/* Grammar Studio v2.5.18 */
.grammar-studio-dialog{width:min(1480px,calc(100vw - 48px));max-width:1480px;max-height:calc(100vh - 48px)}
.grammar-studio-dialog .modal-body{padding:18px;background:#f5f8fc}
.grammar-studio{min-height:560px;color:#10213b}
.gs-loading{min-height:520px;display:grid;place-items:center;align-content:center;gap:14px;color:#70819a}
.gs-loading span{width:72px;height:72px;border-radius:22px;display:grid;place-items:center;background:linear-gradient(145deg,#eaf3ff,#fff);box-shadow:0 12px 35px rgba(26,84,160,.12);font:800 38px "Noto Serif SC",serif;color:#1672f6}
.gs-loading p{margin:0}
.gs-hero{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:20px;padding:26px;border:1px solid #dce7f5;border-radius:24px;background:radial-gradient(circle at 90% 0%,rgba(35,133,255,.16),transparent 34%),linear-gradient(135deg,#0c2342,#123b69);color:#fff;box-shadow:0 18px 40px rgba(12,43,82,.14)}
.gs-kicker,.gs-side-kicker{display:block;font-size:10px;letter-spacing:.14em;font-weight:900;color:#72b8ff}
.gs-hero h2{margin:7px 0 10px;font-size:clamp(25px,3vw,40px);line-height:1.1;max-width:760px}
.gs-hero p{margin:0;max-width:800px;color:#d1ddec;line-height:1.65}
.gs-hero-actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:22px}
.gs-primary,.gs-secondary{border-radius:12px;padding:11px 16px;font-weight:800;border:1px solid transparent}
.gs-primary{background:linear-gradient(180deg,#2c8cff,#126ce8);color:#fff;box-shadow:0 8px 18px rgba(15,107,232,.22)}
.gs-secondary{background:#fff;color:#1a3457;border-color:#dce7f5}
.gs-hero .gs-secondary{background:rgba(255,255,255,.1);border-color:rgba(255,255,255,.25);color:#fff}
.gs-progress-card{border:1px solid rgba(255,255,255,.15);border-radius:20px;background:rgba(255,255,255,.08);backdrop-filter:blur(12px);padding:18px;display:grid;grid-template-columns:132px 1fr;gap:16px;align-items:center}
.gs-progress-ring{--p:0;width:126px;aspect-ratio:1;border-radius:50%;display:grid;place-items:center;align-content:center;background:radial-gradient(circle at center,#123052 0 57%,transparent 58%),conic-gradient(#4fa3ff calc(var(--p)*1%),rgba(255,255,255,.13) 0)}
.gs-progress-ring strong{font-size:26px}.gs-progress-ring span{font-size:11px;color:#bed0e6}
.gs-progress-meta{display:grid;gap:7px}.gs-progress-meta div{display:flex;justify-content:space-between;gap:10px;padding:7px 0;border-bottom:1px solid rgba(255,255,255,.12)}.gs-progress-meta div:last-child{border:0}.gs-progress-meta span{font-size:12px;color:#c9d7e8}
.gs-toolbar{display:grid;grid-template-columns:minmax(260px,1fr) 150px 190px 170px;gap:10px;margin:18px 0 12px}
.gs-toolbar select,.gs-search{height:46px;border:1px solid #dce5f0;background:#fff;border-radius:13px;outline:none;color:#21344f}
.gs-toolbar select{padding:0 12px}.gs-search{display:flex;align-items:center;padding:0 13px;gap:8px}.gs-search span{font-size:22px;color:#5b7290}.gs-search input{flex:1;min-width:0;border:0;outline:0;background:transparent}
.gs-level-strip{display:grid;grid-template-columns:repeat(6,1fr);gap:8px;margin-bottom:18px}
.gs-level-strip button{border:1px solid #dce5f0;background:#fff;border-radius:13px;padding:11px;text-align:left;color:#233752}.gs-level-strip button.active{border-color:#6aaaff;background:#eef6ff;color:#0c68d8}.gs-level-strip span,.gs-level-strip small{display:block}.gs-level-strip span{font-weight:900}.gs-level-strip small{font-size:10px;color:#7f8da1;margin-top:2px}.gs-level-strip i{display:block;height:4px;border-radius:5px;background:#edf1f6;margin-top:8px;overflow:hidden}.gs-level-strip b{display:block;height:100%;background:#2583f5;border-radius:5px}
.gs-list-head{display:flex;align-items:end;justify-content:space-between;gap:12px;margin:4px 2px 12px}.gs-list-head h3{margin:0;font-size:20px}.gs-list-head span{font-size:12px;color:#7c8aa0}.gs-list-head button{border:0;background:transparent;color:#1672f6;font-weight:700}
.gs-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}
.gs-card{display:grid;grid-template-rows:1fr auto;border:1px solid #dfe7f1;border-radius:17px;background:#fff;box-shadow:0 7px 22px rgba(41,75,119,.05);overflow:hidden;transition:.2s}.gs-card:hover{transform:translateY(-2px);border-color:#b7d1f3;box-shadow:0 13px 30px rgba(41,75,119,.1)}.gs-card.gs-status-mastered{box-shadow:inset 4px 0 0 #31b870,0 7px 22px rgba(41,75,119,.05)}.gs-card.gs-status-learning{box-shadow:inset 4px 0 0 #f0a834,0 7px 22px rgba(41,75,119,.05)}
.gs-card-main{border:0;background:transparent;text-align:left;padding:16px 16px 12px;color:inherit}.gs-card-top{display:flex;align-items:center;gap:6px;flex-wrap:wrap}.gs-level,.gs-category,.gs-status{font-size:10px;border-radius:999px;padding:3px 7px}.gs-level{color:#096ddd;background:#edf5ff}.gs-category{color:#6847b5;background:#f2effb}.gs-status{margin-left:auto;color:#68788f;background:#f2f5f8}.gs-status-mastered .gs-status{color:#19774b;background:#eaf8f1}.gs-status-learning .gs-status{color:#9b6717;background:#fff6df}.gs-card h3{font-size:18px;margin:12px 0 8px;line-height:1.3}.gs-card code{display:block;border-radius:10px;padding:9px 10px;background:#f6f9fc;color:#0f63d3;font:700 12px/1.45 ui-monospace,SFMono-Regular,Menlo,monospace;white-space:normal}.gs-card p{color:#6f7e91;font-size:13px;line-height:1.55;margin:10px 0 0;display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}.gs-card-actions{display:flex;border-top:1px solid #edf1f5}.gs-card-actions button{flex:1;border:0;background:#fff;padding:11px;font-size:12px;font-weight:800;color:#52647d}.gs-card-actions button+button{border-left:1px solid #edf1f5;color:#1672f6}.gs-card-actions button:hover{background:#f8fbff}
.gs-empty{grid-column:1/-1;min-height:320px;display:grid;place-items:center;align-content:center;text-align:center;color:#6f7f94}.gs-empty>span{font-size:42px}.gs-empty h3{margin:8px 0 2px;color:#21334c}.gs-empty p{margin:0}
.gs-detail-shell{max-width:1280px;margin:0 auto}.gs-detail-topbar{display:flex;justify-content:space-between;gap:12px;margin-bottom:12px}.gs-detail-topbar>button,.gs-detail-topbar>div button{border:1px solid #dce5f0;background:#fff;border-radius:10px;padding:9px 12px;font-weight:800;color:#37506f}.gs-detail-topbar>div{display:flex;gap:8px}.gs-detail-topbar .is-mastered{background:#eaf8f1;color:#147b4a;border-color:#b9e4cf}
.gs-detail-hero{display:grid;grid-template-columns:minmax(0,1fr) minmax(290px,430px);gap:20px;padding:25px;border-radius:22px;background:linear-gradient(135deg,#fff,#f3f8ff);border:1px solid #dce7f5}.gs-detail-tags{display:flex;gap:6px;flex-wrap:wrap}.gs-detail-tags span{font-size:10px;border-radius:999px;padding:4px 8px;background:#eaf3ff;color:#0b68d5}.gs-detail-hero h2{font-size:clamp(28px,4vw,46px);line-height:1.08;margin:12px 0 10px}.gs-detail-hero p{margin:0;color:#65758b;line-height:1.65}.gs-structure-large{align-self:center;padding:18px;border:1px solid #cfe1f7;border-radius:16px;background:#0e2748;color:#fff}.gs-structure-large small{display:block;font-size:9px;letter-spacing:.13em;color:#79b9ff;font-weight:900;margin-bottom:8px}.gs-structure-large code{font:800 15px/1.6 ui-monospace,SFMono-Regular,Menlo,monospace;white-space:normal}
.gs-detail-grid{display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:16px;margin-top:16px}.gs-detail-main{display:grid;gap:14px}.gs-section,.gs-side-card{border:1px solid #dfe7f1;border-radius:18px;background:#fff;padding:20px}.gs-section-title{display:flex;align-items:center;gap:12px;margin-bottom:15px}.gs-section-title>span{width:34px;height:34px;border-radius:10px;display:grid;place-items:center;background:#edf5ff;color:#1672f6;font-weight:900}.gs-section-title h3{margin:0;font-size:18px}.gs-section-title p{margin:2px 0 0;color:#8290a3;font-size:11px}.gs-prose p{color:#44566f;line-height:1.75;margin:0 0 10px}.gs-tip{display:flex;gap:12px;margin-top:14px;padding:13px;border-radius:13px;background:#fff8e8;border:1px solid #f5dfaa}.gs-tip>span{font-size:22px}.gs-tip strong{display:block}.gs-tip p{margin:3px 0 0;color:#795d20;line-height:1.55}
.gs-example-list{display:grid;gap:9px}.gs-example-card{display:grid;grid-template-columns:34px minmax(0,1fr) 42px;gap:12px;align-items:start;border:1px solid #e3eaf3;border-radius:14px;padding:13px;background:#fbfdff}.gs-example-number{font-size:10px;color:#96a3b4;font-weight:900;padding-top:4px}.gs-example-card strong{display:block;font:700 21px/1.35 "Noto Serif SC",serif;color:#14243b}.gs-example-card span{display:block;color:#1672f6;font-size:12px;margin-top:4px}.gs-example-card p{margin:3px 0 0;color:#697a90;font-size:13px}.gs-example-card button{width:38px;height:38px;border:1px solid #dbe5f0;border-radius:10px;background:#fff}
.gs-mistake-box{display:grid;grid-template-columns:1fr 1fr;gap:9px}.gs-mistake-box>div{border-radius:12px;padding:12px}.gs-mistake-box>div span{display:block;font-size:10px;font-weight:900;margin-bottom:5px}.gs-mistake-box>div strong{font:700 18px "Noto Serif SC",serif}.gs-mistake-box .wrong{background:#fff0f2;color:#a6374a}.gs-mistake-box .correct{background:#ecf9f2;color:#16764a}.gs-mistake-box>p{grid-column:1/-1;margin:4px 0 0;color:#65758a;line-height:1.6}.gs-compare-box{border-radius:13px;padding:15px;background:#f5f1ff;border:1px solid #ded4f7;color:#5e4b88;line-height:1.65}
.gs-detail-side{display:grid;gap:12px;align-content:start;position:sticky;top:0;align-self:start}.gs-side-card h3{margin:7px 0}.gs-side-card p{color:#718198;line-height:1.6}.gs-side-card .gs-primary{width:100%}.gs-side-card.compact{padding:16px}.gs-side-progress{display:flex;align-items:center;gap:12px}.gs-side-progress>b{width:42px;height:42px;border-radius:13px;display:grid;place-items:center;background:#edf5ff;color:#1672f6;font-size:22px}.gs-side-progress strong,.gs-side-progress span{display:block}.gs-side-progress span{font-size:11px;color:#7f8ca0;margin-top:2px}
.gs-detail-nav{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:16px 0 2px}.gs-detail-nav button{border:1px solid #dfe7f1;background:#fff;border-radius:14px;padding:13px;text-align:left;color:#21344e}.gs-detail-nav button:last-child{text-align:right}.gs-detail-nav small,.gs-detail-nav strong{display:block}.gs-detail-nav small{color:#7f8da1}.gs-detail-nav strong{margin-top:3px}
.gs-quiz-shell{max-width:880px;margin:0 auto}.gs-quiz-header{display:grid;grid-template-columns:100px 1fr 100px;align-items:center;gap:10px}.gs-quiz-header>button{justify-self:start;border:0;background:transparent;color:#55708f;font-weight:800}.gs-quiz-header>div{text-align:center}.gs-quiz-header span,.gs-quiz-header strong{display:block}.gs-quiz-header span{font-size:11px;color:#7d8ca0}.gs-quiz-header>b{justify-self:end;color:#168653}.gs-quiz-progress{height:6px;border-radius:6px;background:#e8edf4;margin:12px 0 18px;overflow:hidden}.gs-quiz-progress i{display:block;height:100%;background:linear-gradient(90deg,#1672f6,#51a8ff)}.gs-question-card{border:1px solid #dfe7f1;border-radius:22px;background:#fff;padding:28px;box-shadow:0 15px 40px rgba(42,75,118,.07)}.gs-question-level{font-size:10px;padding:4px 8px;border-radius:999px;background:#edf5ff;color:#1672f6}.gs-question-card h2{font-size:26px;margin:14px 0}.gs-question-context{border-radius:14px;padding:17px;background:#f5f8fc;font:700 21px/1.5 "Noto Serif SC",serif}.gs-question-subcontext{color:#76869a;margin:8px 2px}.gs-question-options{display:grid;gap:9px;margin-top:20px}.gs-question-options button{display:grid;grid-template-columns:32px 1fr;align-items:center;gap:10px;border:1px solid #dfe6ef;background:#fff;border-radius:13px;padding:12px;text-align:left;color:#25384f;font-weight:700}.gs-question-options button span{width:30px;height:30px;border-radius:9px;background:#f1f5f9;display:grid;place-items:center;color:#687b93}.gs-question-options button:hover:not(:disabled){border-color:#8ebcff;background:#f6faff}.gs-question-options button.correct{border-color:#77d5aa;background:#ebfaf3;color:#137246}.gs-question-options button.wrong{border-color:#f1a9b6;background:#fff1f3;color:#a33348}.gs-question-feedback{display:none;margin-top:15px;border-radius:13px;padding:14px}.gs-question-feedback.show{display:block}.gs-question-feedback.correct{background:#ebfaf3;color:#176e48}.gs-question-feedback.wrong{background:#fff3f5;color:#9f3448}.gs-question-feedback p{margin:5px 0 10px}.gs-question-feedback button{border:0;border-radius:9px;padding:9px 13px;background:#fff;color:inherit;font-weight:800}
.gs-quiz-finish{max-width:760px;margin:20px auto;text-align:center;border:1px solid #dfe7f1;border-radius:24px;background:#fff;padding:34px}.gs-score-circle{width:160px;aspect-ratio:1;margin:0 auto 20px;border-radius:50%;display:grid;place-items:center;align-content:center;background:linear-gradient(145deg,#eaf4ff,#fff);border:10px solid #dcecff}.gs-score-circle strong{font-size:38px;color:#1672f6}.gs-score-circle span{font-size:11px;color:#6f8096}.gs-quiz-finish h2{font-size:28px;margin:0 0 6px}.gs-quiz-finish>p{color:#72839a}.gs-review-list{display:grid;gap:7px;margin:18px 0}.gs-review-list button{border:1px solid #e0e7f0;background:#fafcff;border-radius:10px;padding:10px;text-align:left;color:#315273}.gs-quiz-finish-actions{display:flex;justify-content:center;gap:9px;flex-wrap:wrap;margin-top:20px}.gs-muted{color:#7c8ca0}
@media(max-width:1120px){.gs-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.gs-toolbar{grid-template-columns:minmax(220px,1fr) 130px 170px}.gs-toolbar #gsStatus{grid-column:3}.gs-detail-grid{grid-template-columns:minmax(0,1fr) 240px}.gs-hero{grid-template-columns:1fr 290px}}
@media(max-width:860px){.grammar-studio-dialog{width:100vw;max-width:none;height:100dvh;max-height:100dvh;margin:0;border-radius:0}.grammar-studio-dialog .modal-header{padding:12px 15px}.grammar-studio-dialog .modal-body{padding:10px 10px 90px}.gs-hero{grid-template-columns:1fr;padding:18px;border-radius:18px}.gs-progress-card{grid-template-columns:110px 1fr}.gs-progress-ring{width:105px}.gs-toolbar{grid-template-columns:1fr 1fr}.gs-search{grid-column:1/-1}.gs-toolbar #gsStatus{grid-column:auto}.gs-level-strip{grid-template-columns:repeat(3,1fr)}.gs-grid{grid-template-columns:1fr}.gs-detail-hero{grid-template-columns:1fr;padding:18px}.gs-detail-grid{grid-template-columns:1fr}.gs-detail-side{position:static;grid-template-columns:1fr 1fr}.gs-detail-nav{grid-template-columns:1fr}.gs-detail-nav button:last-child{text-align:left}.gs-question-card{padding:19px}.gs-quiz-header{grid-template-columns:70px 1fr 70px}}
@media(max-width:560px){.gs-hero h2{font-size:27px}.gs-hero-actions{display:grid}.gs-hero-actions button{width:100%}.gs-progress-card{grid-template-columns:1fr;justify-items:center}.gs-progress-meta{width:100%;grid-template-columns:repeat(3,1fr);gap:5px}.gs-progress-meta div{display:grid;text-align:center;border:0;background:rgba(255,255,255,.07);border-radius:9px;padding:8px 4px}.gs-toolbar{grid-template-columns:1fr}.gs-search,.gs-toolbar #gsStatus{grid-column:auto}.gs-level-strip{display:flex;overflow-x:auto;padding-bottom:3px;scrollbar-width:none}.gs-level-strip button{min-width:104px}.gs-list-head{align-items:center}.gs-card h3{font-size:17px}.gs-detail-topbar{align-items:center}.gs-detail-topbar>div{gap:5px}.gs-detail-topbar>div button{font-size:11px;padding:8px}.gs-detail-hero h2{font-size:30px}.gs-structure-large{padding:14px}.gs-section{padding:15px}.gs-detail-side{grid-template-columns:1fr}.gs-mistake-box{grid-template-columns:1fr}.gs-example-card{grid-template-columns:28px minmax(0,1fr) 38px}.gs-example-card strong{font-size:19px}.gs-question-card h2{font-size:22px}.gs-question-context{font-size:18px}.gs-quiz-finish{padding:22px 15px}.gs-score-circle{width:135px}}


/* V2.5.19: long-form beginner grammar lessons */
.gs-prose { max-width: 78ch; }
.gs-prose .gs-detail-paragraph { margin: 0 0 1.05rem; line-height: 1.85; }
.gs-prose .gs-detail-paragraph strong { display: block; margin-bottom: .28rem; font-size: 1.02em; color: var(--text, #172033); }
@media (max-width: 720px) {
  .gs-prose .gs-detail-paragraph { line-height: 1.78; margin-bottom: .95rem; }
}

/* V2.5.20 — example-rich lesson reading experience */
.gs-lesson-hook{
  margin-top:18px;padding:15px 17px;border-radius:16px;
  background:linear-gradient(135deg,rgba(99,102,241,.10),rgba(16,185,129,.08));
  border:1px solid rgba(99,102,241,.18);display:flex;gap:10px;align-items:flex-start
}
.gs-lesson-hook>span{font-size:20px;line-height:1.35}.gs-lesson-hook p{margin:0!important;line-height:1.75!important;font-weight:600;color:var(--text,#263238)}
.gs-example-card{align-items:flex-start!important;padding:18px!important}
.gs-example-content{min-width:0;flex:1}.gs-example-content>strong{display:block;font-size:1.18rem;line-height:1.55;color:var(--text,#111827)}
.gs-example-pinyin{display:block;margin-top:4px;font-size:.98rem!important;line-height:1.55;color:#7c3aed!important;font-weight:650;letter-spacing:.01em}
.gs-example-vi{margin:7px 0 0!important;line-height:1.65!important;color:var(--text-secondary,#4b5563)}
.gs-example-analysis{margin-top:13px;padding:12px 14px;border-radius:13px;background:rgba(14,165,233,.07);border-left:3px solid rgba(14,165,233,.65)}
.gs-example-analysis b{display:block;font-size:.82rem;letter-spacing:.04em;text-transform:uppercase;color:#0369a1;margin-bottom:5px}
.gs-example-analysis p{margin:0!important;line-height:1.7!important;color:var(--text,#374151)!important;font-size:.95rem}
@media (max-width:720px){
  .gs-example-card{grid-template-columns:42px minmax(0,1fr) 38px!important;gap:10px!important;padding:14px!important}
  .gs-example-content>strong{font-size:1.08rem}.gs-example-pinyin{font-size:.93rem!important}.gs-example-analysis{padding:10px 11px}
  .gs-lesson-hook{padding:13px 14px}
}


/* V2.5.21 — skim-first, less text density, stronger hierarchy */
.gs-detail-hero{padding:20px 22px;gap:16px}
.gs-detail-hero h2{font-size:clamp(26px,3.4vw,40px);margin:10px 0 8px}
.gs-detail-hero p{max-width:68ch;line-height:1.55}
.gs-section{padding:18px}
.gs-section-title{margin-bottom:13px}
.gs-section-title p{font-size:11px;line-height:1.45}
.gs-key-grid{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(240px,.85fr);gap:10px;margin-bottom:14px}
.gs-key-card{border:1px solid #dfe8f3;border-radius:14px;padding:14px;background:#f8fbff}
.gs-key-card>span{display:block;font-size:10px;letter-spacing:.11em;font-weight:900;color:#5f7898;margin-bottom:7px}
.gs-key-card p{margin:0;color:#263d5b;line-height:1.58;font-weight:650}
.gs-key-card code{display:block;font:800 14px/1.55 ui-monospace,SFMono-Regular,Menlo,monospace;color:#0b68d5;white-space:normal}
.gs-key-structure{background:#f2f7ff;border-color:#cfe0f5}
.gs-usage-block{border-top:1px solid #edf1f6;padding-top:13px}
.gs-usage-block h4{margin:0 0 8px;font-size:15px;color:#1f3655}
.gs-usage-block ul{margin:0;padding-left:20px;display:grid;gap:7px}
.gs-usage-block li{color:#445a74;line-height:1.55;padding-left:2px}
.gs-memory-line,.gs-quick-tip{margin-top:11px;padding:10px 12px;border-radius:11px;font-size:13px;line-height:1.55}
.gs-memory-line{background:#f7f4ff;border:1px solid #e7ddfb;color:#5f4c86}
.gs-quick-tip{background:#fff9ea;border:1px solid #f3e1ad;color:#725a21}
.gs-example-list{gap:10px}
.gs-example-card{padding:15px!important;background:#fff}
.gs-example-content>strong{font-size:1.12rem;line-height:1.45}
.gs-example-pinyin{margin-top:3px!important;font-size:.94rem!important}
.gs-example-vi{margin-top:5px!important;line-height:1.5!important}
.gs-example-analysis{margin-top:10px;padding:10px 12px;background:#f4faff;border-left-width:3px}
.gs-example-analysis b{font-size:.75rem;margin-bottom:4px}
.gs-example-analysis p{line-height:1.58!important;font-size:.91rem!important}
.gs-more-examples{margin-top:12px;border:1px solid #dfe7f1;border-radius:13px;background:#f9fbfd;overflow:hidden}
.gs-more-examples summary{cursor:pointer;list-style:none;padding:12px 14px;font-weight:850;color:#176bc7;user-select:none}
.gs-more-examples summary::-webkit-details-marker{display:none}
.gs-more-examples[open] summary{border-bottom:1px solid #e5ebf2;background:#f2f7fd}
.gs-example-list-extra{padding:12px}
.gs-mistake-box>p{line-height:1.5}
.gs-compare-box{line-height:1.55}
.gs-card p{-webkit-line-clamp:2}
@media(max-width:720px){
  .gs-detail-hero{padding:16px}.gs-section{padding:14px}.gs-key-grid{grid-template-columns:1fr}
  .gs-usage-block ul{gap:6px;padding-left:18px}.gs-usage-block li{font-size:14px}
  .gs-memory-line,.gs-quick-tip{font-size:12.5px}
  .gs-example-card{padding:12px!important}.gs-example-analysis{padding:9px 10px}
}