/* --- CSS VARIABLES (THEMING FOUNDATION) --- */
:root {
  /* Light Theme Defaults */
  --bg-color: #f8f9fa;
  --surface-color: #ffffff;
  --text-main: #212529;
  --text-muted: #6c757d;
  --primary: #007bff;
  --primary-hover: #0056b3;
  --border-color: #dee2e6;
  --radius: 8px;
  --spacing: 1.25rem;
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1);
  --font-family: system-ui, -apple-system, sans-serif;
}

/* Automatic Dark Mode Integration */
/* Manual Dark Mode Override */
[data-theme="dark"] {
  --bg-color: #121212;
  --surface-color: #1e1e1e;
  --text-main: #e0e0e0;
  --text-muted: #a0a0a0;
  --primary: #3b82f6;
  --primary-hover: #60a5fa;
  --border-color: #333333;
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.5);
}

/* Fixed Floating Theme Toggle Button */
.theme-toggle {
  position: fixed; /* Locks it to the screen */
  bottom: 20px;
  right: 20px;
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  width: 50px; /* Made it a bit larger so it's easy to click */
  height: 50px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  padding: 0;
  font-size: 1.5rem;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2); /* Deeper shadow so it floats above content */
  z-index: 9999; /* Ensures nothing ever overlaps it */
  transition: transform 0.2s ease, background-color 0.4s ease, color 0.4s ease;
}

.theme-toggle:hover {
  transform: scale(1.1); /* Slight pop effect on hover */
}

/* --- BASE & TYPOGRAPHY --- */
*, *::before, *::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--font-family);
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.6;
}

body, article, header.container, input, select, textarea, table, th, td {
  transition: background-color 0.4s ease, color 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease;
}

a {
  color: var(--primary);
  text-decoration: none;
  
  /* Native CSS Nesting */
  &:hover {
    text-decoration: underline;
  }
}

/* --- LAYOUT COMPONENTS --- */
.container {
  max-width: 1000px;
  margin: 0 auto;
  padding: var(--spacing);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing);
}

/* --- SEMANTIC TAG STYLING --- */
header.container {
  border-bottom: 1px solid var(--border-color);
  background-color: var(--surface-color);
  margin-bottom: calc(var(--spacing) * 1.5);

  nav {
    display: flex;
    justify-content: space-between;
    align-items: center;

    ul {
      list-style: none;
      display: flex;
      gap: var(--spacing);
      padding: 0;
      margin: 0;
      align-items: center;
    }
  }
}

section {
  margin-bottom: calc(var(--spacing) * 3);
  
  h2, h3 {
    margin-top: 0;
    margin-bottom: var(--spacing);
    color: var(--text-main);
  }
}

article {
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: calc(var(--spacing) * 1.5);
  box-shadow: var(--shadow);

  header {
    font-weight: 600;
    margin-bottom: var(--spacing);
    font-size: 1.1rem;
    color: var(--text-muted);
  }

  p {
    margin: 0 0 var(--spacing) 0;
    
    &:last-child {
      margin-bottom: 0;
    }
  }
}

/* --- FORMS & INPUTS --- */
form {
  display: flex;
  flex-direction: column;
  gap: var(--spacing);

  label {
    font-weight: 500;
    
    input, select, textarea {
      display: block;
      width: 100%;
      margin-top: 0.5rem;
    }
  }

  input, select, textarea {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: calc(var(--radius) / 2);
    background-color: var(--bg-color);
    color: var(--text-main);
    font-family: inherit;

    &:focus {
      outline: 2px solid var(--primary);
      outline-offset: -1px;
    }
  }
}

fieldset {
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: var(--spacing);
  background: var(--surface-color);

  legend {
    font-weight: 600;
    padding: 0 0.5rem;
  }

  label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: normal;
    margin-bottom: 0.5rem;

    input {
      width: auto;
      margin: 0;
    }
  }
}

/* --- BUTTONS --- */
button, [role="button"], .button {
  display: inline-block;
  padding: 0.6rem 1.25rem;
  background-color: var(--primary);
  color: #fff;
  border: none;
  border-radius: calc(var(--radius) / 2);
  cursor: pointer;
  font-weight: 500;
  text-align: center;
  transition: background-color 0.2s;

  &:hover {
    background-color: var(--primary-hover);
    text-decoration: none;
    color: #fff;
  }

  &.secondary {
    background-color: transparent;
    color: var(--text-muted);
    border: 1px solid var(--border-color);

    &:hover {
      background-color: var(--surface-color);
      color: var(--text-main);
    }
  }
}

/* --- TABLES --- */
figure {
  margin: 0;
  overflow-x: auto;
  
  table {
    width: 100%;
    border-collapse: collapse;
    background-color: var(--surface-color);
    border-radius: var(--radius);
    overflow: hidden;

    th, td {
      padding: var(--spacing);
      text-align: left;
      border-bottom: 1px solid var(--border-color);
    }

    th {
      background-color: var(--bg-color);
      font-weight: 600;
    }

    tr:last-child td {
      border-bottom: none;
    }
  }
}