:root{--teal: #12B886;--teal-deep: #0CA678;--coral: #FF8787;--ink: #1E2A32;--bg: #F8FAFB;--bg-tint: #E6F4FE;--card: #FFFFFF;--muted: #5A6B75;--border: #E3EAEF;--to-learn: #FF6B00;--practiced: #00BCD4;--learned: #4CAF50;--error: #FF5252;--success: #4CAF50;--series-added: #7E57C2;--series-checked: #EC407A;--radius: 16px;--shadow: 0 10px 30px rgba(30, 42, 50, .08);--shadow-lg: 0 20px 50px rgba(30, 42, 50, .12);--font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;--sidebar-w: 236px}*{box-sizing:border-box;margin:0;padding:0}html,body,#root{height:100%}body{font-family:var(--font);color:var(--ink);background:var(--bg);line-height:1.55;-webkit-font-smoothing:antialiased}a{color:inherit;text-decoration:none}button{font-family:inherit;cursor:pointer}input,textarea,select{font-family:inherit;font-size:15px}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;background:linear-gradient(135deg,var(--teal),var(--teal-deep));color:#fff;font-weight:700;font-size:15px;padding:11px 20px;border-radius:999px;border:none;box-shadow:0 8px 20px #12b88642;transition:transform .16s ease,box-shadow .16s ease,opacity .16s}.btn:hover:not(:disabled){transform:translateY(-1px);box-shadow:0 12px 26px #12b88657}.btn:disabled{opacity:.5;cursor:default}.btn.secondary{background:var(--card);color:var(--ink);border:1px solid var(--border);box-shadow:none}.btn.secondary:hover:not(:disabled){box-shadow:var(--shadow);transform:none}.btn.danger{background:var(--error);box-shadow:none}.btn.small{padding:7px 14px;font-size:13px}.field{display:flex;flex-direction:column;gap:6px;margin-bottom:14px}.field label{font-size:13px;font-weight:600;color:var(--muted)}.input{width:100%;background:var(--card);border:1px solid var(--border);border-radius:12px;padding:11px 14px;color:var(--ink);outline:none;transition:border-color .15s,box-shadow .15s}.input:focus{border-color:var(--teal);box-shadow:0 0 0 3px #12b8861f}.card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:20px}.chip{display:inline-flex;align-items:center;gap:6px;padding:6px 12px;border-radius:999px;font-size:13px;font-weight:600;background:var(--bg-tint);color:var(--ink);border:1px solid transparent;cursor:pointer}.chip.active{background:var(--teal);color:#fff}.dot{width:9px;height:9px;border-radius:50%;display:inline-block}.dot.to_learn{background:var(--to-learn)}.dot.practiced{background:var(--practiced)}.dot.learned{background:var(--learned)}.muted{color:var(--muted)}.center{display:flex;align-items:center;justify-content:center}.spinner{width:34px;height:34px;border-radius:50%;border:3px solid var(--border);border-top-color:var(--teal);animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}