/* ==========================================================================
   Math Joke Calculator — Iron Mind AI
   Brand tokens sourced from docs/brandbook.md (Iron Mind AI core brand,
   ported from the main iron-mind.ai site: dark surfaces, orange accent,
   Barlow Condensed / DM Sans / JetBrains Mono).
   ========================================================================== */

@font-face {
  font-family: 'Barlow Condensed';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url('../fonts/barlow-condensed-700-latin.woff2') format('woff2');
}

@font-face {
  font-family: 'DM Sans';
  font-style: normal;
  font-weight: 300 700;
  font-display: swap;
  src: url('../fonts/dm-sans-latin.woff2') format('woff2-variations'),
       url('../fonts/dm-sans-latin.woff2') format('woff2');
}

@font-face {
  font-family: 'JetBrains Mono';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('../fonts/jetbrains-mono-400-latin.woff2') format('woff2');
}

:root {
  /* Color System — Iron Mind AI core palette */
  --color-bg-primary: #0E0E0E;
  --color-bg-surface: #161616;
  --color-bg-elevated: #1C1C1C;
  --color-accent: #E87C2E;
  --color-accent-hover: #F08C3E;
  --color-accent-subtle: rgba(232, 124, 46, 0.12);
  --color-text-primary: #FFFFFF;
  --color-text-secondary: #E8EAED;
  --color-text-muted: #888888;
  --color-border: rgba(255, 255, 255, 0.08);
  --color-border-hover: rgba(255, 255, 255, 0.16);
  --color-danger: #C0392B;
  --color-danger-subtle: rgba(192, 57, 43, 0.15);
  --color-success: #3EA86B;

  /* Typography */
  --font-display: 'Barlow Condensed', sans-serif;
  --font-body: 'DM Sans', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Spacing (8px base unit) */
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-5: 48px;
  --space-6: 64px;

  /* Radii */
  --radius-sm: 3px;
  --radius-md: 4px;
  --radius-lg: 8px;
  --radius-xl: 16px;

  /* Motion */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease-out;

  --max-width: 480px;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  background: var(--color-bg-primary);
  background-image:
    radial-gradient(circle at 20% 0%, rgba(232, 124, 46, 0.08), transparent 55%),
    radial-gradient(circle at 80% 100%, rgba(232, 124, 46, 0.05), transparent 55%);
  color: var(--color-text-primary);
  font-family: var(--font-body);
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  min-height: 100dvh;
}
button { font-family: inherit; }
h1, h2, h3 { font-family: var(--font-display); font-weight: 700; margin: 0; }

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

/* ---------- Page shell ---------- */
.page {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--space-4) var(--space-2) var(--space-3);
  gap: var(--space-4);
}

.page__header {
  width: 100%;
  max-width: var(--max-width);
  text-align: center;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  margin-bottom: var(--space-3);
  opacity: 0.85;
}
.brand__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border-radius: var(--radius-sm);
  background: var(--color-accent-subtle);
  border: 1px solid rgba(232, 124, 46, 0.3);
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}
.brand__text {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

.page__title {
  font-size: clamp(1.9rem, 6vw, 2.6rem);
  letter-spacing: 0.01em;
  line-height: 1.05;
  text-transform: uppercase;
}

.page__subtitle {
  margin: var(--space-1) 0 0;
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

.page__footer {
  margin-top: auto;
  padding-top: var(--space-3);
  color: var(--color-text-muted);
  font-size: 0.8rem;
  text-align: center;
}
.page__footer a {
  color: var(--color-text-secondary);
  text-decoration: none;
  border-bottom: 1px solid var(--color-border-hover);
  transition: color var(--transition-fast), border-color var(--transition-fast);
}
.page__footer a:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

/* ---------- Calculator shell ---------- */
.calculator {
  width: 100%;
  max-width: var(--max-width);
  background: var(--color-bg-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-3);
  box-shadow: 0 24px 60px -20px rgba(0, 0, 0, 0.6);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

/* ---------- Screen ---------- */
.calculator__screen-wrap {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.calculator__screen {
  background: var(--color-bg-primary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-3);
  min-height: 108px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: var(--space-1);
  overflow: hidden;
}

.calculator__expression {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--color-text-muted);
  text-align: right;
  word-break: break-all;
  min-height: 1.4em;
  transition: color var(--transition-fast);
}
.calculator__expression[data-error="true"] {
  color: var(--color-danger);
}

.calculator__result {
  font-family: var(--font-mono);
  font-size: clamp(1.8rem, 8vw, 2.6rem);
  font-weight: 400;
  text-align: right;
  color: var(--color-text-primary);
  line-height: 1.1;
  min-height: 1.2em;
  word-break: break-all;
}
.calculator__result:empty::after {
  content: '';
}
.calculator__result[data-fresh="true"] {
  animation: result-pop 260ms ease-out;
}
@keyframes result-pop {
  0% { transform: scale(0.94); opacity: 0.5; }
  100% { transform: scale(1); opacity: 1; }
}

/* ---------- Error banner ---------- */
.calculator__error {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: #ffb4a8;
  background: var(--color-danger-subtle);
  border: 1px solid rgba(192, 57, 43, 0.35);
  border-radius: var(--radius-md);
  padding: var(--space-1) var(--space-2);
  animation: shake-in 220ms ease-out;
}
@keyframes shake-in {
  0% { transform: translateX(0); opacity: 0; }
  30% { transform: translateX(-4px); }
  60% { transform: translateX(3px); }
  100% { transform: translateX(0); opacity: 1; }
}

/* ---------- Joke card ---------- */
.joke {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-2);
  align-items: flex-start;
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-accent);
  border-radius: var(--radius-md);
  padding: var(--space-2);
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  padding-top: 0;
  padding-bottom: 0;
  margin: 0;
  transform: translateY(-4px);
  transition:
    max-height var(--transition-slow),
    opacity var(--transition-slow),
    padding var(--transition-slow),
    transform var(--transition-slow);
}

.joke[data-state="loading"],
.joke[data-state="shown"] {
  max-height: 220px;
  opacity: 1;
  padding: var(--space-2);
  transform: translateY(0);
}

.joke[data-state="shown"] {
  animation: joke-in 360ms ease-out;
}
@keyframes joke-in {
  0% { transform: translateY(-6px); opacity: 0; }
  100% { transform: translateY(0); opacity: 1; }
}

.joke__icon {
  font-size: 1.1rem;
  line-height: 1.5;
}

.joke__label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 2px;
}

.joke__text {
  font-size: 0.92rem;
  line-height: 1.5;
  color: var(--color-text-secondary);
}

/* Thinking / loading dots, shown while waiting on the joke portion */
.joke[data-state="loading"] .joke__text::after {
  content: 'Thinking of a joke';
  color: var(--color-text-muted);
  display: inline-flex;
  align-items: center;
}
.joke[data-state="loading"] .joke__text {
  display: flex;
}
.joke[data-state="loading"] .joke__text .dots::after {
  content: '';
  display: inline-block;
  width: 1.2em;
  text-align: left;
  animation: dots 1.1s steps(4, end) infinite;
}
@keyframes dots {
  0% { content: ''; }
  25% { content: '.'; }
  50% { content: '..'; }
  75% { content: '...'; }
  100% { content: ''; }
}

.joke__text--fallback {
  color: var(--color-text-muted);
  font-style: italic;
}

/* ---------- Keypad ---------- */
.calculator__pad {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-1);
}

.key {
  appearance: none;
  border: 1px solid var(--color-border);
  background: var(--color-bg-elevated);
  color: var(--color-text-primary);
  font-family: var(--font-mono);
  font-size: 1.15rem;
  border-radius: var(--radius-md);
  padding: var(--space-2) 0;
  cursor: pointer;
  transition: background var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
  -webkit-tap-highlight-color: transparent;
}
.key:hover { border-color: var(--color-border-hover); background: #222; }
.key:active { transform: scale(0.96); }
.key:focus-visible {
  outline: none;
  box-shadow: 0 0 0 2px rgba(232, 124, 46, 0.35);
}

.key--fn {
  color: var(--color-text-muted);
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 500;
}

.key--op {
  color: var(--color-accent);
}

.key--equals {
  grid-row: span 1;
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: #1a0f00;
  font-weight: 700;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}
.key--equals:hover { background: var(--color-accent-hover); border-color: var(--color-accent-hover); }
.key--equals .key__spinner { display: none; }
.key--equals[data-busy="true"] .key__label { visibility: hidden; }
.key--equals[data-busy="true"] .key__spinner {
  display: block;
  position: absolute;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: 2px solid rgba(26, 15, 0, 0.35);
  border-top-color: #1a0f00;
  animation: spin 0.6s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.key--equals[disabled] { cursor: default; opacity: 0.85; }

/* zero key spans two columns for the classic calculator feel on wider row */
.calculator__pad .key[data-value="0"] {
  grid-column: span 1;
}

/* ---------- Responsive ---------- */
@media (min-width: 560px) {
  .page { padding-top: var(--space-6); }
  .calculator { padding: var(--space-4); }
  .key { padding: var(--space-2) 0; font-size: 1.3rem; }
}

@media (max-width: 380px) {
  :root { --max-width: 100%; }
  .page { padding-left: var(--space-1); padding-right: var(--space-1); }
  .calculator { padding: var(--space-2); border-radius: var(--radius-lg); }
}