/* One unified catalog of 28 class topics with equal visibility and full lesson materials. */
.v1800-catalog{margin-top:1.35rem;margin-bottom:2rem}
.v1800-class-section{border:1px solid #d6e3e8;background:#fff;border-radius:14px;padding:1.35rem}
.v1800-catalog-intro{max-width:850px}
.v1800-catalog-intro h2{font-size:clamp(1.65rem,3.2vw,2.2rem);line-height:1.2;color:#173950;margin:.4rem 0 .75rem}
.v1800-catalog-intro>p:last-child{color:#445d6b;line-height:1.7}
.v1800-catalog-controls{display:grid;grid-template-columns:minmax(0,2fr) minmax(0,1fr);gap:.85rem;margin:1.3rem 0 .5rem}
.v1800-field{display:grid;gap:.45rem;font-size:.9rem;font-weight:750;color:#25485a}
.v1800-field input,.v1800-field select{background:#fff;color:#183b51;width:100%;font:inherit;font-weight:400;box-sizing:border-box;border:1px solid #b7ccd4;border-radius:8px;padding:.78rem;min-height:45px}
.v1800-class-count{color:#4b6470;font-size:.86rem;font-weight:650;margin:.85rem 0}
.v1800-class-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:.85rem}
.v1800-class-card{border:1px solid #d9e5e9;border-radius:10px;background:#f9fcfc;padding:1.05rem;display:flex;flex-direction:column;gap:.55rem;min-width:0}
.v1800-class-card h3{font-size:1.13rem;line-height:1.3;color:#183b4d;margin:0}
.v1800-class-card p{line-height:1.55;font-size:.92rem;margin:.15rem 0}
.v1800-class-card .v1800-card-kicker{color:#166c77;letter-spacing:.02em;text-transform:uppercase;font-size:.73rem;font-weight:800}
.v1800-class-card .btn{align-self:start;margin-top:auto;min-height:44px;font-size:.85rem;white-space:normal;text-align:center}
.v1800-more{min-height:44px;margin-top:1rem}
.v1800-empty{grid-column:1/-1;min-height:80px}
.v1800-class-viewer{margin-top:1.25rem;padding:1.45rem!important;border:1px solid #b5d3d9!important;scroll-margin-top:135px}
.v1800-class-viewer h3{color:#143951;font-size:1.5rem;margin:.5rem 0}
.v1800-view-label{font-weight:800;letter-spacing:.05em;font-size:.78rem;color:#166d78}
.v1800-material-block{margin-top:1.15rem;padding-top:1rem;border-top:1px solid #dfeaed}
.v1800-material-block h4{font-size:1.15rem;color:#143f54;margin:0 0 .65rem}
.v1800-material-block ol{padding-left:1.25rem}
.v1800-material-block li{line-height:1.65;margin:.35rem 0}
.v1800-glossary{display:grid;grid-template-columns:minmax(130px,1fr) minmax(0,3fr);gap:.45rem 1rem}
.v1800-glossary dt{font-weight:800;color:#174a5c}
.v1800-glossary dd{margin:0;color:#344f5d;line-height:1.5}
.v1800-quiz-question{border:1px solid #d7e5e9;border-radius:10px;padding:.95rem;margin:.85rem 0}
.v1800-quiz-question legend{font-weight:760;line-height:1.45}
.v1800-quiz-choice{display:flex;align-items:flex-start;gap:.7rem;line-height:1.5;padding:.35rem 0;font-size:.93rem}
.v1800-quiz-choice input{width:18px;height:18px;flex:0 0 18px;margin:.22rem 0 0}
.v1800-quiz-feedback{color:#175764;line-height:1.65;font-size:.94rem}
.v1800-quiz-feedback ol{margin:.45rem 0}
.v1800-small{font-size:.86rem;color:#536977;line-height:1.6}
.v1800-mini-actions{display:flex;gap:.65rem;flex-wrap:wrap;margin:1rem 0}
.v1800-mini-actions .btn{min-height:44px}
.v1800-teacher{border-top:1px solid #dfeaed;border-bottom:1px solid #dfeaed;padding-bottom:1rem}
.v1800-teacher>summary{cursor:pointer;font-size:1.1rem;font-weight:780;color:#144b5b;min-height:44px;padding:.65rem .2rem}
.v1800-teacher[open]>summary{margin-bottom:.4rem}
.v1800-teacher h5{font-size:1rem;margin:1rem 0 .5rem}
.v1800-catalog :is(input,select,button,summary):focus-visible,.v1800-class-viewer :is(input,button):focus-visible{outline:3px solid #14798a;outline-offset:3px}
@media(max-width:980px){.v1800-class-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:700px){.v1800-class-section{padding:.9rem}.v1800-class-grid{grid-template-columns:1fr}.v1800-catalog-controls{grid-template-columns:1fr}.v1800-class-viewer{padding:1rem!important}.v1800-mini-actions{display:grid}.v1800-mini-actions .btn{width:100%}}
@media(max-width:420px){.v1800-glossary{grid-template-columns:1fr;gap:.15rem}.v1800-glossary dt{margin-top:.45rem}}
@media(prefers-reduced-motion:reduce){.v1800-catalog *{scroll-behavior:auto!important}}

/* Unified 28-topic public catalog; sample exercises are not separate course topics. */
#courses>.v1800-catalog{margin-top:1rem;margin-bottom:1.5rem}
#courses .v1840-sample-lessons{margin:1.5rem auto;max-width:1200px;padding:0 clamp(1rem,3vw,2rem)}
#courses .v1840-sample-lessons>summary{min-height:44px;cursor:pointer;font-size:1.02rem;color:#155c6b;font-weight:780;padding:.55rem 0}
#courses .v1840-sample-lessons .v1840-sample-note{font-size:.9rem;color:#506977;line-height:1.6}
#courses .v1840-sample-lessons .v1580-course-grid{padding-inline:0}
#courses .v1840-sample-lessons .v1580-section-controls{padding-inline:0}
#courses .v1840-sample-lessons :is(summary,button):focus-visible{outline:3px solid #14798a;outline-offset:3px}
.v1840-course-catalog-mount>.v1800-catalog{margin:0 0 1.75rem;padding:0}
.v1840-course-catalog-mount .v1800-class-section{border-color:#d4e5e9}
@media(max-width:700px){#courses .v1840-sample-lessons{padding-inline:1rem}}