/**
 * Diachronica Design System
 * Professional, textual aesthetic with cream tones
 *
 * Light theme only - optimized for readability and scholarly use
 */

/* ========================================
   COLOR TOKENS - Cream/Professional Palette
   ======================================== */

:root {
  /* Backgrounds - Warm cream paper tones */
  --color-background: #FFFDF8;              /* Warm cream */
  --color-surface: #FFFFFF;                 /* Pure white for cards */
  --color-surface-raised: #FFFEF9;          /* Slightly elevated */
  --color-surface-sunken: #FAF8F3;          /* Recessed/muted areas */

  /* Primary - Deep scholarly brown */
  --color-primary: #3D3028;                 /* Deep warm brown */
  --color-primary-hover: #4A3B31;           /* Lighter on hover */
  --color-primary-active: #2F251E;          /* Darker on active */

  /* Accent - Refined warm tones */
  --color-accent: #8B5A2B;                  /* Saddle brown */
  --color-accent-hover: #9A6633;
  --color-accent-light: #C4956A;            /* Soft terracotta */
  --color-accent-muted: #D4C4B0;            /* Muted warm */

  /* Text - Optimized for readability */
  --color-text: #2C2419;                    /* Near black, warm undertone */
  --color-text-secondary: #5C4D3D;          /* Secondary text */
  --color-text-muted: #8A7B6A;              /* Muted/captions */
  --color-text-inverse: #FFFDF8;            /* Light text on dark */

  /* Borders - Subtle, professional */
  --color-border: #E5DED4;                  /* Light warm border */
  --color-border-strong: #C9BFB0;           /* Emphasized border */
  --color-border-subtle: #F0EBE3;           /* Very subtle */

  /* Semantic Colors */
  --color-success: #4A7C59;                 /* Forest green */
  --color-success-bg: #F0F5F1;
  --color-warning: #B5872A;                 /* Amber */
  --color-warning-bg: #FBF6EC;
  --color-error: #9E3A3A;                   /* Deep red */
  --color-error-bg: #FCF3F3;
  --color-info: #4A6B8A;                    /* Slate blue */
  --color-info-bg: #F3F6F9;

  /* Language Family Colors (for etymology) */
  --color-germanic: #C4956A;                /* Terracotta */
  --color-romance: #9E3A3A;                 /* Deep red */
  --color-hellenic: #4A6B8A;                /* Slate blue */
  --color-slavic: #4A7C59;                  /* Forest green */
  --color-celtic: #5A7C7A;                  /* Teal */
  --color-pie: #3D3028;                     /* Deep brown */
  --color-semitic: #B5872A;                 /* Amber */
  --color-sino: #8B4A4A;                    /* Deep rose */

  /* Chart Colors */
  --chart-1: #8B5A2B;                       /* Primary brown */
  --chart-2: #C4956A;                       /* Terracotta */
  --chart-3: #9E3A3A;                       /* Red */
  --chart-4: #4A6B8A;                       /* Blue */
  --chart-5: #4A7C59;                       /* Green */
}

/* ========================================
   TYPOGRAPHY - Scholarly, Readable
   ======================================== */

:root {
  /* Font Families */
  --font-serif: 'Playfair Display', Georgia, 'Times New Roman', serif;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

  /* Font Sizes - Classic modular scale (1.2 ratio) */
  --text-xs: 0.694rem;    /* ~11px */
  --text-sm: 0.833rem;    /* ~13px */
  --text-base: 1rem;      /* 16px */
  --text-lg: 1.2rem;      /* ~19px */
  --text-xl: 1.44rem;     /* ~23px */
  --text-2xl: 1.728rem;   /* ~28px */
  --text-3xl: 2.074rem;   /* ~33px */
  --text-4xl: 2.488rem;   /* ~40px */

  /* Line Heights - Generous for readability */
  --leading-none: 1;
  --leading-tight: 1.2;
  --leading-snug: 1.4;
  --leading-normal: 1.6;
  --leading-relaxed: 1.75;
  --leading-loose: 2;

  /* Font Weights */
  --font-light: 300;
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;

  /* Letter Spacing */
  --tracking-tighter: -0.03em;
  --tracking-tight: -0.015em;
  --tracking-normal: 0;
  --tracking-wide: 0.015em;
  --tracking-wider: 0.03em;
  --tracking-widest: 0.06em;
}

/* ========================================
   SPACING - Comfortable, Airy
   ======================================== */

:root {
  --space-0: 0;
  --space-px: 1px;
  --space-0.5: 0.125rem;  /* 2px */
  --space-1: 0.25rem;     /* 4px */
  --space-1.5: 0.375rem;  /* 6px */
  --space-2: 0.5rem;      /* 8px */
  --space-2.5: 0.625rem;  /* 10px */
  --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 */
  --space-16: 4rem;       /* 64px */
  --space-20: 5rem;       /* 80px */
  --space-24: 6rem;       /* 96px */
}

/* ========================================
   BORDERS & RADIUS - Minimal, Editorial
   ======================================== */

:root {
  --radius-none: 0;
  --radius-sm: 2px;
  --radius-md: 3px;
  --radius-lg: 4px;
  --radius-xl: 6px;
  --radius-2xl: 8px;
  --radius-full: 9999px;

  --border-thin: 1px;
  --border-medium: 2px;
  --border-thick: 3px;
}

/* ========================================
   SHADOWS - Subtle, Barely There
   ======================================== */

:root {
  --shadow-sm: 0 1px 2px rgba(44, 36, 25, 0.04);
  --shadow-md: 0 2px 4px rgba(44, 36, 25, 0.06);
  --shadow-lg: 0 4px 8px rgba(44, 36, 25, 0.08);
  --shadow-xl: 0 8px 16px rgba(44, 36, 25, 0.08);
  --shadow-inner: inset 0 1px 2px rgba(44, 36, 25, 0.04);
  --shadow-none: none;
}

/* ========================================
   TRANSITIONS
   ======================================== */

:root {
  --duration-fast: 120ms;
  --duration-normal: 200ms;
  --duration-slow: 300ms;

  --ease-linear: linear;
  --ease-in: cubic-bezier(0.4, 0, 1, 1);
  --ease-out: cubic-bezier(0, 0, 0.2, 1);
  --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
}

/* ========================================
   Z-INDEX SCALE
   ======================================== */

:root {
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
}

/* ========================================
   BASE STYLES
   ======================================== */

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-text);
  background-color: var(--color-background);
}

/* ========================================
   TYPOGRAPHY CLASSES
   ======================================== */

.heading-1 {
  font-family: var(--font-serif);
  font-size: var(--text-4xl);
  font-weight: var(--font-bold);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
  color: var(--color-text);
  margin: 0 0 var(--space-6);
}

.heading-2 {
  font-family: var(--font-serif);
  font-size: var(--text-3xl);
  font-weight: var(--font-bold);
  line-height: var(--leading-tight);
  color: var(--color-text);
  margin: 0 0 var(--space-5);
}

.heading-3 {
  font-family: var(--font-serif);
  font-size: var(--text-2xl);
  font-weight: var(--font-semibold);
  line-height: var(--leading-snug);
  color: var(--color-text);
  margin: 0 0 var(--space-4);
}

.heading-4 {
  font-family: var(--font-sans);
  font-size: var(--text-xl);
  font-weight: var(--font-semibold);
  line-height: var(--leading-snug);
  color: var(--color-text);
  margin: 0 0 var(--space-3);
}

.body-large {
  font-size: var(--text-lg);
  line-height: var(--leading-relaxed);
}

.body-small {
  font-size: var(--text-sm);
  line-height: var(--leading-normal);
}

.caption {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  line-height: var(--leading-normal);
}

.mono {
  font-family: var(--font-mono);
}

/* Links */
a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--duration-fast) var(--ease-in-out);
}

a:hover {
  color: var(--color-accent-hover);
  text-decoration: underline;
}

/* ========================================
   COMPONENT CLASSES
   ======================================== */

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  line-height: var(--leading-tight);
  border-radius: var(--radius-md);
  border: var(--border-thin) solid transparent;
  cursor: pointer;
  transition: all var(--duration-fast) var(--ease-in-out);
  text-decoration: none;
}

.btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.btn-primary {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
  border-color: var(--color-primary);
}

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

.btn-secondary {
  background-color: transparent;
  color: var(--color-primary);
  border-color: var(--color-border-strong);
}

.btn-secondary:hover {
  background-color: var(--color-surface-sunken);
  border-color: var(--color-primary);
}

/* Inputs */
.input {
  width: 100%;
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-text);
  background-color: var(--color-surface);
  border: var(--border-thin) solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--duration-fast) var(--ease-in-out);
}

.input:focus {
  outline: none;
  border-color: var(--color-accent);
}

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

/* Cards - Minimal, border-focused */
.card {
  background-color: var(--color-surface);
  border: var(--border-thin) solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
}

.card-elevated {
  background-color: var(--color-surface);
  border: var(--border-thin) solid var(--color-border-subtle);
  box-shadow: var(--shadow-sm);
}

/* KWIC Display (Corpus-specific) */
.kwic-container {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
}

.kwic-line {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-bottom: var(--border-thin) solid var(--color-border-subtle);
  transition: background-color var(--duration-fast) var(--ease-in-out);
}

.kwic-line:hover {
  background-color: var(--color-surface-sunken);
}

.kwic-left {
  text-align: right;
  color: var(--color-text-secondary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.kwic-keyword {
  font-weight: var(--font-semibold);
  color: var(--color-accent);
  text-align: center;
  padding: 0 var(--space-2);
  background-color: rgba(196, 149, 106, 0.15);
  border-radius: var(--radius-sm);
}

.kwic-right {
  text-align: left;
  color: var(--color-text-secondary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* Etymology Language Tags */
.lang-tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-0.5) var(--space-2);
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  border-radius: var(--radius-sm);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
}

.lang-tag-germanic { background-color: var(--color-germanic); color: var(--color-primary); }
.lang-tag-romance { background-color: var(--color-romance); color: white; }
.lang-tag-hellenic { background-color: var(--color-hellenic); color: white; }
.lang-tag-slavic { background-color: var(--color-slavic); color: white; }
.lang-tag-celtic { background-color: var(--color-celtic); color: white; }
.lang-tag-pie { background-color: var(--color-pie); color: white; }
.lang-tag-semitic { background-color: var(--color-semitic); color: white; }
.lang-tag-sino { background-color: var(--color-sino); color: white; }

/* ========================================
   LAYOUT UTILITIES
   ======================================== */

.container {
  width: 100%;
  max-width: 1100px;
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-4);
  padding-right: var(--space-4);
}

@media (min-width: 640px) {
  .container {
    padding-left: var(--space-6);
    padding-right: var(--space-6);
  }
}

@media (min-width: 1024px) {
  .container {
    padding-left: var(--space-8);
    padding-right: var(--space-8);
  }
}

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }

/* ========================================
   ACCESSIBILITY
   ======================================== */

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

.focus-visible:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* Skip Link — defined in nav.css (single source of truth) */

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Text Size Scaling (controlled by JS) */
html[data-text-size="small"] { font-size: 14px; }
html[data-text-size="normal"] { font-size: 16px; }
html[data-text-size="large"] { font-size: 18px; }
html[data-text-size="xlarge"] { font-size: 20px; }

/* ========================================
   FOOTER
   ======================================== */

.site-footer {
  margin-top: auto;
  padding: var(--space-8) var(--space-4);
  background-color: var(--color-surface-sunken);
  border-top: var(--border-thin) solid var(--color-border);
}

.footer-text {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-align: center;
  margin: 0;
}

.footer-text a {
  color: var(--color-accent);
  text-decoration: none;
}

.footer-text a:hover {
  text-decoration: underline;
}

/* ========================================
   PRINT STYLES
   ======================================== */

@media print {
  body {
    background-color: white;
    color: black;
  }

  .no-print {
    display: none !important;
  }

  .card {
    box-shadow: none;
    border: 1px solid #ddd;
  }

  a[href]::after {
    content: " (" attr(href) ")";
    font-size: var(--text-xs);
  }

  .site-footer {
    background: white;
    border-top: 1px solid #ddd;
  }
}