/* ========================================
   sergio.dev — Design System & Global Styles
   ======================================== */

:root {
  --color-primary: #0066FF;
  --color-primary-light: #3388FF;
  --color-primary-dark: #0044CC;
  --color-accent: #00D4FF;
  --color-purple: #7B61FF;
  --color-success: #00FF88;
  --color-warning: #FFB800;
  --color-danger: #FF4757;

  --color-bg: #06060f;
  --color-bg-card: #0d0d1a;
  --color-bg-elevated: #14142b;
  --color-bg-hover: #1a1a3e;
  --color-border: #1e1e3a;
  --color-border-light: #2a2a50;

  --color-text: #ffffff;
  --color-text-secondary: #b4b4d0;
  --color-text-muted: #6e6e8a;

  --font-display: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 96px;

  --shadow-sm: 0 2px 8px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.5);
  --shadow-glow: 0 0 40px rgba(0,102,255,0.15);
  --shadow-glow-accent: 0 0 40px rgba(0,212,255,0.15);

  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 400ms ease;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
input, textarea, select { font-family: inherit; }

/* Utility */
.container { max-width: 1200px; margin: 0 auto; padding: 0 var(--space-lg); }
.text-gradient {
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.text-gradient-purple {
  background: linear-gradient(135deg, var(--color-accent), var(--color-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 12px 28px;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 15px;
  transition: all var(--transition-normal);
  border: none;
  cursor: pointer;
  white-space: nowrap;
}
.btn--primary {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  color: #fff;
  box-shadow: 0 4px 20px rgba(0,102,255,0.3);
}
.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 30px rgba(0,102,255,0.5);
}
.btn--ghost {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border-light);
}
.btn--ghost:hover {
  background: var(--color-bg-elevated);
  border-color: var(--color-primary);
}
.btn--sm { padding: 8px 20px; font-size: 14px; }
.btn--lg { padding: 16px 36px; font-size: 17px; }

/* Flash messages */
.flash {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 10000;
  padding: 14px 24px;
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 500;
  animation: flashIn 0.3s ease;
  max-width: 400px;
}
.flash--notice { background: var(--color-primary); color: #fff; }
.flash--alert { background: var(--color-danger); color: #fff; }
@keyframes flashIn { from { opacity: 0; transform: translateX(20px); } to { opacity: 1; transform: translateX(0); } }
@keyframes flashOut { from { opacity: 1; } to { opacity: 0; transform: translateY(-10px); } }

/* Navbar (non-landing) */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(6,6,15,0.9);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border);
}
.navbar {
  max-width: 1200px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.navbar__logo { font-size: 20px; font-weight: 800; color: var(--color-primary); }
.navbar__links { display: flex; align-items: center; gap: 16px; }
.navbar__link { font-size: 14px; color: var(--color-text-secondary); transition: color var(--transition-fast); }
.navbar__link:hover { color: var(--color-text); }