.wechat-learning-home{--mobile-green:#0c513b;--mobile-green-dark:#073b2d;--mobile-mint:#eaf6f0;--mobile-gold:#ad7c16;color:#13251f;max-width:980px;margin:0 auto}.local-learning-home{border:1px solid #c6d8cf;border-left:5px solid var(--mobile-green);background:#fbfdfc;border-radius:8px;margin-bottom:26px;padding:0 20px 24px}.local-learning-home .wechat-welcome{border-bottom-color:#c8d9d0}.wechat-welcome{border-bottom:1px solid #dbe5df;padding:34px 0 28px}.wechat-brand{color:var(--mobile-green);font-size:15px;font-weight:900}.wechat-welcome p,.wechat-welcome>span:last-child{color:#66736e;margin:6px 0 0;line-height:1.7}.wechat-welcome h1{letter-spacing:0;margin:25px 0 4px;font-size:38px;line-height:1.15}.learner-switcher,.mobile-flow-strip,.daily-learning-plan,.mobile-support-actions,.mobile-safety-disclosure{margin-top:20px}.mobile-section-heading,.daily-plan-title{justify-content:space-between;align-items:flex-start;gap:16px;display:flex}.mobile-section-heading span,.daily-plan-title span{color:var(--mobile-green);align-items:center;gap:6px;font-size:13px;font-weight:900;display:flex}.mobile-section-heading h2,.daily-plan-title h2{letter-spacing:0;margin:3px 0 0;font-size:23px;line-height:1.35}.mobile-section-heading small{color:#6b7772;white-space:nowrap;font-weight:800}.learner-sync-status{align-items:center;gap:7px;display:flex}.learner-sync-status button{width:32px;height:32px;color:var(--mobile-green);cursor:pointer;background:#fff;border:1px solid #c8d9d0;border-radius:7px;place-items:center;padding:0;display:grid}.learner-sync-status button:disabled{opacity:.55}.learner-options{grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;margin-top:14px;display:grid}.learner-options button{color:#42504b;text-align:left;cursor:pointer;background:#fff;border:1px solid #d3ddd8;border-radius:8px;align-content:center;justify-items:start;gap:5px;min-width:0;min-height:106px;padding:14px;display:grid;position:relative}.learner-options button:hover,.learner-options button.active{border-color:var(--mobile-green);color:var(--mobile-green-dark);background:#f3faf6}.learner-options strong,.learner-options span{overflow-wrap:anywhere;max-width:100%}.learner-options strong{font-size:16px}.learner-options span{color:#6b7772;font-size:13px}.learner-options .learner-progress-summary{color:var(--mobile-green-dark);font-weight:900}.learner-check{color:var(--mobile-green);position:absolute;top:9px;right:9px}.learner-sync-error{color:#8d2b24;background:#fff1ef;border-left:3px solid #b8392f;margin:9px 0 0;padding:9px 11px;font-size:12px}.learner-privacy{color:#596861;align-items:flex-start;gap:7px;margin:11px 0 0;font-size:13px;line-height:1.6;display:flex}.learner-privacy svg{color:var(--mobile-green);flex:none;margin-top:2px}.mobile-flow-strip{background:#fbfdfc;border:1px solid #c8d9d0;border-radius:8px;padding:18px}.mobile-flow-steps{grid-template-columns:1fr auto 1fr auto 1fr;align-items:center;gap:10px;margin-top:18px;display:grid}.mobile-flow-steps>div{text-align:center;justify-items:center;gap:4px;min-width:0;display:grid}.mobile-flow-steps>svg{color:#66857a}.mobile-flow-steps>div>svg{color:var(--mobile-green)}.mobile-flow-steps strong{font-size:15px}.mobile-flow-steps span{color:#6c7873;font-size:12px}.daily-learning-plan{border:2px solid var(--mobile-green);background:#fff;border-radius:8px;padding:22px}.daily-plan-title>strong{color:#6b7772;white-space:nowrap;font-size:13px}.duration-segments{border:1px solid #cfdad4;border-radius:7px;grid-template-columns:repeat(3,minmax(0,1fr));gap:0;margin:18px 0;display:grid;overflow:hidden}.graduation-estimate{border-left:3px solid var(--mobile-gold);background:#fff9e8;justify-content:space-between;align-items:center;gap:14px;margin-top:14px;padding:11px 13px;display:flex}.graduation-estimate span,.graduation-estimate strong{display:block}.graduation-estimate span{color:#7b6228;font-size:12px;font-weight:850}.graduation-estimate strong{color:#4f3c10;margin-top:2px;font-size:16px}.graduation-estimate small{color:#7b6b46;text-align:right;line-height:1.45}.duration-segments button{color:#4f5d57;cursor:pointer;background:#f8faf9;border:0;border-right:1px solid #cfdad4;min-height:44px;font-weight:850}.duration-segments button:last-child{border-right:0}.duration-segments button.active{background:var(--mobile-mint);color:var(--mobile-green-dark)}.daily-plan-steps{gap:0;margin:0;padding:0;list-style:none;display:grid}.daily-plan-steps li{border-bottom:1px solid #e4eae7;grid-template-columns:28px 34px minmax(0,1fr) auto;align-items:center;gap:9px;min-height:70px;display:grid}.daily-plan-steps li>span{background:var(--mobile-green);color:#fff;border-radius:50%;place-items:center;width:25px;height:25px;font-size:12px;font-weight:900;display:grid}.daily-plan-steps li>svg{color:var(--mobile-green)}.daily-plan-steps strong,.daily-plan-steps small{display:block}.daily-plan-steps strong{font-size:16px}.daily-plan-steps small{color:#69756f;margin-top:3px;line-height:1.4}.daily-plan-steps b{color:var(--mobile-green);white-space:nowrap;font-size:13px}.mobile-primary-action{background:var(--mobile-green);color:#fff;border-radius:7px;justify-content:center;align-items:center;gap:8px;min-height:54px;margin-top:18px;font-size:17px;font-weight:900;display:flex}.mobile-primary-action:hover{background:var(--mobile-green-dark)}.review-home-entry{border:1px solid #d8c58f;border-left:5px solid var(--mobile-gold);color:#17352a;background:#fff9e8;border-radius:8px;grid-template-columns:50px minmax(0,1fr) auto;align-items:center;gap:14px;min-height:104px;margin-top:20px;padding:17px 19px;display:grid}.challenge-home-entry,.formal-exam-home-entry{border:1px solid #8fc4ab;border-left:5px solid var(--mobile-green);color:#17352a;background:#edf8f2;border-radius:8px;grid-template-columns:54px minmax(0,1fr) auto;align-items:center;gap:15px;min-height:118px;margin-top:20px;padding:19px 21px;display:grid}.formal-exam-home-entry{background:#eef7f9;border-color:#a9c9d2 #a9c9d2 #a9c9d2 #2d6f82}.challenge-home-icon,.formal-exam-home-icon{width:52px;height:52px;color:var(--mobile-green);background:#fff;border-radius:8px;place-items:center;display:grid}.formal-exam-home-icon{color:#2d6f82}.challenge-home-copy,.challenge-home-copy small,.challenge-home-copy strong,.challenge-home-copy>span{min-width:0;display:block}.challenge-home-copy small{color:var(--mobile-green);font-size:12px;font-weight:900}.challenge-home-copy strong{margin-top:3px;font-size:21px;line-height:1.35}.challenge-home-copy>span{color:#5d6d66;margin-top:5px;font-size:13px;line-height:1.55}.challenge-home-action{background:var(--mobile-green);color:#fff;white-space:nowrap;border-radius:7px;justify-content:center;align-items:center;gap:6px;min-height:44px;padding:0 15px;font-size:14px;font-weight:900;display:inline-flex}.challenge-home-entry:hover{border-color:var(--mobile-green);background:#e5f5ed}.formal-exam-home-copy,.formal-exam-home-copy small,.formal-exam-home-copy strong,.formal-exam-home-copy>span{min-width:0;display:block}.formal-exam-home-copy small{color:#2d6f82;font-size:12px;font-weight:900}.formal-exam-home-copy strong{margin-top:3px;font-size:21px;line-height:1.35}.formal-exam-home-copy>span{color:#5d6d66;margin-top:5px;font-size:13px;line-height:1.55}.formal-exam-home-action{color:#fff;white-space:nowrap;background:#2d6f82;border-radius:7px;justify-content:center;align-items:center;gap:6px;min-height:44px;padding:0 15px;font-size:14px;font-weight:900;display:inline-flex}.formal-exam-home-entry:hover{background:#e5f3f6;border-color:#2d6f82}.review-home-icon{color:#8a681b;background:#fff;border-radius:50%;place-items:center;width:48px;height:48px;display:grid}.review-home-copy,.review-home-copy small,.review-home-copy strong,.review-home-copy>span{min-width:0;display:block}.review-home-copy small{color:#80631d;font-size:12px;font-weight:900}.review-home-copy strong{color:#21342d;margin-top:3px;font-size:19px;line-height:1.35}.review-home-copy>span{color:#6f684f;margin-top:4px;font-size:13px;line-height:1.5}.review-home-action{color:#fff;white-space:nowrap;background:#173e31;border-radius:7px;justify-content:center;align-items:center;gap:6px;min-height:42px;padding:0 13px;font-size:13px;font-weight:900;display:inline-flex}.review-home-entry:hover{background:#fff6d9;border-color:#b99b4b}.mobile-support-actions{gap:8px;display:grid}.mobile-support-actions>a{color:#17352a;background:#fff;border:1px solid #d8e0dc;border-radius:8px;grid-template-columns:34px minmax(0,1fr) 22px;align-items:center;gap:10px;min-height:76px;padding:12px 16px;display:grid}.native-app-entry{border:1px solid #d8e0dc;border-left:4px solid var(--mobile-green);color:#17352a;background:#f4faf7;border-radius:8px;grid-template-columns:34px minmax(0,1fr) 22px;align-items:center;gap:10px;min-height:76px;margin-top:8px;padding:12px 16px;display:grid}.native-app-entry>svg:first-child{color:var(--mobile-green)}.native-app-entry strong,.native-app-entry span{display:block}.native-app-entry strong{font-size:16px}.native-app-entry span{color:#6b7772;margin-top:3px;font-size:13px;line-height:1.45}.mobile-support-actions>a>svg:first-child{color:var(--mobile-green)}.mobile-support-actions strong,.mobile-support-actions span{display:block}.mobile-support-actions strong{font-size:16px}.mobile-support-actions span{color:#6b7772;margin-top:3px;font-size:13px;line-height:1.45}.mobile-safety-disclosure{border-top:1px solid #dbe4df;border-bottom:1px solid #dbe4df}.mobile-safety-disclosure>summary{min-height:80px;color:var(--mobile-green-dark);cursor:pointer;grid-template-columns:32px minmax(0,1fr) 20px;align-items:center;gap:10px;list-style:none;display:grid}.mobile-safety-disclosure>summary::-webkit-details-marker{display:none}.mobile-safety-disclosure>summary>svg{color:var(--mobile-green)}.mobile-safety-disclosure>summary strong,.mobile-safety-disclosure>summary small{display:block}.mobile-safety-disclosure>summary small{color:#66736e;margin-top:4px;line-height:1.45}.mobile-safety-disclosure[open]>summary>svg:last-child{transform:rotate(90deg)}.mobile-safety-disclosure .code-safety-guide{margin:0 0 18px}.audio-module-group>summary{cursor:pointer;grid-template-columns:34px minmax(0,1fr) auto;align-items:center;gap:10px;padding:15px 0 10px;list-style:none;display:grid}.audio-module-group>summary::-webkit-details-marker{display:none}.audio-module-group>summary>span:first-child{color:var(--learning);font-family:var(--font-mono);font-size:12px;font-weight:900}.audio-module-toggle{color:var(--safe);font-size:12px;font-weight:900}.audio-module-group[open] .audio-module-toggle{font-size:0}.audio-module-group[open] .audio-module-toggle:after{content:"收起";font-size:12px}.audio-module-group>.audio-select-module{border:1px solid var(--line);min-height:38px;margin-bottom:8px;padding:0 10px}@media (max-width:620px){body.edition-cloud_demo{--mobile-green:#0c513b;--mobile-green-dark:#073b2d;--mobile-mint:#eaf6f0;padding-bottom:calc(78px + env(safe-area-inset-bottom));background:#f7faf8}.edition-cloud_demo .top-safety{min-height:54px;padding:calc(7px + env(safe-area-inset-top)) 14px 7px;background:#073b2d}.edition-cloud_demo .safety-left>span>strong{font-size:13px}.edition-cloud_demo .top-safety-actions .verified-pill{border-color:#ffffff59;max-width:142px}.edition-cloud_demo .content{padding:0 14px 28px}.review-home-entry{grid-template-columns:42px minmax(0,1fr) 22px;gap:10px;min-height:96px;margin-top:14px;padding:14px 13px}.challenge-home-entry,.formal-exam-home-entry{grid-template-columns:42px minmax(0,1fr) 22px;gap:10px;min-height:102px;margin-top:14px;padding:14px 13px}.challenge-home-icon,.formal-exam-home-icon{width:40px;height:40px}.challenge-home-copy strong{font-size:16px}.challenge-home-copy>span{font-size:12px}.challenge-home-action{min-height:0;color:var(--mobile-green);background:0 0;padding:0;font-size:0}.challenge-home-action svg{width:21px;height:21px}.formal-exam-home-copy strong{font-size:16px}.formal-exam-home-copy>span{font-size:12px}.formal-exam-home-action{color:#2d6f82;background:0 0;min-height:0;padding:0;font-size:0}.formal-exam-home-action svg{width:21px;height:21px}.review-home-icon{width:40px;height:40px}.review-home-copy strong{font-size:16px}.review-home-copy>span{font-size:12px}.review-home-action{min-height:0;color:var(--mobile-green);background:0 0;padding:0;font-size:0}.review-home-action svg{width:21px;height:21px}.local-learning-home{background:0 0;border-bottom:1px solid #c6d8cf;border-left:0;border-right:0;border-radius:0;margin:0 0 18px;padding:0 0 18px}.wechat-welcome{padding:17px 2px 14px}.wechat-welcome .wechat-brand,.wechat-welcome p{display:none}.wechat-welcome h1{margin:0 0 3px;font-size:29px}.wechat-welcome p,.wechat-welcome>span:last-child{font-size:14px}.mobile-section-heading h2,.daily-plan-title h2{font-size:19px}.mobile-section-heading small{font-size:12px}.learner-switcher,.mobile-flow-strip,.daily-learning-plan,.mobile-support-actions,.mobile-safety-disclosure{margin-top:14px}.learner-switcher .mobile-section-heading,.mobile-flow-strip .mobile-section-heading{align-items:center}.learner-switcher .mobile-section-heading span,.mobile-flow-strip .mobile-section-heading span{display:none}.learner-switcher .mobile-section-heading h2,.mobile-flow-strip .mobile-section-heading h2{margin:0;font-size:16px}.learner-options{gap:7px;margin-top:10px}.learner-options button{min-height:88px;padding:9px 8px}.learner-options button>svg:not(.learner-check){width:18px;height:18px}.learner-options strong{font-size:14px}.learner-options span{white-space:nowrap;font-size:11px}.learner-privacy{margin-top:8px;font-size:12px;line-height:1.45}.mobile-flow-strip{padding:12px}.mobile-flow-steps{gap:5px;margin-top:12px}.mobile-flow-steps>div{gap:2px}.mobile-flow-steps>div>svg{width:20px;height:20px}.mobile-flow-steps strong{font-size:14px}.daily-learning-plan{padding:14px 13px}.daily-plan-title{gap:8px}.daily-plan-title>strong{font-size:11px}.duration-segments{margin:12px 0}.duration-segments button{min-height:40px}.daily-plan-steps li{grid-template-columns:26px 29px minmax(0,1fr) auto;gap:7px;min-height:61px}.daily-plan-steps small,.daily-plan-steps b{font-size:12px}.mobile-primary-action{min-height:50px;margin-top:13px}.graduation-estimate{margin-top:10px;padding:9px 10px}.graduation-estimate strong{font-size:15px}.graduation-estimate small{max-width:112px;font-size:11px}.edition-cloud_demo .mobile-tabbar{min-height:calc(66px + env(safe-area-inset-bottom));padding:7px 8px env(safe-area-inset-bottom);background:#fffffff7;border:0;border-top:1px solid #d7e0db;border-radius:0;bottom:0;left:0;right:0;box-shadow:0 -5px 18px #0f2d2214}.edition-cloud_demo .mobile-tabbar a{color:#596761;justify-content:center;gap:4px;min-width:0;min-height:50px;padding:4px 2px;font-size:11px}.edition-cloud_demo .mobile-tabbar a:first-child{color:var(--mobile-green)}.edition-cloud_demo .mobile-tabbar a svg{width:20px;height:20px}.edition-cloud_demo .chapter-section>p{line-height:1.85}.edition-cloud_demo .chapter-main{padding-bottom:12px}.edition-cloud_demo .mission-stage{padding:14px}.edition-cloud_demo .mission-options label{min-height:58px;padding:12px}.edition-cloud_demo .listen-page-header{border-radius:0;margin:0 -14px 16px;padding:20px 14px}.edition-cloud_demo .cloud-player{margin:0 -2px;padding:14px 12px}.edition-cloud_demo .audio-module-group{border-bottom:1px solid #dce5e0}.edition-cloud_demo .audio-module-group>summary{cursor:pointer;grid-template-columns:30px minmax(0,1fr) auto;align-items:center;gap:9px;min-height:68px;padding:8px 2px;list-style:none;display:grid}.edition-cloud_demo .audio-module-group>summary::-webkit-details-marker{display:none}.edition-cloud_demo .audio-module-group>summary h2,.edition-cloud_demo .audio-module-group>summary p{margin:0}.edition-cloud_demo .audio-module-group>summary h2{font-size:17px}.edition-cloud_demo .audio-module-group>summary p{color:#68756f;margin-top:3px;font-size:12px}.edition-cloud_demo .audio-module-toggle{color:var(--mobile-green);font-size:12px;font-weight:900}.edition-cloud_demo .audio-module-group[open] .audio-module-toggle:after{content:"收起"}.edition-cloud_demo .audio-module-group[open] .audio-module-toggle{font-size:0}.edition-cloud_demo .audio-module-group[open] .audio-module-toggle:after{font-size:12px}.edition-cloud_demo .audio-module-group>.audio-select-module{width:100%;min-height:42px;margin:4px 0 8px}}@media (min-width:621px){.wechat-learning-home{padding:4px 0 40px}.learner-options button{min-height:118px}.mobile-support-actions{grid-template-columns:repeat(2,minmax(0,1fr))}}
.s2-home,.s2-course-page,.s2-practice-page,.s2-listen-page,.s2-mistakes-page,.s2-stage-one{color:#17251f;max-width:1180px;margin:0 auto;padding:8px 0 48px}.s2-eyebrow{color:#176247;letter-spacing:.06em;font-size:13px;font-weight:900;display:block}.s2-page-header{border-bottom:1px solid var(--line);padding:26px 0 22px}.s2-page-header h1{margin:7px 0 6px;font-size:38px;line-height:1.18}.s2-page-header p{max-width:780px;color:var(--muted);margin:0;font-size:16px;line-height:1.75}.s2-home-hero{color:#fff;background:linear-gradient(135deg,#0b4b38,#12362c);border-radius:14px;grid-template-columns:minmax(0,1.35fr) minmax(260px,.65fr);align-items:center;gap:26px;padding:40px;display:grid}.s2-home-hero .s2-eyebrow{color:#9de2c5}.s2-home-hero h1{margin:8px 0 12px;font-size:46px;line-height:1.1}.s2-home-hero p{color:#d5e8df;max-width:690px;margin:0;font-size:17px;line-height:1.8}.s2-home-actions{flex-wrap:wrap;gap:10px;margin-top:24px;display:flex}.s2-home-actions .button{color:#123e30;background:#fff}.s2-home-actions .button.secondary{color:#fff;background:0 0;border-color:#7db59e}.s2-progress-card{background:#ffffff14;border:1px solid #fff3;border-radius:12px;padding:24px}.s2-progress-card>span,.s2-progress-card>strong{display:block}.s2-progress-card>span{color:#b8d8cb;font-size:13px}.s2-progress-card>strong{margin:8px 0;font-size:54px}.s2-progress-card p{color:#d8e9e1;margin:10px 0 0;font-size:13px}.s2-progress-track{background:#dce6e1;border-radius:99px;height:9px;overflow:hidden}.s2-progress-track span{border-radius:inherit;background:#25a36f;height:100%;transition:width .25s;display:block}.s2-progress-card .s2-progress-track{background:#ffffff29}.s2-progress-card .s2-progress-track span{background:#82e0b8}.s2-learner{background:#fff;border:1px solid #cddbd4;border-radius:9px;justify-content:space-between;align-items:center;gap:18px;margin:18px 0;padding:12px 15px;display:flex}.s2-learner>div:first-child{color:#5d6c66;align-items:center;gap:7px;display:flex}.s2-learner>div:first-child strong{color:#123e30}.s2-learner-buttons{gap:6px;display:flex}.s2-learner-buttons button{color:#57655f;cursor:pointer;background:#f8faf9;border:1px solid #d4dfda;border-radius:6px;align-items:center;gap:4px;padding:7px 11px;display:inline-flex}.s2-learner-buttons button.active{color:#0d5039;background:#e8f5ee;border-color:#176247;font-weight:900}.s2-today{background:#f2faf6;border:1px solid #b9d8ca;border-left:5px solid #176247;border-radius:9px;grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:22px;margin:20px 0;padding:22px 24px;display:grid}.s2-today span{color:#176247;font-size:12px;font-weight:900}.s2-today h2{margin:4px 0;font-size:24px}.s2-today p{color:#617069;margin:0}.s2-today>a{color:#fff;background:#176247;border-radius:7px;align-items:center;gap:6px;padding:12px 16px;font-weight:900;display:flex}.s2-home-section{margin-top:30px}.s2-section-heading h2{margin:3px 0 0;font-size:27px}.s2-section-heading span{color:#176247;font-size:13px;font-weight:900}.s2-home-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin-top:15px;display:grid}.s2-home-grid>a{background:#fff;border:1px solid #d3ddd8;border-radius:9px;grid-template-columns:44px minmax(0,1fr);gap:4px 12px;padding:20px;display:grid}.s2-home-grid>a>svg{color:#176247;grid-row:1/4}.s2-home-grid strong{font-size:19px}.s2-home-grid span{color:#65736d;line-height:1.6}.s2-home-grid b{color:#176247;align-items:center;gap:5px;margin-top:7px;font-size:13px;display:flex}.s2-home-grid>a:hover{background:#f5fbf8;border-color:#70ad91}.s2-route-map{background:#fff;border:1px solid #d4ddd9;border-radius:9px;margin-top:22px;padding:22px}.s2-route-map>div{align-items:center;gap:8px;display:flex}.s2-route-map ol{counter-reset:s2route;flex-wrap:wrap;gap:7px;margin:16px 0;padding:0;list-style:none;display:flex}.s2-route-map li{color:#365247;background:#eef4f1;border-radius:6px;padding:8px 11px;font-size:13px}.s2-route-map li+li:before{content:"→";color:#7c8d86;margin-right:12px}.s2-route-map p{color:#6c756f;align-items:flex-start;gap:7px;margin:12px 0 0;font-size:13px;display:flex}.s2-stage-one-entry{color:#45544e;border:1px dashed #b8c5bf;border-radius:8px;grid-template-columns:36px minmax(0,1fr) 22px;align-items:center;gap:10px;margin-top:18px;padding:15px 18px;display:grid}.s2-stage-one-entry small,.s2-stage-one-entry strong{display:block}.s2-stage-one-entry small{color:#7a8580}.s2-stage-one-entry strong{margin-top:2px}.s2-course-progress,.s2-practice-progress{background:#f3faf6;border:1px solid #cfe0d8;border-radius:8px;grid-template-columns:auto minmax(160px,1fr) auto;align-items:center;gap:16px;margin:16px 0;padding:14px 16px;display:grid}.s2-course-progress span,.s2-course-progress strong{display:block}.s2-course-progress span{color:#6b7973;font-size:12px}.s2-course-progress b,.s2-practice-progress b{color:#176247}.s2-reader-layout{grid-template-columns:275px minmax(0,1fr);align-items:start;gap:24px;display:grid}.s2-outline{background:#fff;border:1px solid #d6dfdb;border-radius:9px;max-height:calc(100vh - 88px);padding:17px;position:sticky;top:68px;overflow:auto}.s2-outline>strong,.s2-outline>small{display:block}.s2-outline>small{color:#78837e;margin:3px 0 11px}.s2-outline nav{gap:4px;display:grid}.s2-outline nav button{color:#3d4d46;text-align:left;cursor:pointer;background:0 0;border:0;border-radius:6px;grid-template-columns:18px 25px minmax(0,1fr);align-items:center;gap:7px;padding:8px;display:grid}.s2-outline nav button span{color:#809089}.s2-outline nav button b{font-size:12px}.s2-outline nav button em{text-overflow:ellipsis;white-space:nowrap;font-size:13px;font-style:normal;overflow:hidden}.s2-outline nav button.active{color:#0e503a;background:#eaf6f0;font-weight:900}.s2-outline nav button.active span{color:#18825b}.s2-outline nav button:has(.lucide-circle-check-big) span{color:#18825b}.s2-outline>a{color:#176247;border-top:1px solid #e3e9e6;align-items:center;gap:5px;margin-top:14px;padding-top:12px;font-size:12px;font-weight:900;display:flex}.s2-lesson{min-width:0}.s2-lesson>section,.s2-lesson-title{background:#fff;border:1px solid #d6dfdb;border-radius:10px;margin-bottom:14px;padding:25px}.s2-lesson-title{justify-content:space-between;gap:18px;display:flex}.s2-lesson-title span{color:#176247;font-size:12px;font-weight:900}.s2-lesson-title h2{margin:5px 0;font-size:31px}.s2-lesson-title p{color:#66746e;margin:0;font-size:16px}.s2-lesson-title>strong{color:#176247;white-space:nowrap;background:#e8f5ee;border-radius:99px;align-self:start;padding:5px 9px;font-size:12px}.s2-section-title{align-items:flex-start;gap:11px;margin-bottom:16px;display:flex}.s2-section-title>span{color:#fff;background:#173f32;border-radius:7px;place-items:center;width:34px;height:34px;font-size:12px;font-weight:900;display:grid}.s2-section-title small{color:#176247;align-items:center;gap:4px;font-weight:850;display:flex}.s2-section-title h3{margin:2px 0 0;font-size:21px}.s2-terms>div:last-child{grid-template-columns:repeat(2,minmax(0,1fr));gap:9px;display:grid}.s2-terms article{background:#fafcfb;border:1px solid #dce5e1;border-radius:7px;padding:14px}.s2-terms article strong{color:#176247}.s2-terms article p{color:#586760;margin:5px 0 0;line-height:1.6}.s2-flow ol{align-items:stretch;margin:0;padding:0;list-style:none;display:flex;overflow-x:auto}.s2-flow li{border-right:1px solid #dfe6e2;grid-template-columns:24px minmax(125px,1fr) 18px;align-items:center;gap:7px;min-width:155px;padding:10px;display:grid}.s2-flow li:last-child{border-right:0}.s2-flow li>span{color:#176247;background:#e6f3ed;border-radius:50%;place-items:center;width:23px;height:23px;font-size:11px;font-weight:900;display:grid}.s2-flow li p{margin:0;font-size:13px;line-height:1.5}.s2-flow li svg{color:#789087}.s2-code{border-top:4px solid #275d81!important}.s2-code-grid{grid-template-columns:minmax(0,1.15fr) minmax(260px,.85fr);gap:14px;display:grid}.s2-code pre,.s2-practice-card pre{color:#e9f5ef;white-space:pre-wrap;background:#14231e;border-radius:8px;margin:0;padding:18px;font:14px/1.75 Consolas,Microsoft YaHei,monospace;overflow:auto}.s2-code-grid>ol{gap:8px;margin:0;padding:0;list-style:none;display:grid}.s2-code-grid>ol li{background:#f8faf9;border:1px solid #dce4e0;border-radius:7px;grid-template-columns:26px minmax(0,1fr);gap:8px;padding:11px;display:grid}.s2-code-grid>ol b{color:#155b42;background:#dbece4;border-radius:50%;place-items:center;width:25px;height:25px;display:grid}.s2-code-grid>ol p{margin:0;line-height:1.55}.s2-code-tip{color:#6c541e;background:#fff8e5;border-left:3px solid #b68724;gap:7px;margin:14px 0 0;padding:11px;display:flex}.s2-quiz{border-top:4px solid #18825b!important}.s2-question{font-size:19px;font-weight:850}.s2-options{gap:8px;margin:14px 0;display:grid}.s2-options button{color:#253a31;text-align:left;cursor:pointer;background:#fff;border:1px solid #d3ddd8;border-radius:7px;grid-template-columns:28px minmax(0,1fr);align-items:center;gap:8px;min-height:50px;padding:10px 13px;display:grid}.s2-options button>span{background:#edf2ef;border-radius:50%;place-items:center;width:27px;height:27px;font-size:12px;font-weight:900;display:grid}.s2-options button.selected{background:#f0f8fb;border-color:#387ca1}.s2-options button.correct{background:#e7f6ee;border-color:#52a27f}.s2-options button.wrong{background:#fff0ed;border-color:#d78479}.s2-options button:disabled{opacity:1;cursor:default}.s2-submit{margin-top:4px}.s2-submit:disabled{opacity:.45;cursor:not-allowed}.s2-answer{border-radius:8px;padding:14px;line-height:1.65}.s2-answer.correct{color:#0c5c3d;background:#e4f5ec}.s2-answer.wrong{color:#8e3025;background:#fff0ed}.s2-answer p{margin:4px 0}.s2-answer small{margin:5px 0;display:block}.s2-answer button{color:inherit;cursor:pointer;background:#fff;border:1px solid;border-radius:6px;align-items:center;gap:5px;margin-top:8px;padding:7px 10px;display:inline-flex}.s2-pager{justify-content:space-between;align-items:center;padding:14px 0;display:flex}.s2-pager button{color:#25483a;cursor:pointer;background:#fff;border:1px solid #cdd8d3;border-radius:7px;align-items:center;gap:5px;padding:10px 13px;display:flex}.s2-pager button:disabled{opacity:.35;cursor:default}.s2-pager span{color:#718079;font-size:13px}.s2-practice-progress>span{font-weight:900}.s2-practice-card{background:#fff;border:1px solid #d5dfda;border-radius:11px;max-width:850px;margin:0 auto;padding:28px}.s2-practice-type{color:#176247;align-items:center;gap:6px;font-size:13px;font-weight:900;display:flex}.s2-practice-card h2{margin:10px 0 18px;font-size:25px;line-height:1.45}.s2-practice-card pre{margin-bottom:16px}.s2-finish,.s2-empty{text-align:center;background:#fff;border:1px solid #cddbd4;border-radius:12px;justify-items:center;max-width:760px;margin:50px auto;padding:48px;display:grid}.s2-finish svg,.s2-empty svg{color:#18825b}.s2-finish span{color:#176247;margin-top:12px;font-weight:900}.s2-finish h1,.s2-empty h2{margin:6px 0}.s2-finish p,.s2-empty p{color:#68756f}.s2-finish>div{gap:8px;display:flex}.s2-listen-note{background:#eef7f9;border-left:4px solid #2d6f82;gap:12px;margin:18px 0;padding:16px;display:flex}.s2-listen-note strong,.s2-listen-note span{display:block}.s2-listen-note span{color:#5f716a;margin-top:3px}.s2-audio-list{gap:12px;display:grid}.s2-audio-list article{background:#fff;border:1px solid #d5dfda;border-radius:10px;grid-template-columns:48px minmax(0,1fr) 110px;gap:16px;padding:22px;display:grid}.s2-audio-list article.active{background:#f3fafc;border-color:#4385a0}.s2-audio-number{color:#2d6f82;background:#e1f0f4;border-radius:50%;place-items:center;width:45px;height:45px;font-weight:900;display:grid}.s2-audio-list article span{color:#2d6f82;font-size:12px;font-weight:850}.s2-audio-list article h2{margin:3px 0 8px;font-size:21px}.s2-audio-list article p{color:#45564f;max-width:850px;margin:0;line-height:1.85}.s2-self-check{color:#65521f;background:#fff8e5;border-left:3px solid #b68724;margin-top:12px;padding:11px}.s2-self-check strong{margin-right:8px}.s2-audio-actions{flex-direction:column;gap:7px;display:flex}.s2-audio-actions button{color:#2d6f82;cursor:pointer;background:#fff;border:1px solid #2d6f82;border-radius:6px;justify-content:center;align-items:center;gap:5px;padding:9px;display:flex}.s2-next-link{color:#176247;background:#f3faf6;border:1px solid #bfd7cc;border-radius:8px;margin-top:18px;padding:16px;font-weight:900;display:block}.s2-next-link span{color:#687770;margin-left:8px;font-weight:400}.s2-mistake-summary{background:#fff9e8;border:1px solid #d8c58f;border-left:4px solid #b68724;align-items:center;gap:8px;padding:15px;display:flex}.s2-mistake-summary span{color:#766a4e;margin-left:auto}.s2-mistake-list>article{background:#fff;border:1px solid #d6dfdb;border-radius:9px;margin-top:12px;padding:22px}.s2-mistake-list>article>span{color:#176247;font-size:12px;font-weight:900}.s2-mistake-list>article h2{font-size:20px}.s2-stage-one header{background:#fff;border:1px solid #d5dfda;border-radius:11px;padding:30px}.s2-stage-one header>a{color:#176247;align-items:center;gap:5px;margin-bottom:22px;font-size:13px;font-weight:900;display:flex}.s2-stage-one header h1{margin:7px 0;font-size:38px}.s2-stage-one header p{color:#63716b;max-width:760px;line-height:1.7}.s2-stage-one-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin:16px 0;display:grid}.s2-stage-one-grid>a{background:#fff;border:1px solid #d5dfda;border-radius:8px;grid-template-columns:34px minmax(0,1fr) 18px;align-items:center;gap:10px;padding:18px;display:grid}.s2-stage-one-grid>a>svg:first-child{color:#176247}.s2-stage-one-grid strong,.s2-stage-one-grid span{display:block}.s2-stage-one-grid span{color:#68756f;margin-top:3px;font-size:13px}.s2-stage-one>.button{display:inline-flex}@media (max-width:980px){.s2-home-hero,.s2-reader-layout{grid-template-columns:1fr}.s2-outline{max-height:none;position:static}.s2-outline nav{grid-template-columns:repeat(2,minmax(0,1fr))}.s2-code-grid{grid-template-columns:1fr}.s2-audio-list article{grid-template-columns:46px minmax(0,1fr)}.s2-audio-actions{flex-direction:row;grid-column:2}.s2-audio-actions button{min-width:100px}}@media (max-width:620px){.s2-home,.s2-course-page,.s2-practice-page,.s2-listen-page,.s2-mistakes-page,.s2-stage-one{padding:0 0 28px}.s2-page-header{padding:8px 0 16px}.s2-page-header h1,.s2-stage-one header h1{font-size:29px}.s2-home-hero{border-radius:0;margin:0 -14px;padding:25px 17px}.s2-home-hero h1{font-size:34px}.s2-learner{flex-direction:column;align-items:stretch}.s2-learner-buttons{grid-template-columns:repeat(3,1fr);display:grid}.s2-learner-buttons button{justify-content:center;padding:7px 4px}.s2-today{grid-template-columns:1fr}.s2-today>a{justify-content:center}.s2-home-grid,.s2-stage-one-grid{grid-template-columns:1fr}.s2-route-map ol{display:grid}.s2-route-map li+li:before{content:"↓";margin-right:8px}.s2-course-progress,.s2-practice-progress{grid-template-columns:1fr auto}.s2-course-progress .s2-progress-track,.s2-practice-progress .s2-progress-track{grid-area:2/1/auto/3}.s2-outline{padding:12px}.s2-outline nav{display:flex;overflow-x:auto}.s2-outline nav button{grid-template-columns:17px 22px;min-width:92px}.s2-outline nav button em{display:none}.s2-lesson>section,.s2-lesson-title,.s2-practice-card{padding:17px}.s2-lesson-title h2{font-size:25px}.s2-terms>div:last-child{grid-template-columns:1fr}.s2-flow ol{display:grid}.s2-flow li{border-bottom:1px solid #dfe6e2;border-right:0;grid-template-columns:24px minmax(0,1fr) 18px}.s2-code pre{font-size:12px}.s2-audio-list article{grid-template-columns:38px minmax(0,1fr);padding:15px}.s2-audio-number{width:36px;height:36px}.s2-audio-actions{grid-column:1/3}.s2-mistake-summary{flex-wrap:wrap;align-items:flex-start}.s2-mistake-summary span{width:100%;margin-left:30px}.s2-stage-one header{padding:20px}}
body.edition-cloud_demo{--s2-green:#176247;--s2-ink:#172b22;--s2-muted:#5d7065;--s2-line:#d9e4dd;background:#f5f8f6}body.edition-cloud_demo .content{width:100%;min-width:0;max-width:none;padding:28px clamp(20px,3vw,56px) 60px}body.edition-cloud_demo :is(.s2-home,.s2-course-page,.s2-practice-page,.s2-listen-page,.s2-mistakes-page){width:100%;max-width:1440px}body.edition-cloud_demo .nav a[aria-current=page]{color:#14553c;background:#e8f3ed;border-color:#c9e0d2}body.edition-cloud_demo .nav a[aria-current=page] .nav-icon{color:#fff;background:#176247}body.edition-cloud_demo .mobile-tabbar a[aria-current=page]{color:#176247;background:#eaf5ee;border-radius:10px}body.edition-cloud_demo .sidebar{overflow-y:auto}body.edition-cloud_demo .nav a{border-radius:10px}body.edition-cloud_demo .s2-page-header{padding:14px 0 24px}body.edition-cloud_demo .s2-page-header h1{letter-spacing:-.02em;overflow-wrap:anywhere;min-width:0;margin:8px 0 12px;font-size:clamp(27px,2.6vw,38px);line-height:1.35}body.edition-cloud_demo .s2-page-header p{max-width:none;color:var(--s2-muted);line-height:1.85}body.edition-cloud_demo .s2-eyebrow{letter-spacing:.04em;font-size:12px;font-weight:650}body.edition-cloud_demo .s2-home-hero{border-radius:20px;gap:32px;padding:clamp(24px,3vw,44px)}body.edition-cloud_demo .s2-home-hero h1{font-size:clamp(29px,3vw,44px);line-height:1.3}body.edition-cloud_demo :is(.s2-home-grid>a,.s2-route-map,.s2-practice-card,.s2-mistake-list>article,.notebook.notebook-page){border-color:var(--s2-line);border-radius:16px}body.edition-cloud_demo .s2-home-grid{gap:16px}body.edition-cloud_demo .s2-home-grid>a{padding:24px;transition:background .15s,border-color .15s}body.edition-cloud_demo .s2-home-grid strong{font-size:18px;font-weight:650}body.edition-cloud_demo .s2-home-grid span{font-size:15px;line-height:1.8}body.edition-cloud_demo .s2-learner{border-bottom:0;border-radius:12px 12px 0 0;flex-wrap:wrap;margin-bottom:0}.s2-sync-status{color:#607268;background:#fff;border:1px solid #cddbd4;border-top:0;border-radius:0 0 12px 12px;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:8px;margin:0 0 24px;padding:8px 15px 12px;font-size:13px;line-height:1.6;display:flex}.s2-sync-status>button{color:#176247;cursor:pointer;background:#f5faf7;border:1px solid #cbdcd1;border-radius:8px;min-height:36px;padding:6px 12px}body.edition-cloud_demo .s2-reader-layout{grid-template-columns:250px minmax(0,1fr);gap:28px}body.edition-cloud_demo .s2-outline{border-radius:14px;padding:14px}body.edition-cloud_demo .s2-outline nav button{border-radius:8px;align-items:start;min-height:44px;padding:10px 8px}body.edition-cloud_demo .s2-outline nav button em{white-space:normal;font-size:13px;line-height:1.6}body.edition-cloud_demo .s2-lesson-title{border-radius:16px;padding:24px}body.edition-cloud_demo .s2-lesson-title h2{font-size:clamp(25px,2.3vw,32px);line-height:1.4}body.edition-cloud_demo .s2-lesson>section{border-radius:16px;padding:clamp(18px,2vw,30px)}body.edition-cloud_demo .s2-lesson :is(p,li){overflow-wrap:anywhere;font-size:16px;line-height:1.95}body.edition-cloud_demo .reader-file pre{font-size:16px;line-height:1.9}body.edition-cloud_demo .reader-file header{background:#f0f6f2;padding:18px 20px}body.edition-cloud_demo .reader-file header code{color:#176247;font-size:14px}body.edition-cloud_demo .reader-connection>.reader-connection-current{color:#204e36;background:#eaf5ee;border-color:#176247}body.edition-cloud_demo .reader-connection-context{opacity:.8}body.edition-cloud_demo :is(.s2-options button,.help-option){min-height:48px;font:inherit;border-radius:10px;line-height:1.75}body.edition-cloud_demo .s2-options button{white-space:normal;grid-template-columns:28px minmax(0,1fr);align-items:start;padding:14px}body.edition-cloud_demo .s2-options button .reader-option-text{width:auto;min-width:0;height:auto;font:inherit;text-align:left;overflow-wrap:anywhere;background:0 0;display:block}body.edition-cloud_demo .s2-options button.selected{background:#edf7f1;border-color:#176247}body.edition-cloud_demo .s2-practice-card{max-width:1000px;padding:clamp(20px,3vw,36px)}body.edition-cloud_demo .s2-practice-card h2{font-size:24px;line-height:1.6}body.edition-cloud_demo .s2-mistake-summary{border-radius:10px;flex-wrap:wrap;line-height:1.7}body.edition-cloud_demo .course-goal-overview{border-radius:16px}body.edition-cloud_demo .course-goal-overview>p{margin:12px 0}body.edition-cloud_demo .course-goal-overview>h2{margin-bottom:16px}body.edition-cloud_demo .course-goal-overview>progress{margin:12px 0;display:block}body.edition-cloud_demo .s2-options button.correct{background:#e7f6ee;border-color:#52a27f}body.edition-cloud_demo .s2-options button.wrong{background:#fff0ed;border-color:#d78479}body.edition-cloud_demo .notebook .help-toolbar{gap:10px}body.edition-cloud_demo .help-thread{border-radius:14px;padding:20px}body.edition-cloud_demo :is(button,a,summary,input,select,textarea):focus-visible{outline-offset:3px;outline:3px solid #36815c}body.edition-cloud_demo :is(button,a,summary){-webkit-tap-highlight-color:transparent}body.edition-cloud_demo button:disabled{cursor:not-allowed}@media (min-width:981px){body.s2-reading-focus .s2-sync-status{display:none}body.edition-cloud_demo.s2-reading-focus .s2-reader-layout{display:block}body.edition-cloud_demo.s2-reading-focus .reader-outline-open{grid-template-columns:250px minmax(0,1fr);display:grid}body.edition-cloud_demo.s2-reading-focus .s2-course-page{max-width:none}body.edition-cloud_demo.s2-reading-focus .reader-file pre{font-size:17px}}@media (max-width:1100px){body.edition-cloud_demo .s2-reader-layout{grid-template-columns:210px minmax(0,1fr);gap:18px}}@media (max-width:980px){body.edition-cloud_demo .content{padding:20px 20px 100px}body.edition-cloud_demo .s2-reader-layout{grid-template-columns:1fr}body.edition-cloud_demo .s2-outline{max-height:280px;position:static}body.edition-cloud_demo .s2-home-hero{grid-template-columns:1fr}body.edition-cloud_demo .s2-progress-card>strong{font-size:38px}}@media (max-width:600px){body.edition-cloud_demo .content{padding:16px 14px 100px}body.edition-cloud_demo .s2-page-header{padding-top:8px}body.edition-cloud_demo .s2-home-grid{grid-template-columns:1fr}body.edition-cloud_demo .s2-learner{gap:12px}.s2-learner-buttons{flex-wrap:wrap;width:100%}.s2-learner-buttons button{flex:1;justify-content:center;min-height:42px}body.edition-cloud_demo .s2-lesson>section{padding:17px}body.edition-cloud_demo .reader-file pre{font-size:15px}body.edition-cloud_demo .s2-pager{flex-wrap:wrap;gap:10px}body.edition-cloud_demo .s2-mistake-summary span{margin-left:0}}@media (prefers-reduced-motion:reduce){body.edition-cloud_demo *{scroll-behavior:auto!important;transition:none!important}}@media print{.s2-sync-status,.s2-audio-player{display:none!important}}