:root {
  /* HSL Color Palette - Premium Dark Theme */
  --hue-primary: 250; /* Deep Purple/Blue */
  --hue-success: 150;
  --hue-warning: 35;
  --hue-danger: 0;

  --color-bg-base: hsl(220, 20%, 10%);
  --color-bg-surface: hsl(220, 20%, 14%);
  --color-bg-surface-hover: hsl(220, 20%, 18%);
  
  --color-text-primary: hsl(220, 10%, 95%);
  --color-text-secondary: hsl(220, 10%, 70%);
  --color-text-muted: hsl(220, 10%, 50%);

  --color-primary: hsl(var(--hue-primary), 80%, 60%);
  --color-primary-hover: hsl(var(--hue-primary), 80%, 70%);
  
  --color-border: hsl(220, 20%, 20%);
  
  /* Spacing & Layout */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 1rem;
  
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
}

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

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: var(--color-bg-base);
  color: var(--color-text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  color: var(--color-primary-hover);
}

/* Utilities */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

.card {
  background-color: var(--color-bg-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-md);
  font-weight: 500;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.2s;
}

.btn-primary {
  background-color: var(--color-primary);
  color: #fff;
}

.btn-primary:hover {
  background-color: var(--color-primary-hover);
}

/* Form Elements */
input[type="text"],
input[type="email"],
input[type="password"] {
  width: 100%;
  padding: 0.5rem;
  background-color: var(--color-bg-base);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text-primary);
}

input:focus {
  outline: 2px solid var(--color-primary);
  border-color: transparent;
}