:root {
  --bg: #FFFBEB;
  --bg-alt: #FFF0C4;
  --surface: #FFFFFF;
  --text: #1A1A2E;
  --text-muted: #5A5A78;
  --border-color: #1A1A2E;

  --pink: #FF3366;
  --blue: #3B82F6;
  --green: #10B981;
  --yellow: #FBBF24;
  --orange: #F97316;
  --purple: #8B5CF6;
  --cyan: #06B6D4;
  --red: #EF4444;
  --lime: #84CC16;
  --teal: #14B8A6;

  --font-display: 'Lilita One', cursive;
  --font-body: 'Plus Jakarta Sans', sans-serif;

  --border-w: 3px;
  --radius: 16px;
  --radius-sm: 10px;

  --container-w: 1100px;

  --converter-color: var(--pink);
}

body[data-converter="age"] { --converter-color: var(--pink); }
body[data-converter="height"] { --converter-color: var(--blue); }
body[data-converter="weight"] { --converter-color: var(--orange); }
body[data-converter="salary"] { --converter-color: var(--green); }
body[data-converter="distance"] { --converter-color: var(--purple); }
body[data-converter="speed"] { --converter-color: var(--cyan); }
body[data-converter="time"] { --converter-color: var(--teal); }
body[data-converter="price"] { --converter-color: var(--lime); }

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

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

body {
  font-family: var(--font-body);
  color: var(--text);
  background: var(--bg);
  background-image: radial-gradient(circle, #e8dfc8 1px, transparent 1px);
  background-size: 28px 28px;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

::selection {
  background: var(--pink);
  color: white;
}

img, svg { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { cursor: pointer; font-family: inherit; border: none; background: none; }
input, select { font-family: inherit; }
ul { list-style: none; }

.container {
  width: 100%;
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 1.25rem;
}

h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 6vw, 3.5rem);
  line-height: 1.15;
  letter-spacing: 0.01em;
}

h2 {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  line-height: 1.2;
}

h3 {
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 3vw, 1.75rem);
}

.highlight { color: var(--pink); }

/* ---- Header ---- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--surface);
  border-bottom: var(--border-w) solid var(--border-color);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 1.25rem;
}

.logo {
  font-family: var(--font-display);
  font-size: 1.4rem;
  display: flex;
  align-items: center;
  gap: 0.35rem;
  white-space: nowrap;
  transition: transform 0.2s;
}

.logo:hover { transform: scale(1.04); }

.site-nav { position: relative; }

.nav-links {
  display: flex;
  gap: 0.25rem;
}

.nav-link {
  padding: 0.45rem 0.9rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  transition: background 0.2s, color 0.2s;
}

.nav-link:hover { background: var(--bg-alt); }
.nav-link.active { background: var(--pink); color: white; }

.nav-toggle {
  display: none;
  font-size: 1.6rem;
  padding: 0.25rem;
  line-height: 1;
}

@media (max-width: 900px) {
  .nav-toggle { display: block; }

  .nav-links {
    display: none;
    position: absolute;
    top: calc(100% + var(--border-w));
    right: 0;
    flex-direction: column;
    background: var(--surface);
    border: var(--border-w) solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 0.5rem;
    min-width: 180px;
    box-shadow: 6px 6px 0 var(--border-color);
    z-index: 50;
  }

  .nav-links.open { display: flex; }

  .nav-link { padding: 0.65rem 1rem; }
}

/* ---- Hero (landing) ---- */

.hero {
  text-align: center;
  padding: 4rem 0 3rem;
  background: linear-gradient(135deg, var(--bg) 0%, #FFE5EC 40%, #E5EDFF 100%);
  background-size: 200% 200%;
  animation: gradientShift 10s ease infinite;
  margin: 0 -9999px;
  padding-left: 9999px;
  padding-right: 9999px;
}

.hero-emoji {
  font-size: 4.5rem;
  display: block;
  animation: bounce 2s ease-in-out infinite;
}

.hero h1 { margin-top: 0.75rem; }

.hero-tagline {
  font-size: 1.15rem;
  color: var(--text-muted);
  margin-top: 0.75rem;
  max-width: 550px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.7;
}

/* ---- Category Grid ---- */

.categories {
  padding: 3rem 0 4rem;
}

.categories h2 {
  text-align: center;
  margin-bottom: 2rem;
}

.category-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
}

.category-card {
  position: relative;
  background: var(--surface);
  border: var(--border-w) solid var(--border-color);
  border-radius: var(--radius);
  padding: 1.75rem;
  box-shadow: 6px 6px 0 var(--card-color, var(--pink));
  transition: transform 0.2s, box-shadow 0.2s;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.category-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 5px;
  background: var(--card-color, var(--pink));
}

.category-card:hover {
  transform: translate(-3px, -3px);
  box-shadow: 9px 9px 0 var(--card-color, var(--pink));
}

.category-card:hover .category-emoji {
  animation: bounce 0.5s ease;
}

.category-emoji {
  font-size: 2.75rem;
  margin-bottom: 0.75rem;
}

.category-title {
  font-family: var(--font-display);
  font-size: 1.6rem;
  margin-bottom: 0.4rem;
}

.category-desc {
  color: var(--text-muted);
  font-size: 0.95rem;
  flex: 1;
  margin-bottom: 1rem;
  line-height: 1.6;
}

.category-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-weight: 700;
  color: var(--card-color, var(--pink));
  font-size: 1rem;
}

/* ---- Converter Hero ---- */

.converter-hero {
  text-align: center;
  padding: 3rem 1.25rem 2rem;
}

.converter-emoji {
  font-size: 3.5rem;
  display: block;
  margin-bottom: 0.75rem;
  animation: bounce 2s ease-in-out infinite;
}

.converter-hero p {
  color: var(--text-muted);
  max-width: 580px;
  margin: 0.75rem auto 0;
  font-size: 1.05rem;
  line-height: 1.7;
}

/* ---- Input Section ---- */

.input-section {
  max-width: 480px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

.input-card {
  background: var(--surface);
  border: var(--border-w) solid var(--border-color);
  border-radius: var(--radius);
  padding: 1.75rem;
  box-shadow: 6px 6px 0 var(--border-color);
}

.input-label {
  display: block;
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 0.5rem;
}

.input-group {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.input-field {
  flex: 1;
  padding: 0.875rem 1rem;
  font-size: 1.35rem;
  font-weight: 700;
  border: var(--border-w) solid var(--border-color);
  border-radius: var(--radius-sm);
  background: var(--bg);
  transition: border-color 0.2s, box-shadow 0.2s;
  min-width: 0;
}

.input-field:focus {
  outline: none;
  border-color: var(--converter-color);
  box-shadow: 0 0 0 3px rgba(255, 51, 102, 0.15);
}

.input-field.shake { animation: shake 0.4s ease; }

.input-select {
  padding: 0.875rem 0.75rem;
  font-size: 1rem;
  font-weight: 700;
  border: var(--border-w) solid var(--border-color);
  border-radius: var(--radius-sm);
  background: var(--bg);
  min-width: 72px;
  cursor: pointer;
}

.input-unit-label {
  display: flex;
  align-items: center;
  padding: 0 0.75rem;
  font-weight: 700;
  font-size: 1rem;
  color: var(--text-muted);
  background: var(--bg-alt);
  border: var(--border-w) solid var(--border-color);
  border-radius: var(--radius-sm);
  white-space: nowrap;
}

.convert-btn {
  width: 100%;
  padding: 1rem;
  font-family: var(--font-display);
  font-size: 1.5rem;
  color: white;
  background: var(--converter-color);
  border: var(--border-w) solid var(--border-color);
  border-radius: var(--radius-sm);
  box-shadow: 4px 4px 0 var(--border-color);
  transition: transform 0.1s, box-shadow 0.1s;
  letter-spacing: 0.02em;
}

.convert-btn:hover {
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 var(--border-color);
}

.convert-btn:active {
  transform: translate(2px, 2px);
  box-shadow: 0 0 0 var(--border-color);
}

/* ---- Results ---- */

.results-section {
  max-width: 900px;
  margin: 2.5rem auto 0;
  padding: 0 1.25rem;
}

.results-section h2 {
  text-align: center;
  margin-bottom: 1.5rem;
}

.results-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.result-card {
  position: relative;
  background: var(--surface);
  border: var(--border-w) solid var(--border-color);
  border-radius: var(--radius);
  padding: 1.25rem 1.25rem 1.25rem 1.5rem;
  box-shadow: 4px 4px 0 var(--card-color, var(--pink));
  opacity: 0;
  animation: slideUp 0.4s ease forwards;
  overflow: hidden;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.result-card.selected {
  border-color: var(--card-color, var(--pink));
  box-shadow: 5px 5px 0 var(--card-color, var(--pink));
}

.result-card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 5px;
  background: var(--card-color, var(--pink));
}

.result-actions {
  position: absolute;
  top: 0.6rem;
  right: 0.6rem;
  display: flex;
  gap: 0.3rem;
  z-index: 2;
}

.result-action-btn {
  width: 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  background: var(--bg);
  border: 2px solid var(--border-color);
  font-size: 0.85rem;
  cursor: pointer;
  transition: background 0.15s, transform 0.1s;
  line-height: 1;
  padding: 0;
}

.result-action-btn:hover {
  background: var(--bg-alt);
  transform: scale(1.08);
}

.result-action-btn:active { transform: scale(0.95); }

.result-select-btn.active {
  background: var(--card-color, var(--pink));
  color: white;
  border-color: var(--card-color, var(--pink));
}

.result-emoji {
  font-size: 2rem;
  margin-bottom: 0.35rem;
}

.result-number {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 2.75rem);
  line-height: 1.1;
  color: var(--card-color, var(--pink));
  word-break: break-word;
}

.result-unit {
  font-weight: 700;
  font-size: 1.05rem;
  margin-top: 0.15rem;
  color: var(--text);
}

.result-fact {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-top: 0.75rem;
  padding-top: 0.75rem;
  border-top: 2px solid var(--bg-alt);
  line-height: 1.55;
}

/* ---- Share Section ---- */

.share-section {
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: var(--border-w) dashed var(--border-color);
}

.share-section h3 {
  text-align: center;
  margin-bottom: 1.25rem;
}

.share-card-inner {
  background: var(--surface);
  border: var(--border-w) solid var(--border-color);
  border-radius: var(--radius);
  overflow: hidden;
  max-width: 380px;
  margin: 0 auto;
  box-shadow: 6px 6px 0 var(--border-color);
}

.share-card-header {
  background: var(--converter-color, var(--pink));
  color: white;
  padding: 0.75rem 1.25rem;
  font-family: var(--font-display);
  font-size: 1.15rem;
  text-align: center;
}

.share-card-results { padding: 0.75rem 1.25rem; }

.share-card-result {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  padding: 0.5rem 0;
}

.share-card-result + .share-card-result {
  border-top: 2px solid var(--bg-alt);
}

.share-card-emoji { font-size: 1.15rem; }

.share-card-value {
  font-family: var(--font-display);
  font-size: 1.15rem;
}

.share-card-unit {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.share-card-footer {
  background: var(--bg);
  padding: 0.5rem;
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 700;
  letter-spacing: 0.03em;
}

.share-card-empty {
  text-align: center;
  color: var(--text-muted);
  padding: 2rem 1rem;
  font-size: 0.95rem;
  line-height: 1.6;
}

.share-buttons {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  margin-top: 1.25rem;
  padding-bottom: 1rem;
  flex-wrap: wrap;
}

.share-btn {
  padding: 0.7rem 1.4rem;
  font-size: 0.95rem;
  font-weight: 700;
  border: var(--border-w) solid var(--border-color);
  border-radius: var(--radius-sm);
  box-shadow: 3px 3px 0 var(--border-color);
  transition: transform 0.1s, box-shadow 0.1s;
  background: var(--surface);
}

.share-btn:hover {
  transform: translate(-1px, -1px);
  box-shadow: 4px 4px 0 var(--border-color);
}

.share-btn:active {
  transform: translate(1px, 1px);
  box-shadow: 1px 1px 0 var(--border-color);
}

/* ---- Ad Slots (hidden until real ads are added) ---- */

.ad-slot { display: none; }

/* ---- Footer ---- */

.site-footer {
  margin-top: auto;
  background: var(--text);
  color: #aaa;
  text-align: center;
  padding: 2rem 1.25rem;
  font-size: 0.9rem;
}

.footer-tagline { margin-bottom: 0.5rem; line-height: 1.6; }
.footer-copy { font-size: 0.8rem; color: #777; }

/* ---- About ---- */

.about-page {
  max-width: 680px;
  margin: 0 auto;
  padding: 3rem 1.25rem 4rem;
}

.about-page h1 { margin-bottom: 1.5rem; }

.about-page p {
  margin-bottom: 1.25rem;
  color: var(--text-muted);
  line-height: 1.8;
  font-size: 1.05rem;
}

.about-page h2 {
  margin-top: 2rem;
  margin-bottom: 0.75rem;
  font-size: 1.5rem;
}

/* ---- Animations ---- */

@keyframes slideUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-8px); }
  40%, 80% { transform: translateX(8px); }
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.fade-in { animation: fadeIn 0.5s ease forwards; }

/* ---- Responsive ---- */

@media (min-width: 500px) {
  .category-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 640px) {
  .results-grid { grid-template-columns: repeat(2, 1fr); }
  .results-grid .ad-slot { grid-column: 1 / -1; }
}

@media (min-width: 900px) {
  .category-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
}