/* ══════════════════════════════════════════════════════
   SubnetCalc — Shared Theme CSS (Light / Dark Toggle)
   ══════════════════════════════════════════════════════ */

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

/* ── Light Theme (default) ── */
:root {
  --bg-primary: #f6f8fb;
  --bg-secondary: #ffffff;
  --bg-tertiary: #eef3f8;
  --bg-card: rgba(255,255,255,0.9);
  --bg-card-hover: rgba(255,255,255,0.98);
  --bg-input: rgba(255,255,255,0.95);
  --border: rgba(15,23,42,0.1);
  --border-hover: rgba(0,143,115,0.34);
  --text-primary: #101828;
  --text-secondary: #475467;
  --text-muted: #667085;
  --cyan: #009f7f;
  --cyan-dim: rgba(0,159,127,0.1);
  --cyan-glow: rgba(0,159,127,0.14);
  --orange: #d9652a;
  --orange-dim: #d9652a22;
  --orange-glow: #d9652a10;
  --red: #dc2f4e;
  --yellow: #b8930a;
  --blue: #2563eb;
  --purple: #7c3aed;
  --purple-dim: #7c5cc422;
  --purple-glow: #7c5cc415;
  --green: #16875a;
  --grid-line: rgba(15,23,42,0.045);
  --card-shadow: 0 16px 40px rgba(15,23,42,0.08);
  --logo-icon-text: #ffffff;
  --nav-bg: rgba(255,255,255,0.82);
  --nav-bg-scrolled: rgba(255,255,255,0.95);
  --nav-mobile-bg: rgba(255,255,255,0.98);
  --hover-soft: rgba(15,23,42,0.045);
  --gradient-hero: linear-gradient(135deg, #009f7f 0%, #2563eb 58%, #7c3aed 100%);
  --font-display: 'Onest', system-ui, sans-serif;
  --font-body: 'IBM Plex Sans', system-ui, sans-serif;
  --nav-height: 80px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --scrollbar-track: #f1f5f9;
  --scrollbar-thumb: #cbd5e1;
  /* badge colors — light */
  --badge-a-bg: #dbeafe; --badge-a-fg: #1d4ed8; --badge-a-border: #93c5fd;
  --badge-b-bg: #ede9fe; --badge-b-fg: #6d28d9; --badge-b-border: #c4b5fd;
  --badge-c-bg: #d1fae5; --badge-c-fg: #047857; --badge-c-border: #6ee7b7;
  --badge-d-bg: #fef3c7; --badge-d-fg: #92400e; --badge-d-border: #fcd34d;
  --badge-e-bg: #ffe4e6; --badge-e-fg: #be123c; --badge-e-border: #fda4af;
  /* scope badges — light */
  --scope-global-bg: #d1fae5; --scope-global-fg: #047857; --scope-global-border: #6ee7b7;
  --scope-link-bg: #dbeafe; --scope-link-fg: #1d4ed8; --scope-link-border: #93c5fd;
  --scope-unique-bg: #ede9fe; --scope-unique-fg: #6d28d9; --scope-unique-border: #c4b5fd;
  --scope-multicast-bg: #fef3c7; --scope-multicast-fg: #92400e; --scope-multicast-border: #fcd34d;
  --scope-loopback-bg: #ffe4e6; --scope-loopback-fg: #be123c; --scope-loopback-border: #fda4af;
  --scope-v4mapped-bg: #ffedd5; --scope-v4mapped-fg: #c2410c; --scope-v4mapped-border: #fdba74;
  --scope-unspecified-bg: #f1f5f9; --scope-unspecified-fg: #475569; --scope-unspecified-border: #cbd5e1;
  /* icon backgrounds — light */
  --icon-blue-bg: #dbeafe;
  --icon-purple-bg: #ede9fe;
  /* subnet map gradients */
  --net-map-from: rgba(14,165,138,0.12);
  --net-map-to: rgba(14,165,138,0.22);
  --host-map-from: rgba(217,101,42,0.08);
  --host-map-to: rgba(217,101,42,0.16);
}

/* ── Dark Theme ── */
[data-theme="dark"] {
  --bg-primary: #0a0e17;
  --bg-secondary: #111827;
  --bg-tertiary: #1a2235;
  --bg-card: #151d2e;
  --bg-card-hover: rgba(20,30,48,0.8);
  --bg-input: #0d1321;
  --border: #1e2d45;
  --border-hover: rgba(0,212,170,0.35);
  --text-primary: #e8ecf4;
  --text-secondary: #8b97b0;
  --text-muted: #4a5568;
  --cyan: #00d4aa;
  --cyan-dim: #00d4aa44;
  --cyan-glow: #00d4aa22;
  --orange: #ff8a3a;
  --orange-dim: #ff8a3a44;
  --orange-glow: #ff8a3a22;
  --red: #ff4d6a;
  --yellow: #ffc93c;
  --blue: #3b82f6;
  --purple: #a78bfa;
  --purple-dim: #a78bfa44;
  --purple-glow: #a78bfa22;
  --green: #34d399;
  --grid-line: #1a2235;
  --card-shadow: 0 1px 3px rgba(0,0,0,0.3), 0 4px 16px rgba(0,0,0,0.2);
  --logo-icon-text: #0a0e17;
  --nav-bg: rgba(6,8,15,0.75);
  --nav-bg-scrolled: rgba(6,8,15,0.92);
  --nav-mobile-bg: rgba(6,8,15,0.97);
  --hover-soft: rgba(255,255,255,0.04);
  --gradient-hero: linear-gradient(135deg, #00d4aa 0%, #38bdf8 55%, #818cf8 100%);
  --scrollbar-track: #0d1321;
  --scrollbar-thumb: #1e2d45;
  /* badge colors — dark */
  --badge-a-bg: #3b82f622; --badge-a-fg: #60a5fa; --badge-a-border: #3b82f644;
  --badge-b-bg: #a78bfa22; --badge-b-fg: #a78bfa; --badge-b-border: #a78bfa44;
  --badge-c-bg: #34d39922; --badge-c-fg: #34d399; --badge-c-border: #34d39944;
  --badge-d-bg: #fbbf2422; --badge-d-fg: #fbbf24; --badge-d-border: #fbbf2444;
  --badge-e-bg: #f4728822; --badge-e-fg: #f47288; --badge-e-border: #f4728844;
  /* scope badges — dark */
  --scope-global-bg: #34d39922; --scope-global-fg: #34d399; --scope-global-border: #34d39944;
  --scope-link-bg: #3b82f622; --scope-link-fg: #60a5fa; --scope-link-border: #3b82f644;
  --scope-unique-bg: #a78bfa22; --scope-unique-fg: #a78bfa; --scope-unique-border: #a78bfa44;
  --scope-multicast-bg: #fbbf2422; --scope-multicast-fg: #fbbf24; --scope-multicast-border: #fbbf2444;
  --scope-loopback-bg: #f4728822; --scope-loopback-fg: #f47288; --scope-loopback-border: #f4728844;
  --scope-v4mapped-bg: #fb923c22; --scope-v4mapped-fg: #fb923c; --scope-v4mapped-border: #fb923c44;
  --scope-unspecified-bg: #64748b22; --scope-unspecified-fg: #94a3b8; --scope-unspecified-border: #64748b44;
  /* icon backgrounds — dark */
  --icon-blue-bg: #3b82f622;
  --icon-purple-bg: #a78bfa22;
  /* subnet map gradients */
  --net-map-from: rgba(0,212,170,0.2);
  --net-map-to: rgba(0,212,170,0.33);
  --host-map-from: rgba(255,138,58,0.13);
  --host-map-to: rgba(255,138,58,0.27);
}

/* IPv6 page overrides for net-map (purple instead of cyan) */
.page-ipv6 {
  --net-map-from: rgba(124,92,196,0.12);
  --net-map-to: rgba(124,92,196,0.22);
}
[data-theme="dark"] .page-ipv6 {
  --net-map-from: rgba(167,139,250,0.2);
  --net-map-to: rgba(167,139,250,0.33);
}

.app {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: calc(var(--nav-height) + 3rem) 2rem 1.5rem;
}

/* ── Header ── */
.app > header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0 1.5rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 2rem;
}

.app > header .logo { display: flex; align-items: center; gap: 0.75rem; }

.logo-icon {
  width: 42px; height: 42px;
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-family: 'JetBrains Mono', monospace;
  font-weight: 700; font-size: 1.1rem;
  color: var(--logo-icon-text);
}

/* Page-specific logo gradients */
.page-ipv4 .logo-icon {
  background: linear-gradient(135deg, var(--cyan), var(--blue));
  box-shadow: 0 4px 12px var(--cyan-dim);
}

.page-ipv6 .logo-icon {
  background: linear-gradient(135deg, var(--purple), var(--blue));
  box-shadow: 0 4px 12px var(--purple-dim);
  /* font-size: 0.9rem; */
}

.app > header .logo h1 { font-family: var(--font-display); font-size: 1.4rem; font-weight: 700; letter-spacing: -0.02em; }
.page-ipv4 .app > header .logo h1 span { color: var(--cyan); }
.page-ipv6 .app > header .logo h1 span { color: var(--purple); }

.header-right { display: flex; align-items: center; gap: 0.75rem; }

.calc-tabs {
  display: flex; gap: 0.25rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 10px; padding: 4px;
}

.calc-tabs a {
  padding: 0.5rem 1.2rem; border-radius: 8px;
  text-decoration: none; font-size: 0.85rem;
  font-weight: 500; color: var(--text-secondary);
  transition: all 0.2s;
}

.calc-tabs a:hover:not(.active) { color: var(--text-primary); background: var(--bg-tertiary); }

.page-ipv4 .calc-tabs a.active { background: var(--cyan); color: var(--logo-icon-text); font-weight: 600; }
.page-ipv6 .calc-tabs a.active { background: var(--purple); color: var(--logo-icon-text); font-weight: 600; }

/* ── Layout ── */
.main-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.full-width { grid-column: 1 / -1; }

/* ── Cards ── */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.5rem;
  position: relative;
  overflow: hidden;
  box-shadow: var(--card-shadow);
  transition: background 0.3s, border-color 0.3s, box-shadow 0.3s;
}

.card::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 1px;
}

.page-ipv4 .card::before { background: linear-gradient(90deg, transparent, var(--cyan-dim), transparent); }
.page-ipv6 .card::before { background: linear-gradient(90deg, transparent, var(--purple-dim), transparent); }

.card-header {
  display: flex; align-items: center; gap: 0.5rem;
  margin-bottom: 1.25rem;
  font-weight: 600; font-size: 0.95rem;
  text-transform: uppercase; letter-spacing: 0.06em;
  color: var(--text-secondary);
}

.card-header .icon {
  width: 28px; height: 28px;
  border-radius: 7px;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.85rem;
}

.icon-cyan { background: var(--cyan-dim); color: var(--cyan); }
.icon-orange { background: var(--orange-dim); color: var(--orange); }
.icon-blue { background: var(--icon-blue-bg); color: var(--blue); }
.icon-purple { background: var(--icon-purple-bg); color: var(--purple); }

/* ── Inputs ── */
.field { margin-bottom: 1rem; }
.field:last-child { margin-bottom: 0; }

.field-label {
  display: block; font-size: 0.75rem; font-weight: 500;
  color: var(--text-muted); text-transform: uppercase;
  letter-spacing: 0.08em; margin-bottom: 0.4rem;
}

.field-input-wrap {
  display: flex; align-items: center;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.page-ipv4 .field-input-wrap:focus-within {
  border-color: var(--cyan);
  box-shadow: 0 0 0 3px var(--cyan-glow);
}

.page-ipv6 .field-input-wrap:focus-within {
  border-color: var(--purple);
  box-shadow: 0 0 0 3px var(--purple-glow);
}

.field-input-wrap input {
  flex: 1; background: none; border: none; outline: none;
  color: var(--text-primary);
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.05rem; font-weight: 500;
  padding: 0.65rem 0.85rem; min-width: 0;
}

.field-input-wrap .prefix {
  padding-left: 0.85rem; color: var(--text-muted);
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.05rem; font-weight: 600; user-select: none;
}

.field-input-wrap .suffix {
  padding-right: 0.85rem; color: var(--text-muted);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
}

.cidr-controls { display: flex; flex-direction: column; margin-right: 4px; }

.cidr-btn {
  background: var(--bg-tertiary); border: 1px solid var(--border);
  color: var(--text-secondary); width: 28px; height: 20px;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer; font-size: 0.7rem; transition: all 0.15s; user-select: none;
}

.cidr-btn:first-child { border-radius: 4px 4px 0 0; }
.cidr-btn:last-child { border-radius: 0 0 4px 4px; }

.page-ipv4 .cidr-btn:hover { background: var(--cyan); color: var(--logo-icon-text); }
.page-ipv6 .cidr-btn:hover { background: var(--purple); color: var(--logo-icon-text); }

/* ── Result Rows ── */
.result-row {
  display: flex; align-items: center;
  justify-content: space-between;
  padding: 0.6rem 0;
  border-bottom: 1px solid var(--border);
}

.result-row:last-child { border-bottom: none; }

.result-label { font-size: 0.8rem; color: var(--text-secondary); font-weight: 400; }

.result-value {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.95rem; font-weight: 500;
  color: var(--text-primary);
}

.result-value.cyan { color: var(--cyan); }
.result-value.orange { color: var(--orange); }
.result-value.green { color: var(--green); }
.result-value.purple { color: var(--purple); }

.result-value .validation {
  font-size: 0.75rem; color: var(--yellow);
  margin-left: 0.5rem; font-weight: 400;
}

/* IPv6 result-value sizing */
.page-ipv6 .result-value {
  font-size: 0.9rem;
  word-break: break-all;
  text-align: right;
  max-width: 65%;
}

/* ── Quick Select ── */
.quick-select { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-bottom: 1.25rem; }

.quick-btn {
  padding: 0.35rem 0.7rem;
  background: var(--bg-input); border: 1px solid var(--border);
  border-radius: 6px; color: var(--text-secondary);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem; font-weight: 500;
  cursor: pointer; transition: all 0.15s; user-select: none;
}

.page-ipv4 .quick-btn:hover { border-color: var(--cyan); color: var(--cyan); }
.page-ipv4 .quick-btn.active { background: var(--cyan); color: var(--logo-icon-text); border-color: var(--cyan); font-weight: 700; }

.page-ipv6 .quick-btn { font-size: 0.72rem; padding: 0.35rem 0.65rem; }
.page-ipv6 .quick-btn:hover { border-color: var(--purple); color: var(--purple); }
.page-ipv6 .quick-btn.active { background: var(--purple); color: var(--logo-icon-text); border-color: var(--purple); font-weight: 700; }

/* ── Binary Display ── */
.binary-display {
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px; padding: 1rem;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.82rem; line-height: 1.8;
  overflow-x: auto;
}

.page-ipv6 .binary-display { font-size: 0.78rem; line-height: 1.9; word-break: break-all; }

.binary-display .octet { display: inline; }
.binary-display .net-bit { color: var(--cyan); font-weight: 600; }
.binary-display .host-bit { color: var(--orange); font-weight: 600; }
.binary-display .dot-sep { color: var(--text-muted); margin: 0 2px; }
.binary-display .label {
  color: var(--text-muted); font-size: 0.7rem;
  display: block; margin-bottom: 0.3rem;
  text-transform: uppercase; letter-spacing: 0.08em;
}

/* IPv6 binary uses purple for network bits */
.page-ipv6 .binary-display .net-bit,
.page-ipv6 .net-bit { color: var(--purple); font-weight: 600; }
.net-char { color: var(--cyan); }
.host-char { color: var(--orange); }
.sep-char { color: var(--text-muted); }
.page-ipv6 .net-char { color: var(--purple); }

/* ── Subnet Map ── */
.subnet-map {
  display: flex; height: 32px;
  border-radius: 6px; overflow: hidden;
  margin-top: 0.75rem;
  border: 1px solid var(--border);
}

.subnet-map .net-portion {
  background: linear-gradient(135deg, var(--net-map-from), var(--net-map-to));
  border-right: 2px solid var(--cyan);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.65rem; font-weight: 600; color: var(--cyan);
  font-family: 'JetBrains Mono', monospace;
  min-width: 30px; transition: width 0.3s ease;
}

.subnet-map .host-portion {
  background: linear-gradient(135deg, var(--host-map-from), var(--host-map-to));
  display: flex; align-items: center; justify-content: center;
  font-size: 0.65rem; font-weight: 600; color: var(--orange);
  font-family: 'JetBrains Mono', monospace;
  flex: 1; min-width: 30px; transition: width 0.3s ease;
}

.page-ipv6 .subnet-map .net-portion {
  border-right-color: var(--purple);
  color: var(--purple);
}

/* ── Class Badges (IPv4) ── */
.class-badge {
  display: inline-flex; align-items: center; gap: 0.4rem;
  padding: 0.3rem 0.7rem; border-radius: 6px;
  font-size: 0.8rem; font-weight: 600;
  font-family: 'JetBrains Mono', monospace;
}

.class-A { background: var(--badge-a-bg); color: var(--badge-a-fg); border: 1px solid var(--badge-a-border); }
.class-B { background: var(--badge-b-bg); color: var(--badge-b-fg); border: 1px solid var(--badge-b-border); }
.class-C { background: var(--badge-c-bg); color: var(--badge-c-fg); border: 1px solid var(--badge-c-border); }
.class-D { background: var(--badge-d-bg); color: var(--badge-d-fg); border: 1px solid var(--badge-d-border); }
.class-E { background: var(--badge-e-bg); color: var(--badge-e-fg); border: 1px solid var(--badge-e-border); }

/* ── Scope Badges (IPv6) ── */
.scope-badge {
  display: inline-flex; padding: 0.3rem 0.7rem;
  border-radius: 6px; font-size: 0.8rem;
  font-weight: 600; font-family: 'JetBrains Mono', monospace;
}

.scope-global { background: var(--scope-global-bg); color: var(--scope-global-fg); border: 1px solid var(--scope-global-border); }
.scope-link { background: var(--scope-link-bg); color: var(--scope-link-fg); border: 1px solid var(--scope-link-border); }
.scope-unique { background: var(--scope-unique-bg); color: var(--scope-unique-fg); border: 1px solid var(--scope-unique-border); }
.scope-multicast { background: var(--scope-multicast-bg); color: var(--scope-multicast-fg); border: 1px solid var(--scope-multicast-border); }
.scope-loopback { background: var(--scope-loopback-bg); color: var(--scope-loopback-fg); border: 1px solid var(--scope-loopback-border); }
.scope-v4mapped { background: var(--scope-v4mapped-bg); color: var(--scope-v4mapped-fg); border: 1px solid var(--scope-v4mapped-border); }
.scope-unspecified { background: var(--scope-unspecified-bg); color: var(--scope-unspecified-fg); border: 1px solid var(--scope-unspecified-border); }

/* ── Reference Table ── */
.ref-table-wrap {
  max-height: 500px; overflow-y: auto;
  border-radius: 8px; border: 1px solid var(--border);
}

.ref-table-wrap::-webkit-scrollbar { width: 6px; }
.ref-table-wrap::-webkit-scrollbar-track { background: var(--scrollbar-track); }
.ref-table-wrap::-webkit-scrollbar-thumb { background: var(--scrollbar-thumb); border-radius: 3px; }

.ref-table {
  width: 100%; border-collapse: collapse; font-size: 0.78rem;
}

.ref-table thead { position: sticky; top: 0; z-index: 2; }

.ref-table th {
  background: var(--bg-tertiary);
  padding: 0.6rem 0.75rem; text-align: left;
  font-weight: 600; font-size: 0.7rem;
  text-transform: uppercase; letter-spacing: 0.06em;
  color: var(--text-muted); border-bottom: 1px solid var(--border);
}

.ref-table td {
  padding: 0.45rem 0.75rem;
  border-bottom: 1px solid var(--border);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem; color: var(--text-secondary); white-space: nowrap;
}

.ref-table tr:hover td { background: var(--bg-tertiary); color: var(--text-primary); }

.page-ipv4 .ref-table tr.active-row td { background: var(--cyan-glow); color: var(--cyan); font-weight: 600; }
.page-ipv4 .ref-table td:first-child { color: var(--cyan); font-weight: 600; }

.page-ipv6 .ref-table tr.active-row td { background: var(--purple-glow); color: var(--purple); font-weight: 600; }
.page-ipv6 .ref-table td:first-child { color: var(--purple); font-weight: 600; }
.page-ipv6 .ref-table td { font-size: 0.72rem; }

/* ── IP Color Display (IPv4) ── */
.ip-color-display {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.3rem; font-weight: 600;
  padding: 0.75rem 1rem;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  display: flex; align-items: center; gap: 0;
  letter-spacing: 0.02em; overflow-x: auto;
}

.ip-color-display .net-char { color: var(--cyan); }
.ip-color-display .host-char { color: var(--orange); }
.ip-color-display .sep { color: var(--text-muted); }

/* ── Common Net Section (IPv4) ── */
.common-net-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

/* ── Animations ── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.card { animation: fadeUp 0.5s ease both; }
.card:nth-child(2) { animation-delay: 0.05s; }
.card:nth-child(3) { animation-delay: 0.1s; }
.card:nth-child(4) { animation-delay: 0.15s; }
.card:nth-child(5) { animation-delay: 0.2s; }

/* ── Responsive ── */
@media (max-width: 968px) {
  .main-grid { grid-template-columns: 1fr; }
  .common-net-grid { grid-template-columns: 1fr; }
  .app > header { flex-direction: column; gap: 1rem; align-items: flex-start; }
  .header-right { width: 100%; justify-content: space-between; }
}

@media (max-width: 600px) {
  .app { padding: calc(var(--nav-height) + 2rem) 1.25rem 1rem; }
  .ip-color-display { font-size: 1rem; }
  .page-ipv6 .result-value { font-size: 0.75rem; }
}