/* ==========================================================================
   base.css — reset, variáveis de design, tipografia
   Portal Python — Introdução à Lógica e Programação
   ========================================================================== */

:root {
  /* Paleta — inspirada em Python (azul/amarelo) com tom educacional moderno */
  --color-bg: #f6f8fb;
  --color-bg-alt: #eef2f8;
  --color-surface: #ffffff;
  --color-surface-raised: #ffffff;

  --color-text: #1a2233;
  --color-text-muted: #5b6577;
  --color-text-faint: #8892a3;

  --color-primary: #2f6690;
  --color-primary-dark: #204a6b;
  --color-primary-light: #eaf2f8;
  --color-primary-contrast: #ffffff;

  --color-accent: #f2b705;
  --color-accent-dark: #cf9c00;
  --color-accent-contrast: #1a2233;

  --color-border: #e0e5ee;
  --color-border-strong: #c7cfdd;

  --color-success: #2a9d63;
  --color-success-bg: #eaf7f0;
  --color-warning: #d97a1f;
  --color-warning-bg: #fdf1e4;
  --color-info: #2f6690;
  --color-info-bg: #eaf2f8;
  --color-tip: #7b3fb5;
  --color-tip-bg: #f4edfb;

  --color-code-bg: #1c2333;
  --color-code-bg-alt: #232c40;
  --color-code-text: #e7ecf7;
  --color-code-border: #303c56;
  --color-code-comment: #8a94ab;
  --color-code-keyword: #7fb3e8;
  --color-code-string: #f2c46d;
  --color-code-number: #d99ee0;
  --color-code-function: #8fd6a8;
  --color-code-builtin: #f28fad;
  --color-code-operator: #e7ecf7;

  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;

  --shadow-sm: 0 1px 2px rgba(26, 34, 51, 0.06), 0 1px 1px rgba(26, 34, 51, 0.04);
  --shadow-md: 0 4px 16px rgba(26, 34, 51, 0.08), 0 2px 6px rgba(26, 34, 51, 0.05);
  --shadow-lg: 0 12px 32px rgba(26, 34, 51, 0.12), 0 4px 10px rgba(26, 34, 51, 0.06);

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;
  --space-8: 64px;

  --container-width: 1100px;
  --sidebar-width: 280px;

  --transition-fast: 150ms ease;
  --transition-base: 220ms ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--space-3) 0;
  line-height: 1.25;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--color-text);
}

h1 { font-size: clamp(1.9rem, 1.5rem + 1.6vw, 2.6rem); }
h2 { font-size: clamp(1.5rem, 1.3rem + 0.8vw, 1.9rem); }
h3 { font-size: 1.3rem; }
h4 { font-size: 1.1rem; }

p {
  margin: 0 0 var(--space-4) 0;
  color: var(--color-text);
}

a {
  color: var(--color-primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

ul, ol {
  margin: 0 0 var(--space-4) 0;
  padding-left: 1.4em;
}

li {
  margin-bottom: var(--space-2);
}

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

button {
  font-family: inherit;
}

code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  padding: 0.1em 0.4em;
  border-radius: 5px;
  color: var(--color-primary-dark);
  word-break: break-word;
}

pre code {
  border: none;
  background: none;
  padding: 0;
  color: inherit;
}

.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--space-5);
}

/* Foco visível e acessível para navegação por teclado */
a:focus-visible,
button:focus-visible,
[tabindex]:focus-visible,
input:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: 4px;
}

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

.skip-link {
  position: absolute;
  left: var(--space-3);
  top: -60px;
  background: var(--color-primary);
  color: #fff;
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-sm);
  z-index: 1000;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--space-3);
}

/* Scrollbar sutil (WebKit) */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--color-border-strong);
  border-radius: 8px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-faint);
}

@media (max-width: 640px) {
  .container {
    padding: 0 var(--space-4);
  }
}