.brand b{color:#79ddd4}.brand-mark{background:#79ddd4}.entry-page{background:radial-gradient(circle at 82% 9%,#d9f5f1 0,transparent 34%),radial-gradient(circle at 12% 90%,#ece8ff 0,transparent 28%),#f4f7fc}.entry-card{border-top-color:#087f87}.side-tip>span{color:#087f87;font:700 1.5rem 'Space Grotesk',Arial,sans-serif}.overall progress::-webkit-progress-value{background:#79ddd4}.overall progress::-moz-progress-bar{background:#79ddd4}

.demo-card{margin-top:28px;border:1px solid var(--line);border-left:5px solid var(--accent);border-radius:14px;background:white;box-shadow:0 8px 25px #263b610d;overflow:hidden}.demo-card summary{list-style:none;display:flex;align-items:center;gap:13px;padding:18px 20px;cursor:pointer;background:linear-gradient(90deg,color-mix(in srgb,var(--accent) 10%,white),white)}.demo-card summary::-webkit-details-marker{display:none}.demo-card summary:focus-visible{outline:3px solid #f1ae2b;outline-offset:-3px}.demo-card summary>span:nth-child(2){display:grid;gap:3px;min-width:0}.demo-card summary small{font-size:.69rem;letter-spacing:1.25px;color:var(--accent);font-weight:800}.demo-card summary b{font:600 1rem/1.4 'Space Grotesk',Arial,sans-serif;color:var(--navy)}.demo-number{width:34px;height:34px;display:grid;place-content:center;border-radius:10px;background:var(--accent);color:white;font-weight:800;flex:0 0 auto}.summary-action{margin-left:auto;color:#718097;font-size:.72rem;font-weight:700;white-space:nowrap}.demo-grid{display:grid;grid-template-columns:minmax(0,1.3fr) minmax(280px,.8fr);gap:0;border-top:1px solid var(--line)}.demo-reasoning{padding:22px}.demo-step{display:grid;grid-template-columns:145px 1fr;gap:16px;padding:13px 0;border-bottom:1px solid #e8edf4}.demo-step:first-child{padding-top:0}.demo-step>span,.column-panel>small{font-size:.68rem;letter-spacing:1.15px;font-weight:800;color:var(--accent)}.demo-step p{margin:0;color:#4f5f77;line-height:1.55}.demo-answer{margin-top:18px;background:color-mix(in srgb,var(--accent) 11%,white);color:color-mix(in srgb,var(--accent) 82%,#15233f);border-radius:10px;padding:15px 18px;font:700 1.12rem 'Space Grotesk',Arial,sans-serif}.column-panel{display:grid;align-content:start;justify-items:center;background:#f8faff;border-left:1px solid var(--line);padding:22px;min-width:0}.column-panel>small{justify-self:start}.column-panel pre{margin:18px 0 0;padding:17px 20px;background:white;border:1px solid #dce4ef;border-radius:10px;color:#23334f;font:700 1.04rem/1.46 Consolas,'Courier New',monospace;overflow:auto;max-width:100%;font-variant-numeric:tabular-nums}

.exercise-label{display:flex;align-items:center;gap:12px;margin-top:28px}.exercise-label span{background:var(--navy);color:white;border-radius:6px;padding:5px 8px;font-size:.67rem;letter-spacing:1px;font-weight:800}.exercise-label b{font-size:.88rem;color:#53627b}.question-tabs{margin-top:12px}.problem-text{font:600 clamp(1.08rem,2vw,1.28rem)/1.62 'Space Grotesk',Arial,sans-serif;color:#263754;margin:25px 0 17px;max-width:900px}.answer-line{min-height:130px;border-radius:11px;background-color:#f8faff;background-image:linear-gradient(#d5ddeb55 1px,transparent 1px),linear-gradient(90deg,#d5ddeb55 1px,transparent 1px);background-size:25px 25px;display:flex;align-items:center;justify-content:center;flex-wrap:wrap;gap:12px;padding:26px;font:600 clamp(1.35rem,3vw,2.15rem) 'Space Grotesk',Arial,sans-serif;font-variant-numeric:tabular-nums;text-align:center}.answer-line input{width:165px;min-height:58px;border:0;border-bottom:4px solid var(--accent);background:#fff;color:var(--accent);padding:6px 10px;text-align:center;font-weight:700;border-radius:7px 7px 2px 2px}.answer-line input:focus{outline:3px solid #f1ae2b;outline-offset:3px}.question-card{border-top-width:5px}.question-meta span:last-child{color:var(--accent)}

@media(max-width:980px){.demo-grid{grid-template-columns:1fr}.column-panel{border-left:0;border-top:1px solid var(--line);justify-items:start}.demo-step{grid-template-columns:120px 1fr}}
@media(max-width:640px){.brand span:last-child{max-width:126px;line-height:1.05}.demo-card{margin-top:21px}.demo-card summary{padding:15px 14px}.summary-action{display:none}.demo-grid{display:block}.demo-reasoning,.column-panel{padding:17px 14px}.demo-step{grid-template-columns:1fr;gap:5px}.column-panel pre{font-size:.88rem;padding:14px}.exercise-label{align-items:flex-start}.exercise-label b{line-height:1.4}.problem-text{font-size:1.06rem;margin-top:20px}.answer-line{min-height:120px;padding:22px 10px;font-size:1.35rem}.answer-line input{width:135px;min-height:52px}}