/* base.css — CSS reset, typography, layout primitives, buttons */

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition: background 0.25s, color 0.25s;
  padding-top: var(--nav-h);
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: 96px 0;
}

h2 {
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  text-align: center;
  font-weight: 700;
  margin-bottom: 12px;
}

.section-subtitle {
  text-align: center;
  color: var(--text-muted);
  margin-bottom: 56px;
  font-size: 1.1rem;
}

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

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

kbd {
  display: inline-block;
  padding: 2px 7px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.82em;
  background: var(--bg-alt);
  font-family: monospace;
}

.hidden {
  display: none !important;
}

/* ── Buttons ─────────────────────────────────────────────────────────────── */

.btn-primary {
  display: inline-block;
  padding: 12px 24px;
  background: var(--primary);
  color: #fff;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  transition: background 0.15s, transform 0.15s;
  cursor: pointer;
  border: none;
  font-family: inherit;
  text-align: center;
}

.btn-primary:hover {
  background: var(--primary-h);
  transform: translateY(-1px);
}

.btn-primary.btn-lg {
  padding: 14px 32px;
  font-size: 1rem;
}

.btn-ghost {
  display: inline-block;
  padding: 12px 24px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-weight: 500;
  background: transparent;
  transition: border-color 0.15s, color 0.15s;
  cursor: pointer;
  font-family: inherit;
  font-size: inherit;
  text-align: center;
}

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

.btn-ghost.btn-lg {
  padding: 14px 32px;
  font-size: 1rem;
}

.btn-icon {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1.5px solid var(--border);
  color: var(--text);
  font-size: 1rem;
  background: transparent;
  transition: border-color 0.15s, color 0.15s;
  cursor: pointer;
  font-family: inherit;
}

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

.btn-danger {
  display: inline-block;
  padding: 12px 24px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-weight: 500;
  background: transparent;
  transition: border-color 0.15s, color 0.15s;
  cursor: pointer;
  font-family: inherit;
  font-size: inherit;
  text-align: center;
}

.btn-danger:hover {
  border-color: #e74c3c;
  color: #e74c3c;
}