/* ============================================================
   ASTRONOMY SITE — MASTER STYLESHEET
   Dark theme · Night-vision optimized · Academic / Professional
   ============================================================

   TABLE OF CONTENTS
   -----------------
   1.  CSS Custom Properties (Design Tokens)
   2.  CSS Reset & Box Model
   3.  Base Typography
   4.  Color Utility Classes
   5.  Layout & Container
   6.  Navigation
   7.  Headings & Section Titles
   8.  Body Text & Prose
   9.  Links & Interactive Elements
   10. Buttons
   11. Tables & Data Display
   12. Cards & Panels
   13. Code & Preformatted Text
   14. Images & Figures
   15. Forms & Inputs
   16. Badges & Tags
   17. Alerts & Callouts
   18. Footer
   19. Utility Classes
   20. Responsive Breakpoints

   NIGHT-VISION PHILOSOPHY
   -----------------------
   Dark-adapted eyes are most sensitive to green wavelengths
   (~555 nm) and severely disrupted by blue/white light.
   Red light (~700 nm) preserves night vision best.
   Amber/gold is the next safest option.
   This theme defaults to:
     - Very dark gray backgrounds (not pure black — easier on eyes)
     - Low-saturation, dimmed text (not pure white)
     - Deep amber as the primary accent (warm, readable, safe)
     - A secondary deep red accent for critical highlights
     - All blues/teals are AVOIDED as primary colors
   ============================================================ */


/* ============================================================
   1. CSS CUSTOM PROPERTIES (DESIGN TOKENS)
   ============================================================ */

:root {

  /* --- Backgrounds ---
     Layered dark grays create depth without harsh contrast.
     bg-base is the page canvas; bg-surface is for cards/panels;
     bg-elevated is for modals, popovers, top-most elements. */
  --bg-base:       #111211;   /* Very dark gray — main page background */
  --bg-surface:    #181A18;   /* Cards, sidebars, panels */
  --bg-elevated:   #202320;   /* Modals, dropdowns, tooltips */
  --bg-subtle:     #252825;   /* Hover states, striped table rows */
  --bg-border:     #2E322E;   /* Borders, dividers, rules */

  /* --- Text ---
     Slightly warm white reduces the harshness of pure #fff on dark
     backgrounds. Muted levels create hierarchy without needing bold
     color, which keeps the overall luminance low at night. */
  --text-primary:   #E8E4D9;  /* Main body text — warm off-white */
  --text-secondary: #A8A49A;  /* Secondary text, captions, metadata */
  --text-muted:     #6B6860;  /* Placeholders, disabled states */
  --text-inverse:   #111211;  /* Text on colored/light backgrounds */

  /* --- Accent: Amber / Gold (Primary) ---
     Amber sits at ~590 nm — warm and relatively safe for dark-adapted
     eyes. Used for interactive elements, links, and key highlights. */
  --accent-amber:        #C8922A;  /* Primary accent — links, active states */
  --accent-amber-light:  #DBA84A;  /* Hover state of amber */
  --accent-amber-dim:    #7A5518;  /* Subtle amber tints, backgrounds */
  --accent-amber-glow:   rgba(200, 146, 42, 0.15); /* Soft glow for focus rings */

  /* --- Accent: Deep Red (Secondary) ---
     Red (~700 nm) is the most night-vision-safe hue. Used sparingly
     for critical highlights, warnings, or active indicators.
     Kept dark/desaturated so it doesn't bloom on screen. */
  --accent-red:        #9E3A2F;  /* Secondary accent — alerts, badges */
  --accent-red-light:  #C04B3E;  /* Hover/emphasis state */
  --accent-red-dim:    #4A1A14;  /* Subtle red tints */

  /* --- Semantic Colors ---
     These map utility meanings (success, warning, etc.) to the
     night-vision palette. Greens are kept muted since they can
     be disruptive to dark-adapted eyes at full saturation. */
  --color-success:  #4A7C59;   /* Muted green */
  --color-warning:  #C8922A;   /* Reuses amber */
  --color-danger:   #9E3A2F;   /* Reuses red */
  --color-info:     #3A6A7A;   /* Muted teal — use only in non-night contexts */

  /* --- Typography ---
     Lora is a serif with strong optical presence at small sizes —
     ideal for headings on dark backgrounds. Source Sans 3 is highly
     legible for body text. Both are available on Google Fonts.
     Fallback stacks ensure the site degrades gracefully. */
  --font-heading:  'Lora', 'Georgia', 'Times New Roman', serif;
  --font-body:     'Source Sans 3', 'Gill Sans', 'Trebuchet MS', sans-serif;
  --font-mono:     'Source Code Pro', 'Courier New', monospace;

  /* --- Type Scale (Major Third — 1.25 ratio) --- */
  --text-xs:   0.64rem;   /*  ~10px */
  --text-sm:   0.8rem;    /*  ~13px */
  --text-base: 1rem;      /*  ~16px */
  --text-md:   1.25rem;   /*  ~20px */
  --text-lg:   1.563rem;  /*  ~25px */
  --text-xl:   1.953rem;  /*  ~31px */
  --text-2xl:  2.441rem;  /*  ~39px */
  --text-3xl:  3.052rem;  /*  ~49px */

  /* --- Font Weights --- */
  --weight-regular: 400;
  --weight-medium:  500;
  --weight-bold:    700;

  /* --- Line Heights --- */
  --leading-tight:  1.25;
  --leading-snug:   1.4;
  --leading-normal: 1.65;
  --leading-loose:  1.85;

  /* --- Letter Spacing --- */
  --tracking-tight:  -0.02em;
  --tracking-normal:  0em;
  --tracking-wide:    0.06em;
  --tracking-widest:  0.12em;

  /* --- Spacing (base-8 scale) --- */
  --space-1:  0.25rem;  /*  4px */
  --space-2:  0.5rem;   /*  8px */
  --space-3:  0.75rem;  /* 12px */
  --space-4:  1rem;     /* 16px */
  --space-5:  1.5rem;   /* 24px */
  --space-6:  2rem;     /* 32px */
  --space-7:  3rem;     /* 48px */
  --space-8:  4rem;     /* 64px */
  --space-9:  6rem;     /* 96px */

  /* --- Layout --- */
  --container-max:   1100px;
  --container-prose:  700px;   /* Optimal reading width for articles */
  --container-narrow: 520px;

  /* --- Border Radius --- */
  --radius-sm:   3px;
  --radius-md:   6px;
  --radius-lg:  12px;
  --radius-full: 9999px;

  /* --- Borders --- */
  --border-default: 1px solid var(--bg-border);
  --border-accent:  1px solid var(--accent-amber-dim);

  /* --- Shadows ---
     Kept very subtle — harsh drop shadows look unnatural on dark UIs. */
  --shadow-sm:  0 1px 3px rgba(0, 0, 0, 0.4);
  --shadow-md:  0 4px 12px rgba(0, 0, 0, 0.5);
  --shadow-lg:  0 8px 30px rgba(0, 0, 0, 0.6);

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

  /* --- Z-Index Scale --- */
  --z-base:    0;
  --z-raised:  10;
  --z-sticky:  100;
  --z-overlay: 200;
  --z-modal:   300;
  --z-toast:   400;
}


/* ============================================================
   2. CSS RESET & BOX MODEL
   ============================================================ */

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

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

body {
  background-color: var(--bg-base);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-regular);
  line-height: var(--leading-normal);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

img, video, svg, canvas {
  display: block;
  max-width: 100%;
  height: auto;
}

input, button, textarea, select {
  font: inherit;
}

p, h1, h2, h3, h4, h5, h6 {
  overflow-wrap: break-word;
}

ul, ol {
  list-style: none;
}

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

hr {
  border: none;
  border-top: var(--border-default);
  margin: var(--space-6) 0;
}


/* ============================================================
   3. BASE TYPOGRAPHY
   ============================================================ */

/* Import Google Fonts — remove if self-hosting */
@import url('https://fonts.googleapis.com/css2?family=Lora:ital,wght@0,400;0,600;0,700;1,400;1,600&family=Source+Code+Pro:wght@400;500&family=Source+Sans+3:ital,wght@0,300;0,400;0,600;1,400&display=swap');


/* ============================================================
   4. COLOR UTILITY CLASSES
   ============================================================ */

.text-primary    { color: var(--text-primary); }
.text-secondary  { color: var(--text-secondary); }
.text-muted      { color: var(--text-muted); }
.text-accent     { color: var(--accent-amber); }
.text-danger     { color: var(--accent-red-light); }
.text-success    { color: var(--color-success); }

.bg-surface      { background-color: var(--bg-surface); }
.bg-elevated     { background-color: var(--bg-elevated); }
.bg-subtle       { background-color: var(--bg-subtle); }


/* ============================================================
   5. LAYOUT & CONTAINER
   ============================================================ */

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

/* Narrower container for reading-heavy pages */
.container--prose {
  max-width: var(--container-prose);
}

/* Tight container for forms, login, etc. */
.container--narrow {
  max-width: var(--container-narrow);
}

/* Standard page section spacing */
.section {
  padding-block: var(--space-8);
}

.section--sm {
  padding-block: var(--space-6);
}

.section--lg {
  padding-block: var(--space-9);
}

/* Simple flex row utility */
.row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-5);
}

/* CSS Grid helper for data-dense pages */
.grid {
  display: grid;
  gap: var(--space-5);
}

.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }


/* ============================================================
   6. NAVIGATION
   ============================================================ */

.nav {
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  background-color: var(--bg-elevated);
  border-bottom: var(--border-default);
  padding-block: var(--space-3);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-5);
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-5);
}

/* Site name / logo */
.nav__brand {
  font-family: var(--font-heading);
  font-size: var(--text-md);
  font-weight: var(--weight-bold);
  color: var(--accent-amber);
  letter-spacing: var(--tracking-tight);
  white-space: nowrap;
}

.nav__brand:hover {
  color: var(--accent-amber-light);
}

/* Nav link list */
.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-5);
  flex-wrap: wrap;
}

.nav__link {
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--text-secondary);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  transition: color var(--transition-fast);
  padding-block: var(--space-1);
  border-bottom: 2px solid transparent;
}

.nav__link:hover,
.nav__link--active {
  color: var(--accent-amber);
  border-bottom-color: var(--accent-amber);
}


/* ============================================================
   7. HEADINGS & SECTION TITLES
   ============================================================ */

h1, h2, h3, h4, h5, h6,
.h1, .h2, .h3, .h4, .h5, .h6 {
  font-family: var(--font-heading);
  font-weight: var(--weight-bold);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
  color: var(--text-primary);
}

h1, .h1 { font-size: var(--text-2xl); margin-bottom: var(--space-5); }
h2, .h2 { font-size: var(--text-xl);  margin-bottom: var(--space-4); }
h3, .h3 { font-size: var(--text-lg);  margin-bottom: var(--space-4); }
h4, .h4 { font-size: var(--text-md);  margin-bottom: var(--space-3); }
h5, .h5 { font-size: var(--text-base); margin-bottom: var(--space-2); }
h6, .h6 { font-size: var(--text-sm);  margin-bottom: var(--space-2); color: var(--text-secondary); }

/* Decorative label above a heading — "ABOUT THE PROJECT" style */
.eyebrow {
  display: block;
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  letter-spacing: var(--tracking-widest);
  text-transform: uppercase;
  color: var(--accent-amber);
  margin-bottom: var(--space-2);
}

/* Subtle amber underline accent on section headings */
.heading--accented {
  display: inline-block;
  padding-bottom: var(--space-2);
  border-bottom: 2px solid var(--accent-amber-dim);
}


/* ============================================================
   8. BODY TEXT & PROSE
   ============================================================ */

/* Use .prose on article/guide wrappers for full editorial styling */
.prose {
  max-width: var(--container-prose);
  color: var(--text-primary);
  line-height: var(--leading-loose);
}

.prose p {
  margin-bottom: var(--space-4);
}

.prose h2,
.prose h3,
.prose h4 {
  margin-top: var(--space-7);
}

.prose ul,
.prose ol {
  margin-bottom: var(--space-4);
  padding-left: var(--space-5);
}

.prose ul { list-style: disc; }
.prose ol { list-style: decimal; }

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

.prose li::marker {
  color: var(--accent-amber);
}

.prose blockquote {
  border-left: 3px solid var(--accent-amber-dim);
  padding-left: var(--space-5);
  margin-block: var(--space-6);
  color: var(--text-secondary);
  font-style: italic;
}

.prose strong {
  font-weight: var(--weight-bold);
  color: var(--text-primary);
}

.prose em {
  font-style: italic;
  color: var(--text-secondary);
}

/* Standalone paragraph helpers */
.lead {
  font-size: var(--text-md);
  color: var(--text-secondary);
  line-height: var(--leading-snug);
  margin-bottom: var(--space-5);
}

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


/* ============================================================
   9. LINKS & INTERACTIVE ELEMENTS
   ============================================================ */

.link,
.prose a {
  color: var(--accent-amber);
  text-decoration: underline;
  text-decoration-color: var(--accent-amber-dim);
  text-underline-offset: 3px;
  transition: color var(--transition-fast),
              text-decoration-color var(--transition-fast);
}

.link:hover,
.prose a:hover {
  color: var(--accent-amber-light);
  text-decoration-color: var(--accent-amber);
}

/* Focus ring — visible for keyboard nav, night-vision safe */
:focus-visible {
  outline: 2px solid var(--accent-amber);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}


/* ============================================================
   10. BUTTONS
   ============================================================ */

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-5);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background-color var(--transition-fast),
              color var(--transition-fast),
              border-color var(--transition-fast),
              box-shadow var(--transition-fast);
}

/* Primary — amber fill */
.btn--primary {
  background-color: var(--accent-amber-dim);
  color: var(--accent-amber-light);
  border-color: var(--accent-amber-dim);
}

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

/* Secondary — outline style */
.btn--secondary {
  background-color: transparent;
  color: var(--accent-amber);
  border-color: var(--accent-amber-dim);
}

.btn--secondary:hover {
  background-color: var(--accent-amber-glow);
  border-color: var(--accent-amber);
}

/* Ghost — minimal */
.btn--ghost {
  background-color: transparent;
  color: var(--text-secondary);
  border-color: var(--bg-border);
}

.btn--ghost:hover {
  background-color: var(--bg-subtle);
  color: var(--text-primary);
}

/* Danger / alert button */
.btn--danger {
  background-color: var(--accent-red-dim);
  color: var(--accent-red-light);
  border-color: var(--accent-red-dim);
}

.btn--danger:hover {
  background-color: var(--accent-red);
  color: var(--text-primary);
}

/* Size variants */
.btn--sm { padding: var(--space-1) var(--space-3); font-size: var(--text-xs); }
.btn--lg { padding: var(--space-3) var(--space-6); font-size: var(--text-base); }

.btn:disabled,
.btn[aria-disabled="true"] {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}


/* ============================================================
   11. TABLES & DATA DISPLAY
   ============================================================ */

/* Wrap tables in .table-wrap for horizontal scroll on mobile */
.table-wrap {
  width: 100%;
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: var(--border-default);
}

table,
.table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
  line-height: var(--leading-snug);
}

thead {
  background-color: var(--bg-elevated);
  border-bottom: 1px solid var(--accent-amber-dim);
}

thead th {
  padding: var(--space-3) var(--space-4);
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  letter-spacing: var(--tracking-widest);
  text-transform: uppercase;
  color: var(--accent-amber);
  text-align: left;
  white-space: nowrap;
}

tbody tr {
  border-bottom: var(--border-default);
  transition: background-color var(--transition-fast);
}

/* Alternating rows — subtle, not jarring at night */
tbody tr:nth-child(even) {
  background-color: var(--bg-subtle);
}

tbody tr:hover {
  background-color: var(--bg-elevated);
}

tbody td {
  padding: var(--space-3) var(--space-4);
  color: var(--text-primary);
  vertical-align: top;
}

/* Numeric columns — monospace for alignment */
td.num,
th.num {
  font-family: var(--font-mono);
  text-align: right;
  letter-spacing: 0.02em;
}

tfoot {
  border-top: 1px solid var(--accent-amber-dim);
  background-color: var(--bg-elevated);
}

tfoot td {
  padding: var(--space-3) var(--space-4);
  color: var(--text-secondary);
  font-size: var(--text-xs);
}


/* ============================================================
   12. CARDS & PANELS
   ============================================================ */

.card {
  background-color: var(--bg-surface);
  border: var(--border-default);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition-base),
              box-shadow var(--transition-base);
}

.card:hover {
  border-color: var(--accent-amber-dim);
  box-shadow: var(--shadow-md);
}

.card__header {
  border-bottom: var(--border-default);
  padding-bottom: var(--space-4);
  margin-bottom: var(--space-4);
}

.card__title {
  font-family: var(--font-heading);
  font-size: var(--text-md);
  color: var(--text-primary);
}

.card__subtitle {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  margin-top: var(--space-1);
}

.card__footer {
  border-top: var(--border-default);
  padding-top: var(--space-4);
  margin-top: var(--space-4);
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

/* Panel — like a card but flush/full-width, for sidebars */
.panel {
  background-color: var(--bg-surface);
  border: var(--border-default);
  border-radius: var(--radius-md);
  padding: var(--space-5);
}


/* ============================================================
   13. CODE & PREFORMATTED TEXT
   ============================================================ */

code,
kbd,
samp {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background-color: var(--bg-elevated);
  color: var(--accent-amber);
  padding: 0.1em 0.35em;
  border-radius: var(--radius-sm);
  border: var(--border-default);
}

pre {
  background-color: var(--bg-elevated);
  border: var(--border-default);
  border-radius: var(--radius-md);
  padding: var(--space-5);
  overflow-x: auto;
  line-height: var(--leading-normal);
  margin-block: var(--space-5);
}

pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: var(--text-sm);
  color: var(--text-primary);
}


/* ============================================================
   14. IMAGES & FIGURES
   ============================================================ */

figure {
  margin-block: var(--space-6);
}

figure img {
  border-radius: var(--radius-md);
  border: var(--border-default);
  width: 100%;
}

figcaption {
  margin-top: var(--space-2);
  font-size: var(--text-sm);
  color: var(--text-muted);
  text-align: center;
  font-style: italic;
}

/* Sky chart / embedded map container */
.sky-embed {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background-color: var(--bg-elevated);
  border: var(--border-default);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.sky-embed iframe,
.sky-embed embed,
.sky-embed object {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: none;
}


/* ============================================================
   15. FORMS & INPUTS
   ============================================================ */

.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

label,
.label {
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--text-secondary);
  letter-spacing: var(--tracking-wide);
}

.input,
input[type="text"],
input[type="email"],
input[type="search"],
input[type="number"],
input[type="date"],
input[type="time"],
textarea,
select {
  width: 100%;
  background-color: var(--bg-elevated);
  color: var(--text-primary);
  border: var(--border-default);
  border-radius: var(--radius-md);
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  transition: border-color var(--transition-fast),
              box-shadow var(--transition-fast);
  appearance: none;
}

.input:hover,
input[type="text"]:hover,
select:hover {
  border-color: var(--accent-amber-dim);
}

.input:focus,
input:focus,
textarea:focus,
select:focus {
  outline: none;
  border-color: var(--accent-amber);
  box-shadow: 0 0 0 3px var(--accent-amber-glow);
}

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

textarea {
  resize: vertical;
  min-height: 120px;
}

select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3E%3Cpath fill='%236B6860' d='M4 6l4 4 4-4'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--space-3) center;
  background-size: 16px;
  padding-right: var(--space-7);
}

.helper-text {
  font-size: var(--text-sm);
  color: var(--text-muted);
}

.error-text {
  font-size: var(--text-sm);
  color: var(--accent-red-light);
}


/* ============================================================
   16. BADGES & TAGS
   ============================================================ */

.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 0.2em 0.6em;
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  border-radius: var(--radius-full);
  border: 1px solid transparent;
}

.badge--amber {
  background-color: var(--accent-amber-dim);
  color: var(--accent-amber-light);
  border-color: var(--accent-amber-dim);
}

.badge--red {
  background-color: var(--accent-red-dim);
  color: var(--accent-red-light);
  border-color: var(--accent-red-dim);
}

.badge--neutral {
  background-color: var(--bg-elevated);
  color: var(--text-secondary);
  border-color: var(--bg-border);
}

.badge--success {
  background-color: rgba(74, 124, 89, 0.2);
  color: #6FAD7F;
  border-color: rgba(74, 124, 89, 0.3);
}


/* ============================================================
   17. ALERTS & CALLOUTS
   ============================================================ */

.alert {
  display: flex;
  gap: var(--space-4);
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  font-size: var(--text-sm);
  line-height: var(--leading-normal);
  margin-block: var(--space-4);
}

.alert--info {
  background-color: var(--accent-amber-glow);
  border-color: var(--accent-amber-dim);
  color: var(--accent-amber-light);
}

.alert--warning {
  background-color: rgba(158, 58, 47, 0.1);
  border-color: var(--accent-red-dim);
  color: var(--accent-red-light);
}

.alert--success {
  background-color: rgba(74, 124, 89, 0.1);
  border-color: rgba(74, 124, 89, 0.3);
  color: #6FAD7F;
}

/* Callout / aside — for "did you know" type boxes in articles */
.callout {
  border-left: 3px solid var(--accent-amber);
  background-color: var(--bg-surface);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: var(--space-4) var(--space-5);
  margin-block: var(--space-6);
}

.callout__title {
  font-family: var(--font-heading);
  font-size: var(--text-base);
  color: var(--accent-amber);
  margin-bottom: var(--space-2);
}


/* ============================================================
   18. FOOTER
   ============================================================ */

.footer {
  background-color: var(--bg-elevated);
  border-top: var(--border-default);
  padding-block: var(--space-7);
  margin-top: var(--space-9);
}

.footer__inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-6);
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-5);
}

.footer__brand {
  font-family: var(--font-heading);
  font-size: var(--text-md);
  color: var(--accent-amber);
  margin-bottom: var(--space-2);
}

.footer__tagline {
  font-size: var(--text-sm);
  color: var(--text-muted);
}

.footer__heading {
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  letter-spacing: var(--tracking-widest);
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: var(--space-3);
}

.footer__links {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.footer__link {
  font-size: var(--text-sm);
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--accent-amber);
}

.footer__bottom {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-5);
  padding-top: var(--space-5);
  margin-top: var(--space-6);
  border-top: var(--border-default);
  font-size: var(--text-xs);
  color: var(--text-muted);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-3);
}


/* ============================================================
   19. UTILITY CLASSES
   ============================================================ */

/* Display */
.hidden        { display: none; }
.block         { display: block; }
.inline-block  { display: inline-block; }
.flex          { display: flex; }
.inline-flex   { display: inline-flex; }
.grid-display  { display: grid; }

/* Flex helpers */
.items-center  { align-items: center; }
.items-start   { align-items: flex-start; }
.justify-between { justify-content: space-between; }
.justify-center  { justify-content: center; }
.flex-wrap     { flex-wrap: wrap; }
.gap-sm        { gap: var(--space-3); }
.gap-md        { gap: var(--space-5); }
.gap-lg        { gap: var(--space-7); }

/* Text alignment */
.text-left     { text-align: left; }
.text-center   { text-align: center; }
.text-right    { text-align: right; }

/* Font sizes */
.text-xs   { font-size: var(--text-xs); }
.text-sm   { font-size: var(--text-sm); }
.text-base { font-size: var(--text-base); }
.text-md   { font-size: var(--text-md); }
.text-lg   { font-size: var(--text-lg); }
.text-xl   { font-size: var(--text-xl); }

/* Spacing — margin */
.mt-0  { margin-top: 0; }
.mt-sm { margin-top: var(--space-3); }
.mt-md { margin-top: var(--space-5); }
.mt-lg { margin-top: var(--space-7); }
.mb-0  { margin-bottom: 0; }
.mb-sm { margin-bottom: var(--space-3); }
.mb-md { margin-bottom: var(--space-5); }
.mb-lg { margin-bottom: var(--space-7); }

/* Spacing — padding */
.p-sm  { padding: var(--space-3); }
.p-md  { padding: var(--space-5); }
.p-lg  { padding: var(--space-7); }

/* Borders */
.border        { border: var(--border-default); }
.border-accent { border: var(--border-accent); }
.border-t      { border-top: var(--border-default); }
.border-b      { border-bottom: var(--border-default); }
.rounded-sm    { border-radius: var(--radius-sm); }
.rounded-md    { border-radius: var(--radius-md); }
.rounded-lg    { border-radius: var(--radius-lg); }
.rounded-full  { border-radius: var(--radius-full); }

/* Width */
.w-full  { width: 100%; }
.w-auto  { width: auto; }

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


/* ============================================================
   20. RESPONSIVE BREAKPOINTS
   ============================================================

   Strategy: mobile-first. Base styles are for small screens.
   Add complexity as screens grow.

   Breakpoints:
   sm  — 480px   (large phones)
   md  — 768px   (tablets)
   lg  — 1024px  (laptops)
   xl  — 1280px  (desktops)
   ============================================================ */

/* Small — 480px+ */
@media (min-width: 480px) {
  :root {
    --text-base: 1.0625rem; /* Slightly larger body on bigger screens */
  }
}

/* Medium — 768px+ */
@media (min-width: 768px) {
  .grid--2,
  .grid--3,
  .grid--4 {
    grid-template-columns: repeat(2, 1fr);
  }

  h1, .h1 { font-size: var(--text-3xl); }
  h2, .h2 { font-size: var(--text-2xl); }
  h3, .h3 { font-size: var(--text-xl); }
}

/* Large — 1024px+ */
@media (min-width: 1024px) {
  .grid--3 { grid-template-columns: repeat(3, 1fr); }
  .grid--4 { grid-template-columns: repeat(4, 1fr); }
}

/* Stacked layout on mobile for footer */
@media (max-width: 767px) {
  .nav__links {
    display: none; /* Implement a hamburger menu with JS */
  }

  .footer__inner {
    flex-direction: column;
  }

  .footer__bottom {
    flex-direction: column;
    text-align: center;
  }

  .grid--2,
  .grid--3,
  .grid--4 {
    grid-template-columns: 1fr;
  }

  .section {
    padding-block: var(--space-6);
  }
}

/* Reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}