:root {
  --kc-bg: #020617;
  --kc-bg-2: #0f172a;
  --kc-panel: rgba(15, 23, 42, 0.72);
  --kc-panel-strong: rgba(15, 23, 42, 0.92);
  --kc-border: rgba(148, 163, 184, 0.18);
  --kc-border-strong: rgba(148, 163, 184, 0.34);
  --kc-text: #f8fafc;
  --kc-muted: #94a3b8;
  --kc-soft: #cbd5e1;
  --kc-blue: #3b82f6;
  --kc-green: #10b981;
  --kc-error: #f87171;
  --kc-warning: #fbbf24;
  --kc-success: #10b981;
  --kc-code-bg: rgba(2, 6, 23, 0.82);
  --kc-radius: 8px;
  --kc-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
}

* {
  box-sizing: border-box;
}

html {
  color-scheme: dark;
  font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.5;
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  margin: 0;
  color: var(--kc-text);
  background:
    linear-gradient(rgba(59, 130, 246, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(16, 185, 129, 0.07) 1px, transparent 1px),
    linear-gradient(135deg, #020617 0%, #08111f 48%, #020617 100%);
  background-size: 44px 44px, 44px 44px, 100% 100%;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(120deg, rgba(59, 130, 246, 0.12), transparent 34%, rgba(16, 185, 129, 0.1));
  opacity: 0.55;
}

button,
input,
textarea,
select {
  font: inherit;
}

a {
  color: var(--kc-soft);
}

a:hover {
  color: var(--kc-text);
}

:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--kc-blue), white 14%);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: 0.75rem;
  z-index: 20;
  transform: translateY(-150%);
  border-radius: 6px;
  background: var(--kc-blue);
  color: white;
  padding: 0.6rem 0.85rem;
  text-decoration: none;
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem clamp(1rem, 3vw, 2rem);
  border-bottom: 1px solid var(--kc-border);
  background: rgba(2, 6, 23, 0.9);
  backdrop-filter: blur(16px);
}

.brand-link {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  min-height: 44px;
  color: var(--kc-text);
  text-decoration: none;
}

.brand-mark {
  flex: 0 0 auto;
  filter: drop-shadow(0 0 18px rgba(59, 130, 246, 0.25));
}

.brand-text {
  display: grid;
  line-height: 1.1;
}

.brand-text span {
  color: var(--kc-muted);
  font-family: var(--kc-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
}

.brand-text strong {
  font-size: 1.05rem;
}

.brand-text strong span {
  color: var(--kc-green);
  font-size: 1.05rem;
}

.header-links {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.9rem;
}

.privacy-chip,
.terminal-prompt,
.eyebrow,
.tool-kicker,
.shortcut,
.empty-state,
.notice {
  font-family: var(--kc-mono);
}

.privacy-chip {
  border: 1px solid rgba(16, 185, 129, 0.36);
  border-radius: 999px;
  padding: 0.45rem 0.7rem;
  color: #d1fae5;
  background: rgba(16, 185, 129, 0.1);
  white-space: nowrap;
}

main {
  position: relative;
  z-index: 1;
  width: min(1440px, 100%);
  margin: 0 auto;
  padding: clamp(1rem, 3vw, 2rem);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 420px);
  gap: 1rem;
  align-items: stretch;
  margin-bottom: 1rem;
}

.terminal-card,
.tool-rail,
.workspace {
  border: 1px solid var(--kc-border);
  border-radius: var(--kc-radius);
  background: var(--kc-panel);
  box-shadow: 0 20px 70px rgba(0, 0, 0, 0.28);
  backdrop-filter: blur(16px);
}

.hero-copy {
  padding: clamp(1.2rem, 4vw, 2rem);
}

.eyebrow,
.tool-kicker {
  margin: 0 0 0.35rem;
  color: var(--kc-green);
  font-size: 0.78rem;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(2rem, 5vw, 4.4rem);
  font-weight: 800;
  line-height: 1;
}

.lede {
  max-width: 760px;
  margin: 1rem 0 0;
  color: var(--kc-soft);
  font-size: clamp(1rem, 2vw, 1.2rem);
}

.terminal-card {
  display: grid;
  align-content: center;
  min-height: 170px;
  padding: 1.25rem;
  background: linear-gradient(150deg, rgba(2, 6, 23, 0.94), rgba(15, 23, 42, 0.78));
}

.terminal-prompt {
  color: var(--kc-green);
  font-size: 2.4rem;
}

.terminal-card p {
  margin: 0.6rem 0 0;
  color: var(--kc-soft);
}

.app-layout {
  display: grid;
  grid-template-columns: 290px minmax(0, 1fr);
  gap: 1rem;
  align-items: start;
}

.tool-rail {
  position: sticky;
  top: 86px;
  padding: 1rem;
}

.search-box label,
.tool-panel label,
legend {
  display: block;
  margin-bottom: 0.45rem;
  color: var(--kc-soft);
  font-weight: 650;
}

.search-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 44px;
  gap: 0.5rem;
}

input,
textarea,
select {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--kc-border-strong);
  border-radius: 6px;
  background: var(--kc-code-bg);
  color: var(--kc-text);
}

input {
  padding: 0 0.75rem;
}

select {
  padding: 0 0.65rem;
}

textarea {
  min-height: 210px;
  padding: 0.85rem;
  resize: vertical;
  font-family: var(--kc-mono);
  font-size: 0.92rem;
}

input:hover,
textarea:hover,
select:hover {
  border-color: rgba(59, 130, 246, 0.58);
}

input:focus,
textarea:focus,
select:focus {
  border-color: var(--kc-blue);
}

button {
  min-height: 44px;
  border: 1px solid rgba(59, 130, 246, 0.52);
  border-radius: 6px;
  padding: 0.65rem 0.9rem;
  background: var(--kc-blue);
  color: white;
  font-weight: 700;
  cursor: pointer;
}

button:hover {
  border-color: rgba(16, 185, 129, 0.78);
  background: #2563eb;
}

button:active {
  transform: translateY(1px);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

.secondary-button,
.icon-button {
  border-color: var(--kc-border-strong);
  background: rgba(15, 23, 42, 0.7);
  color: var(--kc-soft);
}

.secondary-button:hover,
.icon-button:hover {
  background: rgba(30, 41, 59, 0.95);
}

.shortcut,
.empty-state {
  margin: 0.55rem 0 0;
  color: var(--kc-muted);
  font-size: 0.78rem;
}

.tool-tabs {
  display: grid;
  gap: 0.55rem;
  margin-top: 1rem;
}

.tool-tab {
  display: grid;
  justify-items: start;
  width: 100%;
  min-height: 58px;
  border-color: var(--kc-border);
  background: rgba(15, 23, 42, 0.62);
  color: var(--kc-soft);
  text-align: left;
}

.tool-tab span {
  color: var(--kc-text);
}

.tool-tab small {
  color: var(--kc-muted);
  font-family: var(--kc-mono);
}

.tool-tab.active {
  border-color: rgba(16, 185, 129, 0.72);
  background: linear-gradient(90deg, rgba(59, 130, 246, 0.26), rgba(16, 185, 129, 0.13));
  box-shadow: inset 4px 0 0 var(--kc-green);
}

.workspace {
  min-width: 0;
  padding: clamp(1rem, 3vw, 1.4rem);
  background: var(--kc-panel-strong);
}

.tool-panel {
  display: none;
}

.tool-panel.active {
  display: block;
}

.tool-heading {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1rem;
}

.tool-heading h2,
.content-section h2 {
  margin: 0;
  font-size: clamp(1.35rem, 3vw, 2rem);
  line-height: 1.15;
}

.tool-heading p:not(.tool-kicker),
.content-section p,
.faq p {
  color: var(--kc-soft);
}

.notice {
  margin: 0 0 1rem;
  border: 1px solid rgba(59, 130, 246, 0.26);
  border-radius: 6px;
  padding: 0.75rem;
  background: rgba(59, 130, 246, 0.1);
  color: #dbeafe;
  font-size: 0.86rem;
}

.notice.warning {
  border-color: rgba(251, 191, 36, 0.35);
  background: rgba(251, 191, 36, 0.1);
  color: #fef3c7;
}

.tool-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin: 0.9rem 0;
}

.tool-actions.standalone {
  margin-top: 0;
}

.field-grid,
.diff-inputs,
.regex-main-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

fieldset {
  min-width: 0;
  margin: 0;
  border: 1px solid var(--kc-border);
  border-radius: 6px;
  padding: 0.7rem;
}

.radio-option {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  min-height: 34px;
  margin-right: 0.8rem;
  color: var(--kc-soft);
}

.radio-option input {
  width: auto;
  min-height: auto;
}

.advanced-panel {
  margin: 1rem 0;
  border: 1px solid var(--kc-border);
  border-radius: 6px;
  padding: 0.75rem;
  background: rgba(2, 6, 23, 0.36);
}

.advanced-panel summary {
  min-height: 44px;
  cursor: pointer;
  color: var(--kc-text);
  font-weight: 700;
}

.advanced-panel[open] summary {
  margin-bottom: 0.75rem;
}

.regex-cases {
  margin-top: 1rem;
}

.regex-case-row {
  display: grid;
  grid-template-columns: minmax(120px, 180px) minmax(0, 1fr);
  gap: 0.75rem;
  align-items: end;
}

.regex-case-row + .regex-case-row {
  margin-top: 0.75rem;
}

.regex-case-row span {
  display: block;
  margin-bottom: 0.35rem;
  color: var(--kc-soft);
  font-weight: 650;
}

.output-area {
  min-height: 112px;
  overflow: auto;
  border: 1px solid var(--kc-border);
  border-radius: 6px;
  padding: 0.85rem;
  background: var(--kc-code-bg);
  color: var(--kc-text);
  font-family: var(--kc-mono);
  font-size: 0.9rem;
  white-space: pre-wrap;
  user-select: text;
}

.output-area:empty::before {
  content: "Output appears here.";
  color: var(--kc-muted);
}

.large-result {
  font-size: clamp(0.86rem, 2vw, 1.15rem);
}

.output-area pre {
  margin: 0;
  overflow: auto;
  white-space: pre-wrap;
}

.output-status {
  margin: 0 0 0.65rem;
  font-family: var(--kc-mono);
}

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

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

.warning {
  color: var(--kc-warning);
}

.muted {
  color: var(--kc-muted);
}

.json-output-block + .json-output-block {
  margin-top: 1rem;
}

.json-output-block h3 {
  margin: 0 0 0.45rem;
  color: var(--kc-green);
  font-size: 0.92rem;
}

.diff-rows {
  display: grid;
  gap: 0.2rem;
}

.diff-row {
  display: grid;
  grid-template-columns: 2rem minmax(0, 1fr);
  border-left: 3px solid var(--kc-border-strong);
  border-radius: 4px;
  padding: 0.25rem 0.45rem;
}

.diff-row.added {
  border-left-color: var(--kc-green);
  background: rgba(16, 185, 129, 0.1);
}

.diff-row.removed {
  border-left-color: var(--kc-error);
  background: rgba(248, 113, 113, 0.1);
}

.diff-marker {
  color: var(--kc-muted);
}

.diff-text {
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

.regex-output {
  white-space: normal;
}

.regex-result-section {
  margin-top: 1rem;
  padding-top: 0.85rem;
  border-top: 1px solid var(--kc-border);
}

.regex-result-section h3 {
  margin: 0 0 0.55rem;
  color: var(--kc-green);
  font-size: 0.95rem;
}

.regex-result-section ol,
.regex-result-section ul {
  margin: 0;
  padding-left: 1.35rem;
}

.regex-result-section li + li {
  margin-top: 0.45rem;
}

.regex-match-summary,
.kv-line {
  margin: 0.2rem 0;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

.regex-warnings h3 {
  color: var(--kc-warning);
}

.content-section {
  margin-top: 1rem;
  border-top: 1px solid var(--kc-border);
  padding: clamp(1rem, 3vw, 1.5rem);
}

.tool-cards {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.75rem;
}

.tool-cards article {
  border: 1px solid var(--kc-border);
  border-radius: 8px;
  padding: 1rem;
  background: rgba(2, 6, 23, 0.48);
}

.tool-cards h3 {
  margin: 0 0 0.4rem;
  font-size: 1rem;
}

.tool-cards p {
  margin: 0;
}

.faq details {
  border-top: 1px solid var(--kc-border);
  padding: 0.8rem 0;
}

.faq summary {
  min-height: 44px;
  color: var(--kc-text);
  cursor: pointer;
  font-weight: 700;
}

.site-footer {
  position: relative;
  z-index: 1;
  padding: 1rem clamp(1rem, 3vw, 2rem) 2rem;
  color: var(--kc-muted);
  text-align: center;
}

.site-footer code {
  color: var(--kc-soft);
  font-family: var(--kc-mono);
}

@media (max-width: 1080px) {
  .hero,
  .app-layout {
    grid-template-columns: 1fr;
  }

  .tool-rail {
    position: static;
  }

  .tool-tabs {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .tool-cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  html {
    scroll-behavior: auto;
  }

  .site-header,
  .header-links,
  .tool-heading {
    align-items: stretch;
    flex-direction: column;
  }

  .header-links {
    gap: 0.6rem;
  }

  .privacy-chip {
    white-space: normal;
  }

  .terminal-card {
    min-height: 130px;
  }

  .tool-tabs,
  .field-grid,
  .diff-inputs,
  .regex-main-grid,
  .regex-case-row,
  .tool-cards {
    grid-template-columns: 1fr;
  }

  .tool-tab {
    min-height: 54px;
  }

  .tool-actions button,
  .tool-heading .secondary-button {
    width: 100%;
  }

  textarea {
    min-height: 170px;
  }
}

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


[hidden] {
  display: none !important;
}