/* ===== CSS Variables ===== */
:root {
  --color-bg: #0a0a0f;
  --color-surface: rgba(20, 20, 30, 0.75);
  --color-surface-hover: rgba(30, 30, 45, 0.85);
  --color-border: rgba(255, 255, 255, 0.1);
  --color-text: #e8e8ec;
  --color-text-muted: #8a8a9a;
  --color-accent: #6b7cff;
  --color-accent-hover: #8b9aff;
  --color-overlay: rgba(5, 5, 10, 0.7);
  
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  --header-height: 64px;
  --border-radius: 12px;
  --transition: 0.2s ease;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  color: var(--color-text);
  background-color: var(--color-bg);
  background-image: url('./background.png');
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
  background-repeat: no-repeat;
  min-height: 100vh;
  line-height: 1.6;
}

/* ===== Background Overlay ===== */
.background-overlay {
  position: fixed;
  inset: 0;
  background: var(--color-overlay);
  z-index: -1;
  pointer-events: none;
}

/* ===== Header ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.5rem;
  background: var(--color-surface);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
}

.logo {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.02em;
  transition: color var(--transition);
}

.logo:hover,
.logo:focus {
  color: var(--color-accent);
}

.logo:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 4px;
  border-radius: 4px;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.625rem 1.25rem;
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  border-radius: 8px;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
  cursor: pointer;
  transition: all var(--transition);
}

.btn:hover,
.btn:focus {
  background: var(--color-surface-hover);
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.btn-auth {
  background: rgba(107, 124, 255, 0.15);
  border-color: rgba(107, 124, 255, 0.3);
}

.btn-auth:hover,
.btn-auth:focus {
  background: rgba(107, 124, 255, 0.25);
  border-color: var(--color-accent);
}

/* ===== Main Content ===== */
.main-content {
  max-width: 800px;
  margin: 0 auto;
  padding: calc(var(--header-height) + 3rem) 1.5rem 3rem;
  min-height: calc(100vh - 60px);
}

/* ===== Sections ===== */
.section {
  margin-bottom: 3rem;
}

.section-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--color-border);
}

/* ===== Cards Grid ===== */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1rem;
}

.card {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  padding: 1.5rem 1rem;
  background: var(--color-surface);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  text-decoration: none;
  color: var(--color-text);
  transition: all var(--transition);
}

.card:hover,
.card:focus {
  background: var(--color-surface-hover);
  border-color: var(--color-accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.card:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.card-icon {
  font-size: 2rem;
}

.card-label {
  font-size: 0.9375rem;
  font-weight: 500;
}

.card-subtitle {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

/* ===== Placeholder Text ===== */
.placeholder-text {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
  font-style: italic;
  padding: 1.5rem;
  background: var(--color-surface);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px dashed var(--color-border);
  border-radius: var(--border-radius);
  text-align: center;
}

/* ===== Footer ===== */
.footer {
  text-align: center;
  padding: 1.5rem;
  color: var(--color-text-muted);
  font-size: 0.8125rem;
  border-top: 1px solid var(--color-border);
  background: var(--color-surface);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

/* ===== Responsive ===== */
@media (max-width: 600px) {
  :root {
    --header-height: 56px;
  }

  .header {
    padding: 0 1rem;
  }

  .logo {
    font-size: 1.1rem;
  }

  .btn {
    padding: 0.5rem 1rem;
    font-size: 0.8125rem;
  }

  .main-content {
    padding: calc(var(--header-height) + 2rem) 1rem 2rem;
  }

  .section-title {
    font-size: 1rem;
  }

  .cards-grid {
    grid-template-columns: 1fr;
  }

  .card {
    flex-direction: row;
    justify-content: flex-start;
    padding: 1rem 1.25rem;
  }

  .card-icon {
    font-size: 1.5rem;
  }
}

/* ===== Reduced Motion ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }

  html {
    scroll-behavior: auto;
  }
}