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

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  transition: background var(--transition-base), color var(--transition-base);
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border-hover); border-radius: var(--radius-full); }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* Typography */
h1 { font-size: 2rem; font-weight: 700; letter-spacing: -0.02em; }
h2 { font-size: 1.5rem; font-weight: 600; letter-spacing: -0.01em; }
h3 { font-size: 1.125rem; font-weight: 600; }
h4 { font-size: 0.9375rem; font-weight: 600; }
p  { color: var(--text-secondary); }

a { color: var(--accent); text-decoration: none; transition: color var(--transition-fast); }
a:hover { color: var(--accent-hover); }

button {
  font-family: var(--font-sans);
  cursor: pointer;
  border: none;
  outline: none;
  transition: all var(--transition-fast);
}

input, select, textarea {
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  color: var(--text-primary);
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 10px 14px;
  width: 100%;
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

input:focus, select:focus, textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

input::placeholder, textarea::placeholder { color: var(--text-muted); }

select option { background: var(--bg-secondary); color: var(--text-primary); }

label {
  display: block;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

/* Utility */
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }
.text-muted { color: var(--text-muted); }
.text-secondary { color: var(--text-secondary); }
.text-accent { color: var(--accent); }
.text-income { color: var(--color-income); }
.text-expense { color: var(--color-expense); }
.text-sm { font-size: 0.8125rem; }
.text-xs { font-size: 0.75rem; }
.font-mono { font-family: var(--font-mono); }
.truncate { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.hidden { display: none !important; }
.w-full { width: 100%; }

@media (max-width: 600px) {
  h1 { font-size: 1.5rem; }
  h2 { font-size: 1.25rem; }
  h3 { font-size: 1rem; }
  input, select, textarea { padding: 8px 12px; font-size: 0.9rem; }
}