/* ================================
   ROOT VARIABLES
   ================================ */
:root {
  --clr-bg: #ffffff;
  --clr-bg-alt: #f7f7f9;
  --clr-surface: #ffffff;
  --clr-border: #e1e1e6;
  --clr-text: #1a1a2e;
  --clr-text-muted: #4b5563;
  --clr-accent: #2563eb;
  --clr-accent-hover: #1d4ed8;
  --clr-success: #16a34a;
  --clr-on-accent: #ffffff;
  --clr-on-success: #1a1a2e;
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'Fira Code', 'Courier New', Courier, monospace;
  --radius: 0.5rem;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.12);
}

/* ================================
   DARK MODE VARIABLES
   ================================ */
[data-theme="dark"] {
  --clr-bg: #0f0f17;
  --clr-bg-alt: #1a1a2e;
  --clr-surface: #16213e;
  --clr-border: #2d2d4e;
  --clr-text: #e2e8f0;
  --clr-text-muted: #94a3b8;
  --clr-accent: #60a5fa;
  --clr-accent-hover: #93c5fd;
  --clr-success: #4ade80;
  --clr-on-accent: #0f0f17;
  --clr-on-success: #0f0f17;
}

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

[hidden] {
  display: none !important;
}

html {
  font-size: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background-color: var(--clr-bg);
  color: var(--clr-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img,
video {
  max-width: 100%;
  display: block;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* ================================
   SKIP LINK
   ================================ */
.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  z-index: 9999;
  background-color: var(--clr-accent);
  color: var(--clr-on-accent);
  padding: 0.5rem 1rem;
  border-radius: var(--radius);
  font-weight: 600;
  text-decoration: none;
}

.skip-link:focus {
  top: 1rem;
  color: var(--clr-on-accent);
}

/* ================================
   TYPOGRAPHY
   ================================ */
h1,
h2,
h3,
h4,
h5,
h6 {
  line-height: 1.25;
  font-weight: 700;
}

h1 { font-size: clamp(1.75rem, 1.4rem + 1.75vw, 2.75rem); }
h2 { font-size: clamp(1.375rem, 1.1rem + 1.375vw, 2rem); }
h3 { font-size: clamp(1.125rem, 1rem + 0.625vw, 1.5rem); }

p {
  margin-bottom: 1rem;
}

p:last-child {
  margin-bottom: 0;
}

a {
  color: var(--clr-accent);
  text-decoration: underline;
}

a:hover {
  color: var(--clr-accent-hover);
}

/* ================================
   LAYOUT
   ================================ */
.site-main {
  width: 100%;
  max-width: 72rem;
  margin-inline: auto;
  padding-inline: 1.25rem;
  padding-block: 2rem;
}

/* ================================
   SITE HEADER
   ================================ */
.site-header {
  border-bottom: 1px solid var(--clr-border);
  padding-block: 1rem;
  background-color: var(--clr-surface);
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-header__inner {
  max-width: 72rem;
  margin-inline: auto;
  padding-inline: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-header__logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.25rem;
  font-weight: 700;
  text-decoration: none;
  color: var(--clr-text);
}

.site-header__logo-icon {
  flex-shrink: 0;
}

.site-header__logo:hover {
  color: var(--clr-accent);
}

/* ================================
   THEME TOGGLE
   ================================ */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  background-color: var(--clr-bg-alt);
  color: var(--clr-text);
  cursor: pointer;
  font-size: 1.25rem;
  line-height: 1;
  transition: background-color 0.15s ease, border-color 0.15s ease;
}

.theme-toggle:hover {
  border-color: var(--clr-accent);
  background-color: var(--clr-surface);
  color: var(--clr-text);
}

.theme-toggle:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.4);
  outline-offset: 2px;
}

[data-theme="dark"] .theme-toggle:focus-visible {
  outline-color: rgba(96, 165, 250, 0.4);
}

.theme-toggle__icon--dark {
  display: none;
}

[data-theme="dark"] .theme-toggle__icon--light {
  display: none;
}

[data-theme="dark"] .theme-toggle__icon--dark {
  display: inline;
}

/* ================================
   HERO SECTION
   ================================ */
.hero-section {
  background-color: var(--clr-bg-alt);
  border-bottom: 1px solid var(--clr-border);
  padding-block: 3rem 2.5rem;
}

.hero-section__inner {
  max-width: 72rem;
  margin-inline: auto;
  padding-inline: 1.25rem;
}

.hero-section__title {
  margin-bottom: 0.5rem;
}

.hero-section__description {
  color: var(--clr-text-muted);
  max-width: 60ch;
}

/* ================================
   TOOLBAR
   ================================ */
.toolbar {
  display: grid;
  gap: 1rem;
  margin-bottom: 2rem;
}

.toolbar__label {
  font-size: 0.875rem;
  font-weight: 600;
}

.toolbar__input {
  width: 100%;
  padding: 0.625rem 0.875rem;
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  font-family: var(--font-sans);
  font-size: 1rem;
  background-color: var(--clr-surface);
  color: var(--clr-text);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.toolbar__input:focus {
  outline: none;
  border-color: var(--clr-accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

[data-theme="dark"] .toolbar__input:focus {
  box-shadow: 0 0 0 3px rgba(96, 165, 250, 0.2);
}

.toolbar__chip-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.toolbar__chip {
  border: 1px solid var(--clr-border);
  background-color: var(--clr-bg-alt);
  color: var(--clr-text-muted);
  padding: 0.375rem 0.75rem;
  border-radius: 999px;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.15s ease, color 0.15s ease;
}

.toolbar__chip:hover {
  background-color: var(--clr-surface);
  color: var(--clr-text);
}

.toolbar__chip:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.4);
  outline-offset: 2px;
}

[data-theme="dark"] .toolbar__chip:focus-visible {
  outline-color: rgba(96, 165, 250, 0.4);
}

.toolbar__chip.is-active {
  background-color: var(--clr-accent);
  border-color: var(--clr-accent);
  color: var(--clr-on-accent);
}

.toolbar__count {
  color: var(--clr-text-muted);
  font-size: 0.875rem;
}

/* ================================
   TOOL DIRECTORY GRID
   ================================ */
.directory__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(18rem, 1fr));
  gap: 1.25rem;
}

.tool-card {
  background-color: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.15s ease, border-color 0.15s ease;
}

.tool-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--clr-accent);
}

.tool-card__name {
  font-size: 1.125rem;
}

.tool-card__meta {
  color: var(--clr-text-muted);
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.tool-card__description {
  color: var(--clr-text-muted);
  font-size: 0.9375rem;
}

.tool-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem;
}

.tool-card__tag {
  background-color: var(--clr-bg-alt);
  border: 1px solid var(--clr-border);
  border-radius: 0.25rem;
  padding: 0.125rem 0.375rem;
  font-size: 0.75rem;
  color: var(--clr-text-muted);
}

.tool-card__cta {
  margin-top: auto;
  align-self: flex-start;
  display: inline-block;
  background-color: var(--clr-accent);
  color: var(--clr-on-accent);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.875rem;
  padding: 0.5rem 0.875rem;
  border-radius: var(--radius);
  transition: background-color 0.15s ease;
}

.tool-card__cta:hover {
  background-color: var(--clr-accent-hover);
  color: var(--clr-on-accent);
}

.tool-card__cta:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.4);
  outline-offset: 2px;
}

[data-theme="dark"] .tool-card__cta:focus-visible {
  outline-color: rgba(96, 165, 250, 0.4);
}

.directory__empty {
  padding: 1.25rem;
  border: 1px dashed var(--clr-border);
  border-radius: var(--radius);
  color: var(--clr-text-muted);
  margin-top: 1.25rem;
}

/* ================================
   CONTENT LAYOUT (SEO + SIDEBAR AD)
   ================================ */
.content-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 2rem;
  align-items: start;
  margin-block: 2.5rem;
}

@media (max-width: 64em) {
  .content-layout {
    grid-template-columns: 1fr;
  }
}

.content-section__body h2 {
  margin-bottom: 0.75rem;
}

.content-section__body h2 + p {
  margin-top: 0;
}

.content-section__body h2:not(:first-child) {
  margin-top: 2rem;
}

.content-section__body p + p {
  margin-top: 0.5rem;
}

/* ================================
   CONTENT SIDEBAR
   ================================ */
.content-sidebar {
  position: sticky;
  top: 5rem;
}

/* ================================
   SITE FOOTER
   ================================ */
.site-footer {
  background-color: var(--clr-bg-alt);
  border-top: 1px solid var(--clr-border);
  padding-block: 1.5rem;
  margin-top: 3rem;
}

.site-footer__inner {
  max-width: 72rem;
  margin-inline: auto;
  padding-inline: 1.25rem;
}

.site-footer__copy {
  color: var(--clr-text-muted);
  font-size: 0.8125rem;
}

/* ================================
   REDUCED MOTION
   ================================ */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}