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.swiper-slide-shadow-bottom{pointer-events:none;z-index:10;width:100%;height:100%;position:absolute;top:0;left:0}.swiper-3d .swiper-slide-shadow{background:#00000026}.swiper-3d .swiper-slide-shadow-left{background-image:linear-gradient(270deg,#00000080,#0000)}.swiper-3d .swiper-slide-shadow-right{background-image:linear-gradient(90deg,#00000080,#0000)}.swiper-3d .swiper-slide-shadow-top{background-image:linear-gradient(#0000,#00000080)}.swiper-3d .swiper-slide-shadow-bottom{background-image:linear-gradient(#00000080,#0000)}.swiper-lazy-preloader{z-index:10;transform-origin:50%;box-sizing:border-box;border:4px solid var(--swiper-preloader-color,var(--swiper-theme-color));border-top-color:#0000;border-radius:50%;width:42px;height:42px;margin-top:-21px;margin-left:-21px;position:absolute;top:50%;left:50%}:is(.swiper:not(.swiper-watch-progress),.swiper-watch-progress .swiper-slide-visible) .swiper-lazy-preloader{animation:1s linear infinite 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.swiper-button-next,.swiper-horizontal.swiper-rtl~.swiper-button-next{left:var(--swiper-navigation-sides-offset,4px);right:auto}.swiper-horizontal .swiper-button-next,.swiper-horizontal~.swiper-button-next,.swiper-horizontal.swiper-rtl .swiper-button-prev,.swiper-horizontal.swiper-rtl~.swiper-button-prev{right:var(--swiper-navigation-sides-offset,4px);left:auto}:is(.swiper-horizontal .swiper-button-prev,.swiper-horizontal~.swiper-button-prev,.swiper-horizontal.swiper-rtl .swiper-button-next,.swiper-horizontal.swiper-rtl~.swiper-button-next) ::slotted(.swiper-navigation-icon),:is(.swiper-horizontal .swiper-button-prev,.swiper-horizontal~.swiper-button-prev,.swiper-horizontal.swiper-rtl .swiper-button-next,.swiper-horizontal.swiper-rtl~.swiper-button-next) .swiper-navigation-icon{transform:rotate(180deg)}:is(.swiper-horizontal.swiper-rtl .swiper-button-prev,.swiper-horizontal.swiper-rtl~.swiper-button-prev) ::slotted(.swiper-navigation-icon),:is(.swiper-horizontal.swiper-rtl 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::slotted(.swiper-navigation-icon),:is(.swiper-vertical .swiper-button-next,.swiper-vertical~.swiper-button-next) .swiper-navigation-icon{transform:rotate(90deg)}*{box-sizing:border-box;margin:0;padding:0}:root{--bg:#121212;--bg-card:#1e1e2e;--bg-card-hover:#2a2a3e;--text:#e0e0e0;--text-secondary:#9ca3af;--text-muted:#6b7280;--accent:#3b82f6;--accent-hover:#2563eb;--border:#2e303a;--error:#ef4444;--success:#22c55e}body{background:var(--bg);color:var(--text);min-height:100vh;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif}.navbar{border-bottom:1px solid var(--border);z-index:100;background:#0d0d0d;justify-content:space-between;align-items:center;padding:16px 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var(--border);border-radius:20px;justify-content:center;align-items:center;display:flex;position:absolute;inset:0;overflow:hidden}.flashcard-back{transform:rotateY(180deg)}.flashcard-content{text-align:center;width:100%;padding:32px}.flashcard-word{color:#fff;margin-bottom:12px;font-size:72px;font-weight:300;line-height:1.2}.flashcard-pinyin{color:var(--text-secondary);margin-bottom:16px;font-size:22px}.flashcard-pos{color:var(--text-muted);text-transform:uppercase;letter-spacing:1px;margin-bottom:12px;font-size:13px}.flashcard-translation{color:var(--text);font-size:18px}.audio-btn{border:2px solid var(--border);color:var(--accent);cursor:pointer;background:0 0;border-radius:50%;justify-content:center;align-items:center;margin-top:20px;padding:10px;transition:background .2s,border-color .2s;display:inline-flex}.audio-btn:hover{background:var(--accent);border-color:var(--accent);color:#fff}.audio-btn 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