.app[data-v-99d86b36]{display:flex;flex-direction:column;min-height:100vh;padding:var(--spacing-xl);padding-top:calc(var(--spacing-xl) + 80px)}.app[data-v-99d86b36],header[data-v-99d86b36]{background:var(--color-bg-app);transition:background var(--transition-normal)}header[data-v-99d86b36]{box-shadow:0 2px 8px #0000001a;color:#fff;left:0;padding:var(--spacing-md) var(--spacing-xl);position:fixed;right:0;top:0;z-index:1000}.header-content[data-v-99d86b36]{align-items:center;display:flex;flex-wrap:wrap;gap:var(--spacing-sm);justify-content:space-between;position:relative;width:100%}.online-count-container[data-v-99d86b36]{-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);background:#ffffff1a;border:2px solid hsla(0,0%,100%,.3);border-radius:var(--radius-md);flex-shrink:0;height:30px;overflow:hidden;width:200px}.online-count-scroll[data-v-99d86b36]{align-items:center;animation:scroll-left-99d86b36 20s linear infinite;display:flex;height:100%;white-space:nowrap}.online-count-text[data-v-99d86b36]{color:var(--color-text-white);display:inline-block;font-size:13px;font-weight:500;min-width:200px;padding:0 var(--spacing-lg);text-align:center}@keyframes scroll-left-99d86b36{0%{transform:translate(0)}to{transform:translate(-66.666%)}}.header-controls[data-v-99d86b36]{align-items:center;display:flex;flex-shrink:0;flex-wrap:wrap;gap:var(--spacing-lg);margin-left:auto}.main-nav[data-v-99d86b36]{-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-radius:var(--radius-md);display:flex;gap:var(--spacing-sm);padding:var(--spacing-xs)}.main-nav[data-v-99d86b36],.nav-btn[data-v-99d86b36]{background:#ffffff1a}.nav-btn[data-v-99d86b36]{border:2px solid hsla(0,0%,100%,.5);border-radius:var(--radius-sm);color:var(--color-text-white);cursor:pointer;font-size:14px;font-weight:500;padding:var(--spacing-sm) var(--spacing-lg);transition:all var(--transition-normal);white-space:nowrap}.nav-btn[data-v-99d86b36]:hover{background:#fff3;border-color:#fffc;transform:translateY(-2px)}.nav-btn.active[data-v-99d86b36]{background:#ffffff4d;border-color:#fff;box-shadow:0 2px 8px var(--color-shadow-md)}.theme-switcher[data-v-99d86b36]{align-items:center;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);background:#ffffff1a;border-radius:var(--radius-md);display:flex;gap:var(--spacing-xs);padding:var(--spacing-xs)}.theme-label[data-v-99d86b36]{color:var(--color-text-white);font-size:14px;font-weight:500;margin-right:var(--spacing-xs);white-space:nowrap}.theme-btn[data-v-99d86b36]{align-items:center;background:#ffffff1a;border:2px solid hsla(0,0%,100%,.5);border-radius:var(--radius-sm);cursor:pointer;display:flex;height:36px;justify-content:center;position:relative;transition:all var(--transition-normal);width:36px}.theme-btn[data-v-99d86b36]:hover{background:#fff3;border-color:#fffc;transform:translateY(-2px)}.theme-btn.active[data-v-99d86b36]{background:#ffffff4d;border-color:#fff;box-shadow:0 2px 8px var(--color-shadow-md)}.theme-icon[data-v-99d86b36]{border-radius:50%;display:block;height:20px;width:20px}.theme-icon[data-theme=light][data-v-99d86b36]{background:linear-gradient(135deg,#4caf50,#2e7d32)}.theme-icon[data-theme=dark][data-v-99d86b36]{background:linear-gradient(135deg,#2c3e50,#34495e)}.theme-icon[data-theme=blue][data-v-99d86b36]{background:linear-gradient(135deg,#1565c0,#0d47a1)}.language-switcher[data-v-99d86b36]{display:flex;gap:var(--spacing-sm)}.lang-btn[data-v-99d86b36]{-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);background:#ffffff1a;border:2px solid hsla(0,0%,100%,.5);border-radius:var(--radius-md);color:var(--color-text-white);cursor:pointer;font-size:14px;font-weight:500;padding:var(--spacing-sm) var(--spacing-lg);transition:all var(--transition-normal)}.lang-btn[data-v-99d86b36]:hover{background:#fff3;border-color:#fffc;transform:translateY(-2px)}.lang-btn.active[data-v-99d86b36]{background:#ffffff4d;border-color:#fff;box-shadow:0 2px 8px var(--color-shadow-md)}.mobile-menu-btn[data-v-99d86b36]{-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);background:#ffffff1a;border:2px solid hsla(0,0%,100%,.5);border-radius:var(--radius-sm);cursor:pointer;display:none;padding:var(--spacing-xs);transition:all var(--transition-normal);z-index:1001}.mobile-menu-btn[data-v-99d86b36]:hover{background:#fff3;border-color:#fffc}.hamburger-icon[data-v-99d86b36]{display:flex;flex-direction:column;height:18px;justify-content:space-between;width:24px}.hamburger-icon[data-v-99d86b36],.hamburger-icon span[data-v-99d86b36]{transition:all var(--transition-normal)}.hamburger-icon span[data-v-99d86b36]{background:var(--color-text-white);border-radius:2px;display:block;height:2px;width:100%}.hamburger-icon.active span[data-v-99d86b36]:first-child{transform:rotate(45deg) translate(7px,7px)}.hamburger-icon.active span[data-v-99d86b36]:nth-child(2){opacity:0}.hamburger-icon.active span[data-v-99d86b36]:nth-child(3){transform:rotate(-45deg) translate(7px,-7px)}@media(max-width:768px){.header-content[data-v-99d86b36]{align-items:center;flex-wrap:nowrap;gap:4px;justify-content:space-between;min-height:40px;padding:2px 6px}.online-count-container[data-v-99d86b36]{flex:1;height:20px;margin-right:6px;min-width:0;width:auto}.online-count-text[data-v-99d86b36]{font-size:10px;min-width:120px;padding:0 8px}.mobile-menu-btn[data-v-99d86b36]{border-width:1px;display:block;flex-shrink:0;min-height:28px;min-width:28px;padding:4px}.hamburger-icon[data-v-99d86b36]{height:12px;width:16px}.hamburger-icon span[data-v-99d86b36]{height:1.5px}.hamburger-icon.active span[data-v-99d86b36]:first-child{transform:rotate(45deg) translate(5px,5px)}.hamburger-icon.active span[data-v-99d86b36]:nth-child(3){transform:rotate(-45deg) translate(5px,-5px)}.header-controls[data-v-99d86b36]{background:var(--color-bg-app);box-shadow:0 4px 12px #00000026;flex-direction:column;gap:var(--spacing-sm);left:0;max-height:calc(100vh - 40px);opacity:0;overflow-y:auto;padding:var(--spacing-md);position:fixed;right:0;top:40px;transform:translateY(-100%);transition:all var(--transition-normal);visibility:hidden;width:100%;z-index:1000}.header-controls.mobile-open[data-v-99d86b36]{opacity:1;transform:translateY(0);visibility:visible}.main-nav[data-v-99d86b36]{flex-direction:column;gap:var(--spacing-xs);padding:var(--spacing-xs);width:100%}.nav-btn[data-v-99d86b36]{border-width:1.5px;font-size:13px;padding:var(--spacing-xs) var(--spacing-md)}.nav-btn[data-v-99d86b36],.theme-switcher[data-v-99d86b36]{justify-content:center;width:100%}.theme-switcher[data-v-99d86b36]{gap:var(--spacing-xs);padding:var(--spacing-xs)}.theme-label[data-v-99d86b36]{font-size:13px}.theme-btn[data-v-99d86b36]{border-width:1.5px;height:32px;width:32px}.theme-icon[data-v-99d86b36]{height:18px;width:18px}.language-switcher[data-v-99d86b36]{gap:var(--spacing-xs);justify-content:center;width:100%}.lang-btn[data-v-99d86b36]{border-width:1.5px;font-size:13px;padding:var(--spacing-xs) var(--spacing-md)}.app[data-v-99d86b36]{padding-top:calc(var(--spacing-xl) + 40px)}header[data-v-99d86b36]{min-height:40px;padding:2px 6px}}@media(max-width:480px){.header-content[data-v-99d86b36]{gap:3px;min-height:36px;padding:2px 4px}.online-count-container[data-v-99d86b36]{height:18px;margin-bottom:3px;margin-right:0;width:100%}.online-count-text[data-v-99d86b36]{font-size:9px;min-width:100px;padding:0 6px}.header-content[data-v-99d86b36]{align-items:stretch;flex-direction:column}.mobile-menu-btn[data-v-99d86b36]{align-self:flex-end;margin-top:3px;min-height:24px;min-width:24px;padding:3px}.hamburger-icon[data-v-99d86b36]{height:10px;width:14px}.hamburger-icon span[data-v-99d86b36]{height:1.5px}.hamburger-icon.active span[data-v-99d86b36]:first-child{transform:rotate(45deg) translate(4px,4px)}.hamburger-icon.active span[data-v-99d86b36]:nth-child(3){transform:rotate(-45deg) translate(4px,-4px)}.app[data-v-99d86b36]{padding-top:calc(var(--spacing-xl) + 36px)}header[data-v-99d86b36]{min-height:36px;padding:2px 4px}.header-controls[data-v-99d86b36]{max-height:calc(100vh - 36px);top:36px}}.app-footer[data-v-99d86b36]{background:var(--color-bg-app);border-top:1px solid hsla(0,0%,100%,.1);color:var(--color-text-white);margin-top:auto;padding:var(--spacing-lg) var(--spacing-xl);text-align:center;transition:background var(--transition-normal)}.footer-content[data-v-99d86b36]{align-items:center;display:flex;flex-wrap:wrap;font-size:13px;gap:var(--spacing-md);justify-content:center}.beian-link[data-v-99d86b36]{color:var(--color-text-white);text-decoration:none;transition:opacity .2s ease}.beian-link[data-v-99d86b36]:hover{opacity:.8;text-decoration:underline}.copyright[data-v-99d86b36]{color:var(--color-text-white);opacity:.9}[data-theme=dark] .app-footer[data-v-99d86b36]{background:var(--color-bg-app);border-top-color:#ffffff1a}[data-theme=light] .app-footer[data-v-99d86b36]{background:var(--color-bg-app);border-top-color:#fff3}[data-theme=blue] .app-footer[data-v-99d86b36]{background:var(--color-bg-app);border-top-color:#ffffff1a}@media(max-width:768px){.app-footer[data-v-99d86b36]{padding:var(--spacing-md) var(--spacing-sm)}.footer-content[data-v-99d86b36]{flex-direction:column;font-size:12px;gap:var(--spacing-sm)}}.book-index[data-v-7293bb4e]{align-items:center;background:linear-gradient(135deg,#4c63d2,#764ba2);display:flex;flex-direction:column;justify-content:center;min-height:100vh;padding:var(--spacing-2xl)}.book-cover[data-v-7293bb4e]{background:linear-gradient(145deg,#2c3e50,#34495e);border-radius:var(--radius-lg);box-shadow:0 20px 60px #0000004d;color:#fff;margin-bottom:var(--spacing-2xl);max-width:800px;padding:var(--spacing-3xl);text-align:center;width:100%}.cover-content[data-v-7293bb4e]{position:relative}.book-title[data-v-7293bb4e]{font-size:3.5em;font-weight:700;letter-spacing:2px;margin:0 0 var(--spacing-md) 0;text-shadow:2px 2px 4px rgba(0,0,0,.3)}.book-subtitle[data-v-7293bb4e]{font-size:1.3em;font-weight:300;margin:0;opacity:.9}.book-decoration[data-v-7293bb4e]{background:#ffffff80;border-radius:2px;height:4px;margin-left:auto;margin-right:auto;margin-top:var(--spacing-xl);width:100px}.book-content[data-v-7293bb4e]{max-width:900px;width:100%}.book-page[data-v-7293bb4e]{background:var(--color-bg-primary);border-radius:var(--radius-lg);box-shadow:0 10px 40px #0003;min-height:500px;padding:var(--spacing-3xl)}.page-header[data-v-7293bb4e]{border-bottom:2px solid var(--color-border-primary);margin-bottom:var(--spacing-2xl);padding-bottom:var(--spacing-md)}.page-number[data-v-7293bb4e]{color:var(--color-text-primary);font-size:24px;font-weight:600;letter-spacing:2px}.chapters[data-v-7293bb4e]{display:flex;flex-direction:column;gap:var(--spacing-2xl)}.chapter[data-v-7293bb4e]{margin-bottom:var(--spacing-xl)}.chapter-title[data-v-7293bb4e]{align-items:center;border-bottom:2px solid var(--color-border-primary);color:var(--color-text-primary);display:flex;font-size:1.5em;font-weight:600;gap:var(--spacing-md);margin:0 0 var(--spacing-lg) 0;padding-bottom:var(--spacing-sm)}.chapter-number[data-v-7293bb4e]{color:#4c63d2;font-weight:700;min-width:60px}.sections[data-v-7293bb4e]{display:flex;flex-direction:column;gap:0;margin-left:var(--spacing-lg)}.section-item[data-v-7293bb4e]{align-items:center;border-left:3px solid transparent;cursor:pointer;display:flex;padding:var(--spacing-md) var(--spacing-lg);position:relative;transition:all var(--transition-normal)}.section-item[data-v-7293bb4e]:hover:not(.disabled){background:var(--color-bg-secondary);border-left-color:#4c63d2;transform:translate(5px)}.section-item.disabled[data-v-7293bb4e]{cursor:not-allowed;opacity:.6;position:relative}.section-item.disabled[data-v-7293bb4e]:hover{background:var(--color-bg-secondary);border-left-color:var(--color-border-primary);transform:none}.coming-soon-badge[data-v-7293bb4e]{background:#4c63d21a;border-radius:12px;color:#4c63d2;font-size:.75em;font-weight:500;margin-left:auto;padding:2px 8px;white-space:nowrap}.section-number[data-v-7293bb4e]{color:var(--color-text-secondary);font-family:Courier New,monospace;font-size:.95em;font-weight:600;min-width:50px}.section-heading[data-v-7293bb4e]{color:var(--color-text-primary);flex:1;font-size:1em;font-weight:600;line-height:1.6}@media(max-width:768px){.book-index[data-v-7293bb4e]{padding:var(--spacing-lg)}.book-cover[data-v-7293bb4e]{padding:var(--spacing-xl)}.book-title[data-v-7293bb4e]{font-size:2.5em}.book-subtitle[data-v-7293bb4e]{font-size:1.1em}.book-page[data-v-7293bb4e]{padding:var(--spacing-xl)}.chapter-title[data-v-7293bb4e]{align-items:flex-start;flex-direction:column;font-size:1.3em;gap:var(--spacing-xs)}.chapter-number[data-v-7293bb4e]{min-width:auto}.sections[data-v-7293bb4e]{margin-left:var(--spacing-md)}.section-item[data-v-7293bb4e]{padding:var(--spacing-sm) var(--spacing-md)}.section-item[data-v-7293bb4e]:hover{transform:translate(3px)}.section-number[data-v-7293bb4e]{font-size:.9em;min-width:40px}.section-heading[data-v-7293bb4e]{font-size:.95em}}.determinant[data-v-5438ab0d]{margin:0 auto;max-width:1200px;padding:var(--spacing-xl)}.controls[data-v-5438ab0d]{background:var(--color-bg-secondary);border-radius:var(--radius-md);flex-wrap:wrap;gap:var(--spacing-lg);margin-bottom:var(--spacing-2xl);padding:var(--spacing-lg)}.control-group[data-v-5438ab0d],.controls[data-v-5438ab0d]{align-items:center;display:flex}.control-group[data-v-5438ab0d]{gap:var(--spacing-md)}.control-group label[data-v-5438ab0d]{color:var(--color-text-primary);font-weight:500}.size-select[data-v-5438ab0d]{background:var(--color-bg-primary);border:2px solid var(--color-border-primary);border-radius:var(--radius-sm);color:var(--color-text-primary);cursor:pointer;font-size:14px;padding:var(--spacing-sm) var(--spacing-md)}.size-select[data-v-5438ab0d]:focus{border-color:var(--color-border-focus);outline:none}.btn[data-v-5438ab0d]{border:none;border-radius:var(--radius-sm);cursor:pointer;font-size:14px;font-weight:500;padding:var(--spacing-sm) var(--spacing-lg);transition:all var(--transition-normal)}.btn-primary[data-v-5438ab0d]{background:linear-gradient(135deg,#4c63d2,#764ba2);color:#fff}.btn-primary[data-v-5438ab0d]:hover{box-shadow:0 4px 12px #667eea66;transform:translateY(-2px)}.btn-secondary[data-v-5438ab0d]{background:var(--color-bg-tertiary);border:2px solid var(--color-border-primary);color:var(--color-text-primary)}.btn-secondary[data-v-5438ab0d]:hover{background:var(--color-bg-secondary);border-color:var(--color-border-focus)}.matrix-section[data-v-5438ab0d]{margin-bottom:var(--spacing-2xl)}.matrix-section h3[data-v-5438ab0d]{color:var(--color-text-primary);font-size:1.5em;margin-bottom:var(--spacing-lg)}.matrix-display[data-v-5438ab0d]{background:var(--color-bg-secondary);border-radius:var(--radius-md);display:flex;justify-content:center;padding:var(--spacing-xl)}.matrix-wrapper[data-v-5438ab0d]{align-items:center;display:flex;gap:var(--spacing-md)}.matrix-bracket[data-v-5438ab0d]{color:var(--color-text-secondary);font-size:4em;font-weight:300;line-height:1}.matrix[data-v-5438ab0d]{flex-direction:column}.matrix[data-v-5438ab0d],.matrix-row[data-v-5438ab0d]{display:flex;gap:var(--spacing-sm)}.matrix-cell[data-v-5438ab0d]{position:relative}.cell-input[data-v-5438ab0d]{background:var(--color-bg-primary);border:2px solid var(--color-border-primary);border-radius:var(--radius-sm);color:var(--color-text-primary);font-size:16px;padding:var(--spacing-sm);text-align:center;transition:all var(--transition-normal);width:80px}.cell-input[data-v-5438ab0d]:focus{border-color:var(--color-border-focus);box-shadow:0 0 0 3px #667eea1a;outline:none}.matrix-cell.highlighted .cell-input[data-v-5438ab0d]{background:#667eea1a;border-color:#4c63d2}.results-section[data-v-5438ab0d]{margin-top:var(--spacing-2xl)}.results-section h3[data-v-5438ab0d]{color:var(--color-text-primary);font-size:1.5em;margin-bottom:var(--spacing-lg)}.result-card[data-v-5438ab0d]{background:var(--color-bg-secondary);border-radius:var(--radius-md);margin-bottom:var(--spacing-lg);padding:var(--spacing-xl)}.result-label[data-v-5438ab0d]{color:var(--color-text-secondary);font-size:14px;margin-bottom:var(--spacing-sm)}.result-value[data-v-5438ab0d]{color:#4c63d2;font-size:2.5em;font-weight:700;margin:var(--spacing-md) 0}.warning-message[data-v-5438ab0d]{background:#e74c3c1a;border-left:4px solid #e74c3c;border-radius:var(--radius-sm);color:#e74c3c;margin-top:var(--spacing-md);padding:var(--spacing-md)}.steps-section[data-v-5438ab0d]{background:var(--color-bg-secondary);border-radius:var(--radius-md);margin-top:var(--spacing-xl);padding:var(--spacing-xl)}.steps-section h4[data-v-5438ab0d]{color:var(--color-text-primary);margin-bottom:var(--spacing-lg)}.steps-list[data-v-5438ab0d]{flex-direction:column}.step-item[data-v-5438ab0d],.steps-list[data-v-5438ab0d]{display:flex;gap:var(--spacing-lg)}.step-item[data-v-5438ab0d]{background:var(--color-bg-primary);border-left:4px solid #4c63d2;border-radius:var(--radius-md);padding:var(--spacing-lg)}.step-number[data-v-5438ab0d]{align-items:center;background:linear-gradient(135deg,#4c63d2,#764ba2);border-radius:50%;color:#fff;display:flex;font-size:18px;font-weight:700;height:40px;justify-content:center;min-width:40px}.step-content[data-v-5438ab0d]{flex:1}.step-description[data-v-5438ab0d]{color:var(--color-text-primary);font-weight:500;margin-bottom:var(--spacing-sm)}.step-formula[data-v-5438ab0d]{background:var(--color-bg-secondary);border-radius:var(--radius-sm);padding:var(--spacing-md)}.step-formula[data-v-5438ab0d],.step-submatrix[data-v-5438ab0d]{margin:var(--spacing-md) 0}.submatrix-label[data-v-5438ab0d]{color:var(--color-text-secondary);font-size:14px;margin-bottom:var(--spacing-sm)}.matrix-display-small[data-v-5438ab0d]{display:inline-block;margin-left:var(--spacing-md)}.matrix-wrapper-small[data-v-5438ab0d]{align-items:center;display:flex;gap:var(--spacing-xs)}.matrix-small[data-v-5438ab0d]{display:flex;flex-direction:column;gap:2px}.matrix-row-small[data-v-5438ab0d]{display:flex;gap:4px}.matrix-cell-small[data-v-5438ab0d]{color:var(--color-text-primary);font-size:12px;min-width:30px;padding:2px 6px;text-align:center}.step-value[data-v-5438ab0d]{color:#4c63d2;font-size:1.2em;font-weight:600;margin-top:var(--spacing-sm)}@media(max-width:768px){.determinant[data-v-5438ab0d]{padding:var(--spacing-md)}.matrix-wrapper[data-v-5438ab0d]{flex-direction:column}.matrix-bracket[data-v-5438ab0d]{font-size:2em;transform:rotate(90deg)}.cell-input[data-v-5438ab0d]{font-size:14px;width:60px}.result-value[data-v-5438ab0d]{font-size:2em}.step-item[data-v-5438ab0d]{flex-direction:column}.step-number[data-v-5438ab0d]{align-self:flex-start}}:root{--color-bg-primary:var(--color-bgPrimary,#fff);--color-bg-secondary:var(--color-bgSecondary,#f5f5f5);--color-bg-tertiary:var(--color-bgTertiary,#f9f9f9);--color-bg-app:var(--color-bgApp,linear-gradient(135deg,#4c63d2 0%,#764ba2 100%));--color-text-primary:var(--color-textPrimary,#333);--color-text-secondary:var(--color-textSecondary,#666);--color-text-tertiary:var(--color-textTertiary,#999);--color-text-white:var(--color-textWhite,#fff);--color-title:var(--color-titleColor,var(--color-text-primary));--color-chapter-title:var(--color-chapterTitleColor,var(--color-text-primary));--color-border-primary:var(--color-borderPrimary,#e0e0e0);--color-border-secondary:var(--color-borderSecondary,#ddd);--color-border-focus:var(--color-borderFocus,#4a90e2);--color-btn-primary:var(--color-btnPrimary,#4a90e2);--color-btn-primary-hover:var(--color-btnPrimaryHover,#357abd);--color-btn-secondary:var(--color-btnSecondary,#6c757d);--color-btn-secondary-hover:var(--color-btnSecondaryHover,#5a6268);--color-btn-danger:var(--color-btnDanger,#dc3545);--color-btn-danger-hover:var(--color-btnDangerHover,#c82333);--color-input-bg:var(--color-inputBg,#fff);--color-input-border:var(--color-inputBorder,#ddd);--color-input-focus-shadow:var(--color-inputFocusShadow,rgba(74,144,226,.3));--color-matrix-bg:var(--color-matrixBg,#fff);--color-matrix-bracket:var(--color-matrixBracket,#333);--color-matrix-separator:var(--color-matrixSeparator,#555);--color-vector-blue:var(--color-vectorBlue,#1e3a8a);--color-vector-yellow:var(--color-vectorYellow,#b45309);--color-diagram-muted:var(--color-diagramMuted,#64748b);--color-left-null-line:var(--color-leftNullLine,#8a8a8a);--color-question-bg:var(--color-questionBg,var(--color-bg-secondary));--color-correct:var(--color-correct,#27ae60);--color-correct-bg:var(--color-correctBg,rgba(39,174,96,.15));--color-correct-border:var(--color-correctBorder,#27ae60);--color-incorrect:var(--color-incorrect,#e74c3c);--color-incorrect-bg:var(--color-incorrectBg,rgba(231,76,60,.15));--color-incorrect-border:var(--color-incorrectBorder,#e74c3c);--color-selected:var(--color-selected,#4c63d2);--color-selected-bg:var(--color-selectedBg,rgba(76,99,210,.1));--color-selected-border:var(--color-selectedBorder,#4c63d2);--color-shadow-sm:var(--color-shadowSm,rgba(0,0,0,.1));--color-shadow-md:var(--color-shadowMd,rgba(0,0,0,.15));--color-shadow-lg:var(--color-shadowLg,rgba(0,0,0,.2));--spacing-xs:4px;--spacing-sm:8px;--spacing-md:12px;--spacing-lg:16px;--spacing-xl:20px;--spacing-2xl:30px;--radius-sm:4px;--radius-md:6px;--radius-lg:8px;--transition-fast:.2s;--transition-normal:.3s}.btn{border:none;border-radius:var(--radius-md);cursor:pointer;font-size:14px;font-weight:500;padding:10px 20px;transition:all var(--transition-fast)}.btn:hover:not(:disabled){box-shadow:0 2px 8px var(--color-shadow-md);transform:translateY(-1px)}.btn:disabled{cursor:not-allowed;opacity:.5;transform:none}.btn:disabled:hover{box-shadow:none;transform:none}.btn-primary{background:var(--color-btn-primary);color:var(--color-text-white)}.btn-primary:hover:not(:disabled){background:var(--color-btn-primary-hover)}.btn-secondary{background:var(--color-btn-secondary);color:var(--color-text-white)}.btn-secondary:hover:not(:disabled){background:var(--color-btn-secondary-hover)}.btn-danger{background:var(--color-btn-danger);color:var(--color-text-white)}.btn-danger:hover:not(:disabled){background:var(--color-btn-danger-hover)}.input-base{background-color:var(--color-input-bg);border:1px solid var(--color-input-border);border-radius:var(--radius-sm);color:var(--color-text-primary);font-size:14px;padding:var(--spacing-sm);transition:all var(--transition-fast)}.input-base:focus{border-color:var(--color-border-focus);box-shadow:0 0 0 2px var(--color-input-focus-shadow);outline:none}.input-base::placeholder{color:var(--color-text-tertiary)}@keyframes pulse-scale{0%{transform:scale(1)}50%{transform:scale(1.3)}to{transform:scale(1)}}.animate-pulse{animation:pulse-scale .6s ease-in-out}.section-header{margin-bottom:var(--spacing-xl)}.section-title,h1.section-title,h2.section-title{color:var(--color-title)!important;font-size:2em;font-weight:700;margin:0 0 var(--spacing-lg) 0;text-align:center}.subsection-title,h1.subsection-title,h2.subsection-title{color:var(--color-title)!important}.section-heading,h1.section-heading,h2.section-heading{color:var(--color-text-primary)!important;font-size:2em;font-weight:700;margin:0 0 var(--spacing-lg) 0;text-align:left}.subsection-heading,h1.subsection-heading,h2.subsection-heading,h3.subsection-heading{color:var(--color-text-primary)!important}.article-title{font-size:2.5em;line-height:1.3;margin:0 0 var(--spacing-lg) 0}.article-formulas-page strong,.article-page strong,.article-title,.emphasis-strong{color:var(--color-text-primary);font-weight:700}.chapter-title,h1.chapter-title,h2.chapter-title{color:var(--color-chapter-title)!important}.section-description{border-left:none!important}.math-formula{display:inline-block;font-family:Times New Roman,serif;font-style:italic;font-weight:500;margin:0 2px;padding:2px 4px}.practice-section{background:var(--color-bg-primary);margin-top:var(--spacing-lg)}.practice-section,.question-item{border-radius:var(--radius-md);padding:var(--spacing-lg)}.question-item{background:var(--color-bg-secondary);border:2px solid var(--color-border-primary);margin:var(--spacing-md) 0;transition:all var(--transition-fast)}.question-item.answered{border-color:var(--color-border-secondary)}.question-item.correct{background:var(--color-correct-bg);border-color:var(--color-correct-border)}.question-item.incorrect{background:var(--color-incorrect-bg);border-color:var(--color-incorrect-border)}.question-header{align-items:center;display:flex;gap:var(--spacing-sm);margin-bottom:var(--spacing-md)}.question-number{color:var(--color-text-primary);font-size:16px;font-weight:600}.question-type{color:var(--color-text-secondary);font-size:14px;font-style:italic}.question-content{color:var(--color-text-primary);margin-bottom:var(--spacing-md)}.question-answer{margin-top:var(--spacing-md)}.answer-title{color:var(--color-text-primary);font-size:15px;font-weight:600;margin:var(--spacing-md) 0 var(--spacing-sm) 0}.options-container{display:grid;gap:var(--spacing-md);grid-template-columns:repeat(auto-fit,minmax(200px,1fr));margin-top:var(--spacing-sm)}.answer-btn,.option-button{align-items:center;background:var(--color-bg-primary);border:2px solid var(--color-border-primary);border-radius:var(--radius-md);color:var(--color-text-primary);cursor:pointer;display:flex;font-size:14px;font-weight:500;justify-content:center;min-height:50px;padding:var(--spacing-sm) var(--spacing-md);text-align:center;transition:all var(--transition-fast)}.answer-btn:hover:not(:disabled),.option-button:hover:not(:disabled){background:var(--color-bg-secondary);border-color:var(--color-border-focus);box-shadow:0 4px 8px var(--color-shadow-sm);transform:translateY(-2px)}.answer-btn:disabled,.option-button:disabled{cursor:not-allowed;opacity:.7}.answer-btn.selected,.option-button.selected{background:var(--color-selected-bg);border-color:var(--color-selected-border);color:var(--color-selected);font-weight:600}.answer-btn.correct,.option-button.correct{background:var(--color-correct-bg);border-color:var(--color-correct-border);color:var(--color-correct);font-weight:600}.answer-btn.incorrect,.option-button.incorrect{background:var(--color-incorrect-bg);border-color:var(--color-incorrect-border);color:var(--color-incorrect);font-weight:600}.answer-btn.show-correct,.option-button.show-correct{background:var(--color-correct-bg);border-color:var(--color-correct-border);border-style:dashed}.option-content{align-items:center;display:flex;gap:var(--spacing-sm);width:100%}.option-label{color:var(--color-selected);flex-shrink:0;font-weight:600;min-width:24px}.answer-btn.correct .option-label,.answer-btn.show-correct .option-label,.option-button.correct .option-label,.option-button.show-correct .option-label{color:var(--color-correct)}.answer-btn.incorrect .option-label,.option-button.incorrect .option-label{color:var(--color-incorrect)}.option-text{flex:1;line-height:1.6}.result-feedback{border-radius:var(--radius-md);margin-top:var(--spacing-lg);padding:var(--spacing-md)}.feedback-correct{background:var(--color-correct-bg);border:2px solid var(--color-correct-border);border-radius:var(--radius-md)}.feedback-correct,.feedback-incorrect{align-items:center;display:flex;gap:var(--spacing-sm);margin-bottom:var(--spacing-md);padding:var(--spacing-md)}.feedback-incorrect{background:var(--color-incorrect-bg);border:2px solid var(--color-incorrect-border);border-radius:var(--radius-md)}.feedback-icon{flex-shrink:0;font-size:20px;font-weight:900}.feedback-correct .feedback-icon{color:var(--color-correct)}.feedback-incorrect .feedback-icon{color:var(--color-incorrect)}.feedback-text{align-items:center;color:var(--color-text-primary);display:flex;flex:1;font-size:15px;font-weight:600;gap:var(--spacing-xs)}.explanation-text{background:var(--color-bg-secondary);border-radius:var(--radius-sm);color:var(--color-text-primary);font-size:14px;line-height:1.6;margin-top:var(--spacing-sm);padding:var(--spacing-md)}.practice-controls-bottom,.practice-controls-top{display:flex;gap:var(--spacing-md);justify-content:flex-end;margin-top:var(--spacing-md)}.btn-check-answer,.btn-reset{background:var(--color-btn-primary);border:none;border-radius:var(--radius-sm);box-shadow:0 2px 4px var(--color-shadow-sm);color:var(--color-text-white);cursor:pointer;font-size:14px;font-weight:600;padding:var(--spacing-sm) var(--spacing-lg);transition:all var(--transition-fast)}.btn-check-answer:hover:not(:disabled),.btn-reset:hover:not(:disabled){background:var(--color-btn-primary-hover);box-shadow:0 4px 8px var(--color-shadow-md);transform:translateY(-2px)}.btn-check-answer:disabled,.btn-reset:disabled{background:var(--color-bg-secondary);cursor:not-allowed;opacity:.5}.exercise-summary,.summary-stats{background:var(--color-bg-secondary);border-radius:var(--radius-md);color:var(--color-text-primary);font-size:15px;margin-top:var(--spacing-lg);padding:var(--spacing-md);text-align:center}@media(max-width:768px){:root{--spacing-xl:10px;--spacing-2xl:20px}.options-container{grid-template-columns:1fr}.answer-btn,.option-button{font-size:13px;min-height:45px}.article-title{font-size:2em}.question-item{padding:var(--spacing-md)}.question-number{font-size:14px}}
