.nbc-wrap{margin-bottom:2rem;}
.nbc-card{background:var(--surface,#fff);border:1px solid var(--border,#e5e7eb);border-radius:12px;box-shadow:0 2px 12px var(--shadow-soft,rgba(0,0,0,.06));padding:1.25rem;overflow:hidden;}
.nbc-input-group{display:flex;flex-direction:column;gap:0.375rem;margin-bottom:1rem;}
.nbc-label{font-size:0.8125rem;font-weight:600;color:var(--text-muted,#6b7280);text-transform:uppercase;letter-spacing:0.03em;}
.nbc-input{width:100%;padding:0.875rem 1rem;font-size:1.125rem;font-family:ui-monospace,monospace;line-height:1.4;color:var(--text-main,#111);background:var(--surface,#fff);border:1px solid var(--border,#e5e7eb);border-radius:10px;box-sizing:border-box;transition:border-color .15s,box-shadow .15s;-webkit-appearance:none;appearance:none;}
.nbc-input:focus{outline:none;border-color:var(--primary,#5e35b1);box-shadow:0 0 0 3px rgba(94,53,177,.12);}
.nbc-input::placeholder{color:var(--text-muted,#9ca3af);}
.nbc-base-row{display:flex;flex-wrap:wrap;align-items:center;gap:0.75rem;margin-bottom:1rem;}
.nbc-base-label{font-size:0.8125rem;font-weight:600;color:var(--text-muted,#6b7280);}
.nbc-base-chips{display:flex;flex-wrap:wrap;gap:0.5rem;}
.nbc-chip{min-width:2.75rem;padding:0.5rem 0.75rem;font-size:0.875rem;font-weight:600;color:var(--text-muted,#6b7280);background:var(--surface-muted,#f3f4f6);border:1px solid var(--border,#e5e7eb);border-radius:8px;cursor:pointer;transition:background .15s,border-color .15s,color .15s;}
.nbc-chip:hover{color:var(--text-main,#111);background:var(--surface,#fff);border-color:var(--primary,#5e35b1);}
.nbc-chip-active,.nbc-chip[aria-pressed="true"]{color:#fff;background:var(--primary,#5e35b1);border-color:var(--primary,#5e35b1);}
.nbc-chip-active:hover,.nbc-chip[aria-pressed="true"]:hover{background:var(--primary-dark,#4527a0);border-color:var(--primary-dark,#4527a0);color:#fff;}
.nbc-custom-row{display:flex;align-items:center;gap:0.5rem;}
.nbc-custom-row[hidden]{display:none;}
.nbc-label-inline{font-size:0.875rem;font-weight:500;color:var(--text-main,#111);}
.nbc-input-num{width:4.5rem;padding:0.5rem 0.5rem;font-size:0.9375rem;text-align:center;color:var(--text-main,#111);background:var(--surface,#fff);border:1px solid var(--border,#e5e7eb);border-radius:8px;box-sizing:border-box;}
.nbc-input-num:focus{outline:none;border-color:var(--primary,#5e35b1);}
.nbc-select-hidden{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0;}
.nbc-actions{display:flex;flex-wrap:wrap;align-items:center;gap:0.75rem 1.25rem;margin-bottom:1.25rem;}
.nbc-swap{display:inline-flex;align-items:center;justify-content:center;width:2.5rem;height:2.5rem;padding:0;font-size:1.25rem;color:var(--text-muted,#6b7280);background:var(--surface-muted,#f3f4f6);border:1px solid var(--border,#e5e7eb);border-radius:10px;cursor:pointer;transition:background .15s,color .15s,border-color .15s;}
.nbc-swap:hover{color:var(--primary,#5e35b1);background:rgba(94,53,177,.08);border-color:var(--primary,#5e35b1);}
.nbc-swap-icon{line-height:1;}
.nbc-examples{display:flex;flex-wrap:wrap;align-items:center;gap:0.5rem;}
.nbc-examples-label{font-size:0.75rem;font-weight:600;color:var(--text-muted,#9ca3af);text-transform:uppercase;letter-spacing:0.04em;}
.nbc-example{padding:0.35rem 0.6rem;font-size:0.8125rem;color:var(--primary,#5e35b1);background:transparent;border:1px solid var(--border,#e5e7eb);border-radius:6px;cursor:pointer;transition:background .15s,border-color .15s;}
.nbc-example:hover{background:rgba(94,53,177,.08);border-color:var(--primary,#5e35b1);}
.nbc-example-clear{color:var(--text-muted,#6b7280);}
.nbc-example-clear:hover{color:var(--text-main,#111);border-color:var(--text-muted,#9ca3af);}
.nbc-results{display:grid;grid-template-columns:1fr;gap:0.75rem;}
.nbc-tile{display:flex;flex-wrap:wrap;align-items:center;gap:0.5rem 0.75rem;padding:0.875rem 1rem;background:var(--surface-muted,#f8f9fa);border:1px solid var(--border,#e5e7eb);border-radius:10px;}
.nbc-tile-label{font-size:0.75rem;font-weight:600;color:var(--text-muted,#6b7280);text-transform:uppercase;letter-spacing:0.03em;flex:0 0 auto;}
.nbc-tile-value{font-size:1rem;font-weight:600;font-family:ui-monospace,monospace;color:var(--primary,#5e35b1);word-break:break-all;flex:1 1 4rem;min-width:0;}
.nbc-copy{padding:0.35rem 0.6rem;font-size:0.75rem;font-weight:600;color:var(--text-muted,#6b7280);background:var(--surface,#fff);border:1px solid var(--border,#e5e7eb);border-radius:6px;cursor:pointer;transition:background .15s,color .15s;}
.nbc-copy:hover{color:var(--primary,#5e35b1);}
.nbc-tile-custom .nbc-tile-value{flex:1 1 auto;}
.nbc-tile-custom-row{display:flex;flex-wrap:wrap;align-items:center;gap:0.5rem 0.75rem;width:100%;}
.nbc-select-small{padding:0.35rem 1.75rem 0.35rem 0.5rem;font-size:0.875rem;color:var(--text-main,#111);background:var(--surface,#fff);border:1px solid var(--border,#e5e7eb);border-radius:6px;appearance:none;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='10' fill='%236b7280' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10l-5 5z'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 0.4rem center;}
.nbc-details{margin-top:0.75rem;border:1px solid var(--border,#e5e7eb);border-radius:10px;overflow:hidden;background:var(--surface,#fff);}
.nbc-details-summary{padding:0.875rem 1.25rem;font-size:0.9375rem;font-weight:600;color:var(--text-main,#111);cursor:pointer;list-style:none;}
.nbc-details-summary::-webkit-details-marker{display:none;}
.nbc-details-summary:hover{background:var(--surface-muted,rgba(0,0,0,.04));}
.nbc-details-body{padding:1rem 1.25rem;border-top:1px solid var(--border,#e5e7eb);font-size:0.875rem;line-height:1.6;color:var(--text-muted,#6b7280);}
.nbc-placeholder{margin:0;}
.nbc-details-body .conversion-step{padding:0.5rem 0 0.5rem 0.75rem;margin:0.25rem 0;border-left:3px solid var(--border,#e5e7eb);}
.nbc-details-body .conversion-step.final{border-left-color:var(--primary,#5e35b1);background:rgba(94,53,177,.06);margin-left:-0.75rem;padding-left:0.75rem;border-radius:0 6px 6px 0;}
.nbc-details-body .error-message{background:rgba(185,28,28,.08);color:#b91c1c;padding:0.75rem 1rem;border-radius:8px;border:1px solid rgba(185,28,28,.2);margin:0;}
.nbc-details-body .fraction-step{margin:0.25rem 0;}
.nbc-fraction-row{display:flex;flex-direction:column;gap:1rem;margin-bottom:1rem;}
.nbc-fraction-result{padding:0.875rem 1rem;background:var(--surface-muted,#f8f9fa);border:1px solid var(--border,#e5e7eb);border-radius:8px;font-size:0.875rem;}
.nbc-table-controls{display:flex;align-items:center;gap:0.5rem;margin-bottom:1rem;}
.nbc-table-wrap{overflow-x:auto;-webkit-overflow-scrolling:touch;}
.nbc-table-wrap table{width:100%;border-collapse:collapse;font-size:0.8125rem;}
.nbc-table-wrap th,.nbc-table-wrap td{border:1px solid var(--border,#e5e7eb);padding:0.4rem 0.6rem;text-align:center;}
.nbc-table-wrap th{background:var(--primary,#5e35b1);color:#fff;font-weight:600;}
.nbc-table-wrap .decimal-col{background:var(--surface-muted,#f3f4f6);font-weight:600;}
.nbc-select{width:100%;padding:0.6rem 2rem 0.6rem 0.75rem;font-size:0.9375rem;color:var(--text-main,#111);background:var(--surface,#fff);border:1px solid var(--border,#e5e7eb);border-radius:8px;appearance:none;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='10' fill='%236b7280' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10l-5 5z'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 0.75rem center;}
.nbc-edu{margin-top:2rem;padding-top:1.5rem;border-top:1px solid var(--border,#e5e7eb);}
.nbc-edu-h2{font-size:1.25rem;font-weight:700;color:var(--text-main,#111);margin:0 0 0.75rem;}
.nbc-edu-h3{font-size:1.0625rem;font-weight:600;color:var(--text-main,#111);margin:1.25rem 0 0.5rem;}
.nbc-edu-h4{font-size:0.9375rem;font-weight:600;color:var(--text-main,#111);margin:0 0 0.35rem;}
.nbc-edu p{font-size:0.9375rem;color:var(--text-muted,#6b7280);line-height:1.6;margin:0 0 0.75rem;}
.nbc-edu p:last-child{margin-bottom:0;}
.nbc-edu-grid{display:grid;grid-template-columns:1fr;gap:1rem;margin:0.75rem 0;}
.nbc-edu-block{padding:1rem;background:var(--surface-muted,#f8f9fa);border:1px solid var(--border,#e5e7eb);border-radius:8px;}
.nbc-edu-block p{margin:0;font-size:0.875rem;}
@media (min-width:480px){.nbc-results{grid-template-columns:repeat(2,1fr);}}
@media (min-width:640px){.nbc-card{padding:1.5rem;}.nbc-fraction-row{flex-direction:row;flex-wrap:wrap;}.nbc-fraction-row .nbc-input-group{flex:1 1 12rem;}}
@media (min-width:768px){.nbc-results{grid-template-columns:repeat(3,1fr);}.nbc-tile-custom{grid-column:1 / -1;}.nbc-edu-grid{grid-template-columns:repeat(2,1fr);}}
@media (min-width:960px){.nbc-results{grid-template-columns:repeat(2,1fr);}.nbc-tile-custom{grid-column:span 1;}.nbc-edu-grid{grid-template-columns:repeat(4,1fr);}}