: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 35px rgba(15, 23, 42, 0.18);
  --shadow-strong: 0 28px 60px rgba(15, 23, 42, 0.28);
  --transition-base: 220ms ease;
  --transition-slow: 360ms ease;
}

:root[data-theme='light'] {
  color-scheme: light;
  --bg-surface: #f7f9fc;
  --bg-gradient-one: rgba(59, 130, 246, 0.18);
  --bg-gradient-two: rgba(236, 72, 153, 0.12);
  --panel-surface: rgba(255, 255, 255, 0.9);
  --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-text: #0f172a;
  --chrome-muted: #475569;
  --chrome-link: #1d4ed8;
  --nav-surface: linear-gradient(135deg, rgba(59, 130, 246, 0.22), rgba(14, 165, 233, 0.18));
  --nav-border: rgba(59, 130, 246, 0.25);
  --nav-hover: rgba(255, 255, 255, 0.72);
  --nav-hover-border: rgba(99, 102, 241, 0.24);
  --nav-active: linear-gradient(135deg, #6366f1, #38bdf8);
  --nav-active-text: #f8fafc;
  --input-surface: rgba(255, 255, 255, 0.96);
  --input-border: rgba(148, 163, 184, 0.35);
  --input-placeholder: rgba(148, 163, 184, 0.9);
  --input-focus: rgba(59, 130, 246, 0.45);
  --button-gradient: linear-gradient(135deg, #38bdf8, #6366f1);
  --button-text: #0f172a;
  --status-info: #64748b;
  --status-success: #16a34a;
  --status-error: #dc2626;
  --highlight-bg: rgba(94, 234, 212, 0.35);
  --chip-bg: rgba(59, 130, 246, 0.18);
  --chip-border: rgba(59, 130, 246, 0.22);
  --divider: rgba(15, 23, 42, 0.08);
  --footer-surface: rgba(255, 255, 255, 0.8);
}

:root[data-theme='dark'] {
  color-scheme: dark;
  --bg-surface: #0b1120;
  --bg-gradient-one: rgba(56, 189, 248, 0.22);
  --bg-gradient-two: rgba(129, 140, 248, 0.2);
  --panel-surface: rgba(15, 23, 42, 0.84);
  --panel-border: rgba(148, 163, 184, 0.18);
  --text-primary: #e2e8f0;
  --text-secondary: #cbd5f5;
  --text-muted: #94a3b8;
  --chrome-surface: rgba(15, 23, 42, 0.88);
  --chrome-border: rgba(148, 163, 184, 0.24);
  --chrome-text: #e2e8f0;
  --chrome-muted: #94a3b8;
  --chrome-link: #60a5fa;
  --nav-surface: linear-gradient(135deg, rgba(56, 189, 248, 0.26), rgba(129, 140, 248, 0.24));
  --nav-border: rgba(148, 163, 184, 0.24);
  --nav-hover: rgba(15, 23, 42, 0.55);
  --nav-hover-border: rgba(148, 163, 184, 0.24);
  --nav-active: linear-gradient(135deg, rgba(56, 189, 248, 0.5), rgba(59, 130, 246, 0.58));
  --nav-active-text: #020617;
  --input-surface: rgba(15, 23, 42, 0.78);
  --input-border: rgba(148, 163, 184, 0.28);
  --input-placeholder: rgba(148, 163, 184, 0.65);
  --input-focus: rgba(56, 189, 248, 0.55);
  --button-gradient: linear-gradient(135deg, #38bdf8, #818cf8);
  --button-text: #020617;
  --status-info: #94a3b8;
  --status-success: #4ade80;
  --status-error: #f87171;
  --highlight-bg: rgba(56, 189, 248, 0.35);
  --chip-bg: rgba(56, 189, 248, 0.2);
  --chip-border: rgba(56, 189, 248, 0.28);
  --divider: rgba(148, 163, 184, 0.18);
  --footer-surface: rgba(15, 23, 42, 0.78);
}

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

body,
input,
textarea,
select,
button {
  font-family: inherit;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background:
    radial-gradient(circle at 12% 20%, var(--bg-gradient-one), transparent 60%),
    radial-gradient(circle at 88% 78%, var(--bg-gradient-two), transparent 65%),
    var(--bg-surface);
  color: var(--text-primary);
  transition: background var(--transition-slow), color var(--transition-base);
}

::selection {
  background: rgba(56, 189, 248, 0.35);
  color: inherit;
}

.app-hero {
  padding: clamp(1.5rem, 4vw, 3rem) clamp(1rem, 5vw, 4rem) clamp(1rem, 3vw, 1.5rem);
  width: min(1100px, 100%);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
}

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

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  border-radius: 14px;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.28), rgba(236, 72, 153, 0.28));
  color: var(--text-primary);
  font-size: 1.4rem;
  box-shadow: var(--shadow-soft);
}

.app-hero h1 {
  margin: 0;
  font-size: clamp(1.9rem, 4vw, 2.75rem);
  letter-spacing: -0.01em;
}

.app-hero p {
  margin: 0;
  max-width: 640px;
  color: var(--text-secondary);
  font-size: clamp(1rem, 2.2vw, 1.1rem);
  line-height: 1.6;
}

.global-header {
  width: min(1100px, 100%);
  margin: clamp(1rem, 4vw, 2.5rem) auto 0;
  padding: 0.9rem 1.4rem;
  border-radius: var(--radius-lg);
  background: var(--chrome-surface);
  border: 1px solid var(--chrome-border);
  box-shadow: 0 20px 38px rgba(15, 23, 42, 0.18);
  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: 0.65rem;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--chrome-text);
  text-decoration: none;
  letter-spacing: -0.01em;
}

.global-header__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.2), rgba(236, 72, 153, 0.2));
  box-shadow: 0 8px 16px rgba(56, 189, 248, 0.18);
}

.global-header__nav {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.9rem;
}

.global-header__nav a {
  color: var(--chrome-link);
  font-weight: 600;
  text-decoration: none;
  padding: 0.4rem 0.65rem;
  border-radius: 0.65rem;
  transition: background var(--transition-base), color 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);
  color: var(--chrome-text);
  outline: none;
  transform: translateY(-1px);
}

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

.theme-toggle {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.55rem 0.95rem;
  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);
  border-color: var(--input-focus);
  outline: none;
  box-shadow: 0 16px 35px rgba(56, 189, 248, 0.22);
}

.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;
  transition: color var(--transition-base);
}

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

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

:root[data-theme='light'] .theme-toggle__label {
  color: #0f172a;
}

:root[data-theme='dark'] .theme-toggle__label {
  color: #e2e8f0;
}

.noscript {
  margin: 0 auto 1.5rem;
  padding: 1rem 1.5rem;
  max-width: 760px;
  background: rgba(248, 113, 113, 0.12);
  border: 1px solid rgba(248, 113, 113, 0.28);
  border-radius: var(--radius-lg);
  color: var(--text-primary);
}

.layout {
  flex: 1;
  display: grid;
  gap: clamp(1.2rem, 3vw, 2rem);
  padding: 0 clamp(1rem, 5vw, 4rem) 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: 0.65rem;
  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(20px);
}

.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 0.9rem;
  border-radius: 0.85rem;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition-base), border var(--transition-base), transform 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);
  border-color: var(--nav-hover-border);
  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-active-text);
  border-color: transparent;
  box-shadow: 0 18px 36px rgba(79, 70, 229, 0.24);
}

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

.tool-panel {
  display: none;
  position: relative;
  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(22px);
  transform: translateY(12px);
  opacity: 0;
  transition: transform var(--transition-slow), opacity var(--transition-base);
}

.tool-panel::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  border: 1px solid transparent;
  pointer-events: none;
}

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

.tool-panel.active::before {
  border-color: rgba(99, 102, 241, 0.2);
}

.tool-panel h2 {
  margin: 0 0 0.75rem 0;
  font-size: 1.35rem;
}

.tool-info {
  margin: -0.35rem 0 0.75rem 0;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.55;
}

.panel-grid {
  display: grid;
  gap: 0.9rem;
}

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

textarea,
input,
select {
  width: 100%;
  border-radius: var(--radius-md);
  border: 1px solid var(--input-border);
  background: var(--input-surface);
  color: var(--text-primary);
  padding: 0.75rem 0.95rem;
  font-size: 0.95rem;
  line-height: 1.45;
  transition: border var(--transition-base), box-shadow var(--transition-base), background var(--transition-base), color var(--transition-base);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04);
}

textarea::placeholder,
input::placeholder {
  color: var(--input-placeholder);
}

textarea:focus,
input:focus,
select:focus {
  outline: none;
  border-color: var(--input-focus);
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.18);
}

textarea {
  min-height: 160px;
  resize: vertical;
}

select {
  appearance: none;
  background-image: linear-gradient(45deg, transparent 50%, currentColor 50%), linear-gradient(135deg, currentColor 50%, transparent 50%);
  background-position: calc(100% - 22px) calc(50% - 3px), calc(100% - 16px) calc(50% - 3px);
  background-size: 7px 7px;
  background-repeat: no-repeat;
}

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

.button-row button {
  border: none;
  background: var(--button-gradient);
  color: var(--button-text);
  font-weight: 600;
  letter-spacing: 0.01em;
  padding: 0.65rem 1.1rem;
  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 36px rgba(56, 189, 248, 0.28);
}

.button-row button:hover,
.button-row button:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 22px 44px rgba(56, 189, 248, 0.32);
  outline: none;
}

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

.status {
  min-height: 1.2rem;
  font-size: 0.9rem;
  color: var(--status-info);
  transition: color var(--transition-base), opacity var(--transition-base);
}

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

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

.password-length-control {
  display: flex;
  align-items: center;
  gap: 0.9rem;
}

.password-length-control input[type="range"] {
  flex: 1;
  accent-color: var(--chrome-link);
}

.password-length-control span {
  min-width: 2.5rem;
  text-align: right;
  font-weight: 600;
  color: var(--text-primary);
}

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

.password-options .option {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.95rem;
  color: var(--text-primary);
}

.password-options input[type="checkbox"] {
  width: 20px;
  height: 20px;
  border-radius: 0.4rem;
  border: 1px solid var(--input-border);
  background: var(--input-surface);
  accent-color: var(--chrome-link);
}

.password-options span {
  flex: 1;
}

.inline {
  display: block;
  font-weight: 600;
}

.indent-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.65rem;
}

.case-results {
  display: grid;
  gap: 0.5rem;
  background: var(--input-surface);
  border: 1px solid var(--input-border);
  border-radius: var(--radius-md);
  padding: 0.85rem 1rem;
  min-height: 150px;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  white-space: pre-wrap;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04);
}

.case-results strong {
  color: var(--text-primary);
}

.regex-output {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  align-items: flex-start;
}

.regex-output h3 {
  margin: 0 0 0.4rem 0;
}

#regex-matches {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.5rem;
  font-family: var(--font-mono);
}

#regex-matches li {
  background: var(--chip-bg);
  border: 1px solid var(--chip-border);
  border-radius: 0.65rem;
  padding: 0.55rem 0.75rem;
}

.highlight {
  min-height: 120px;
  padding: 0.8rem;
  background: var(--input-surface);
  border: 1px solid var(--input-border);
  border-radius: var(--radius-md);
  white-space: pre-wrap;
  font-family: var(--font-mono);
  line-height: 1.5;
}

.highlight mark {
  background: var(--highlight-bg);
  color: inherit;
  padding: 0.1rem 0.2rem;
  border-radius: 0.3rem;
}

.global-footer {
  width: min(1100px, 100%);
  margin: clamp(2.2rem, 6vw, 3.5rem) auto clamp(1.5rem, 4vw, 2.5rem);
  padding: clamp(1.4rem, 4vw, 1.8rem) clamp(1.2rem, 5vw, 2.4rem);
  border-radius: 1.2rem;
  background: var(--footer-surface);
  border: 1px solid var(--divider);
  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 {
  margin: 0;
}

.global-footer__love {
  margin: 0;
  font-weight: 600;
  color: var(--chrome-text);
}

.global-footer__copy {
  margin: 0;
}

@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 180px;
    justify-content: center;
  }
}

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

  .theme-toggle {
    align-self: flex-start;
  }

  .layout {
    padding-bottom: clamp(2rem, 8vw, 3rem);
  }

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

  .indent-controls {
    flex-direction: column;
    align-items: stretch;
  }
}

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