@import "https://cdn.jsdelivr.net/gh/orioncactus/pretendard@v1.3.9/dist/web/static/pretendard.min.css";
:root{--font-family-base:"Pretendard Variable", Pretendard, -apple-system, BlinkMacSystemFont, system-ui, Roboto, "Helvetica Neue", "Segoe UI", "Apple SD Gothic Neo", "Noto Sans KR", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Malgun Gothic", sans-serif;--duo-green:#58cc02;--duo-green-dark:#46a302;--duo-green-light:#89e219;--duo-green-bg:#e5f8d0;--duo-blue:#1cb0f6;--duo-blue-dark:#1899d6;--duo-blue-bg:#ddf4ff;--duo-orange:#ff9600;--duo-orange-dark:#e58400;--duo-yellow:#ffc800;--duo-yellow-dark:#e5b200;--duo-purple:#ce82ff;--duo-purple-dark:#b75dff;--duo-rose:#ff4b4b;--duo-rose-dark:#ea2b2b;--duo-card-bg:#fff;--duo-border:#e5e5e5;--duo-border-dark:#cecece;--duo-text-dark:#3c3c3c;--duo-text-muted:#777;--bg-gradient:#f7f7f7;--radius-large:24px;--radius-medium:16px;--radius-small:12px}*{box-sizing:border-box;font-family:var(--font-family-base);-webkit-tap-highlight-color:transparent;margin:0;padding:0}body{background-color:var(--bg-gradient);min-height:100vh;color:var(--duo-text-dark);justify-content:center;align-items:flex-start;padding:24px 16px;display:flex}.app-container{flex-direction:column;align-items:center;gap:20px;width:100%;max-width:1160px;margin:0 auto;display:flex}.main-tab-nav{border-radius:var(--radius-large);border:2px solid var(--duo-border);border-bottom:5px solid var(--duo-border-dark);scrollbar-width:none;background:#fff;gap:8px;width:100%;padding:8px;display:flex;overflow-x:auto;box-shadow:0 4px 12px #0000000a}.main-tab-nav::-webkit-scrollbar{display:none}.main-tab-btn{border-radius:var(--radius-medium);color:var(--duo-text-muted);cursor:pointer;white-space:nowrap;text-transform:uppercase;letter-spacing:.3px;background:0 0;border:2px solid #0000;border-bottom-width:4px;flex:1;padding:12px 18px;font-size:14px;font-weight:800;transition:all .15s}.main-tab-btn:hover{color:var(--duo-text-dark);background:#f1f1f1}.main-tab-btn.active{background:var(--duo-green);color:#fff;border-color:var(--duo-green-dark);border-bottom:4px solid var(--duo-green-dark);box-shadow:0 4px 0 var(--duo-green-dark)}.main-tab-btn.active:active{box-shadow:0 2px 0 var(--duo-green-dark);transform:translateY(2px)}.category-nav-wrapper{background:#fff;border:2px solid #e9ecef;border-bottom:5px solid #dee2e6;border-radius:24px;flex-direction:column;gap:12px;margin-bottom:24px;padding:16px 20px;display:flex;box-shadow:0 8px 24px #0000000d}.category-nav-group{flex-wrap:wrap;align-items:center;gap:8px;display:flex}.category-label{white-space:nowrap;letter-spacing:-.3px;border-radius:12px;padding:6px 12px;font-size:12px;font-weight:900}.nav-pill-btn{color:#4a5568;cursor:pointer;white-space:nowrap;background:#f8f9fa;border:2px solid #e9ecef;border-radius:14px;align-items:center;gap:6px;padding:9px 15px;font-size:14px;font-weight:800;transition:all .15s;display:inline-flex;box-shadow:0 3px #e2e8f0}.nav-pill-btn:hover{color:#2d3748;background:#edf2f7;transform:translateY(-1px)}.nav-pill-btn:active{transform:translateY(2px);box-shadow:0 1px #e2e8f0}.nav-pill-btn.active{color:#fff;background:#58cc02;border-color:#46a302;box-shadow:0 4px #46a302}.app-header{text-align:center;border-radius:var(--radius-large);border:2px solid var(--duo-border);border-bottom:5px solid var(--duo-border-dark);background:#fff;width:100%;padding:20px 24px}.app-title{color:var(--duo-green-dark);letter-spacing:-.5px;font-size:26px;font-weight:900}.user-manager-header-bar{border-radius:var(--radius-large);border:2px solid var(--duo-border);border-bottom:4px solid var(--duo-border-dark);background:#fff;justify-content:space-between;align-items:center;gap:8px;width:100%;margin-bottom:6px;padding:10px 16px;display:flex}.user-info-group{align-items:center;gap:8px;min-width:0;display:flex}.user-name-title{color:var(--duo-text-dark);align-items:center;gap:4px;font-size:14px;font-weight:800;display:inline-flex}.user-grade-tag{color:var(--duo-text-muted);font-size:12px;font-weight:700}.user-study-info-pill{color:var(--duo-blue-dark);background:var(--duo-blue-bg);border:1px solid var(--duo-blue);white-space:nowrap;border-radius:8px;padding:4px 10px;font-size:12px;font-weight:800}.user-actions-group{flex-shrink:0;align-items:center;gap:6px;display:flex}.user-free-badge{color:#15803d;white-space:nowrap;background:#dcfce7;border:1px solid #86efac;border-radius:8px;align-items:center;gap:3px;padding:6px 10px;font-size:11px;font-weight:900;display:inline-flex}.btn-user-edit{background:var(--duo-green);border:2px solid var(--duo-green-dark);border-bottom:3px solid var(--duo-green-dark);color:#fff;cursor:pointer;white-space:nowrap;border-radius:8px;padding:6px 12px;font-size:12px;font-weight:900;transition:all .15s}.btn-user-edit:hover{background:var(--duo-green-light)}.btn-user-edit:active{border-bottom-width:2px;transform:translateY(1px)}.btn-user-logout{border:2px solid var(--duo-rose);border-bottom:3px solid var(--duo-rose-dark);color:var(--duo-rose);cursor:pointer;white-space:nowrap;background:#fff;border-radius:8px;padding:6px 12px;font-size:12px;font-weight:900;transition:all .15s}.btn-user-logout:hover{background:var(--duo-rose);color:#fff}.btn-user-logout:active{border-bottom-width:2px;transform:translateY(1px)}.btn-text-hide-mobile{display:inline}.btn-text-show-mobile{display:none}.action-buttons-toolbar{background:#fff;border:2px solid #ebf5fb;border-radius:16px;flex-wrap:wrap;justify-content:center;align-items:center;gap:8px;width:100%;margin-bottom:6px;padding:8px 12px;display:flex;box-shadow:0 4px 14px #0000000a}.action-btn-item{cursor:pointer;white-space:nowrap;box-sizing:border-box;border-radius:12px;justify-content:center;align-items:center;gap:5px;height:40px;padding:0 14px;font-size:13px;font-weight:800;transition:all .2s;display:inline-flex}.lang-speed-toolbar{background:#fff;border:2px solid #e2e8f0;border-radius:18px;flex-direction:column;justify-content:center;align-items:center;gap:8px;width:100%;max-width:820px;margin:8px auto 10px;padding:10px 16px;display:flex;box-shadow:0 4px 14px #0000000a}@media (max-width:768px){body{-webkit-text-size-adjust:100%;padding:6px 4px}.app-container{max-width:100%;padding:0 2px}.app-header{margin:2px 0 4px!important;padding:0!important}.app-title{margin:0!important;font-size:16px!important}.user-manager-header-bar{border-width:1.5px 1.5px 3px;border-radius:12px;flex-direction:row;justify-content:space-between;align-items:center;gap:4px;margin-bottom:4px;padding:6px 10px}.user-name-title{font-size:12px}.user-grade-tag{font-size:10px}.user-study-info-pill{border-radius:6px;padding:2px 6px;font-size:10px}.user-free-badge{display:none}.btn-user-edit,.btn-user-logout{border-radius:6px;padding:4px 8px;font-size:11px}.btn-text-hide-mobile{display:none}.btn-text-show-mobile{display:inline}.action-buttons-toolbar{border-radius:12px;grid-template-columns:1fr 1fr;gap:4px;margin-bottom:4px;padding:6px;display:grid}.action-btn-item{white-space:nowrap;border-radius:8px!important;height:32px!important;padding:0 6px!important;font-size:11px!important}.action-btn-item-full{grid-column:span 2}.category-nav{margin-bottom:4px!important}.category-nav-group{-webkit-overflow-scrolling:touch;display:flex;overflow-x:auto;flex-wrap:nowrap!important;justify-content:flex-start!important;gap:4px!important;padding:2px 2px 6px!important}.nav-tab-btn{flex-shrink:0;white-space:nowrap!important;border-radius:10px!important;padding:6px 12px!important;font-size:12px!important}.flashcard-wrapper{margin:2px auto!important}.flashcard,.card-face{border-radius:18px!important;min-height:250px!important;padding:12px 10px!important}.word-en{margin:4px 0!important;font-size:28px!important}.word-ko{margin:4px 0!important;font-size:18px!important;line-height:1.25!important}.flashcard-img-container{max-height:110px!important;margin:4px auto!important}.options-grid{grid-template-columns:1fr;gap:8px}}.flashcard-wrapper{perspective:1200px;width:100%;max-width:820px;margin:4px auto}.flashcard{width:100%;min-height:360px;transform-style:preserve-3d;cursor:pointer;border-radius:28px;transition:transform .6s cubic-bezier(.34,1.56,.64,1);position:relative}.flashcard.flipped{transform:rotateY(180deg)}.card-face{backface-visibility:hidden;border:3px solid var(--duo-border);text-align:center;box-sizing:border-box;background:#fff;border-radius:28px;flex-direction:column;justify-content:center;align-items:center;width:100%;min-height:360px;padding:32px 24px;display:flex;box-shadow:0 10px #e5e5e5}.card-back{border-color:var(--duo-blue);box-shadow:0 10px 0 var(--duo-blue-dark);position:absolute;top:0;left:0;transform:rotateY(180deg)}.card-category-badge{background:var(--duo-green-bg);color:var(--duo-green-dark);border:2px solid var(--duo-green);border-radius:var(--radius-medium);padding:6px 16px;font-size:13px;font-weight:900;position:absolute;top:18px;left:20px}.word-en{color:var(--duo-text-dark);letter-spacing:-.5px;margin-top:10px;font-size:46px;font-weight:900}.word-phonics{color:var(--duo-blue-dark);margin-top:6px;font-size:20px;font-weight:800}.word-ko{color:var(--duo-rose-dark);margin-top:10px;font-size:46px;font-weight:900}.word-meaning-title{color:var(--duo-text-muted);font-size:15px;font-weight:800}.flip-hint{color:var(--duo-text-muted);font-size:13px;font-weight:800;position:absolute;bottom:16px}.audio-btn{background:var(--duo-blue);border:2px solid var(--duo-blue-dark);border-bottom:4px solid var(--duo-blue-dark);color:#fff;border-radius:var(--radius-medium);cursor:pointer;padding:12px 24px;font-size:15px;font-weight:900;transition:all .15s}.audio-btn:hover{background:#2cbdff}.audio-btn:active{border-bottom-width:2px;transform:translateY(2px)}.card-nav-buttons{border-radius:var(--radius-large);border:2px solid var(--duo-border);border-bottom:5px solid var(--duo-border-dark);background:#fff;justify-content:space-between;align-items:center;width:100%;margin-top:18px;padding:16px 22px;display:flex}.btn-nav{border:2px solid var(--duo-border);border-bottom:4px solid var(--duo-border-dark);border-radius:var(--radius-medium);color:var(--duo-text-dark);cursor:pointer;white-space:nowrap;background:#fff;padding:12px 22px;font-size:14px;font-weight:900;transition:all .15s}.btn-nav:hover{background:var(--duo-green);color:#fff;border-color:var(--duo-green-dark);border-bottom-color:var(--duo-green-dark)}.btn-nav:active{border-bottom-width:2px;transform:translateY(2px)}.card-counter{color:var(--duo-green-dark);margin:0 12px;font-size:20px;font-weight:900}.word-list-section{border-radius:var(--radius-large);border:2px solid var(--duo-border);border-bottom:5px solid var(--duo-border-dark);background:#fff;width:100%;padding:24px}.word-list-header{text-align:center;margin-bottom:20px}.word-list-subtitle{color:var(--duo-text-muted);margin-top:6px;font-size:14px;font-weight:700}.word-card-grid{flex-direction:column;gap:12px;display:flex}.word-list-item-card{border:2px solid var(--duo-border);border-bottom:4px solid var(--duo-border-dark);border-radius:var(--radius-medium);background:#fff;align-items:center;gap:16px;padding:16px 20px;transition:all .15s;display:flex}.word-list-item-card:hover{border-color:var(--duo-green);border-bottom-color:var(--duo-green-dark);transform:translateY(-2px)}.word-item-index{background:var(--duo-green);color:#fff;width:36px;height:36px;box-shadow:0 3px 0 var(--duo-green-dark);border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;font-size:15px;font-weight:900;display:flex}.word-item-main{flex:1}.word-item-header{align-items:baseline;gap:10px;display:flex}.word-item-en{color:var(--duo-text-dark);font-size:22px;font-weight:900}.word-item-phonics{color:var(--duo-blue-dark);font-size:15px;font-weight:800}.word-item-meaning{color:var(--duo-rose-dark);margin-top:3px;font-size:17px;font-weight:900}.word-item-example{border-top:2px stroke var(--duo-border);margin-top:8px;padding-top:8px}.example-en-sm{color:var(--duo-text-dark);font-size:13px;font-weight:800}.example-ko-sm{color:var(--duo-text-muted);font-size:12px}.audio-btn-sm{border:2px solid var(--duo-blue);border-bottom:4px solid var(--duo-blue-dark);background:var(--duo-blue-bg);width:44px;height:44px;color:var(--duo-blue-dark);cursor:pointer;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;font-size:18px;transition:all .15s;display:flex}.audio-btn-sm:hover{background:var(--duo-blue);color:#fff}.audio-btn-sm:active{border-bottom-width:2px;transform:translateY(2px)}.quiz-container{width:100%}.quiz-tab-buttons{flex-wrap:wrap;gap:10px;margin-bottom:16px;display:flex}.tab-btn{border:2px solid var(--duo-border);border-bottom:4px solid var(--duo-border-dark);border-radius:var(--radius-medium);min-height:48px;color:var(--duo-text-muted);cursor:pointer;-webkit-user-select:none;user-select:none;background:#fff;flex:1;justify-content:center;align-items:center;gap:6px;padding:12px 18px;font-size:15px;font-weight:900;transition:all .15s;display:inline-flex}.tab-btn:hover{color:var(--duo-text-dark);background:#f8f9fa}.tab-btn:active{border-bottom-width:2px;transform:translateY(2px)}.tab-btn.active{background:var(--duo-purple);color:#fff;border-color:var(--duo-purple-dark);border-bottom-color:var(--duo-purple-dark);box-shadow:0 2px 0 var(--duo-purple-dark)}.quiz-card{border-radius:var(--radius-large);border:2px solid var(--duo-border);border-bottom:5px solid var(--duo-border-dark);background:#fff;padding:28px}.quiz-level-btn{border:2px solid var(--duo-border);border-bottom:4px solid var(--duo-border-dark);border-radius:var(--radius-small);min-height:44px;color:var(--duo-text-muted);cursor:pointer;-webkit-user-select:none;user-select:none;background:#fff;justify-content:center;align-items:center;gap:6px;padding:10px 16px;font-size:14px;font-weight:900;transition:all .15s;display:inline-flex}.quiz-level-btn:hover{color:var(--duo-text-dark);background:#f8f9fa}.quiz-level-btn:active{border-bottom-width:2px;transform:translateY(2px)}.quiz-level-btn.active{background:var(--duo-green);color:#fff;border-color:var(--duo-green-dark);border-bottom-color:var(--duo-green-dark);box-shadow:0 2px 0 var(--duo-green-dark)}.options-grid{grid-template-columns:1fr 1fr;gap:14px;display:grid}.option-btn{border:2px solid var(--duo-border);border-bottom:4px solid var(--duo-border-dark);border-radius:var(--radius-medium);min-height:64px;color:var(--duo-text-dark);cursor:pointer;text-align:center;-webkit-user-select:none;user-select:none;background:#fff;justify-content:center;align-items:center;padding:14px 20px;font-size:17px;font-weight:900;line-height:1.35;transition:all .15s;display:flex}.option-btn:hover{background:var(--duo-blue-bg);border-color:var(--duo-blue);border-bottom-color:var(--duo-blue-dark);color:var(--duo-blue-dark);transform:translateY(-2px)}.option-btn:active{border-bottom-width:2px;transform:translateY(2px)}.btn-unified-primary{background:var(--duo-green);border:2px solid var(--duo-green-dark);border-bottom:4px solid var(--duo-green-dark);color:#fff;cursor:pointer;-webkit-user-select:none;user-select:none;border-radius:14px;justify-content:center;align-items:center;gap:8px;min-height:48px;padding:12px 24px;font-size:15px;font-weight:900;transition:all .15s;display:inline-flex}.btn-unified-primary:hover{background:var(--duo-green-light)}.btn-unified-primary:active{border-bottom-width:2px;transform:translateY(2px)}.btn-unified-blue{background:var(--duo-blue);border:2px solid var(--duo-blue-dark);border-bottom:4px solid var(--duo-blue-dark);color:#fff;cursor:pointer;-webkit-user-select:none;user-select:none;border-radius:14px;justify-content:center;align-items:center;gap:8px;min-height:48px;padding:12px 24px;font-size:15px;font-weight:900;transition:all .15s;display:inline-flex}.btn-unified-blue:hover{background:#2cbdff}.btn-unified-blue:active{border-bottom-width:2px;transform:translateY(2px)}.btn-unified-secondary{border:2px solid var(--duo-border);border-bottom:4px solid var(--duo-border-dark);min-height:44px;color:var(--duo-text-dark);cursor:pointer;-webkit-user-select:none;user-select:none;background:#fff;border-radius:12px;justify-content:center;align-items:center;gap:6px;padding:10px 20px;font-size:14px;font-weight:800;transition:all .15s;display:inline-flex}.btn-unified-secondary:hover{background:#f8f9fa;border-color:#cbd5e1}.btn-unified-secondary:active{border-bottom-width:2px;transform:translateY(2px)}.btn-speed-item{cursor:pointer;color:#475569;-webkit-user-select:none;user-select:none;background:#f8fafc;border:2px solid #cbd5e1;border-bottom:3px solid #94a3b8;border-radius:10px;justify-content:center;align-items:center;min-width:64px;height:38px;padding:6px 12px;font-size:13px;font-weight:900;transition:all .15s;display:inline-flex}.btn-speed-item:hover{background:#e2e8f0}.btn-speed-item.active{color:#fff;background:#58cc02;border-color:#46a302 #46a302 #388e00;box-shadow:0 2px #388e00}.spelling-input{border:3px solid var(--duo-blue);border-bottom:5px solid var(--duo-blue-dark);border-radius:var(--radius-medium);text-align:center;background:#fff;width:100%;padding:18px;font-size:22px;font-weight:900}