin-left:auto;flex:0 0 auto}.compact-actions{margin:0;justify-content:flex-end}.home-section{margin:22px 0}.home-grid{display:grid;gap:14px}.home-grid.three{grid-template-columns:repeat(3,1fr)}.home-grid.two{grid-template-columns:repeat(2,1fr)}.continue-card,.start-here{display:flex;justify-content:space-between;align-items:center;gap:18px;padding:18px 20px;margin-bottom:14px;border:1px solid var(--line);border-radius:18px;background:#fff;box-shadow:var(--shadow)}.continue-card h2,.start-here h2{margin:3px 0;color:var(--blue);font-size:1.18rem}.continue-card p,.start-here p{margin:0;color:var(--muted)}.start-here{margin-top:22px;background:linear-gradient(135deg,#fff7ea,#fff)}.start-here .toolbar{margin:0;justify-content:flex-end}.inline-label{margin-left:8px}.search-row{position:relative;margin-bottom:9px}.search-row>input{width:100%;padding:11px 14px;border:1px solid var(--line);border-radius:12px;background:#fff}.search-results{position:absolute;z-index:30;left:0;right:0;top:calc(100% + 4px);display:grid;max-height:320px;overflow:auto;border:1px solid var(--line);border-radius:12px;background:#fff;box-shadow:var(--shadow)}.search-results button{border:0;border-bottom:1px solid var(--line);background:#fff;text-align:left;padding:11px 13px;color:var(--blue);font-weight:700}.search-results button:hover{background:var(--wash)}.empty-result{padding:13px;color:var(--muted)}.reading-tools,.next-prev{display:flex;justify-content:space-between;align-items:center;gap:10px}.reading-tools>div{display:flex;gap:6px}.next-prev{margin-top:22px}.next-prev>*{max-width:48%}.article-body{overflow-wrap:anywhere}.dashboard-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.dashboard-grid>.panel h2{margin-top:0;color:var(--blue);font-size:1.15rem}.admin-row,.saved-row{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:11px 0;border-bottom:1px solid var(--line)}.admin-row:last-child,.saved-row:last-child{border-bottom:0}.admin-row>div,.saved-row>div{min-width:0}.admin-row b,.saved-row b{display:block;color:var(--deep)}.admin-row small,.saved-row small{display:block;color:var(--muted);overflow-wrap:anywhere}.alert-row{border-left:4px solid var(--danger);padding-left:10px}.notice,.critical{padding:13px 15px;border-radius:13px;margin:12px 0}.notice{background:#eaf6ef;color:var(--ok)}.notice p,.critical p,.warning p{margin:4px 0 0}.critical{background:#fce9e6;color:var(--danger);border:1px solid #efc0ba}.curriculum{display:grid;gap:8px}.curriculum-row{display:grid;grid-template-columns:42px 1fr auto;gap:10px;align-items:center;padding:12px;border:1px solid var(--line);border-radius:12px;background:#fff}.curriculum-row b{display:block;color:var(--deep)}.curriculum-row small{display:block;color:var(--muted)}.lesson-row.done,.curriculum-row.done{background:#eaf6ef;border-color:#badbc8}.lesson-row.done .lesson-index{background:var(--ok);color:#fff}.error-text{color:var(--danger)!important;font-weight:700}.footer-tools{display:flex;gap:8px;flex-wrap:wrap}.footer-tools .btn{flex:1}.form-grid label{line-height:1.35}.account-card .toolbar{margin-bottom:0}
@media(max-width:840px){.home-grid.three{grid-template-columns:1fr 1fr}.home-grid.three>.door:last-child{grid-column:1/-1}.dashboard-grid{grid-template-columns:1fr}}
@media(max-width:720px){.home-grid.three,.home-grid.two{grid-template-columns:1fr}.home-grid.three>.door:last-child{grid-column:auto}.continue-card,.start-here{align-items:stretch;flex-direction:column}.continue-card .btn,.start-here .btn{width:100%}.start-here .toolbar{width:100%}.offline-note>div{align-items:flex-start;flex-direction:column;gap:2px}.offline-note .btn{width:100%;margin-left:0}.next-prev{align-items:stretch}.next-prev>*{max-width:50%;white-space:normal}.admin-row,.saved-row{align-items:stretch;flex-direction:column}.admin-row .btn,.saved-row .btn{width:100%}.curriculum-row{grid-template-columns:36px 1fr}.curriculum-row>:last-child{grid-column:2}.reading-tools{align-items:flex-start}.account-card .toolbar{width:100%;justify-content:stretch}.account-card .toolbar .btn{flex:1}}

/* Chuẩn bị tích hợp online: chuyển App, trạng thái đồng bộ, hướng dẫn cài đặt. */
body,button,input,select,textarea{font-family:"Lora",serif}
.app-switch a{white-space:nowrap;border:1px solid var(--line);border-radius:999px;background:#fff;padding:9px 13px;color:var(--blue);font-weight:750;text-decoration:none}.app-switch a.active{background:var(--blue);color:#fff;border-color:var(--blue)}
.offline-note.online{background:#eef8f1;border-color:#bfe0ca}.offline-note.online b{color:var(--ok)}.offline-note.stale{background:#fff7ea;border-color:#f1d2a9}
.sync-state{display:inline-flex;align-items:center;gap:6px}.sync-dot{width:8px;height:8px;border-radius:50%;background:currentColor}
.install-steps{display:grid;gap:10px;margin:14px 0}.install-step{display:grid;grid-template-columns:34px 1fr;gap:10px;align-items:start;border:1px solid var(--line);border-radius:13px;padding:11px}.install-step>span{width:30px;height:30px;border-radius:50%;display:grid;place-items:center;background:var(--wash);color:var(--blue);font-weight:800}.install-step b{display:block}.install-step small{color:var(--muted)}
.modal-card .share-options{display:grid;grid-template-columns:1fr 1fr;gap:9px;margin:14px 0}.modal-card .share-options .btn{width:100%}
.data-source-note{margin-top:12px;color:var(--muted);font-size:.82rem}.skeleton{min-height:180px;display:grid;place-items:center;color:var(--muted)}
.payment-qr{width:min(100%,360px);display:block;margin:14px auto;border:1px solid var(--line);border-radius:18px}
.video-frame iframe,.video-frame [data-youtube-player]{width:100%;height:100%;border:0;border-radius:inherit}.video-frame{min-height:260px}.field-help{display:block;color:var(--muted);font-size:.8rem;margin-top:5px}
@media(max-width:520px){.modal-card .share-options{grid-template-columns:1fr}.app-switch{justify-content:flex-start}.video-frame{min-height:210px}}