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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  line-height: var(--line-height-normal);
  color: var(--text-primary);
  background: var(--bg-body);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* Background decoration */
body::before {
  content: '';
  position: fixed;
  top: -50%;
  right: -30%;
  width: 80vw;
  height: 80vw;
  max-width: 900px;
  max-height: 900px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.06) 0%, transparent 70%);
  pointer-events: none;
  z-index: -1;
}

body::after {
  content: '';
  position: fixed;
  bottom: -40%;
  left: -20%;
  width: 70vw;
  height: 70vw;
  max-width: 800px;
  max-height: 800px;
  background: radial-gradient(circle, rgba(124, 58, 237, 0.05) 0%, transparent 70%);
  pointer-events: none;
  z-index: -1;
}

img,
svg,
video {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input,
select,
textarea {
  font-family: inherit;
  font-size: inherit;
}

ul,
ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: var(--text-primary);
}

h1 {
  font-size: var(--font-size-4xl);
  font-weight: var(--font-weight-extrabold);
  letter-spacing: -0.025em;
}

h2 {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  letter-spacing: -0.015em;
}

h3 {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-semibold);
}

p {
  color: var(--text-secondary);
  line-height: var(--line-height-relaxed);
}

/* ===== Layout Utilities ===== */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.container--narrow {
  max-width: var(--container-narrow);
}

.section {
  padding: var(--space-16) 0;
}

/* ===== Animations ===== */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInScale {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

@keyframes progressBar {
  from { width: 0%; }
  to { width: 100%; }
}

.animate-fade-in {
  animation: fadeIn var(--transition-base) both;
}

.animate-fade-in-up {
  animation: fadeInUp 0.5s cubic-bezier(0.16, 1, 0.3, 1) both;
}

.animate-fade-in-scale {
  animation: fadeInScale 0.4s cubic-bezier(0.16, 1, 0.3, 1) both;
}

/* Stagger children */
.stagger > *:nth-child(1) { animation-delay: 0ms; }
.stagger > *:nth-child(2) { animation-delay: 80ms; }
.stagger > *:nth-child(3) { animation-delay: 160ms; }
.stagger > *:nth-child(4) { animation-delay: 240ms; }
.stagger > *:nth-child(5) { animation-delay: 320ms; }
.stagger > *:nth-child(6) { animation-delay: 400ms; }

/* ===== Scrollbar ===== */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-gray-100);
}

::-webkit-scrollbar-thumb {
  background: var(--color-gray-300);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-gray-400);
}

/* ===== Selection ===== */
::selection {
  background: var(--color-primary-200);
  color: var(--color-primary-900);
}

/* ===== Responsive Text ===== */
@media (max-width: 768px) {
  h1 { font-size: var(--font-size-3xl); }
  h2 { font-size: var(--font-size-xl); }
  h3 { font-size: var(--font-size-lg); }

  .container {
    padding: 0 var(--space-4);
  }

  .section {
    padding: var(--space-10) 0;
  }
}