:root{--primary: #0EA5E9;--primary-dark: #0284C7;--primary-light: #E0F2FE;--secondary: #F97316;--secondary-dark: #EA580C;--secondary-light: #FEF3C7;--success: #10B981;--success-dark: #059669;--success-light: #D1FAE5;--error: #F87171;--error-dark: #DC2626;--error-light: #FEE2E2;--purple: #8B5CF6;--purple-light: #EDE9FE;--cyan: #06B6D4;--gold: #FBBF24;--gold-light: #FEF3C7;--warning: #F59E0B;--warning-light: #FEF3C7;--text-primary: #1E293B;--text-secondary: #64748B;--text-hint: #94A3B8;--background: #F8FAFC;--bg: #F0F9FF;--surface: #FFFFFF;--surface-alt: #F8FAFC;--border-color: #E2E8F0;--difficulty-easy: #10B981;--difficulty-medium: #F97316;--difficulty-hard: #F87171;--radius-sm: 8px;--radius-md: 16px;--radius-lg: 24px;--radius-xl: 28px;--shadow-card: 0 4px 12px rgba(14, 165, 233, .08);--shadow-elevated: 0 8px 24px rgba(14, 165, 233, .12);--shadow-strong: 0 20px 48px rgba(14, 165, 233, .18);--shadow-hover: 0 4px 16px rgba(14, 165, 233, .15);--primary-gradient: linear-gradient(135deg, var(--primary), var(--primary-dark));--secondary-gradient: linear-gradient(135deg, var(--secondary), var(--secondary-dark));--login-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);--transition-fast: .15s;--transition-normal: .25s;--transition-slow: .35s}body{font-family:Nunito,Noto Sans SC,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;color:var(--text-primary);background-color:var(--bg)}.el-card{--el-card-border-radius: var(--radius-md);border:none!important;box-shadow:var(--shadow-card)!important}.el-button{--el-button-border-radius: var(--radius-sm)}.el-input{--el-input-border-radius: var(--radius-sm)}.el-progress__text{font-weight:700!important}.text-primary{color:var(--primary)}.text-secondary{color:var(--text-secondary)}.text-success{color:var(--success)}.text-error{color:var(--error)}.text-warning{color:var(--warning)}.bg-primary{background-color:var(--primary)}.bg-success{background-color:var(--success)}.bg-warning{background-color:var(--warning-light)}.gradient-primary{background:linear-gradient(135deg,var(--primary),var(--primary-dark))}.gradient-secondary{background:linear-gradient(135deg,var(--secondary),var(--secondary-dark))}.gradient-success{background:linear-gradient(135deg,var(--success),#059669)}*{margin:0;padding:0;box-sizing:border-box}html,body,#app{width:100%;height:100%;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif}.el-table th.el-table__cell{background-color:#f5f7fa!important;color:#606266;font-weight:600}.el-table{border:1px solid #ebeef5!important}.el-table__inner-wrapper{border:none!important}.el-table--border:after,.el-table--group:after,.el-table:before{background-color:transparent!important}.el-table .el-table__header-wrapper th.el-table__cell.is-leaf,.el-table .el-table__body td.el-table__cell{border-bottom:1px solid #e4e7ed}