:root{--ink:#172326;--muted:#607277;--paper:#f4f0e7;--card:#fffdf8;--teal:#0b6f68;--teal2:#dcefeb;--line:#cbd5cf;--warn:#fff3cf;--shadow:0 12px 34px rgba(22,45,44,.10);font-family:"Segoe UI","Noto Sans SC","Microsoft YaHei",Arial,sans-serif;color:var(--ink);background:var(--paper);font-size:16px;line-height:1.65}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:76px}body{margin:0;overflow-wrap:anywhere}button,a{font:inherit}button{min-height:44px;cursor:pointer}.skip{position:fixed;left:8px;top:-60px;z-index:99;background:#fff;padding:10px 14px}.skip:focus{top:8px}.hero{background:linear-gradient(145deg,#073f3c,#0b6f68 62%,#1c8e82);color:white;padding:max(32px,env(safe-area-inset-top)) 18px 30px}.hero__inner,.shell,.footer{width:min(1120px,100%);margin:auto}.eyebrow{font-size:.78rem;letter-spacing:.12em;text-transform:uppercase;font-weight:800;margin:0 0 8px}.hero h1{font-size:clamp(2rem,7vw,4.4rem);line-height:1.07;margin:.1em 0}.hero h1 span{color:#b9eee4}.lead{font-size:clamp(1rem,2vw,1.25rem);max-width:760px}.hero__actions{display:flex;flex-wrap:wrap;gap:10px;margin:20px 0 10px}.button,.play,.complete-btn,.quiz-option{border:1px solid transparent;border-radius:12px;padding:10px 16px;background:white;color:var(--ink);font-weight:700}.button.primary,.complete-btn{background:#ffdf83}.button.ghost{background:transparent;border-color:rgba(255,255,255,.55);color:#fff}.status,.progress-text{font-size:.9rem;margin:7px 0}.progress{height:9px;background:rgba(255,255,255,.24);border-radius:99px;overflow:hidden;max-width:520px}.progress span{display:block;height:100%;width:0;background:#ffdf83;transition:width .25s}.lesson-nav{position:sticky;top:0;z-index:20;display:flex;gap:8px;overflow-x:auto;padding:10px max(14px,calc((100vw - 1120px)/2));background:rgba(244,240,231,.95);backdrop-filter:blur(12px);border-bottom:1px solid var(--line);scrollbar-width:thin}.lesson-nav a{flex:0 0 auto;min-width:44px;min-height:44px;display:grid;place-items:center;padding:6px 12px;border-radius:99px;border:1px solid var(--line);color:var(--ink);text-decoration:none;background:var(--card)}.lesson-nav a.done{background:var(--teal);color:white}.shell{padding:22px 14px 60px}.panel,.lesson{background:var(--card);border:1px solid var(--line);border-radius:20px;box-shadow:var(--shadow);padding:clamp(18px,4vw,34px);margin:0 0 22px}.method{display:grid;gap:20px}.method h2,.lesson h2{font-size:clamp(1.45rem,4vw,2.3rem);line-height:1.22;margin:.1em 0 .55em}.mouth-figure{margin:0;background:var(--teal2);border-radius:16px;padding:12px}.mouth-figure img{display:block;width:100%;height:auto;max-height:260px}.mouth-figure figcaption{font-size:.86rem;color:var(--muted);margin-top:8px}.warning{background:var(--warn);border-color:#ddc678}.lesson-head{display:flex;align-items:flex-start;justify-content:space-between;gap:14px}.lesson-no{color:var(--teal);font-weight:900}.focus{font-family:"Segoe UI Symbol","Noto Sans",sans-serif;color:var(--teal);font-size:clamp(1rem,3vw,1.3rem);font-weight:750}.sequence-note{border-left:4px solid var(--teal);padding-left:12px;color:var(--muted)}.sound-grid{display:grid;gap:12px;margin:20px 0}.sound-card{border:1px solid var(--line);border-radius:15px;background:#fff;overflow:hidden}.sound-card summary{list-style:none;display:grid;grid-template-columns:auto 1fr auto;align-items:center;gap:12px;min-height:58px;padding:10px 14px;cursor:pointer}.sound-card summary::-webkit-details-marker{display:none}.symbol{font-family:"Segoe UI Symbol","Noto Sans",sans-serif;font-size:2rem;color:var(--teal);font-weight:750;min-width:56px}.sample strong{display:block;font-size:1.05rem}.badge{font-size:.72rem;border:1px solid var(--teal);color:var(--teal);padding:3px 8px;border-radius:99px;white-space:nowrap}.card-body{padding:0 14px 16px;border-top:1px solid var(--line)}.fact-list{display:grid;gap:8px;margin:14px 0}.fact{background:#f7f7f2;border-radius:10px;padding:9px 11px}.fact b{color:var(--teal)}.ipa{font-family:"Segoe UI Symbol","Noto Sans",sans-serif;letter-spacing:.08em}.advanced{margin:10px 0}.advanced summary{min-height:44px;padding:8px 0;color:var(--muted)}.audio-row{display:flex;flex-wrap:wrap;gap:8px;margin:12px 0}.play{border-color:var(--teal);color:var(--teal);background:#fff;min-width:112px}.play.playing{background:var(--teal);color:#fff}.play.slow{border-style:dashed}.street{background:#eef7f5;border-radius:16px;padding:14px;margin:22px 0}.street h3,.quiz h3{margin:.1em 0 .6em}.phrase{padding:14px 0;border-bottom:1px solid #c8dfda}.phrase:last-child{border:0}.phrase-text{font-size:1.15rem;font-weight:800;margin:0}.translation{color:var(--muted);margin:2px 0 10px}.word-ipa{display:flex;flex-wrap:wrap;gap:7px}.word-chip{background:white;border:1px solid var(--line);border-radius:10px;padding:6px 9px;min-width:62px;text-align:center}.word-chip b,.word-chip span{display:block}.word-chip span{font-family:"Segoe UI Symbol","Noto Sans",sans-serif;color:var(--teal);font-size:.86rem}.quiz{border-top:1px solid var(--line);padding-top:18px}.quiz-options{display:grid;gap:8px}.quiz-option{text-align:left;border-color:var(--line);background:#fff}.quiz-option.correct{border-color:#17834f;background:#e3f6ea}.quiz-option.wrong{border-color:#b3453d;background:#fae8e5}.lesson-foot{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-top:20px}.complete-btn.done{background:var(--teal);color:#fff}.footer{padding:22px 16px 50px;color:var(--muted);font-size:.9rem}.footer a{color:var(--teal)}@media(min-width:680px){.method{grid-template-columns:1.15fr .85fr}.sound-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.street-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}.phrase{border-bottom:0}.quiz-options{grid-template-columns:repeat(3,1fr)}}@media(min-width:1000px){.sound-grid{grid-template-columns:repeat(3,minmax(0,1fr))}}@media(max-width:390px){.hero{padding-left:14px;padding-right:14px}.shell{padding-left:10px;padding-right:10px}.panel,.lesson{border-radius:15px;padding:16px}.sound-card summary{grid-template-columns:auto 1fr}.badge{grid-column:2}.lesson-foot{align-items:stretch;flex-direction:column}.complete-btn{width:100%}}@media print{.hero__actions,.lesson-nav,.audio-row,.quiz,.complete-btn,.status,.progress,.progress-text{display:none!important}.hero{background:white;color:#000;padding:10mm 0}.hero h1 span{color:#000}.shell{width:100%;padding:0}.panel,.lesson{box-shadow:none;break-inside:avoid;border:1px solid #999;margin-bottom:8mm}.sound-card{break-inside:avoid}.sound-card:not([open]) .card-body{display:block}.sound-card summary{border-bottom:1px solid #ccc}.footer{padding:0}.word-chip{break-inside:avoid}@page{size:A4;margin:12mm}}