/* =========================
   Global & Variables
   ========================= */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* Color and gradient variables from style guide */
:root {
  --background: var(--light-gradient);
  --header-bg: #fff;
  --card-bg: var(--neutral-0);
  --card-border: var(--neutral-200);
  --text-main: var(--neutral-900);
  --text-secondary: var(--neutral-600);
  --filter-bg: #fff;
  --filter-active-bg: var(--red-400);
  --filter-active-color: #fff;
  --remove-btn-bg: var(--red-400);
  --remove-btn-hover: var(--red-700);

  /* Style guide colors */
  --light-gradient: linear-gradient(180deg, #EBF2FC 0%, #EEF8F9 100%);
  --dark-gradient: linear-gradient(180deg, #040918 0%, #091540 100%);
  --neutral-0: hsl(200, 60%, 99%);
  --neutral-100: hsl(0, 0%, 93%);
  --neutral-200: hsl(217, 61%, 90%);
  --neutral-300: hsl(0, 0%, 78%);
  --neutral-600: hsl(226, 11%, 37%);
  --neutral-700: hsl(225, 23%, 24%);
  --neutral-800: hsl(226, 25%, 17%);
  --neutral-900: hsl(227, 75%, 14%);
  --red-400: hsl(3, 86%, 64%);
  --red-500: hsl(3, 71%, 56%);
  --red-700: hsl(3, 77%, 44%);
}

/* Dark theme overrides */
body.dark-theme {
  --background: var(--dark-gradient);
  --header-bg: var(--neutral-900);
  --card-bg: var(--neutral-800);
  --card-border: var(--neutral-700);
  --text-main: var(--neutral-100);
  --text-secondary: var(--neutral-300);
  --filter-bg: var(--neutral-700);
  --filter-active-bg: var(--red-400);
  --filter-active-color: #fff;
  --remove-btn-bg: var(--red-400);
  --remove-btn-hover: var(--red-700);
}

/* =========================
   Base Styles
   ========================= */
body {
  font-family: 'Noto Sans', Arial, sans-serif;
  background: var(--background);
  color: var(--text-main);
  padding: 2rem;
  min-height: 100vh;
  transition: background 0.3s, color 0.3s;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
}

/* =========================
   Top Bar (Design Header)
   ========================= */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--neutral-900);
  border-radius: 20px;
  padding: 0.75rem 1.5rem;
  margin-bottom: 2.5rem;
  box-shadow: 0 4px 24px rgba(0,0,0,0.18);
  width: 100%;
  max-width: 1200px; /* Match grid/container width */
  margin-left: auto;
  margin-right: auto;
}
.topbar-left {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.topbar .logo {
  width: 36px;
  height: 36px;
}
.topbar-title {
  font-family: 'Noto Sans', Arial, sans-serif;
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: 0.5px;
}

/* Theme toggle button in topbar */
.theme-btn {
  background: rgba(255,255,255,0.08);
  border: none;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  font-size: 1.3rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
  color: #fff;
}
.theme-btn:hover,
.theme-btn:focus {
  background: rgba(255,255,255,0.18);
  outline: none;
}
body.dark-theme .theme-btn {
  color: #ffe066;
}

/* =========================
   Header & Filters
   ========================= */
header {
  background: transparent;
  box-shadow: none;
  border-radius: 0;
  padding: 0 0 1.5rem 0;
  margin-bottom: 0.5rem;
  align-items: flex-start;
}

/* Flex row for heading and filters */
.header-flex {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  flex-wrap: wrap;
}

header h1 {
  font-size: 2.2rem;
  color: var(--neutral-900);
  font-weight: 700;
  letter-spacing: 1px;
  margin-bottom: 0;
}

body.dark-theme header h1 {
  color: #fff;
}

.filters {
  display: flex;
  gap: 0.5rem;
  margin-top: 0;
}

/* =========================
   Filter Buttons
   ========================= */
.filters {
  display: flex;
  gap: 0.5rem;
  margin-top: 1rem;
}

.filters button {
  padding: 0.5em 1.6em;
  border: 2px solid transparent;
  border-radius: 999px;
  background: var(--filter-bg);
  color: var(--text-main);
  font-size: 1em;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s, color 0.2s, border 0.2s;
  box-shadow: 0 1px 2px rgba(0,0,0,0.03);
}
.filters button.active,
.filters button:focus {
  background: var(--filter-active-bg);
  color: var(--filter-active-color);
  border: 2px solid var(--filter-active-bg);
  outline: none;
}
.filters button:hover:not(.active) {
  background: var(--neutral-200);
  color: var(--text-main);
}

/* =========================
   Extensions Grid
   ========================= */
#extensions-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 2rem;
  margin-top: 1.5rem;
}

/* =========================
   Extension Card
   ========================= */
.tool-card {
  background: var(--card-bg);
  padding: 1.5rem 1.2rem 1.2rem 1.2rem;
  border-radius: 16px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  border: 2px solid var(--card-border);
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  min-height: 180px;
  position: relative;
  transition: box-shadow 0.3s, transform 0.3s, border 0.2s;
}
.tool-card:hover {
  box-shadow: 0 6px 24px rgba(0,0,0,0.12);
  transform: translateY(-4px) scale(1.03);
  border: 2px solid var(--red-400);
}

.tool-card .icon-circle {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
}
.tool-card .icon-circle img {
  width: 24px;
  height: 24px;
  object-fit: contain;
}

.tool-card h2 {
  font-size: 1.1em;
  font-weight: 700;
  margin: 0 0 8px 0;
  color: var(--text-main);
  border: none;
  padding-bottom: 0;
}

.tool-card p {
  font-size: 1em;
  color: var(--text-secondary);
  font-weight: 400;
  margin-bottom: 18px;
  min-height: 48px;
}

/* Remove button styled as in design */
.tool-card .remove-btn {
  margin-top: auto;
  align-self: flex-start;
  padding: 0.4em 1.4em;
  background: var(--remove-btn-bg);
  color: #fff;
  border: 2px solid var(--remove-btn-bg);
  border-radius: 999px;
  cursor: pointer;
  font-size: 1em;
  font-weight: 500;
  transition: background 0.2s, color 0.2s, border 0.2s;
  box-shadow: 0 1px 2px rgba(0,0,0,0.03);
}
.tool-card .remove-btn:hover,
.tool-card .remove-btn:focus {
  background: #fff;
  color: var(--remove-btn-bg);
  border: 2px solid var(--remove-btn-bg);
  outline: none;
}

/* =========================
   Toggle Switch
   ========================= */
.switch {
  position: absolute;
  top: 18px;
  right: 18px;
  display: flex;
  align-items: center;
}
.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}
.slider {
  position: relative;
  width: 38px;
  height: 22px;
  background: #e5e7eb;
  border-radius: 22px;
  transition: background 0.2s;
  cursor: pointer;
  display: inline-block;
  box-shadow: 0 1px 2px rgba(0,0,0,0.03);
}
.slider:before {
  content: "";
  position: absolute;
  left: 3px;
  top: 3px;
  width: 16px;
  height: 16px;
  background: #fff;
  border-radius: 50%;
  transition: transform 0.2s;
  box-shadow: 0 1px 4px rgba(0,0,0,0.08);
}
input:checked + .slider {
  background: var(--red-400);
}
input:checked + .slider:before {
  transform: translateX(16px);
}
body.dark-theme .slider {
  background: #374151;
}
body.dark-theme input:checked + .slider {
  background: var(--red-400);
}

/* =========================
   Responsive Design
   ========================= */
@media (max-width: 700px) {
  .container {
    padding: 1rem;
  }
  header {
    padding: 1.2rem 1rem 1rem 1rem;
  }
  #extensions-container {
    grid-template-columns: 1fr;
    gap: 1.2rem;
  }
  .tool-card {
    width: 100%;
    min-width: 0;
  }
}

/* =========================
   Accessibility & Focus
   ========================= */
button:focus,
input:focus,
.filters button:focus {
  outline: 2px solid var(--red-400);
  outline-offset: 2px;
}


/* Responsive adjustments */
@media (max-width: 700px) {
  .container {
    padding: 1rem;
  }
  header {
    padding: 1.2rem 1rem 1rem 1rem;
  }
  #extensions-container {
    grid-template-columns: 1fr;
    gap: 1.2rem;
  }
  .tool-card {
    width: 100%;
    min-width: 0;
  }
}