:root{--bg-main:#f8fafc;--bg-card:#fff;--text-main:#0f172a;--text-muted:#475569;--border-color:#e2e8f0;--primary:#2563eb;--primary-hover:#1d4ed8;--primary-light:#eff6ff;--secondary:#64748b;--secondary-hover:#475569;--danger:#dc2626;--danger-hover:#b91c1c;--warning:#d97706;--warning-bg:#fffbeb;--success:#16a34a;--success-bg:#f0fdf4;--shadow-sm:0 1px 2px 0 #0000000d;--shadow-md:0 4px 6px -1px #0000001a;--radius-sm:6px;--radius-md:10px;--radius-lg:16px;--radius-xl:24px;--radius-pill:999px;--font-stack:"Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;--slate-50:#f8fafc;--slate-100:#f1f5f9;--slate-200:#e2e8f0;--slate-300:#cbd5e1;--slate-400:#94a3b8;--slate-500:#64748b;--slate-600:#475569;--slate-700:#334155;--slate-800:#1e293b;--slate-900:#0f172a;--indigo-50:#eef2ff;--indigo-100:#e0e7ff;--indigo-500:#6366f1;--indigo-600:#4f46e5;--indigo-700:#4338ca;--shadow-lg:0 10px 15px -3px #0000001a, 0 4px 6px -4px #0000001a;--shadow-card:0 4px 14px #0f172a0f;--shadow-card-hover:0 8px 24px #2563eb29;--gradient-primary:linear-gradient(135deg, #2563eb, #1d4ed8);--font-size-sm:.875rem;--font-size-subtitle:13px;--touch-target-min:44px;--bottom-nav-height:65px;--bottom-nav-clearance:calc(var(--bottom-nav-height) + env(safe-area-inset-bottom,0px) + 16px)}:root *,:root :before,:root :after{box-sizing:border-box;margin:0;padding:0}:root html,:root body{width:100%;max-width:100%;font-family:var(--font-stack);background-color:var(--bg-main);color:var(--text-main);-webkit-tap-highlight-color:transparent;line-height:1.5;overflow-x:hidden}:root .sr-only{clip:rect(0, 0, 0, 0);white-space:nowrap;border-width:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}:root :focus-visible{outline:3px solid var(--primary);outline-offset:2px}:root button{cursor:pointer;background:0 0;border:none;font-family:inherit;font-size:1rem}:root .app-container{width:100%;max-width:100%;min-height:100vh;padding-bottom:var(--bottom-nav-clearance);flex-direction:column;display:flex}:root .app-header{background-color:var(--bg-card);border-bottom:1px solid var(--border-color);z-index:10;box-shadow:var(--shadow-sm);padding:12px 16px;position:sticky;top:0}:root .header-container{max-width:900px;margin:0 auto}:root .lesson-picker{border-top:1px solid var(--border-color);padding-top:14px}:root .lesson-list{gap:8px;margin-top:12px;display:grid}:root .lesson-row{border-radius:12px;grid-template-columns:36px 1fr auto;align-items:center;gap:10px;width:100%;padding:11px 12px;display:grid}:root .lesson-number{color:var(--primary);font-variant-numeric:tabular-nums;font-weight:800}:root .phrase-picker{background:var(--bg-main);border-radius:12px;margin-top:14px;padding:14px}:root .phrase-chip-list{flex-wrap:wrap;gap:8px;margin-top:10px;display:flex}:root .cefr-track{border:1px solid var(--border-color);background:var(--bg-main);border-radius:13px;margin:14px 0 16px;padding:13px}:root .cefr-track-heading{color:var(--text-muted);justify-content:space-between;gap:12px;font-size:.84rem;display:flex}:root .cefr-track-heading strong{color:var(--text)}:root .cefr-level-list{grid-template-columns:repeat(5,minmax(0,1fr));gap:8px;margin-top:10px;display:grid}:root .cefr-level{background:var(--bg-card);text-align:center;border-radius:10px;flex-direction:column;justify-content:center;gap:3px;min-height:62px;padding:9px;display:flex}:root .cefr-level strong{color:var(--primary);font-size:1.05rem}:root .cefr-level span,:root .cefr-level small{font-size:.72rem}:root .cefr-level small{color:var(--text-muted)}:root .phrase-chip{color:var(--text);border-radius:999px;padding:8px 11px;font-size:.85rem}:root .selected-phrase-hint,:root .loading-inline,:root .error-inline{margin:10px 0 0;font-size:.88rem}:root .error-inline{color:#b42318}:root .target-phrase-card{background:linear-gradient(135deg,#f2f7ff,#fff);border:1px solid #cfe1ff;border-radius:18px;max-width:920px;margin:0 auto 18px;padding:20px;display:block}:root .target-phrase-card .eyebrow{color:var(--primary);letter-spacing:.08em;text-transform:uppercase;font-size:.75rem;font-weight:800}:root .target-phrase-card h2{margin:12px 0 2px;font-size:clamp(1.35rem,3vw,2rem)}:root .target-phrase-phonetic{color:var(--primary);font-family:ui-monospace,SFMono-Regular,Consolas,monospace}:root .progress-module-list{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin-top:14px;display:grid}:root .progress-module-card{border:1px solid var(--border-color);background:var(--bg-card);border-radius:14px;padding:14px}:root .progress-module-title span{color:var(--primary);font-weight:800}:root .progress-bar{background:var(--bg-main);border-radius:999px;height:7px;margin:10px 0 12px;overflow:hidden}:root .progress-bar span{border-radius:inherit;background:var(--primary);height:100%;transition:width .25s;display:block}:root .progress-lesson-list{gap:7px;display:grid}:root .progress-lesson-row{grid-template-columns:22px 1fr auto;align-items:center;gap:6px;font-size:.84rem;display:grid}:root .progress-lesson-row small{color:var(--text-muted)}:root .progress-status{font-weight:800}:root .progress-status.complete{color:#138a52}:root .progress-status.open{color:var(--primary)}:root .progress-status.locked{filter:grayscale();opacity:.65}@media (width<=640px){:root .module-grid,:root .progress-module-list{grid-template-columns:1fr}:root .section-heading-row,:root .progress-section-header,:root .target-phrase-meta,:root .lesson-picker-header,:root .phrase-picker-title{flex-direction:column;align-items:flex-start}:root .lesson-row{grid-template-columns:30px 1fr}:root .lesson-phrase-count{grid-column:2}:root .phrase-chip{width:100%}:root .cefr-level-list{grid-template-columns:repeat(3,minmax(0,1fr))}:root .cefr-track-heading{flex-direction:column;align-items:flex-start}}:root .app-header .header-container{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:8px 16px;display:flex}:root .app-header .brand{align-items:center;gap:10px;display:flex}:root .app-header .brand-title{font-size:1.35rem;font-weight:800;line-height:1.2}:root .app-header .header-nav{flex-wrap:wrap;align-items:center;gap:8px;display:flex}:root .app-header .nav-tab{border:1px solid var(--border-color);background:var(--bg-card);min-height:44px;color:var(--text-main);border-radius:999px;align-items:center;padding:8px 12px;font-size:.95rem;text-decoration:none;display:inline-flex}:root .app-header .nav-tab.active{background:var(--primary);border-color:var(--primary);color:#fff;font-weight:700}:root .app-header .session-badge{flex-wrap:wrap;align-items:center;gap:6px 8px;display:flex}:root .app-header .end-session-btn{border:1px solid var(--border-color);background:var(--bg-card);border-radius:999px;align-items:center;min-height:44px;padding:8px 12px;display:inline-flex}:root .bottom-nav-bar{padding:6px 8px calc(6px + env(safe-area-inset-bottom,0px));border-top:1px solid var(--border-color);z-index:100;background:#fff;justify-content:space-around;align-items:stretch;gap:2px;display:flex;position:fixed;bottom:0;left:0;right:0;box-shadow:0 -2px 10px #0000000a}:root .bottom-nav-tab{color:#64748b;text-align:center;border-radius:12px;flex-direction:column;flex:1 1 0;justify-content:center;align-items:center;gap:2px;min-width:0;min-height:52px;padding:6px 2px;font-size:.72rem;font-weight:600;display:flex}:root .bottom-nav-tab.active{color:var(--primary);font-weight:800}:root .bottom-nav-icon{font-size:1.3rem;line-height:1}:root .r02-learning button{border:1px solid var(--border-color);background:var(--bg-card);min-height:44px;color:var(--text-main);text-align:left;border-radius:12px;padding:8px 12px}:root .r02-learning button:disabled{color:#475569;cursor:not-allowed;opacity:1;background:#f1f5f9}:root .r02-learning .r02-choice{text-align:center;border-radius:999px;align-items:center;margin:0 8px 8px 0;display:inline-flex}:root .r02-learning .r02-choice[aria-pressed=true]{background:var(--primary);border-color:var(--primary);color:#fff;font-weight:700}:root .r02-learning ul{padding-left:20px}:root .r02-learning li{margin-bottom:4px}:root .r02-learning li.is-locked{color:#475569}:root .r02-learning select{border:1px solid var(--border-color);background:var(--bg-card);border-radius:12px;min-height:44px;padding:8px 10px;font-size:1rem}:root .app-error-toast{color:#991b1b;background:#fef2f2;border:1px solid #fecaca;border-radius:12px;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:12px;margin-bottom:16px;padding:12px 14px;display:flex}@media (width<=480px){:root .app-header .header-container{flex-direction:column;align-items:flex-start}:root .bottom-nav-tab{font-size:.68rem}}:root .modal-overlay{z-index:200;padding:16px;padding-bottom:calc(16px + env(safe-area-inset-bottom,0px));background:#0f172a80;justify-content:center;align-items:center;display:flex;position:fixed;inset:0;overflow-y:auto}:root .modal-content{width:100%;max-height:88vh;max-height:calc(100dvh - 32px - env(safe-area-inset-bottom,0px));background:#fff;border-radius:24px;flex-direction:column;display:flex;overflow:hidden;box-shadow:0 20px 40px #0003}:root .modal-header{flex-shrink:0}:root .modal-body{min-height:0;overflow-y:auto}:root .modal-footer{flex-shrink:0}:root .modal-close-btn{min-width:44px;min-height:44px}:root .floating-dictionary-btn{right:16px;bottom:calc(var(--bottom-nav-height) + env(safe-area-inset-bottom,0px) + 12px);z-index:90;background:var(--primary);color:#fff;min-height:44px;box-shadow:var(--shadow-md);border-radius:999px;align-items:center;padding:10px 16px;font-weight:700;display:inline-flex;position:fixed}:root .action-dock-senior{bottom:calc(20px + env(safe-area-inset-bottom,0px))!important}:root .journey-top-bar{border-bottom:1px solid var(--border-color);z-index:9;background:#fff;flex-direction:column;gap:12px;padding:16px 20px;display:flex;position:sticky;top:60px;box-shadow:0 2px 4px #00000005}:root .stage-selector{scrollbar-width:thin;-webkit-overflow-scrolling:touch;gap:8px;padding-bottom:6px;display:flex;overflow-x:auto}:root .stage-tab-btn{color:#475569;white-space:nowrap;cursor:pointer;background:#f1f5f9;border:1px solid #e2e8f0;border-radius:20px;align-items:center;gap:6px;min-height:44px;padding:8px 16px;font-size:.9rem;font-weight:700;transition:all .2s;display:inline-flex;box-shadow:0 1px 3px #0f172a0f}:root .stage-tab-btn:hover{color:#0f172a;background:#e2e8f0}:root .stage-tab-btn.active{background:var(--gradient-primary);color:#fff;border-color:var(--primary);box-shadow:0 4px 12px #2563eb59}:root .profile-bar{flex-wrap:wrap;align-items:center;gap:8px;display:flex}:root .profile-chips{flex-wrap:wrap;gap:6px;display:flex}:root .profile-chip{color:#475569;cursor:pointer;background:#f8fafc;border:2px solid #cbd5e1;border-radius:12px;align-items:center;gap:4px;min-height:44px;padding:8px 14px;font-size:.875rem;font-weight:600;transition:all .2s;display:inline-flex}:root .profile-chip:hover{color:#0f172a;background:#e2e8f0}:root .profile-chip.active{border-color:var(--primary);color:#1d4ed8;background:#eff6ff;font-weight:800}:root .top-vocab-btn{color:#1e293b;cursor:pointer;background:#fff;border:1.5px solid #cbd5e1;border-radius:18px;align-items:center;gap:6px;min-height:44px;padding:6px 14px;font-size:.875rem;font-weight:700;transition:all .2s;display:inline-flex}:root .top-vocab-btn:hover{border-color:var(--primary);color:var(--primary)}:root .vocab-badge-count{color:#fff;background:#ef4444;border-radius:10px;padding:2px 6px;font-size:.72rem}:root .journey-map-wrapper{max-width:680px;margin:0 auto;padding:24px 16px 100px;position:relative}:root .part-section{margin-bottom:48px;position:relative}:root .part-header{text-align:center;margin-bottom:32px;padding:0 10px;position:relative}:root .part-header-divider{justify-content:center;align-items:center;gap:12px;margin-bottom:6px;display:flex}:root .part-header-line{background:#cbd5e1;flex:1;height:1px}:root .part-number-badge{letter-spacing:.1em;color:#64748b;text-transform:uppercase;font-size:.8rem;font-weight:800}:root .part-title{color:#1e293b;margin-bottom:4px;font-size:1.35rem;font-weight:800}:root .part-desc{color:#64748b;max-width:480px;margin:0 auto;font-size:.9rem}:root .part-vocab-badge-btn{color:#475569;cursor:pointer;background:#fff;border:1.5px solid #cbd5e1;border-radius:20px;align-items:center;gap:6px;min-height:44px;margin-top:8px;padding:5px 12px;font-size:.875rem;font-weight:700;transition:all .2s;display:inline-flex;box-shadow:0 1px 3px #0000000d}:root .part-vocab-badge-btn:hover{border-color:var(--primary);color:var(--primary);transform:translateY(-1px)}:root .nodes-path-container{flex-direction:column;align-items:center;gap:28px;display:flex;position:relative}:root .lesson-node-wrap{z-index:1;justify-content:center;width:100%;display:flex;position:relative}:root .lesson-node-wrap.align-center{justify-content:center}:root .lesson-node-wrap.align-left{justify-content:flex-start;padding-left:6%}:root .lesson-node-wrap.align-right{justify-content:flex-end;padding-right:6%}:root .lesson-node-card{text-align:left;cursor:pointer;background:#fff;border:2px solid #e2e8f0;border-radius:24px;align-items:center;gap:16px;width:100%;min-width:280px;max-width:360px;padding:14px 20px 14px 14px;transition:all .25s cubic-bezier(.34,1.56,.64,1);display:flex;position:relative;box-shadow:0 4px 14px #0f172a0f}:root .lesson-node-card:hover:not(:disabled){border-color:var(--primary);transform:translateY(-3px)scale(1.02);box-shadow:0 8px 24px #2563eb29}:root .lesson-node-card.status-active{border-color:var(--primary);background:linear-gradient(135deg,#fff 0%,#eff6ff 100%);box-shadow:0 0 0 4px #2563eb33,0 8px 20px #2563eb26}:root .lesson-node-card.status-completed{background:#fff;border-color:#16a34a}:root .lesson-node-card.status-completed .node-icon-circle{background:#f0fdf4;border-color:#16a34a}:root .lesson-node-card.status-locked{opacity:.68;box-shadow:none;cursor:not-allowed;background:#f8fafc;border-color:#e2e8f0}:root .lesson-node-card.status-locked:hover{border-color:#cbd5e1;transform:none}:root .lesson-node-card.boss-card{background:linear-gradient(135deg,#fffbeb 0%,#fef3c7 100%);border-width:2.5px;border-color:#f59e0b;box-shadow:0 6px 18px #f59e0b33}:root .node-icon-circle{background:#f1f5f9;border:2px dashed #cbd5e1;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:52px;height:52px;font-size:1.6rem;display:flex;position:relative}:root .node-lock-overlay{color:#fff;background:#475569;border:2px solid #fff;border-radius:50%;justify-content:center;align-items:center;width:20px;height:20px;font-size:.7rem;display:flex;position:absolute;bottom:-4px;right:-4px;box-shadow:0 1px 3px #0003}:root .node-info{flex-direction:column;flex:1;min-width:0;display:flex}:root .node-title-vi{color:#0f172a;word-break:break-word;margin-bottom:0;font-size:16px;font-weight:800;line-height:1.35;display:block}:root .node-title-en{color:#64748b;word-break:break-word;margin-top:4px;font-size:13px;font-weight:400;line-height:1.3;display:block}:root .node-meta-row{flex-wrap:wrap;align-items:center;gap:6px;margin-top:6px;display:flex}:root .node-badge{border-radius:12px;align-items:center;gap:4px;padding:3px 8px;font-size:.75rem;font-weight:700;display:inline-flex}:root .node-badge.active-badge{color:#15803d;background:#dcfce7;font-weight:800}:root .node-badge.boss-badge{color:#b45309;background:#fef3c7}:root .r02-learning{box-sizing:border-box;width:100%;min-width:0;max-width:820px;margin:0 auto;padding:24px 20px 100px}:root .r02-header-card{color:#fff;background:linear-gradient(135deg,#1e293b 0%,#0f172a 100%);border-radius:24px;margin-bottom:24px;padding:24px 28px;box-shadow:0 10px 25px -5px #0f172a33}:root .r02-header-card h2{color:#fff;margin:0 0 6px;font-size:1.4rem;font-weight:800;line-height:1.3}:root .r02-header-card p{color:#94a3b8;margin:0;font-size:.9rem;line-height:1.5}:root .r02-panel{background:#fff;border:1px solid #e2e8f0;border-radius:20px;margin-bottom:20px;padding:22px;box-shadow:0 2px 8px #0f172a0a}:root .r02-panel-title{color:#0f172a;align-items:center;gap:8px;margin:0 0 14px;font-size:1.05rem;font-weight:800;display:flex}:root .r02-choice-grid{flex-wrap:wrap;gap:10px;display:flex}:root .r02-choice{color:#334155;cursor:pointer;text-align:center;background:#f8fafc;border:2px solid #e2e8f0;border-radius:14px;align-items:center;gap:6px;padding:10px 18px;font-size:.92rem;font-weight:600;transition:all .2s cubic-bezier(.4,0,.2,1);display:inline-flex}:root .r02-choice:hover{color:#1d4ed8;background:#eff6ff;border-color:#3b82f6;transform:translateY(-1px)}:root .r02-choice[aria-pressed=true]{color:#fff;background:#2563eb;border-color:#2563eb;font-weight:800;box-shadow:0 4px 12px #2563eb40}:root .r02-lesson-cards{flex-direction:column;gap:10px;margin:0;padding:0;list-style:none;display:flex}:root .r02-lesson-row{background:#fff;border:1.5px solid #e2e8f0;border-radius:16px;justify-content:space-between;align-items:center;gap:12px;min-width:0;padding:14px 18px;transition:all .2s;display:flex}:root .r02-lesson-row:hover:not(.is-locked){border-color:#3b82f6;transform:translate(2px);box-shadow:0 4px 12px #0000000d}:root .r02-lesson-row.is-locked{opacity:.7;background:#f8fafc}:root .r02-lesson-row.is-completed{background:#f0fdf4;border-color:#10b981}:root .r02-lesson-btn{color:#0f172a;cursor:pointer;text-align:left;background:0 0;border:none;flex:1;min-width:0;padding:0;font-size:.98rem;font-weight:700}:root .r02-lesson-btn:disabled{color:#64748b;cursor:not-allowed}:root .r02-lesson-status-tag{white-space:normal;border-radius:12px;padding:4px 10px;font-size:.875rem;font-weight:700}:root .r02-lesson-status-tag.open{color:#1d4ed8;background:#dbeafe}:root .r02-lesson-status-tag.locked{color:#64748b;background:#f1f5f9}:root .r02-lesson-status-tag.completed{color:#047857;background:#d1fae5}:root .r02-detail-container{background:#fff;border:2px solid #3b82f6;border-radius:20px;margin-top:24px;padding:24px;box-shadow:0 10px 30px #3b82f614}:root .r02-dialogue-card{flex-direction:column;gap:10px;margin:14px 0;display:flex}:root .r02-dialogue-line{border-radius:16px;align-items:center;gap:10px;max-width:90%;padding:10px 16px;display:flex}:root .r02-dialogue-line.speaker-a{background:#eff6ff;border-left:4px solid #3b82f6;align-self:flex-start}:root .r02-dialogue-line.speaker-b{background:#f0fdf4;border-left:4px solid #10b981;align-self:flex-end}:root .r02-speech-btn{cursor:pointer;background:#fff;border:1px solid #cbd5e1;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:32px;height:32px;transition:all .2s;display:inline-flex}:root .r02-speech-btn:hover{background:#eff6ff;border-color:#3b82f6;transform:scale(1.1)}:root .r02-vocab-card-grid{grid-template-columns:repeat(auto-fit,minmax(min(260px,100%),1fr));gap:12px;margin-top:12px;display:grid}:root .r02-vocab-item{background:#f8fafc;border:1.5px solid #e2e8f0;border-radius:14px;padding:14px}:root .r02-word-title{color:#0f172a;font-size:1.1rem;font-weight:800}:root .r02-ipa-badge{color:#7c3aed;background:#f1f5f9;border-radius:8px;margin-left:8px;padding:2px 8px;font-size:.875rem;font-weight:700;display:inline-block}:root .app-container.theme-kids{--primary:#f59e0b;--primary-hover:#d97706;--primary-light:#fef3c7;--text-main:#1e293b;--bg-main:#fffbeb;font-size:1.05rem}:root .app-container.theme-senior{--primary:#0284c7;--primary-hover:#0369a1;--primary-light:#e0f2fe;--text-main:#0f172a;--text-muted:#334155;--bg-main:#f8fafc;font-size:1.18rem;line-height:1.65}:root .node-stars{color:#f59e0b;letter-spacing:1px;font-size:.875rem}:root .modal-title{color:#1e293b;align-items:center;gap:8px;font-size:1.2rem;font-weight:800;display:flex}:root .modal-close-btn:hover{color:#0f172a;background:#e2e8f0}:root .floating-dictionary-btn:hover{background:#1e293b;transform:translateY(-2px);box-shadow:0 6px 18px #00000059}:root .lesson-node-card.boss-card:hover{transform:translateY(-4px)scale(1.03);box-shadow:0 10px 25px #f59e0b4d}:root .flashcard-wrapper{perspective:1000px;cursor:pointer;min-height:220px}:root .flashcard-inner{text-align:center;width:100%;min-height:220px;transform-style:preserve-3d;background:linear-gradient(135deg,#fff 0%,#f8fafc 100%);border:2px solid #e2e8f0;border-radius:18px;flex-direction:column;justify-content:center;align-items:center;padding:24px;transition:transform .5s;display:flex;position:relative;box-shadow:0 4px 12px #0000000f}:root .flashcard-inner.flipped{border-color:var(--primary);background:linear-gradient(135deg,#eff6ff 0%,#dbeafe 100%);transform:rotateY(180deg)}:root .flashcard-front,:root .flashcard-back{backface-visibility:hidden;flex-direction:column;justify-content:center;align-items:center;width:100%;height:100%;padding:20px;display:flex;position:absolute;top:0;left:0}:root .flashcard-back{transform:rotateY(180deg)}:root .flashcard-word{color:#1e293b;font-size:2.1rem;font-weight:800}:root .flashcard-ipa{color:var(--primary);margin-top:4px;font-family:monospace;font-size:1.15rem}:root .flashcard-meaning{color:#0f172a;font-size:1.45rem;font-weight:800}:root .flashcard-example{color:#475569;margin-top:10px;font-size:1rem;font-style:italic}:root .flashcard-hint{color:#94a3b8;margin-top:12px;font-size:.78rem}:root .srs-boxes-row{flex-wrap:wrap;justify-content:center;gap:8px;margin-bottom:12px;display:flex}:root .srs-box-badge{color:#64748b;cursor:pointer;background:#f1f5f9;border:1px solid #0000;border-radius:14px;padding:5px 12px;font-size:.8rem;font-weight:700;transition:all .2s}:root .srs-box-badge:hover{border-color:var(--primary);color:var(--primary)}:root .srs-box-badge.active{background:var(--primary);color:#fff}:root .r02-dialogue-body{flex:1;min-width:0}:root .r02-dialogue-speaker{font-weight:800}:root .r02-dialogue-text{color:var(--text-main);font-size:1rem;line-height:1.5}:root .r02-dialogue-text-vi{color:#64748b;margin-top:2px;font-size:.875rem;line-height:1.45}:root .r02-vocab-actions{flex-wrap:wrap;align-items:center;gap:8px;margin-top:10px;display:flex}:root .r02-vocab-meta{color:#64748b;margin:4px 0 8px;font-size:.88rem;font-style:italic}:root .r02-vocab-example{color:#334155;background:#fff;border:1px solid #e2e8f0;border-radius:10px;margin-top:8px;padding:10px;font-size:.9rem}:root .r02-vocab-example-en{font-weight:600;line-height:1.5}:root .r02-vocab-example-vi{color:#64748b;margin-top:3px;font-size:.875rem}:root .r02-lesson-title{color:#0f172a;font-size:1rem;font-weight:700;line-height:1.35;display:block}:root .r02-lesson-title-vi{color:#64748b;margin-top:2px;font-size:.88rem;line-height:1.35;display:block}:root .r02-lesson-btn:hover{color:var(--primary-hover)}:root .r02-lesson-row:focus-within{border-color:#3b82f6;box-shadow:0 4px 12px #0000000d}:root .r02-learning .r02-contrast-speak-btn,:root .r02-learning .r02-contrast-reveal-btn{border:1.5px solid var(--border-color);background:var(--bg-card);min-height:44px;color:var(--text-main);cursor:pointer;border-radius:12px;padding:11px 16px;font-size:.875rem;font-weight:700;transition:all .2s}:root .r02-learning .r02-contrast-reveal-btn{background:var(--primary-light);color:var(--primary-hover);border-color:#bfdbfe}:root .r02-learning .r02-contrast-speak-btn:hover,:root .r02-learning .r02-contrast-reveal-btn:hover{border-color:var(--primary);background:var(--primary-light);color:var(--primary-hover)}:root .r02-choice:focus-visible,:root .r02-lesson-btn:focus-visible,:root .r02-learning .r02-contrast-speak-btn:focus-visible,:root .r02-learning .r02-contrast-reveal-btn:focus-visible{outline:3px solid var(--primary);outline-offset:2px}:root .submit-btn,:root .primary-btn{background:var(--gradient-primary);color:#fff;cursor:pointer;border:1px solid #0000;border-radius:12px;justify-content:center;align-items:center;gap:8px;min-height:44px;padding:10px 22px;font-size:1rem;font-weight:700;text-decoration:none;transition:all .2s;display:inline-flex;box-shadow:0 4px 12px #2563eb40}:root .submit-btn:hover:not(:disabled),:root .primary-btn:hover:not(:disabled){background:var(--primary-hover);transform:translateY(-1px);box-shadow:0 6px 16px #1d4ed859}:root .submit-btn:disabled,:root .primary-btn:disabled{color:#64748b;cursor:not-allowed;box-shadow:none;background:#e2e8f0;transform:none}:root .start-screen{width:100%}:root .empty-state-card{background:var(--bg-card);border:1px solid var(--border-color);border-radius:var(--radius-xl);max-width:560px;box-shadow:var(--shadow-card);text-align:center;margin:0 auto;padding:32px 24px}:root .empty-state-icon{font-size:3rem;line-height:1;display:block}:root .empty-state-title{color:var(--text-main);margin-top:12px;font-size:1.4rem;font-weight:800;line-height:1.3}:root .empty-state-status{color:#92400e;background:#fef3c7;border:1.5px solid #f59e0b;border-radius:12px;margin:12px 0 0;padding:6px 14px;font-size:.95rem;font-weight:800;display:inline-block}:root .empty-state-desc{color:#64748b;max-width:420px;margin:8px auto 20px;font-size:.95rem;line-height:1.5}:root .empty-state-cta{width:100%;max-width:260px;margin:0 auto}:root .brand-logo{align-items:center;font-size:1.6rem;line-height:1;display:inline-flex}:root .badge-item{background:var(--primary-light);color:var(--primary-hover);white-space:nowrap;border-radius:999px;padding:4px 10px;font-size:.875rem;font-weight:700}:root .badge-divider{color:var(--secondary)}:root .app-header .nav-tab:not(.active):hover{background:var(--primary-light);border-color:var(--primary)}:root .app-header .end-session-btn:hover{border-color:var(--primary);color:var(--primary-hover)}:root .bottom-nav-tab:hover{background:var(--primary-light);color:var(--primary-hover)}:root .bottom-nav-tab.active{background:var(--primary-light)}