/* ============================================================
   itops.theadminstack.com/cidr — Styles
   OSINT Design System v2 · portfolio_v2_style.md
   ============================================================ */

/* ── Tokens (light) ─────────────────────────────────────────── */
:root {
  color-scheme: light;

  /* Surfaces */
  --bg:   #f9fafb;
  --bg-1: #ffffff;
  --bg-2: #f3f4f6;
  --bg-3: #e5e7eb;

  /* Text */
  --text:   #111827;
  --text-2: #4b5563;
  --text-3: #9ca3af;

  /* Borders */
  --border:   #e5e7eb;
  --border-2: #d1d5db;

  /* Accent (monochrome) */
  --accent:        #111827;
  --accent-inv:    #ffffff;
  --accent-subtle: #f3f4f6;
  --accent-glow:   rgba(17,24,39,.08);

  /* Nav */
  --nav-bg: rgba(249,250,251,0.92);
  --nav-h:  64px;

  /* Border radius */
  --r-sm:   6px;
  --r:      10px;
  --r-lg:   14px;
  --r-pill: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.05);
  --shadow:    0 4px 16px rgba(0,0,0,.08), 0 2px 6px rgba(0,0,0,.05);
  --shadow-lg: 0 10px 32px rgba(0,0,0,.10);

  /* Functional colors */
  --green:  #16a34a;
  --orange: #d97706;
  --red:    #dc2626;

  /* CIDR-specific bit coloring */
  --bit-net:     #111827;
  --bit-host:    #4b5563;
  --bit-net-bg:  rgba(17,24,39,0.12);
  --bit-host-bg: rgba(75,85,99,0.07);

  /* Typography */
  --font-body: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'IBM Plex Mono', 'SFMono-Regular', Consolas, monospace;

  /* Layout */
  --container: 1200px;
  --t-mid: 150ms ease;
}

/* ── Tokens (dark) ───────────────────────────────────────────── */
html.dark {
  color-scheme: dark;

  --bg:   #0f1117;
  --bg-1: #161b22;
  --bg-2: #21262d;
  --bg-3: #30363d;

  --text:   #f0f6fc;
  --text-2: #8b949e;
  --text-3: #484f58;

  --border:   #30363d;
  --border-2: #3d444d;

  --accent:        #f0f6fc;
  --accent-inv:    #0f1117;
  --accent-subtle: #21262d;
  --accent-glow:   rgba(240,246,252,.08);

  --nav-bg: rgba(15,17,23,0.92);

  --shadow-sm: 0 1px 3px rgba(0,0,0,.35);
  --shadow:    0 4px 16px rgba(0,0,0,.35);
  --shadow-lg: 0 10px 32px rgba(0,0,0,.45);

  --bit-net:     #f0f6fc;
  --bit-host:    #8b949e;
  --bit-net-bg:  rgba(240,246,252,0.12);
  --bit-host-bg: rgba(139,148,158,0.08);
}

/* ── Reset ───────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding-top: var(--nav-h);
}

/* ── Nav ─────────────────────────────────────────────────────── */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 200;
  height: var(--nav-h);
  background: var(--nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow var(--t-mid);
}
.nav.scrolled { box-shadow: var(--shadow-sm); }

.nav-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  text-decoration: none;
  flex-shrink: 0;
}
.nav-brand-mark {
  width: 32px; height: 32px;
  background: var(--accent);
  color: var(--accent-inv);
  border-radius: var(--r-sm);
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  flex-shrink: 0;
}

.nav-brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}
.nav-brand-name {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text);
  letter-spacing: -0.01em;
}
.nav-brand-sub {
  font-size: 0.7rem;
  color: var(--text-3);
  font-family: var(--font-mono);
}

.nav-sep { flex: 1; }

.nav-back {
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-2);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.375rem;
  padding: 6px 14px;
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  transition: color var(--t-mid), border-color var(--t-mid), background var(--t-mid);
  white-space: nowrap;
}
.nav-back:hover {
  color: var(--text);
  border-color: var(--border-2);
  background: var(--bg-2);
}

.theme-toggle {
  background: transparent;
  border: 1px solid var(--border-2);
  border-radius: var(--r-sm);
  width: 34px; height: 34px;
  cursor: pointer;
  color: var(--text-2);
  display: flex; align-items: center; justify-content: center;
  transition: color var(--t-mid), border-color var(--t-mid), background var(--t-mid);
  flex-shrink: 0;
}
.theme-toggle:hover {
  color: var(--text);
  border-color: var(--border-2);
  background: var(--bg-2);
}

/* ── Hero ────────────────────────────────────────────────────── */
.hero {
  background: var(--bg-1);
  border-bottom: 1px solid var(--border);
  padding: 48px 0 32px;
  text-align: center;
}
.hero-wrap {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-3);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  padding: 4px 12px;
  margin-bottom: 1rem;
}

.hero h1 {
  font-size: clamp(1.5rem, 3.5vw, 2.125rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
  line-height: 1.2;
  margin-bottom: 0.75rem;
}

.hero-sub {
  font-size: 0.9375rem;
  color: var(--text-2);
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.65;
}

/* ── Main layout ─────────────────────────────────────────────── */
main {
  flex: 1;
  max-width: var(--container);
  width: 100%;
  margin: 0 auto;
  padding: 2rem 24px 4rem;
}

/* ── Tab bar ─────────────────────────────────────────────────── */
.tab-bar {
  display: flex;
  gap: 0.25rem;
  background: var(--bg-1);
  border: 1px solid var(--border);
  border-radius: var(--r);
  padding: 3px;
  margin-bottom: 1.75rem;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  box-shadow: var(--shadow-sm);
}

.tab-btn {
  flex: 1;
  min-width: 0;
  background: none;
  border: none;
  border-radius: var(--r-sm);
  padding: 6px 14px;
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-2);
  cursor: pointer;
  white-space: nowrap;
  transition: color var(--t-mid), background var(--t-mid);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.375rem;
}
.tab-btn:hover { color: var(--text); background: var(--accent-subtle); }
.tab-btn.active {
  background: var(--accent);
  color: var(--accent-inv);
}

.tab-icon { font-size: 0.875rem; }

/* ── Tab panels ──────────────────────────────────────────────── */
.tab-panel { display: block; }
.tab-panel[hidden] { display: none; }

/* ── Card ────────────────────────────────────────────────────── */
.card {
  background: var(--bg-1);
  border: 1px solid var(--border);
  border-radius: var(--r);
  padding: 20px 24px;
  margin-bottom: 1.25rem;
  box-shadow: var(--shadow-sm);
  transition: border-color var(--t-mid);
}
.card:hover { border-color: var(--border-2); }

.card-title {
  font-size: 0.775rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-3);
  margin-bottom: 1rem;
}

/* ── Form elements ───────────────────────────────────────────── */
.input-row {
  display: flex;
  gap: 0.625rem;
  align-items: flex-end;
  flex-wrap: wrap;
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
  flex: 1;
  min-width: 180px;
}

label {
  font-size: 0.775rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--text-2);
}

input[type="text"],
input[type="number"],
textarea {
  width: 100%;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  background: var(--bg);
  border: 1px solid var(--border-2);
  border-radius: var(--r-sm);
  padding: 8px 12px;
  color: var(--text);
  outline: none;
  transition: border-color var(--t-mid), box-shadow var(--t-mid);
}
input:focus, textarea:focus {
  border-color: var(--text-3);
  box-shadow: 0 0 0 3px var(--accent-glow);
}
input::placeholder, textarea::placeholder { color: var(--text-3); }

textarea {
  font-size: 0.875rem;
  resize: vertical;
  min-height: 110px;
}

/* ── Buttons ─────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 500;
  border: 1px solid transparent;
  border-radius: var(--r-sm);
  padding: 8px 18px;
  cursor: pointer;
  white-space: nowrap;
  transition: opacity var(--t-mid), background var(--t-mid), border-color var(--t-mid), color var(--t-mid);
}
.btn:active { opacity: 0.85; }

.btn-primary {
  background: var(--accent);
  color: var(--accent-inv);
  border-color: var(--accent);
}
.btn-primary:hover { opacity: .88; }

.btn-ghost {
  background: transparent;
  color: var(--text-2);
  border-color: var(--border);
}
.btn-ghost:hover {
  color: var(--text);
  border-color: var(--border-2);
  background: var(--bg-2);
}

.btn-sm {
  padding: 5px 12px;
  font-size: 0.8rem;
}

/* ── Example buttons ─────────────────────────────────────────── */
.examples {
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem;
  margin-top: 0.875rem;
}
.examples-label {
  font-size: 0.75rem;
  color: var(--text-3);
  display: flex;
  align-items: center;
  margin-right: 0.25rem;
}
.example-btn {
  font-size: 0.75rem;
  font-family: var(--font-mono);
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  padding: 4px 10px;
  cursor: pointer;
  color: var(--text-2);
  transition: background var(--t-mid), color var(--t-mid), border-color var(--t-mid);
}
.example-btn:hover {
  background: var(--bg-3);
  color: var(--text);
  border-color: var(--border-2);
}

/* ── Result area ─────────────────────────────────────────────── */
.result-area {
  background: var(--bg-1);
  border: 1px solid var(--border);
  border-radius: var(--r);
  padding: 20px;
  min-height: 60px;
  transition: border-color var(--t-mid), box-shadow var(--t-mid);
}
.result-area:empty::before {
  content: 'Results will appear here';
  color: var(--text-3);
  font-size: 0.875rem;
}
.result-area.has-result {
  box-shadow: var(--shadow-sm);
  border-color: var(--border-2);
}

/* ── Result table ────────────────────────────────────────────── */
.result-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}
.result-table th {
  text-align: left;
  font-size: 0.725rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-3);
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
}
.result-table td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
.result-table tr:last-child td { border-bottom: none; }
.result-table tbody tr:hover { background: var(--bg-2); }

.rt-label {
  color: var(--text-2);
  font-size: 0.8125rem;
  white-space: nowrap;
  width: 45%;
}
.rt-value { color: var(--text); font-weight: 500; }
.rt-note  { color: var(--text-3); font-size: 0.8rem; }

.mono { font-family: var(--font-mono); }
.txt-green { color: var(--green); font-weight: 600; }
.txt-red   { color: var(--red);   font-weight: 600; }

/* ── Range bar ───────────────────────────────────────────────── */
.range-bar-wrap { margin-top: 1rem; }
.range-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  padding: 8px 16px;
  font-size: 0.78rem;
  font-family: var(--font-mono);
  overflow: hidden;
}
.rb-net, .rb-bcast { color: var(--text-3); white-space: nowrap; }
.rb-range { color: var(--text); font-weight: 600; text-align: center; flex: 1; }

/* ── Alerts ──────────────────────────────────────────────────── */
.alert {
  border-radius: var(--r-sm);
  padding: 12px 16px;
  font-size: 0.875rem;
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  border: 1px solid;
}
.alert-error {
  background: color-mix(in srgb, #dc2626 10%, transparent);
  color: #dc2626;
  border-color: color-mix(in srgb, #dc2626 30%, transparent);
}
.alert-warn {
  background: color-mix(in srgb, #d97706 10%, transparent);
  color: #d97706;
  border-color: color-mix(in srgb, #d97706 30%, transparent);
  margin-bottom: 1rem;
}
.alert-icon { font-weight: 700; flex-shrink: 0; }

/* ── Tags ────────────────────────────────────────────────────── */
.tag {
  display: inline-block;
  background: var(--bg-2);
  color: var(--text-2);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  padding: 2px 10px;
  font-size: 0.8rem;
  font-family: var(--font-mono);
  font-weight: 500;
}

/* ── Subnet splitter ─────────────────────────────────────────── */
.prefix-row {
  display: flex;
  gap: 0.625rem;
  align-items: flex-end;
  flex-wrap: wrap;
}
.prefix-row .input-group { flex: 2; }
.prefix-input-group { flex: 0 0 140px; }

.prefix-hint {
  font-size: 0.78rem;
  font-family: var(--font-mono);
  color: var(--green);
  margin-top: 0.25rem;
  min-height: 1.2em;
}

.split-summary {
  font-size: 0.9375rem;
  margin-bottom: 1rem;
  color: var(--text-2);
}
.split-summary strong { color: var(--text); }

/* Tree */
.subnet-tree {
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  background: var(--bg-1);
  padding: 14px 16px;
  margin-bottom: 1rem;
  font-size: 0.875rem;
  font-family: var(--font-mono);
  overflow-x: auto;
}
.tree-node { padding: 0.2rem 0; display: flex; align-items: center; gap: 0.4rem; }
.tree-parent { font-weight: 700; color: var(--text); }
.tree-children { margin-left: 1.25rem; max-height: 260px; overflow-y: auto; }
.tree-child { color: var(--text-2); }
.tree-child:hover { color: var(--text); }
.tree-icon { color: var(--text-3); font-size: 0.7rem; }
.tree-connector { color: var(--text-3); }
.tree-meta { color: var(--text-3); font-size: 0.8rem; }

.split-table-wrap { margin-top: 0.75rem; }
.split-table-wrap > summary {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-2);
  cursor: pointer;
  user-select: none;
  padding: 0.5rem 0;
}
.split-table-wrap > summary:hover { color: var(--text); }
.split-table { margin-top: 0.5rem; }

/* ── Binary display ──────────────────────────────────────────── */
.binary-display {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  overflow-x: auto;
}

.bin-row {
  display: flex;
  align-items: center;
  gap: 0;
  margin-bottom: 0.5rem;
}

.bin-octet {
  display: flex;
  align-items: center;
  gap: 2px;
  min-width: 160px;
  justify-content: center;
  flex: 1;
}

.bin-header .bin-octet-label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-3);
  flex: 1;
  text-align: center;
}

.bin-decimal .bin-octet {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  border-bottom: 2px solid var(--border-2);
  padding-bottom: 0.375rem;
  margin-bottom: 0.125rem;
}

.bin-bit {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px; height: 22px;
  border-radius: 3px;
  font-size: 0.8rem;
  font-weight: 600;
  transition: background var(--t-mid);
}

.bit-net {
  background: var(--bit-net-bg);
  color: var(--bit-net);
}
.bit-host {
  background: var(--bit-host-bg);
  color: var(--bit-host);
}

/* Right boundary marker */
.bit-boundary-right {
  border-right: 2px solid var(--red);
  margin-right: 2px;
}

.bin-dot {
  color: var(--text-3);
  font-size: 1rem;
  margin: 0 4px;
  align-self: center;
  padding-bottom: 4px;
}

.bin-legend {
  display: flex;
  gap: 1.5rem;
  font-size: 0.78rem;
  color: var(--text-3);
  margin: 0.75rem 0;
}
.legend-net  { color: var(--text-2); font-weight: 600; }
.legend-host { color: var(--text-3); }

.bin-mask-row, .bin-hex-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.82rem;
  margin-top: 0.375rem;
  flex-wrap: wrap;
}
.bin-mask-label {
  color: var(--text-3);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  min-width: 40px;
}
.bin-mask-octet { color: var(--text-2); }

/* ── Supernet ────────────────────────────────────────────────── */
.super-summary {
  text-align: center;
  padding: 20px;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--r);
  margin-bottom: 1.25rem;
}
.super-cidr {
  font-size: 1.75rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--text);
  letter-spacing: -0.02em;
  margin-bottom: 0.25rem;
}
.super-meta { color: var(--text-2); font-size: 0.875rem; }

/* ── Footer ──────────────────────────────────────────────────── */
.site-footer {
  background: var(--bg-1);
  border-top: 1px solid var(--border);
  margin-top: 80px;
  padding: 32px 0;
  text-align: center;
}
.footer-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}
.site-footer p {
  font-size: 0.8rem;
  color: var(--text-3);
}
.site-footer a { color: var(--text-2); text-decoration: none; }
.site-footer a:hover { color: var(--text); text-decoration: underline; }

/* ── Custom checkboxes ───────────────────────────────────────── */
.subnet-check {
  appearance: none;
  -webkit-appearance: none;
  width: 15px; height: 15px;
  border: 1.5px solid var(--border-2);
  border-radius: 3px;
  background: var(--bg-1);
  cursor: pointer;
  flex-shrink: 0;
  position: relative;
  transition: background var(--t-mid), border-color var(--t-mid);
  vertical-align: middle;
}
.subnet-check:hover  { border-color: var(--accent); }
.subnet-check:checked {
  background: var(--accent);
  border-color: var(--accent);
}
.subnet-check:checked::after {
  content: '';
  position: absolute;
  left: 3px; top: 0px;
  width: 5px; height: 9px;
  border: 2px solid var(--accent-inv);
  border-top: none;
  border-left: none;
  transform: rotate(45deg);
}

.tree-check-wrap {
  display: flex;
  align-items: center;
  cursor: pointer;
  flex-shrink: 0;
}

.th-check { width: 32px; padding-left: 0.5rem !important; }
.td-check  { width: 32px; padding-left: 0.5rem !important; text-align: center; }

/* Selected row highlight */
.row-selected { background: var(--bg-2) !important; }
.row-selected .mono { color: var(--accent); }

/* ── Subnet merge panel ──────────────────────────────────────── */
.merge-panel {
  margin-top: 1.25rem;
  border: 1px solid var(--border-2);
  border-radius: var(--r);
  background: var(--bg-1);
  overflow: hidden;
}

.merge-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 12px 16px;
  background: var(--bg-2);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.merge-count {
  font-size: 0.8125rem;
  color: var(--text-2);
  flex: 1;
}

.merge-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

#mergeResult:not(:empty) { padding: 16px; }

.merge-result {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.merge-result-header { display: flex; align-items: center; }

.merge-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  font-size: 0.8rem;
  font-weight: 600;
  border-radius: var(--r-pill);
  padding: 4px 12px;
  border: 1px solid;
}
.merge-badge-ok {
  background: color-mix(in srgb, #16a34a 12%, transparent);
  color: #16a34a;
  border-color: color-mix(in srgb, #16a34a 30%, transparent);
}
.merge-badge-warn {
  background: color-mix(in srgb, #d97706 12%, transparent);
  color: #d97706;
  border-color: color-mix(in srgb, #d97706 30%, transparent);
}

.merge-cidr-row {
  display: flex;
  align-items: center;
  gap: 0.875rem;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  padding: 14px 16px;
  flex-wrap: wrap;
}

.merge-arrow {
  font-size: 1.1rem;
  color: var(--text-3);
  flex-shrink: 0;
}

.merge-cidr {
  font-size: 1.375rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--text);
  letter-spacing: -0.02em;
  flex-shrink: 0;
}

.merge-details {
  display: flex;
  flex-direction: column;
  gap: 0.125rem;
}
.merge-meta  { font-family: var(--font-mono); font-size: 0.82rem; color: var(--text-2); }
.merge-hosts { font-size: 0.78rem; color: var(--text-3); }

/* Absorbed subnets warning */
.merge-absorbed {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  padding: 10px 12px;
  background: color-mix(in srgb, #d97706 10%, transparent);
  border: 1px solid color-mix(in srgb, #d97706 30%, transparent);
  border-radius: var(--r-sm);
  font-size: 0.8125rem;
  flex-wrap: wrap;
}
.merge-absorbed-label {
  color: #d97706;
  font-weight: 600;
  white-space: nowrap;
  flex-shrink: 0;
}
.merge-absorbed-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem;
}
.merge-absorbed-item {
  background: var(--bg-1);
  border: 1px solid color-mix(in srgb, #d97706 30%, transparent);
  border-radius: var(--r-pill);
  padding: 1px 8px;
  font-size: 0.78rem;
  color: var(--text);
}

/* Valid buddy pairs tip */
.merge-tip {
  font-size: 0.78rem;
  color: var(--text-3);
  padding: 0.375rem 0;
}
.merge-tip-label {
  font-weight: 600;
  color: var(--text-2);
  margin-right: 0.25rem;
}

/* ── Responsive ──────────────────────────────────────────────── */
@media (max-width: 900px) {
  .nav-back { display: none; }
}

@media (max-width: 640px) {
  body { padding-top: var(--nav-h); }
  .hero { padding: 32px 0 24px; }
  .hero-wrap, .footer-inner { padding: 0 16px; }
  main  { padding: 1.25rem 16px 3rem; }
  .nav-inner { padding: 0 16px; }
  .card { padding: 16px; }

  .tab-btn { padding: 5px 10px; font-size: 0.75rem; }
  .tab-icon { display: none; }

  .bin-bit { width: 14px; height: 18px; font-size: 0.7rem; }
  .bin-octet { min-width: 120px; gap: 1px; }

  .super-cidr { font-size: 1.25rem; }

  .input-row, .prefix-row { flex-direction: column; }
  .input-group, .prefix-input-group { min-width: 0; width: 100%; }
}