/* Shared navigation and optional guided tour across the three modules. */
header{height:auto;min-height:103px;padding-top:15px;padding-bottom:15px;gap:18px;flex-wrap:wrap}.module-nav{flex-shrink:0;padding-left:18px;gap:4px}.module-nav a{white-space:nowrap;padding:9px 10px}.header-actions{margin-left:auto;gap:2px;flex-wrap:wrap}.header-actions .quiet{font-size:13px;padding:10px 9px}.header-actions .tour-start{border:1px solid #a9c5b5;border-radius:10px;color:var(--green);margin-left:5px}.header-actions .calculator-shortcut{padding:11px 15px}.tour-welcome{position:fixed;z-index:60;bottom:22px;left:50%;transform:translateX(-50%);display:flex;align-items:center;gap:20px;background:#173f2d;color:white;border:1px solid #b1cebb;border-radius:16px;padding:18px 20px;box-shadow:0 8px 35px #133b2530;max-width:calc(100vw - 32px);width:max-content}.tour-welcome b{display:block;font-size:16px}.tour-welcome span{display:block;font-size:14px;color:#c5dece;margin-top:5px}.welcome-start{background:white;color:#174a32;border-radius:9px;padding:11px 15px;font-size:14px;white-space:nowrap}.welcome-close{color:#e1eee6;background:transparent;padding:8px;font-size:18px}#courseTour{position:fixed;inset:0;width:100vw;height:100dvh;max-width:none;max-height:none;margin:0;padding:0;border:none;border-radius:0;background:transparent;overflow:hidden;pointer-events:none}#courseTour::backdrop{background:transparent}.tour-spotlight{position:fixed;border:2px solid #69cf94;border-radius:13px;box-shadow:0 0 0 9999px #081e19b5;pointer-events:none}.tour-card{position:fixed;pointer-events:auto;background:#fff;border:1px solid #d8e7dc;border-radius:19px;padding:24px;max-height:calc(100dvh - 32px);overflow:auto;box-shadow:0 15px 65px #00150f40;color:#173e2b}.tour-top{display:flex;justify-content:space-between;align-items:center;gap:15px}.tour-top>span{font-size:12px;letter-spacing:.1em;font-weight:650;color:#468363}.tour-top button{padding:7px;background:transparent;color:#496453;font-size:18px}.tour-card h2{font-size:27px;line-height:1.15;letter-spacing:-.025em;margin:18px 0 15px}.tour-card p{font-size:16px;line-height:1.65;color:#55695d;margin:0 0 23px}.tour-controls{display:flex;justify-content:space-between;gap:15px}.tour-controls button{font-size:14px;min-height:43px;padding:11px 16px;border-radius:9px;background:#edf4ef;color:#24573a}.tour-controls button:last-child{background:#078459;color:white}.tour-controls button:disabled{opacity:.4}.tour-try{display:block;width:100%;padding:12px 0 0;margin:14px 0 0;border-top:1px solid #dce8df;background:none;color:#078459;font-size:14px;text-align:left}.tour-try[hidden]{display:none}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #439568;outline-offset:3px}#slide{animation:lessonEnter .24s ease-out}@keyframes lessonEnter{from{opacity:.55;transform:translateY(5px)}to{opacity:1;transform:none}}
@media(max-width:1250px){header{display:grid;grid-template-columns:auto 1fr;gap:13px 24px}.module-nav{justify-self:end}.header-actions{grid-column:1/-1;justify-content:flex-end;width:100%;margin:0}.header-actions .quiet{font-size:14px;padding:10px 13px}#fullBtn span{display:inline}}
@media(max-width:700px){header{padding:15px 19px;gap:12px}.brand>span{font-size:12px}.brand img{width:38px;height:38px}.module-nav{border:0;padding:0;gap:3px}.module-nav a{padding:9px 8px;font-size:11px;gap:4px}.module-nav b{font-size:13px}.header-actions{justify-content:space-between;gap:5px}.header-actions .quiet{font-size:12px;padding:8px}.header-actions .calculator-shortcut{font-size:12px;padding:9px 11px;min-height:38px}.header-actions .tour-start{margin-left:0}#fullBtn span{display:none}.tour-welcome{gap:12px;padding:16px;width:calc(100vw - 30px);bottom:14px}.tour-welcome b{font-size:14px}.tour-welcome span{font-size:12px;max-width:210px}.welcome-start{font-size:12px;padding:10px}.welcome-close{padding:4px;font-size:16px}.tour-card{padding:21px}.tour-card h2{font-size:25px}}
@media(max-width:540px){header{display:flex;flex-wrap:wrap}.brand{width:100%}.module-nav{width:100%;justify-content:space-between;margin:0}.module-nav a{justify-content:center;flex:1;padding:10px 8px}.module-nav b{font-size:15px}.header-actions{display:flex;flex-wrap:wrap;width:100%}.header-actions #studyBtn{font-size:12px}.header-actions .quiet{padding:8px 6px}.header-actions .tour-start{padding:8px}.tour-welcome span{display:none}.tour-welcome{gap:10px}.tour-welcome b{font-size:13px}}
@media(prefers-reduced-motion:reduce){#slide{animation:none}*{scroll-behavior:auto!important}}