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

:root {
  --bg:         #0a0b0e;
  --bg-card:    #0f1115;
  --bg-input:   #13161c;
  --bg-hover:   #1a1e27;
  --border:     #1e2330;
  --accent:     #3a7bd5;
  --accent-dim: rgba(58,123,213,0.15);
  --text:       #e8eaf0;
  --text-2:     #8b91a6;
  --text-3:     #4e5568;
  --success:    #22d3a8;
  --warn:       #f59e0b;
  --danger:     #ef4444;
  --purple:     #a78bfa;
}

html, body {
  background: var(--bg);
  color: var(--text);
  font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
  font-size: 14px;
  min-height: 100vh;
  line-height: 1.5;
}

/* ── App layout ─────────────────────────────────────────────── */
.app-layout { display: flex; flex-direction: column; min-height: 100vh; }

/* ── Site header ─────────────────────────────────────────────── */
.site-header {
  position: sticky; top: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0.7rem 1.5rem;
  border-bottom: 1px solid var(--border);
  background: rgba(10,11,14,0.95);
  backdrop-filter: blur(10px);
  gap: 1rem; flex-shrink: 0;
}
.header-left  { display: flex; align-items: center; gap: 1.25rem; }
.header-right { display: flex; align-items: center; gap: 0.35rem; }

.logo {
  display: flex; align-items: center; gap: 0.55rem;
  text-decoration: none; color: var(--text); flex-shrink: 0;
}
.logo-text { font-size: 0.88rem; font-weight: 700; letter-spacing: 0.08em; line-height: 1.2; }
.logo-sub  { font-size: 0.66rem; color: var(--text-3); letter-spacing: 0.04em; line-height: 1.1; }

/* ── Buttons ─────────────────────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; gap: 0.4rem;
  border: none; border-radius: 6px; cursor: pointer;
  font-family: inherit; font-weight: 500; transition: background 0.12s, color 0.12s;
  white-space: nowrap; text-decoration: none;
}
.btn-sm { font-size: 0.78rem; padding: 0.3rem 0.65rem; }
.btn-icon { font-size: 0.78rem; padding: 0.3rem 0.45rem; }
.btn-ghost { background: transparent; color: var(--text-2); }
.btn-ghost:hover { background: rgba(255,255,255,0.07); color: var(--text); opacity: 1; }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { opacity: 0.85; }

/* ── Main ───────────────────────────────────────────────────── */
main {
  flex: 1;
  max-width: 920px;
  margin: 0 auto; width: 100%;
  padding: 2rem 1.25rem 4rem;
}

/* ── Search ─────────────────────────────────────────────────── */
.search-wrap { margin-bottom: 2rem; }

.search-box {
  display: flex;
  gap: 0.65rem;
}

.search-box input {
  flex: 1;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 7px;
  color: var(--text);
  font-family: inherit;
  font-size: 0.95rem;
  padding: 0.7rem 1rem;
  outline: none;
  transition: border-color 0.15s;
  min-width: 0;
}

.search-box input:focus { border-color: var(--accent); }
.search-box input::placeholder { color: var(--text-3); }

button {
  background: var(--accent);
  border: none;
  border-radius: 7px;
  color: #fff;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.88rem;
  font-weight: 600;
  padding: 0.7rem 1.35rem;
  transition: opacity 0.15s;
  white-space: nowrap;
}

button:hover  { opacity: 0.82; }
button:active { opacity: 0.65; }

.error-msg {
  color: var(--danger);
  font-size: 0.8rem;
  margin-top: 0.45rem;
  min-height: 1.1rem;
}

.hidden { display: none !important; }

/* ── Result header ───────────────────────────────────────────── */
.result-header { margin-bottom: 1.25rem; }

.result-title-row {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  flex-wrap: wrap;
}

.result-title-row h2 {
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: 0.03em;
}

.host-note {
  color: var(--text-2);
  font-size: 0.8rem;
  margin-top: 0.35rem;
}

/* ── Badges ──────────────────────────────────────────────────── */
.badge {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  padding: 0.22rem 0.55rem;
  border-radius: 4px;
  border: 1px solid;
}

.badge-private   { color: var(--success); border-color: var(--success); background: rgba(34,211,168,0.08); }
.badge-public    { color: var(--accent);  border-color: var(--accent);  background: rgba(58,123,213,0.08); }
.badge-loopback  { color: var(--text-2);  border-color: var(--text-3);  background: rgba(139,145,166,0.08); }
.badge-link-local{ color: var(--warn);    border-color: var(--warn);    background: rgba(245,158,11,0.08); }
.badge-multicast { color: var(--purple);  border-color: var(--purple);  background: rgba(167,139,250,0.08); }
.badge-reserved  { color: var(--danger);  border-color: var(--danger);  background: rgba(239,68,68,0.08); }
.badge-class     { color: var(--text-2);  border-color: var(--border);  background: transparent; }

/* ── Cards ───────────────────────────────────────────────────── */
.cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.85rem;
  margin-bottom: 0.85rem;
}

@media (max-width: 680px) { .cards { grid-template-columns: 1fr; } }

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.15rem 1.2rem;
}

.card-title {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.8rem;
}

/* ── Info table ──────────────────────────────────────────────── */
.info-table { width: 100%; border-collapse: collapse; }

.info-table tr + tr td { border-top: 1px solid var(--border); }

.info-table td { padding: 0.45rem 0; vertical-align: middle; }

.info-table .lbl { color: var(--text-2); font-size: 0.8rem; width: 52%; }

.info-table .val { color: var(--text); font-weight: 600; }

.info-table .copyable {
  cursor: pointer;
  position: relative;
}

.info-table .copyable:hover { color: var(--accent); }

/* ── Binary table ─────────────────────────────────────────────── */
.binary-card { overflow-x: auto; }

.prefix-legend {
  font-size: 0.7rem;
  font-weight: 400;
  letter-spacing: 0.04em;
  text-transform: none;
  display: flex;
  align-items: center;
  gap: 0.3rem;
  color: var(--text-3);
}

.net-bit-ex {
  display: inline-block;
  width: 8px; height: 8px;
  border-radius: 2px;
  background: var(--accent);
}

.host-bit-ex {
  display: inline-block;
  width: 8px; height: 8px;
  border-radius: 2px;
  background: var(--text-3);
}

.binary-table { border-collapse: collapse; white-space: nowrap; }

.binary-table tr + tr td { border-top: 1px solid var(--border); }

.binary-table td { padding: 0.38rem 0; }

.b-label {
  color: var(--text-2);
  font-size: 0.78rem;
  padding-right: 1rem;
  min-width: 75px;
}

.b-bits {
  font-size: 0.82rem;
  letter-spacing: 0.04em;
}

.net-bit  { color: var(--accent); }
.host-bit { color: var(--text-3); }
.b-dim    { color: var(--text-2); }
.b-dot    { color: var(--text-3); padding: 0 1px; }

/* ── Split card ──────────────────────────────────────────────── */
.split-card { margin-bottom: 0; }

.split-controls {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}

.split-label { color: var(--text-2); font-size: 0.88rem; }
.split-label strong { color: var(--text); }

select {
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  font-family: inherit;
  font-size: 0.85rem;
  padding: 0.38rem 0.6rem;
  outline: none;
  cursor: pointer;
}

select:focus { border-color: var(--accent); }

.btn-secondary {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-2);
  font-size: 0.83rem;
  padding: 0.38rem 0.9rem;
  border-radius: 6px;
}

.btn-secondary:hover { background: var(--bg-hover); color: var(--text); opacity: 1; }

.split-summary {
  color: var(--text-2);
  font-size: 0.8rem;
  margin-bottom: 0.7rem;
}

.table-scroll { overflow-x: auto; }

.split-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.82rem;
  min-width: 540px;
}

.split-table th {
  color: var(--text-3);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0 0.5rem 0.55rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.split-table td { padding: 0.38rem 0.5rem; color: var(--text); }

.split-table tr + tr td { border-top: 1px solid rgba(30,35,48,0.6); }
.split-table tr:hover td { background: var(--bg-hover); }

.split-table td:first-child { color: var(--text-3); font-size: 0.78rem; }
.split-table td:first-child { width: 40px; }

/* ── Usage bar ───────────────────────────────────────────────── */
.usage-bar {
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  padding: 0.6rem 2rem;
  font-size: 0.8rem;
  min-height: 2.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.usage-anon { color: var(--text-2); }
.usage-anon a { color: var(--accent); text-decoration: none; }
.usage-anon a:hover { text-decoration: underline; }

.usage-licensed {
  color: var(--success);
  font-weight: 600;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
}

.usage-info {
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.usage-label { color: var(--text-2); }
.usage-count { font-weight: 700; }

.usage-track {
  width: 100px;
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  overflow: hidden;
}

.usage-fill {
  height: 100%;
  border-radius: 2px;
  transition: width 0.3s;
}

.usage-reset { color: var(--text-3); font-size: 0.75rem; }
.usage-reset a { color: var(--accent); text-decoration: none; }
.usage-reset a:hover { text-decoration: underline; }

/* ── Copy toast ──────────────────────────────────────────────── */
.copy-toast {
  position: fixed;
  bottom: 1.75rem;
  left: 50%;
  transform: translateX(-50%) translateY(10px);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--success);
  font-size: 0.82rem;
  padding: 0.45rem 1rem;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.15s, transform 0.15s;
  z-index: 100;
}

.copy-toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ── Footer ──────────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border);
  color: var(--text-3);
  font-size: 0.76rem;
  padding: 1.1rem 1.5rem;
  text-align: center;
  line-height: 1.9;
  flex-shrink: 0;
}
.site-footer a {
  color: var(--success); text-decoration: none;
  display: inline-flex; align-items: center; gap: 3px;
  transition: color 0.15s;
}
.site-footer a:hover { color: #fff; }