:root {
  /* Brighter & More Engaging Color Palette */
  --primary-color: #007BFF; /* A vibrant, welcoming blue */
  --primary-dark: #0056b3;  /* Darker shade for accents/hover */
  --secondary-color: #28a745; /* A complementary green for highlights */
  --background-light: #ffffff;
  --background-off-white: #f8f9fa;
  --text-dark: #343a40;
  --text-medium: #6c757d;
  --text-light: #ffffff;
  --border-color: #e9ecef;
  --shadow-light: rgba(0, 0, 0, 0.05);
  --shadow-medium: rgba(0, 0, 0, 0.1);

  /* Typography */
  --font-family-base: 'Noto Sans KR', sans-serif;
  --font-size-base: 1.1rem; /* 17.6px */
  --font-size-large: 1.35rem; /* 21.6px */
  --font-size-h1: 3rem; /* 48px */
  --font-size-h2: 2.25rem; /* 36px */
  --line-height-base: 1.7;
  --spacing-unit: 1rem;

  /* Category Button Colors */
  --category-health-color: #20c997; /* Teal/Mint green */
  --category-work-color: #fd7e14;   /* Orange */
  --category-housing-color: #6f42c1; /* Purple */
  --category-education-color: #00bcd4; /* Cyan */
  --category-all-color: var(--primary-color);
}

body {
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  line-height: var(--line-height-base);
  color: var(--text-dark);
  background-color: var(--background-light);
  margin: 0;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Global Elements */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-dark);
  line-height: 1.3;
}

a {
  color: var(--primary-color);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

/* Header */
header {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  color: var(--text-light);
  padding: calc(var(--spacing-unit) * 1.5) var(--spacing-unit);
  text-align: center;
  box-shadow: 0 2px 5px var(--shadow-medium);
}

header h1 {
  margin: 0;
  font-size: var(--font-size-h1);
  font-weight: 700;
  color: var(--text-light);
  text-shadow: 0 2px 4px var(--shadow-medium);
}

header p {
  margin-top: 0.5rem;
  font-size: var(--font-size-large);
  opacity: 0.95;
  font-weight: 400;
}

/* Hero Section */
.hero-section {
  background-color: var(--background-off-white);
  padding: calc(var(--spacing-unit) * 4) var(--spacing-unit);
  text-align: center;
  border-bottom: 1px solid var(--border-color);
}

.hero-content {
  max-width: 900px;
  margin: 0 auto;
}

.hero-content h2 {
  font-size: var(--font-size-h2);
  color: var(--primary-dark);
  margin-bottom: var(--spacing-unit);
}

.hero-content p {
  font-size: var(--font-size-large);
  color: var(--text-medium);
  margin-bottom: calc(var(--spacing-unit) * 2);
}

.call-to-action {
  background-color: var(--secondary-color);
  color: var(--text-light);
  padding: 0.8rem 2rem;
  border: none;
  border-radius: 8px;
  font-size: var(--font-size-large);
  font-weight: 700;
  cursor: pointer;
  transition: background-color 0.3s ease, transform 0.2s ease;
  box-shadow: 0 4px 10px var(--shadow-medium);
}

.call-to-action:hover {
  background-color: #218838; /* specific darker green */
  transform: translateY(-2px);
}

/* Main Content Grid */
main {
  max-width: 1400px;
  margin: calc(var(--spacing-unit) * 3) auto;
  padding: 0 calc(var(--spacing-unit) * 1.5);
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: calc(var(--spacing-unit) * 2);
}

/* Filter Section */
.filter-section {
  grid-column: 1 / -1; /* Span across all columns in the grid */
  display: flex;
  flex-direction: column;
  gap: var(--spacing-unit);
  margin-bottom: calc(var(--spacing-unit) * 2);
  padding: var(--spacing-unit) 0;
  border-bottom: 1px solid var(--border-color);
  background-color: var(--background-light);
}

#policy-search {
  width: 100%;
  padding: 0.8rem var(--spacing-unit);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  font-size: var(--font-size-base);
  box-shadow: inset 0 1px 3px var(--shadow-light);
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

#policy-search:focus {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
  outline: none;
}

.category-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
}

.category-button {
  background-color: var(--background-off-white);
  color: var(--text-dark);
  padding: 0.6rem 1.2rem;
  border: 1px solid var(--border-color);
  border-radius: 20px;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.3s ease, border-color 0.3s ease, color 0.3s ease;
}

.category-button:hover:not(.active) {
  background-color: var(--border-color);
}

.category-button.active {
  background-color: var(--primary-color);
  color: var(--text-light);
  border-color: var(--primary-color);
  box-shadow: 0 2px 5px var(--shadow-medium);
}

/* Footer */
footer {
  background-color: var(--background-off-white);
  color: var(--text-medium);
  text-align: center;
  padding: calc(var(--spacing-unit) * 2) var(--spacing-unit);
  margin-top: calc(var(--spacing-unit) * 4);
  border-top: 1px solid var(--border-color);
  font-size: 0.9rem;
}

/* Responsive Adjustments */
@media (max-width: 992px) {
  main {
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  }
}

@media (max-width: 768px) {
  :root {
    --font-size-base: 1rem;
    --font-size-large: 1.2rem;
    --font-size-h1: 2.5rem;
    --font-size-h2: 1.8rem;
  }

  header {
    padding: var(--spacing-unit) 0.8rem;
  }

  .hero-section {
    padding: calc(var(--spacing-unit) * 3) var(--spacing-unit);
  }

  .call-to-action {
    padding: 0.7rem 1.5rem;
    font-size: var(--font-size-base);
  }

  main {
    margin: calc(var(--spacing-unit) * 2) auto;
    gap: var(--spacing-unit);
    padding: 0 var(--spacing-unit);
  }

  .filter-section {
    flex-direction: column;
    gap: 0.8rem;
  }

  .category-buttons {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  :root {
    --font-size-h1: 2rem;
    --font-size-h2: 1.5rem;
  }

  .hero-section {
    padding: calc(var(--spacing-unit) * 2) var(--spacing-unit) * 0.8;
  }

  #policy-search {
    padding: 0.7rem 0.8rem;
  }

  .category-button {
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
  }
}

/* Specific Category Button Styling */
.category-button[data-category="all"].active {
  background-color: var(--category-all-color);
  border-color: var(--category-all-color);
  color: var(--text-light); /* Ensure text is light for colored buttons */
}
.category-button[data-category="health"].active {
  background-color: var(--category-health-color);
  border-color: var(--category-health-color);
  color: var(--text-light);
}
.category-button[data-category="work"].active {
  background-color: var(--category-work-color);
  border-color: var(--category-work-color);
  color: var(--text-light);
}
.category-button[data-category="housing"].active {
  background-color: var(--category-housing-color);
  border-color: var(--category-housing-color);
  color: var(--text-light);
}
.category-button[data-category="education"].active {
  background-color: var(--category-education-color);
  border-color: var(--category-education-color);
  color: var(--text-light);
}

/* General hover for non-active buttons to show the new color */
.category-button[data-category="health"]:hover:not(.active) { background-color: var(--category-health-color); color: var(--text-light); }
.category-button[data-category="work"]:hover:not(.active) { background-color: var(--category-work-color); color: var(--text-light); }
.category-button[data-category="housing"]:hover:not(.active) { background-color: var(--category-housing-color); color: var(--text-light); }
.category-button[data-category="education"]:hover:not(.active) { background-color: var(--category-education-color); color: var(--text-light); }
.category-button[data-category="all"]:hover:not(.active) { background-color: var(--category-all-color); color: var(--text-light); }


/* Responsive Adjustments for Filter Section */
@media (max-width: 576px) {
  .category-buttons {
    gap: 0.5rem; /* Reduce gap on very small screens */
  }
  .category-button {
    padding: 0.5rem 0.9rem; /* Smaller padding */
    font-size: 0.8rem; /* Smaller font size */
  }
  .filter-section {
    padding: calc(var(--spacing-unit) * 0.5) 0; /* Reduce padding */
  }
}