/* Authored opening in the same 16:9 engine; scoped away from lesson layouts. */
.opening-slide{position:absolute;inset:0;width:1600px;height:900px;background:#fff;overflow:hidden;color:var(--ink)}
.opening-slide .slide-content{position:absolute;left:76px;right:76px;top:114px;bottom:144px;z-index:1}
.opening-slide h1{font-size:62px;font-weight:750;line-height:1.06;letter-spacing:-.045em;max-width:none;margin:0 0 24px}
.opening-slide h3{font-size:29px;font-weight:700;line-height:1.2;letter-spacing:-.025em;margin:0}
.opening-slide p{font-size:27px;line-height:1.35;margin:0}
.opening-slide .eyebrow{font-size:21px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;margin:0 0 18px}
.opening-slide .cover-heading{display:flex;align-items:center;gap:34px;height:146px;margin-bottom:14px}.opening-slide .cover-heading h1{margin:0}
.opening-slide .chatgpt-logo{display:block;width:194px;height:194px;flex:none}
.opening-slide.layout-cover{background:var(--yellow)}.opening-slide.layout-cover::after{content:'';position:absolute;inset:0 0 0 1030px;clip-path:polygon(42% 0,100% 0,100% 100%,0 100%);background:#111}.opening-slide.layout-cover .slide-top,.opening-slide.layout-cover .slide-bottom{z-index:2}.opening-slide.layout-cover .brand::before{background:#111}.opening-slide.layout-cover .slide-top>span:last-child{color:#fff}.opening-slide.layout-cover .slide-bottom>span:last-child{color:#fff}.opening-slide.layout-cover .slide-content{inset:0;z-index:1}.opening-slide .cover-copy{position:absolute;top:172px;left:76px;width:990px}.opening-slide .cover-copy h1{font-size:138px;font-weight:800;margin:0 0 14px;letter-spacing:-.065em}.opening-slide .cover-copy .eyebrow{margin-bottom:35px}.opening-slide .cover-title{font-size:77px!important;line-height:1.06!important;font-weight:700;letter-spacing:-.05em}.opening-slide .cover-description{font-size:30px!important;margin-top:38px;line-height:1.4!important}.opening-slide .cover-route{position:absolute;left:1185px;top:238px;width:340px;height:432px;color:white;z-index:2}.opening-slide .route-line{position:absolute;left:27px;top:30px;width:2px;height:329px;background:#777}.opening-slide .route-stop{position:relative;display:flex;align-items:center;gap:20px;height:110px}.opening-slide .route-stop span{width:56px;height:56px;display:flex;align-items:center;justify-content:center;background:#111;border:2px solid #777;font-size:19px}.opening-slide .route-stop strong{font-size:27px;font-weight:550}.opening-slide .route-stop:last-child span{background:var(--yellow);border-color:var(--yellow);color:#111}.opening-slide .route-stop:last-child strong{color:var(--yellow);font-weight:700}.opening-slide .cover-bottom{position:absolute;left:76px;bottom:107px;font-size:24px!important;font-weight:550}.opening-slide .lead{color:var(--muted);font-size:29px!important;line-height:1.4!important}.opening-slide .purpose-grid{display:grid;grid-template-columns:1fr 1fr;column-gap:80px;row-gap:30px;margin:32px 0 28px}.opening-slide .purpose-item{display:flex;gap:28px;align-items:center}.opening-slide .purpose-item svg{width:88px;height:80px;flex:none;background:var(--yellow);padding:9px}.opening-slide .purpose-item h3{margin-bottom:7px;font-size:32px}.opening-slide .purpose-item p{font-size:26px}.opening-slide .takeaway{border-left:8px solid var(--yellow);padding:12px 24px;font-weight:600;font-size:29px!important;line-height:1.35!important}.opening-slide.layout-day .slide-content,.opening-slide.layout-day-two .slide-content{top:114px}.opening-slide.layout-day h1,.opening-slide.layout-day-two h1{font-size:58px}.opening-slide .day-rows{margin-top:20px}.opening-slide .day-row{display:grid;grid-template-columns:64px minmax(0,1fr) 356px;gap:22px;padding:26px 0;border-top:2px solid #111;align-items:start;min-height:138px}.opening-slide .chapter-no{font-size:41px;font-weight:750;line-height:1.25;background:var(--yellow);width:62px;height:62px;display:flex;align-items:center;justify-content:center}.opening-slide .chapter-text h3{margin-bottom:9px;font-size:29px}.opening-slide .chapter-text p{font-size:26px;max-width:870px}.opening-slide .day-result{padding:2px 0 0 25px;border-left:2px solid #d3d3d6;min-height:89px}.opening-slide .day-result span{display:block;font-size:19px;color:var(--muted);margin-bottom:8px}.opening-slide .day-result strong{font-size:27px;line-height:1.25;display:block;letter-spacing:-.025em}.opening-slide .slide-note{font-size:24px!important;margin-top:21px;color:var(--muted)}.opening-slide .second-day{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:42px;margin-top:15px}.opening-slide .second-row{display:grid;grid-template-columns:62px minmax(0,1fr);gap:22px;margin-bottom:12px;padding-top:12px;border-top:2px solid #111}.opening-slide .second-row h3{font-size:25px;line-height:1.18;margin:3px 0 8px}.opening-slide .second-row p{font-size:24px;line-height:1.25}.opening-slide .second-row .mode{font-size:17px;text-transform:uppercase;letter-spacing:.07em;font-weight:700;color:var(--muted)}.opening-slide .final-task{background:var(--yellow);padding:27px 30px;align-self:stretch}.opening-slide .final-task>p{font-size:24px}.opening-slide .final-task h3{font-size:36px;margin:10px 0 0}.opening-slide .final-task>strong{font-size:24px;line-height:1.3;display:block}.opening-slide .task-graphic{height:139px;position:relative;margin:18px 0 8px;border:3px solid #111;background:#fff;width:174px;transform:rotate(-5deg);padding:26px 18px}.opening-slide .task-graphic span{display:block;width:55%;height:8px;background:#111;margin-bottom:17px}.opening-slide .task-graphic i{display:block;width:100%;height:4px;background:#aaa;margin-bottom:12px}.opening-slide .task-graphic b{position:absolute;bottom:-15px;right:-26px;width:61px;height:61px;background:#111;color:var(--yellow);font-size:45px;display:flex;align-items:center;justify-content:center;transform:rotate(5deg)}.opening-slide .boundaries{display:grid;grid-template-columns:1fr 1fr;gap:30px;border-top:1px solid #bbb;margin-top:8px;padding-top:17px}.opening-slide .boundaries p{font-size:22px;line-height:1.35}.opening-slide .boundaries strong{font-size:23px}.opening-slide .work-path{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:26px;list-style:none;margin:45px 0 0;padding:0}.opening-slide .work-path li{position:relative;padding-top:22px;border-top:3px solid #111}.opening-slide .work-path li:not(:last-child)::after{content:'→';position:absolute;right:-23px;top:-26px;font-size:36px;background:#fff;padding:0 3px}.opening-slide .step-no{font-size:25px;font-weight:700;background:var(--yellow);display:inline-block;padding:4px 12px;margin-bottom:23px}.opening-slide .work-path h3{font-size:30px;margin-bottom:12px}.opening-slide .work-path p{font-size:25px;line-height:1.35}.opening-slide .loop{display:flex;gap:18px;align-items:center;background:var(--wash);padding:18px 24px;margin:35px 0 28px}.opening-slide .loop>span{display:flex;align-items:center}.opening-slide .loop svg{width:52px;height:40px}.opening-slide .loop p{font-size:26px}.opening-slide .support-lines{display:grid;grid-template-columns:1fr 1fr;gap:50px}.opening-slide .support-lines p{font-size:26px;line-height:1.4}.opening-slide .material-route{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:42px;margin-top:30px;padding-bottom:27px;border-bottom:2px solid #111}.opening-slide .material-route>div{position:relative;display:grid;grid-template-columns:62px minmax(0,1fr);column-gap:20px}.opening-slide .material-route>div:not(:last-child)::after{content:'→';position:absolute;right:-35px;top:14px;font-size:34px}.opening-slide .material-route>div>span{grid-row:1/3;width:62px;height:62px;background:var(--yellow);font-size:24px;font-weight:700;display:flex;align-items:center;justify-content:center}.opening-slide .material-route h3{font-size:28px;margin-bottom:7px}.opening-slide .material-route p{font-size:23px}.opening-slide .burger{display:flex;flex-direction:column;width:29px;gap:6px}.opening-slide .burger b{display:block;height:3px;background:#111}.opening-slide .tool-lines{display:grid;grid-template-columns:1fr 1fr 1fr;gap:45px;margin:30px 0 32px}.opening-slide .tool-lines section>span{font-size:19px;font-weight:700;color:var(--muted)}.opening-slide .tool-lines h3{font-size:28px;margin:10px 0 12px}.opening-slide .tool-lines p{font-size:25px;line-height:1.4}.opening-slide.layout-start::after{content:'';position:absolute;right:0;top:0;width:170px;height:900px;background:var(--yellow);clip-path:polygon(100% 0,100% 100%,0 100%)}.opening-slide.layout-start .slide-content{z-index:1}.opening-slide.layout-start h1{font-size:76px;margin-top:42px}.opening-slide .start-description{font-size:34px!important;color:var(--muted);margin-top:30px}.opening-slide .interests{display:flex;gap:32px;margin-top:40px}.opening-slide .interests span{font-size:26px;border-bottom:5px solid var(--yellow);padding-bottom:9px}.opening-slide .start-bridge{position:absolute;left:0;right:85px;bottom:12px;display:flex;align-items:center;gap:26px;border-top:2px solid #111;padding-top:27px}.opening-slide .start-bridge>span{font-size:57px;background:var(--yellow);width:78px;height:78px;text-align:center;line-height:1.2;flex:none}.opening-slide .start-bridge p{font-size:24px;margin-bottom:5px;color:var(--muted)}.opening-slide .start-bridge h3{font-size:34px}

.opening-slide.layout-cover .slide-content{inset:0;z-index:1}.opening-slide.layout-cover .cover-bottom{bottom:167px}
.opening-slide.layout-cover .cover-copy{width:1060px;top:150px}
.opening-slide.layout-cover .cover-heading h1{font-size:138px;letter-spacing:-.065em}
.opening-slide .day-row{padding:18px 0;min-height:122px}.opening-slide .slide-note{margin-top:12px}
.opening-slide .purpose-grid{margin:24px 0 20px;row-gap:24px}
.opening-slide .work-path{margin-top:24px}.opening-slide .loop{margin:24px 0 20px}
.opening-slide.layout-start .start-bridge{bottom:64px}
#slide-canvas.has-opening::before{display:none}
#slide-canvas.has-opening+.stage-toolbar{z-index:2}
#slide-canvas.has-opening~.stage-footer{z-index:2}
#slide-canvas.is-cover~.stage-footer{background:#fff;padding:12px 16px;left:calc(64px * var(--scale));right:calc(64px * var(--scale));border:0}
#slide-canvas.is-cover+.stage-toolbar .brand{color:#000}
.opening-slide:is(.layout-day,.layout-day-two) .slide-content{bottom:114px}