/* =============================================
   base.css - Design Tokens & Reset
   Java Interview Questions Reader
   ============================================= */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+TC:wght@300;400;500;700&display=swap');

/* --- CSS Variables (Design Tokens) --- */
:root {
  /* Colors - Light Theme */
  --color-bg-primary:       #ffffff;
  --color-bg-secondary:     #f6f8fa;
  --color-bg-tertiary:      #eef0f3;
  --color-bg-card:          #ffffff;
  --color-bg-hover:         #f0f2f5;

  /* Accent Colors */
  --color-accent-orange:    #ea6f0a;
  --color-accent-orange-dim: rgba(234,111,10,0.10);
  --color-accent-blue:      #2563eb;
  --color-accent-blue-dim:  rgba(37,99,235,0.09);
  --color-accent-green:     #059669;
  --color-accent-green-dim: rgba(5,150,105,0.10);
  --color-accent-purple:    #7c3aed;
  --color-accent-yellow:    #d97706;
  --color-accent-red:       #dc2626;

  /* Text Colors */
  --color-text-primary:     #111827;
  --color-text-secondary:   #374151;
  --color-text-muted:       #9ca3af;
  --color-text-accent:      #ea6f0a;

  /* Border */
  --color-border:           rgba(0,0,0,0.10);
  --color-border-accent:    rgba(234,111,10,0.4);

  /* Typography */
  --font-body:              'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono:              'JetBrains Mono', 'Fira Code', monospace;

  --text-xs:    0.75rem;    /* 12px */
  --text-sm:    0.875rem;   /* 14px */
  --text-base:  1rem;       /* 16px */
  --text-lg:    1.125rem;   /* 18px */
  --text-xl:    1.25rem;    /* 20px */
  --text-2xl:   1.5rem;     /* 24px */
  --text-3xl:   1.875rem;   /* 30px */

  --font-light:   300;
  --font-normal:  400;
  --font-medium:  500;
  --font-semi:    600;
  --font-bold:    700;

  --leading-tight:  1.25;
  --leading-normal: 1.6;
  --leading-loose:  1.8;

  /* Spacing */
  --space-1:   0.25rem;   /* 4px */
  --space-2:   0.5rem;    /* 8px */
  --space-3:   0.75rem;   /* 12px */
  --space-4:   1rem;      /* 16px */
  --space-5:   1.25rem;   /* 20px */
  --space-6:   1.5rem;    /* 24px */
  --space-8:   2rem;      /* 32px */
  --space-10:  2.5rem;    /* 40px */
  --space-12:  3rem;      /* 48px */

  /* Border Radius */
  --radius-sm:  6px;
  --radius-md:  10px;
  --radius-lg:  14px;
  --radius-xl:  20px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm:   0 1px 3px rgba(0,0,0,0.08);
  --shadow-md:   0 4px 12px rgba(0,0,0,0.10);
  --shadow-lg:   0 8px 32px rgba(0,0,0,0.12);
  --shadow-glow: 0 0 20px rgba(234,111,10,0.15);

  /* Transitions */
  --transition-fast:   150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow:   400ms ease;

  /* Layout */
  --max-width:    430px;
  --nav-height:   56px;
  --bottom-bar:   64px;

  /* Z-index */
  --z-base:     0;
  --z-dropdown: 100;
  --z-sticky:   200;
  --z-overlay:  300;
  --z-modal:    400;
  --z-toast:    500;
}

/* --- Reset --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: 'Noto Sans TC', var(--font-body);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  min-height: 100vh;
  min-height: 100dvh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- Typography Base --- */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-semi);
  line-height: var(--leading-tight);
  color: var(--color-text-primary);
}

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

a:hover { color: var(--color-accent-orange); }

p {
  line-height: var(--leading-loose);
  color: var(--color-text-secondary);
}

code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: #fef3e8;
  border: 1px solid rgba(234,111,10,0.2);
  border-radius: var(--radius-sm);
  padding: 0.1em 0.35em;
  color: var(--color-accent-orange);
}

pre {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  background: #f6f8fa;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  overflow-x: auto;
  line-height: 1.6;
  color: #24292e;
}

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

ul, ol { padding-left: var(--space-5); }

li {
  line-height: var(--leading-loose);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-1);
}

blockquote {
  border-left: 3px solid var(--color-accent-orange);
  padding: var(--space-3) var(--space-4);
  background: var(--color-accent-orange-dim);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: var(--space-4) 0;
  font-style: italic;
  color: var(--color-text-secondary);
}

/* --- Tables --- */
table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
  margin: var(--space-4) 0;
  border-radius: var(--radius-md);
  overflow: hidden;
}

th {
  background: var(--color-bg-tertiary);
  color: var(--color-text-primary);
  font-weight: var(--font-semi);
  text-align: left;
  padding: var(--space-2) var(--space-3);
  border-bottom: 1px solid var(--color-border);
  border-right: 1px solid var(--color-border);
  font-size: var(--text-xs);
  letter-spacing: 0.03em;
}

td {
  padding: var(--space-2) var(--space-3);
  border-bottom: 1px solid var(--color-border);
  border-right: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  vertical-align: top;
  font-size: var(--text-sm);
}

th:last-child, td:last-child { border-right: none; }
tr:last-child td { border-bottom: none; }
tr:hover td { background: var(--color-bg-hover); }

/* --- Scrollbar --- */
::-webkit-scrollbar { width: 4px; height: 4px; }
::-webkit-scrollbar-track { background: #f0f2f5; }
::-webkit-scrollbar-thumb {
  background: #d1d5db;
  border-radius: var(--radius-full);
}
::-webkit-scrollbar-thumb:hover { background: var(--color-accent-orange); }

/* --- Selection --- */
::selection {
  background: var(--color-accent-orange-dim);
  color: var(--color-accent-orange);
}

/* --- Utility Classes --- */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}

.text-accent   { color: var(--color-accent-orange); }
.text-muted    { color: var(--color-text-muted); }
.text-secondary { color: var(--color-text-secondary); }
.text-bold     { font-weight: var(--font-bold); }
.text-mono     { font-family: var(--font-mono); }

.flex          { display: flex; }
.flex-col      { flex-direction: column; }
.items-center  { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-2         { gap: var(--space-2); }
.gap-3         { gap: var(--space-3); }
.gap-4         { gap: var(--space-4); }

.w-full  { width: 100%; }
.h-full  { height: 100%; }
.hidden  { display: none !important; }
.visible { display: block !important; }