:root {
      color-scheme: light;
      --ink: #17233b;
      --muted: #65718a;
      --line: #e4e9f2;
      --blue: #3859e8;
      --blue-dark: #2947cb;
      --mint: #dff7ed;
      --canvas: #f4f6fb;
      font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    }
    * { box-sizing: border-box; }
    body {
      min-width: 320px;
      margin: 0;
      color: var(--ink);
      background:
        radial-gradient(ellipse at 79% 0%, rgba(216, 226, 255, .75), transparent 32rem),
        var(--canvas);
    }
    .topbar {
      width: min(1120px, calc(100% - 48px));
      height: 82px;
      margin: auto;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .brand { display: flex; gap: 11px; align-items: center; font-weight: 750; letter-spacing: -.03em; }
    .brand-icon {
      width: 34px; height: 34px; display: grid; place-items: center;
      color: white; background: var(--blue); border-radius: 11px;
      box-shadow: 0 5px 12px rgba(56, 89, 232, .22);
    }
    .top-note { color: var(--muted); font-size: 13px; }
    main { width: min(1120px, calc(100% - 48px)); margin: 0 auto; }
    .hero { padding: 57px 0 36px; text-align: center; }
    .eyebrow {
      display: inline-flex; align-items: center; gap: 8px; padding: 7px 11px;
      color: #3853bb; background: #e8edff; border: 1px solid #dbe3ff;
      border-radius: 999px; font-size: 11px; font-weight: 750; letter-spacing: .09em;
      text-transform: uppercase;
    }
    .eyebrow span { width: 6px; height: 6px; border-radius: 50%; background: #5675ff; }
    h1 { margin: 20px 0 11px; font-size: clamp(38px, 6vw, 58px); line-height: 1.05; letter-spacing: -.06em; }
    h1 em { color: var(--blue); font-style: normal; }
    .hero p { max-width: 570px; margin: auto; color: var(--muted); font-size: 16px; line-height: 1.65; }
    .workspace {
      display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, .94fr);
      overflow: hidden; background: white; border: 1px solid #e8ebf2;
      border-radius: 20px; box-shadow: 0 18px 60px rgba(30, 46, 82, .08);
    }
    .form-panel { padding: 34px 36px 32px; }
    .section-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; margin-bottom: 27px; }
    h2 { margin: 0 0 6px; font-size: 18px; letter-spacing: -.025em; }
    .section-head p, .result-head p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.5; }
    .reset {
      flex: none; padding: 7px 10px; border: 1px solid var(--line); border-radius: 8px;
      background: white; color: #5d6880; font: inherit; font-size: 12px; cursor: pointer;
    }
    .reset:hover { background: #f6f8fc; }
    .field { margin-bottom: 20px; }
    label { display: block; margin-bottom: 9px; color: #4b5872; font-size: 12px; font-weight: 700; }
    .input-wrap { position: relative; }
    .input-wrap svg { position: absolute; top: 13px; left: 14px; color: #929db1; }
    input {
      width: 100%; height: 48px; padding: 0 14px 0 43px; color: var(--ink);
      border: 1px solid #dfe4ee; border-radius: 10px; outline: none;
      background: #fff; font: 500 15px ui-monospace, SFMono-Regular, Menlo, monospace;
      transition: border-color .15s, box-shadow .15s;
    }
    input::placeholder { color: #adb5c4; }
    input:focus { border-color: #748bf0; box-shadow: 0 0 0 3px rgba(56, 89, 232, .11); }
    .range-connector { height: 12px; margin: -15px 0 4px 23px; border-left: 1px dashed #c8d0df; }
    .helper { margin: -4px 0 22px; color: #8490a4; font-size: 11px; }
    .convert {
      width: 100%; height: 48px; display: flex; align-items: center; justify-content: center; gap: 9px;
      border: 0; border-radius: 10px; color: white; background: var(--blue);
      box-shadow: 0 7px 14px rgba(56, 89, 232, .2); font: 700 14px system-ui, sans-serif; cursor: pointer;
      transition: background .15s, transform .15s;
    }
    .convert:hover { background: var(--blue-dark); transform: translateY(-1px); }
    .convert:active { transform: translateY(0); }
    .error { min-height: 18px; margin: 10px 0 -8px; color: #b53e4c; font-size: 12px; }
    .result-panel { padding: 34px 34px 28px; background: #fafbfe; border-left: 1px solid #edf0f5; }
    .result-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 14px; margin-bottom: 22px; }
    .result-head h2 { display: flex; align-items: center; gap: 8px; }
    .result-head h2 svg { color: #32a878; }
    .count { padding: 5px 9px; color: #597166; background: #e5f5ed; border: 1px solid #d3eee0; border-radius: 999px; font-size: 11px; font-weight: 700; white-space: nowrap; }
    .result-box { min-height: 207px; max-height: 320px; overflow: auto; padding: 9px; border: 1px solid #e6eaf1; border-radius: 12px; background: white; }
    .empty {
      min-height: 185px; display: flex; flex-direction: column; align-items: center; justify-content: center;
      color: #9aa5b7; text-align: center;
    }
    .empty-icon { width: 42px; height: 42px; display: grid; place-items: center; margin-bottom: 12px; border-radius: 13px; background: #f0f3fa; }
    .empty strong { margin-bottom: 5px; color: #6c7890; font-size: 13px; }
    .empty span { font-size: 11px; }
    .cidr-row { min-height: 42px; display: flex; align-items: center; justify-content: space-between; gap: 8px; padding: 0 9px 0 11px; border-radius: 8px; }
    .cidr-row + .cidr-row { margin-top: 3px; }
    .cidr-row:hover { background: #f5f7fb; }
    .cidr-copy { min-width: 0; }
    .cidr-range { display: block; margin-top: 4px; color: #8792a5; font: 11px ui-monospace, SFMono-Regular, Menlo, monospace; }
    .cidr { font: 650 14px ui-monospace, SFMono-Regular, Menlo, monospace; color: #243454; }
    .copy-one { width: 29px; height: 29px; display: grid; place-items: center; flex: none; border: 0; border-radius: 7px; color: #8591a6; background: transparent; cursor: pointer; }
    .copy-one:hover { color: var(--blue); background: #eaf0ff; }
    .copy-all {
      display: flex; align-items: center; justify-content: center; gap: 7px; width: 100%; height: 39px;
      margin-top: 12px; border: 1px solid #dce2ee; border-radius: 9px; color: #45536d;
      background: white; font: 650 12px system-ui, sans-serif; cursor: pointer;
    }
    .copy-all:hover:not(:disabled) { border-color: #bdcaff; color: var(--blue); }
    .copy-all:disabled { color: #a9b1bf; cursor: not-allowed; }
    .explain { display: flex; gap: 10px; margin-top: 17px; padding: 12px 13px; border: 1px solid #e2e9ff; border-radius: 10px; background: #f0f4ff; color: #61708f; font-size: 11px; line-height: 1.55; }
    .explain svg { flex: none; margin-top: 1px; color: #5e78dc; }
    .below { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; padding: 23px 0 42px; }
    .feature { display: flex; gap: 11px; align-items: flex-start; padding: 13px 15px; }
    .feature-icon { width: 30px; height: 30px; display: grid; place-items: center; flex: none; border-radius: 9px; color: #516bdd; background: #e8edff; }
    .feature strong { display: block; margin: 1px 0 4px; font-size: 12px; }
    .feature span { display: block; color: var(--muted); font-size: 11px; line-height: 1.45; }
    footer { padding: 17px 24px 25px; color: #8994a7; border-top: 1px solid #e7eaf1; text-align: center; font-size: 11px; }
    @media (max-width: 760px) {
      .topbar, main { width: min(100% - 32px, 560px); }
      .topbar { height: 68px; }
      .top-note { font-size: 11px; }
      .hero { padding: 42px 0 28px; }
      .hero p { font-size: 14px; }
      .workspace { grid-template-columns: 1fr; }
      .form-panel, .result-panel { padding: 25px 23px; }
      .result-panel { border-top: 1px solid #edf0f5; border-left: 0; }
      .below { grid-template-columns: 1fr; gap: 2px; padding: 14px 0 30px; }
      .feature { padding: 10px 8px; }
    }
    @media (max-width: 400px) {
      .topbar, main { width: calc(100% - 24px); }
      .form-panel, .result-panel { padding: 21px 17px; }
      .section-head { gap: 8px; }
      .section-head p { font-size: 12px; }
    }