/* ==========================================================================
   BillApp — base.css
   Reset, design tokens (CSS variables), and typography. Mobile-first.
   ========================================================================== */

:root {
  /* Brand palette */
  --color-primary: #14532d;
  --color-primary-dark: #0d3a1f;
  --color-primary-light: #1e7a42;
  --color-accent: #d68910;
  --color-accent-dark: #b3720c;

  /* Neutrals */
  --color-bg: #f4f5f7;
  --color-surface: #ffffff;
  --color-surface-alt: #f8fafc;
  --color-text: #1c2733;
  --color-text-muted: #64748b;
  --color-text-faint: #94a3b8;
  --color-border: #e2e8f0;
  --color-border-strong: #cbd5e1;

  /* Semantic */
  --color-success: #16a34a;
  --color-danger: #dc2626;
  --color-warning: #d97706;

  /* Elevation */
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06), 0 1px 1px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.10), 0 2px 4px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 12px 32px rgba(15, 23, 42, 0.16), 0 4px 8px rgba(15, 23, 42, 0.08);

  /* Radius */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-pill: 999px;

  /* Spacing scale */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;

  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.375rem;
  --font-size-2xl: 1.75rem;

  /* Layout */
  --header-height: 56px;
  --bottom-nav-height: 64px;
  --safe-bottom: env(safe-area-inset-bottom, 0px);
  --safe-top: env(safe-area-inset-top, 0px);

  /* Motion */
  --ease-standard: cubic-bezier(0.2, 0, 0, 1);
  --duration-fast: 120ms;
  --duration-base: 200ms;
  --duration-slow: 320ms;

  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #10151b;
    --color-surface: #1a2129;
    --color-surface-alt: #212a33;
    --color-text: #e7ebef;
    --color-text-muted: #9aa7b5;
    --color-text-faint: #6b7885;
    --color-border: #2b3540;
    --color-border-strong: #3a4552;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.35);
    --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.45);
    color-scheme: dark;
  }
}

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

html,
body {
  height: 100%;
}

body {
  margin: 0;
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overscroll-behavior-y: none;
}

h1, h2, h3, h4, p, figure {
  margin: 0;
}

ul, ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

button {
  font-family: inherit;
  color: inherit;
}

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

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

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

button,
[role='button'],
input,
select,
textarea {
  -webkit-tap-highlight-color: transparent;
}

/* Utility classes */
.u-flex { display: flex; }
.u-flex-col { display: flex; flex-direction: column; }
.u-items-center { align-items: center; }
.u-justify-between { justify-content: space-between; }
.u-gap-1 { gap: var(--space-1); }
.u-gap-2 { gap: var(--space-2); }
.u-gap-3 { gap: var(--space-3); }
.u-gap-4 { gap: var(--space-4); }
.u-text-muted { color: var(--color-text-muted); }
.u-text-faint { color: var(--color-text-faint); }
.u-text-sm { font-size: var(--font-size-sm); }
.u-text-xs { font-size: var(--font-size-xs); }
.u-font-medium { font-weight: 500; }
.u-font-semibold { font-weight: 600; }
.u-font-bold { font-weight: 700; }
.u-w-full { width: 100%; }
.u-hidden { display: none !important; }
.u-text-right { text-align: right; }
.u-text-center { text-align: center; }
.u-mt-1 { margin-top: var(--space-1); }
.u-mt-2 { margin-top: var(--space-2); }
.u-mt-4 { margin-top: var(--space-4); }

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}