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

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

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--gray-900);
  background: var(--surface);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

ul, ol {
  list-style: none;
}

button, input, textarea, select {
  font: inherit;
}

/* Typography */
h1, h2, h3, h4 {
  line-height: 1.2;
  font-weight: 700;
  letter-spacing: -0.02em;
}

h1 { font-size: var(--text-hero); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-xl); }

p {
  color: var(--gray-600);
  line-height: 1.7;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: background var(--transition), color var(--transition),
              box-shadow var(--transition), transform var(--transition);
  white-space: nowrap;
  text-decoration: none;
}

.btn:active { transform: translateY(1px); }

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

.btn-primary:hover {
  background: var(--accent-hover);
  box-shadow: 0 4px 12px rgba(29,78,216,.35);
}

.btn-primary:disabled {
  background: var(--gray-400);
  cursor: not-allowed;
  box-shadow: none;
  transform: none;
}

.btn-ghost {
  background: transparent;
  color: var(--gray-600);
  border: 1px solid var(--gray-200);
}

.btn-ghost:hover {
  background: var(--gray-50);
  color: var(--gray-900);
}

.btn-link {
  background: none;
  border: none;
  padding: 0;
  color: var(--accent);
  font-size: inherit;
  font-weight: 500;
  cursor: pointer;
}

.btn-link:hover { text-decoration: underline; }

/* Focus */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}