.interval-hero{max-width:850px;margin:58px auto 38px;text-align:center}.interval-hero h1{font-size:clamp(42px,7vw,72px);line-height:1.02;margin:16px 0}.interval-hero h1 em{font-style:normal;color:#c9a04e}.interval-hero p{max-width:720px;margin:auto;color:#62748e;font-size:17px;line-height:1.7}.interval-learning{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin:34px 0}.interval-lesson{display:flex;gap:14px;padding:22px;background:#f5f8fd;border:1px solid #dbe4f1;border-radius:15px}.interval-step{display:grid;place-items:center;flex:0 0 36px;height:36px;border-radius:50%;background:#c9a04e;color:#18345e;font:700 13px Georgia}.interval-lesson h2{margin:1px 0 10px;font:22px Georgia;color:#173b79}.interval-lesson p,.interval-reference p{font-size:13px;line-height:1.7;color:#62748e;margin:0}.interval-reference{display:grid;grid-template-columns:minmax(180px,.7fr) 1.5fr;gap:25px;align-items:start;margin:18px 0 30px}.interval-reference h2,.interval-practice h2{font:32px Georgia;color:#173b79;margin:10px 0}.interval-table-wrap{overflow-x:auto}.interval-table{border-collapse:collapse;width:100%;font-size:13px}.interval-table th,.interval-table td{text-align:left;padding:10px 12px;border-bottom:1px solid #e3e9f2}.interval-table th{color:#886923;font-size:10px;letter-spacing:.12em;text-transform:uppercase}.interval-table td{color:#36506f}.interval-practice{margin:25px 0 36px}.interval-practice-head{display:flex;justify-content:space-between;gap:24px;align-items:start;flex-wrap:wrap}.interval-practice-head p{color:#62748e;line-height:1.6}.interval-controls{display:grid;grid-template-columns:1fr 1fr;align-items:center;gap:8px 12px;min-width:300px}.interval-controls label{font-size:10px;letter-spacing:.12em;font-weight:800;color:#62748e}.interval-controls select{margin:0}.interval-display{display:grid;grid-template-columns:1fr auto;gap:20px;align-items:center;padding:18px 0}.interval-notes{font:clamp(30px,5vw,48px) Georgia;color:#183b75;letter-spacing:.06em;margin:16px 0 4px}.interval-audio{text-align:center}.interval-choices{border:0;padding:0;margin:8px 0 16px}.interval-choices legend{font-size:12px;font-weight:800;color:#536780}.interval-choices .choice-grid{grid-template-columns:repeat(4,1fr);margin:12px 0}.interval-choices button{text-align:center}.interval-choices button[aria-pressed="true"]{background:#225bdc;color:white}.interval-actions{display:flex;gap:10px;flex-wrap:wrap}.interval-practice .feedback{min-height:28px}.interval-mixed-cta{margin:35px 0 68px;padding:30px;border-radius:16px;background:#f7f3e8;border:1px solid #d7ba76}.interval-mixed-cta h2{font:30px Georgia;color:#173b79;margin:10px 0}.interval-mixed-cta p{max-width:780px;color:#536780;line-height:1.7}.interval-mixed-cta a{display:inline-block;margin-top:8px}@media(max-width:760px){.interval-learning{grid-template-columns:1fr}.interval-reference{grid-template-columns:1fr}.interval-display{grid-template-columns:1fr}.interval-audio{text-align:left}.interval-choices .choice-grid{grid-template-columns:repeat(2,1fr)}.interval-controls{width:100%;min-width:0}.interval-hero{margin:35px auto}.interval-mixed-cta{padding:23px}}
.interval-notes.note-arrive{animation:pt-note-arrive .32s ease-out}
.interval-choices button{transition:transform .16s ease,background-color .16s ease,color .16s ease}
.interval-choices button:hover{transform:translateY(-2px)}
.interval-audio .playing{animation:pt-piano-play .55s ease-in-out 2}
@media(prefers-reduced-motion:reduce){.interval-notes.note-arrive,.interval-choices button{animation:none!important;transition:none!important}}