@layer reset, base, themes, layout, components, utilities;

@layer reset {
  *, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }
}

@layer base {
  :root {
    --font-main: 'Pretendard', system-ui, -apple-system, sans-serif;
    
    /* Base Colors in OKLCH */
    --lotto-yellow: oklch(80% 0.15 85);
    --lotto-blue: oklch(65% 0.18 240);
    --lotto-red: oklch(60% 0.2 25);
    --lotto-gray: oklch(70% 0.05 200);
    --lotto-green: oklch(75% 0.18 145);
    
    --transition-speed: 0.3s;
  }

  body {
    font-family: var(--font-main);
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color var(--transition-speed), color var(--transition-speed);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
  }
}

@layer themes {
  [data-theme="light"] {
    --bg-color: oklch(98% 0.01 200);
    --text-color: oklch(20% 0.02 200);
    --card-bg: oklch(100% 0 0);
    --card-shadow: 0 10px 30px oklch(0% 0 0 / 10%);
    --btn-primary: oklch(60% 0.15 250);
    --btn-primary-text: white;
  }

  [data-theme="dark"] {
    --bg-color: oklch(15% 0.02 200);
    --text-color: oklch(90% 0.01 200);
    --card-bg: oklch(20% 0.02 200);
    --card-shadow: 0 10px 30px oklch(0% 0 0 / 40%);
    --btn-primary: oklch(75% 0.12 250);
    --btn-primary-text: oklch(15% 0.02 200);
  }
}

@layer layout {
  header {
    padding: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1000px;
    margin: 0 auto;
    width: 100%;
    flex-wrap: wrap;
    gap: 1rem;
  }

  nav {
    display: flex;
    gap: 1.5rem;
  }

  .nav-link {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 700;
    opacity: 0.6;
    transition: opacity 0.2s, transform 0.2s;
    font-size: 1.125rem;
  }

  .nav-link:hover {
    opacity: 1;
    transform: translateY(-2px);
  }

  .nav-link.active {
    opacity: 1;
    border-bottom: 2px solid var(--btn-primary);
  }

  main {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem 1rem;
  }

  footer {
    text-align: center;
    padding: 2rem;
    font-size: 0.875rem;
    opacity: 0.7;
  }
}

@layer components {
  #theme-toggle {
    background: var(--card-bg);
    border: 2px solid var(--text-color);
    border-radius: 50%;
    width: 48px;
    height: 48px;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    transition: transform 0.2s, background-color var(--transition-speed);
    box-shadow: var(--card-shadow);
  }

  #theme-toggle:hover {
    transform: scale(1.1);
  }

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

  lotto-generator {
    display: block;
    width: 100%;
    max-width: 500px;
  }

  /* Form & Contact Styles */
  .card {
    background: var(--card-bg);
    padding: 2.5rem;
    border-radius: 24px;
    box-shadow: var(--card-shadow);
    width: 100%;
    max-width: 600px;
    transition: background-color var(--transition-speed);
  }

  .card h2 {
    margin-bottom: 0.5rem;
    font-size: 1.75rem;
  }

  .card p {
    margin-bottom: 2rem;
    opacity: 0.7;
  }

  .form-group {
    margin-bottom: 1.5rem;
    text-align: left;
  }

  .form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 700;
    font-size: 0.9rem;
  }

  .form-group input,
  .form-group textarea {
    width: 100%;
    padding: 1rem;
    border-radius: 12px;
    border: 2px solid oklch(50% 0 0 / 10%);
    background: var(--bg-color);
    color: var(--text-color);
    font-family: inherit;
    font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
  }

  .form-group input:focus,
  .form-group textarea:focus {
    outline: none;
    border-color: var(--btn-primary);
    box-shadow: 0 0 0 4px oklch(60% 0.15 250 / 10%);
  }

  .form-group textarea {
    min-height: 150px;
    resize: vertical;
  }

  .btn-submit {
    width: 100%;
    background-color: var(--btn-primary);
    color: var(--btn-primary-text);
    border: none;
    padding: 1.25rem;
    font-size: 1.125rem;
    font-weight: 700;
    border-radius: 12px;
    cursor: pointer;
    transition: transform 0.2s, filter 0.2s;
    box-shadow: 0 4px 12px var(--btn-primary);
  }

  .btn-submit:hover {
    transform: translateY(-2px);
    filter: brightness(1.1);
  }
}

@layer utilities {
  .sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
  }
}