:root {
  font-family: "Inter", "Segoe UI", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Mono", "SFMono-Regular", monospace;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --shadow-soft: 0 18px 36px rgba(15, 23, 42, 0.2);
  --shadow-strong: 0 32px 80px rgba(15, 23, 42, 0.28);
  --transition-base: 220ms ease;
  --transition-slow: 360ms ease;
}

:root[data-theme='light'] {
  color-scheme: light;
  --bg-surface: #f4f7fb;
  --bg-gradient-one: rgba(59, 130, 246, 0.18);
  --bg-gradient-two: rgba(236, 72, 153, 0.12);
  --panel-surface: rgba(255, 255, 255, 0.94);
  --panel-border: rgba(15, 23, 42, 0.08);
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --chrome-surface: rgba(255, 255, 255, 0.95);
  --chrome-border: rgba(15, 23, 42, 0.1);
  --chrome-link: #1d4ed8;
  --status-info: #475569;
  --status-success: #15803d;
  --status-error: #b91c1c;
  --nav-surface: linear-gradient(135deg, rgba(59, 130, 246, 0.25), rgba(56, 189, 248, 0.18));
  --nav-border: rgba(59, 130, 246, 0.24);
  --nav-active: linear-gradient(135deg, #6366f1, #38bdf8);
  --nav-hover: rgba(255, 255, 255, 0.72);
  --nav-text-active: #f8fafc;
}

:root[data-theme='dark'] {
  color-scheme: dark;
  --bg-surface: #050a19;
  --bg-gradient-one: rgba(56, 189, 248, 0.24);
  --bg-gradient-two: rgba(129, 140, 248, 0.25);
  --panel-surface: rgba(15, 23, 42, 0.82);
  --panel-border: rgba(148, 163, 184, 0.2);
  --text-primary: #e2e8f0;
  --text-secondary: #cbd5f5;
  --text-muted: #94a3b8;
  --chrome-surface: rgba(15, 23, 42, 0.9);
  --chrome-border: rgba(148, 163, 184, 0.24);
  --chrome-link: #60a5fa;
  --status-info: #94a3b8;
  --status-success: #4ade80;
  --status-error: #f87171;
  --nav-surface: linear-gradient(135deg, rgba(56, 189, 248, 0.24), rgba(99, 102, 241, 0.24));
  --nav-border: rgba(148, 163, 184, 0.24);
  --nav-active: linear-gradient(135deg, rgba(56, 189, 248, 0.5), rgba(99, 102, 241, 0.56));
  --nav-hover: rgba(15, 23, 42, 0.55);
  --nav-text-active: #020617;
}

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

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background:
    radial-gradient(circle at 12% 18%, var(--bg-gradient-one), transparent 55%),
    radial-gradient(circle at 88% 70%, var(--bg-gradient-two), transparent 60%),
    var(--bg-surface);
  color: var(--text-primary);
  transition: background var(--transition-slow), color var(--transition-base);
}

.global-header {
  width: min(1100px, 100%);
  margin: clamp(1.4rem, 4vw, 2.5rem) auto 0;
  padding: clamp(1rem, 3vw, 1.4rem) clamp(1.2rem, 4vw, 1.9rem);
  border-radius: var(--radius-lg);
  background: var(--chrome-surface);
  border: 1px solid var(--chrome-border);
  box-shadow: var(--shadow-soft);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  backdrop-filter: blur(20px);
}

.global-header__brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text-primary);
  text-decoration: none;
}

.global-header__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.22), rgba(129, 140, 248, 0.22));
  box-shadow: 0 16px 32px rgba(56, 189, 248, 0.2);
}

.global-header__nav {
  display: inline-flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.85rem;
}

.global-header__nav a {
  padding: 0.45rem 0.85rem;
  border-radius: 0.75rem;
  text-decoration: none;
  font-weight: 600;
  color: var(--chrome-link);
  transition: background var(--transition-base), transform var(--transition-base);
}

.global-header__nav a:hover,
.global-header__nav a:focus-visible {
  background: rgba(56, 189, 248, 0.18);
  transform: translateY(-1px);
  outline: none;
}

.global-header__actions {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.55rem 0.9rem;
  border-radius: 999px;
  border: 1px solid var(--panel-border);
  background: var(--panel-surface);
  color: var(--text-primary);
  cursor: pointer;
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
  box-shadow: var(--shadow-soft);
}

.theme-toggle:hover,
.theme-toggle:focus-visible {
  transform: translateY(-1px);
  outline: none;
  border-color: rgba(56, 189, 248, 0.45);
  box-shadow: 0 16px 35px rgba(56, 189, 248, 0.18);
}

.theme-toggle__icon {
  font-size: 1.1rem;
  opacity: 0;
  transform: scale(0.75);
  transition: opacity var(--transition-base), transform var(--transition-base);
}

.theme-toggle__label {
  font-weight: 600;
  font-size: 0.95rem;
}

:root[data-theme='light'] .theme-toggle__icon--sun,
:root[data-theme='dark'] .theme-toggle__icon--moon {
  opacity: 1;
  transform: scale(1);
}

.app-hero {
  padding: clamp(1.4rem, 4vw, 2.8rem) clamp(1.2rem, 5vw, 3.5rem) clamp(1rem, 3vw, 1.6rem);
  width: min(1100px, 100%);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.8rem;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 14px;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.28), rgba(129, 140, 248, 0.28));
  color: var(--text-primary);
  font-size: 1.45rem;
  box-shadow: var(--shadow-soft);
}

.app-hero h1 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 2.85rem);
  letter-spacing: -0.01em;
}

.app-hero p {
  margin: 0;
  max-width: 620px;
  color: var(--text-secondary);
  font-size: clamp(1rem, 2.1vw, 1.12rem);
  line-height: 1.6;
}

.noscript {
  margin: 0 auto 1.5rem;
  padding: 1rem 1.6rem;
  max-width: 760px;
  border-radius: var(--radius-lg);
  background: rgba(248, 113, 113, 0.14);
  border: 1px solid rgba(248, 113, 113, 0.28);
  color: var(--text-primary);
}

.layout {
  flex: 1;
  display: grid;
  gap: clamp(1.4rem, 3vw, 2rem);
  padding: 0 clamp(1.2rem, 5vw, 3.5rem) clamp(2.5rem, 6vw, 4rem);
  grid-template-columns: minmax(230px, 260px) 1fr;
  width: min(1200px, 100%);
  margin: 0 auto;
}

.tool-nav {
  position: sticky;
  top: clamp(1rem, 3vw, 1.6rem);
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  padding: 1.35rem;
  border-radius: var(--radius-lg);
  background: var(--nav-surface);
  border: 1px solid var(--nav-border);
  box-shadow: var(--shadow-soft);
  backdrop-filter: blur(16px);
}

.tool-nav button {
  appearance: none;
  border: 1px solid transparent;
  background: transparent;
  color: inherit;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.6rem;
  padding: 0.65rem 0.95rem;
  border-radius: 0.85rem;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition-base), transform var(--transition-base), border var(--transition-base), color var(--transition-base);
}

.tool-nav button::after {
  content: '›';
  font-size: 0.9rem;
  opacity: 0;
  transform: translateX(-6px);
  transition: opacity var(--transition-base), transform var(--transition-base);
}

.tool-nav button:hover,
.tool-nav button:focus-visible {
  background: var(--nav-hover);
  outline: none;
  transform: translateY(-1px);
}

.tool-nav button:hover::after,
.tool-nav button:focus-visible::after,
.tool-nav button.active::after {
  opacity: 1;
  transform: translateX(2px);
}

.tool-nav button.active {
  background: var(--nav-active);
  color: var(--nav-text-active);
  border-color: transparent;
  box-shadow: 0 18px 38px rgba(79, 70, 229, 0.24);
}

.tool-panels {
  display: flex;
  flex-direction: column;
  gap: clamp(1.2rem, 3vw, 2rem);
}

.tool-panel {
  display: none;
  padding: clamp(1.2rem, 2.5vw, 2rem);
  background: var(--panel-surface);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-strong);
  backdrop-filter: blur(18px);
  position: relative;
  transform: translateY(12px);
  opacity: 0;
  transition: transform var(--transition-slow), opacity var(--transition-base);
}

.tool-panel.active {
  display: block;
  transform: translateY(0);
  opacity: 1;
}

.tool-panel h2 {
  margin: 0 0 0.75rem 0;
  font-size: 1.3rem;
}

.tool-info {
  margin: -0.35rem 0 0.85rem 0;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.55;
}

.panel-grid {
  display: grid;
  gap: 0.85rem;
}

label {
  font-weight: 600;
  color: var(--text-muted);
}

input,
textarea {
  width: 100%;
  border-radius: var(--radius-md);
  border: 1px solid rgba(148, 163, 184, 0.28);
  background: rgba(15, 23, 42, 0.06);
  color: var(--text-primary);
  padding: 0.7rem 0.95rem;
  font-size: 0.95rem;
  line-height: 1.45;
  transition: border var(--transition-base), box-shadow var(--transition-base), background var(--transition-base);
}

textarea {
  min-height: 150px;
  resize: vertical;
  font-family: var(--font-mono);
}

input:focus,
textarea:focus {
  outline: none;
  border-color: rgba(56, 189, 248, 0.45);
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.22);
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
}

.button-row button {
  border: none;
  background: linear-gradient(135deg, #38bdf8, #6366f1);
  color: #020617;
  font-weight: 600;
  padding: 0.6rem 1.05rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: transform var(--transition-base), box-shadow var(--transition-base), filter var(--transition-base);
  box-shadow: 0 18px 38px rgba(56, 189, 248, 0.26);
}

.button-row button:hover,
.button-row button:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 22px 48px rgba(56, 189, 248, 0.32);
  outline: none;
}

.button-row button:active {
  transform: translateY(0);
  filter: brightness(0.96);
}

.status {
  min-height: 1.1rem;
  font-size: 0.9rem;
  color: var(--status-info);
  transition: color var(--transition-base);
}

.status.success {
  color: var(--status-success);
}

.status.error {
  color: var(--status-error);
}

.cidr-summary {
  background: rgba(15, 23, 42, 0.05);
  border: 1px solid rgba(148, 163, 184, 0.25);
  border-radius: var(--radius-md);
  padding: 0.7rem 0.9rem;
  font-family: var(--font-mono);
  white-space: pre-wrap;
  min-height: 70px;
}

.password-options {
  margin: 0;
  padding: 0;
  border: none;
  display: grid;
  gap: 0.55rem;
}

.option {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  color: var(--text-primary);
}

.option input[type="checkbox"] {
  width: 20px;
  height: 20px;
  border-radius: 0.4rem;
  border: 1px solid rgba(148, 163, 184, 0.28);
  background: rgba(15, 23, 42, 0.06);
  accent-color: var(--chrome-link);
}

.notes-help {
  margin: 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.global-footer {
  width: min(1100px, 100%);
  margin: clamp(2.2rem, 5vw, 3.4rem) auto clamp(1.6rem, 4vw, 2.4rem);
  padding: clamp(1.4rem, 4vw, 1.9rem) clamp(1.2rem, 5vw, 2.4rem);
  border-radius: 1.2rem;
  background: var(--chrome-surface);
  border: 1px solid var(--chrome-border);
  box-shadow: var(--shadow-soft);
  color: var(--text-muted);
  display: grid;
  gap: 0.6rem;
  text-align: center;
}

.global-footer__links {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.9rem;
  font-weight: 600;
}

.global-footer__links a {
  color: var(--chrome-link);
  text-decoration: none;
}

.global-footer__links a:hover,
.global-footer__links a:focus-visible {
  text-decoration: underline;
  outline: none;
}

.global-footer__note,
.global-footer__love,
.global-footer__copy {
  margin: 0;
}

.global-footer__love {
  font-weight: 600;
  color: var(--text-primary);
}

@media (max-width: 1024px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .tool-nav {
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
  }

  .tool-nav button {
    flex: 1 1 170px;
    justify-content: center;
  }
}

@media (max-width: 720px) {
  .global-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .tool-nav button {
    flex: 1 1 140px;
  }

  .button-row {
    flex-direction: column;
    align-items: stretch;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition: none !important;
    animation: none !important;
  }
}