/* ============================================================
   Unit Converter Calculator Pro — Premium Stylesheet
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Syne:wght@400;600;700;800&family=DM+Sans:wght@300;400;500;600&display=swap');

:root {
  --ucc-primary:      #0a0a0f;
  --ucc-surface:      #13131a;
  --ucc-surface-2:    #1c1c28;
  --ucc-surface-3:    #242433;
  --ucc-border:       rgba(255,255,255,0.08);
  --ucc-border-focus: rgba(99,102,241,0.6);
  --ucc-accent:       #6366f1;
  --ucc-accent-2:     #8b5cf6;
  --ucc-accent-3:     #06b6d4;
  --ucc-gold:         #f59e0b;
  --ucc-text:         #f0f0f8;
  --ucc-text-muted:   #8888aa;
  --ucc-text-dim:     #555570;
  --ucc-success:      #10b981;
  --ucc-radius-sm:    8px;
  --ucc-radius:       16px;
  --ucc-radius-lg:    24px;
  --ucc-radius-xl:    32px;
  --ucc-shadow:       0 4px 24px rgba(0,0,0,0.4);
  --ucc-shadow-lg:    0 20px 60px rgba(0,0,0,0.5);
  --ucc-glow:         0 0 40px rgba(99,102,241,0.15);
  --ucc-font-display: 'Syne', sans-serif;
  --ucc-font-body:    'DM Sans', sans-serif;
  --ucc-transition:   0.25s cubic-bezier(0.4,0,0.2,1);
}

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

.ucc-wrapper {
  font-family: var(--ucc-font-body);
  background: var(--ucc-primary);
  color: var(--ucc-text);
  border-radius: var(--ucc-radius-xl);
  overflow: hidden;
  position: relative;
  line-height: 1.6;
  max-width: 1100px;
  margin: 0 auto 40px;
  box-shadow: var(--ucc-shadow-lg), var(--ucc-glow);
  border: 1px solid var(--ucc-border);
}

/* ── Hero ── */
.ucc-hero {
  position: relative;
  overflow: hidden;
  padding: 64px 48px 48px;
  background: linear-gradient(135deg, #0a0a18 0%, #0f0f22 40%, #12101e 100%);
  border-bottom: 1px solid var(--ucc-border);
  text-align: center;
}

.ucc-hero-inner { position: relative; z-index: 2; }

.ucc-hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.35;
  pointer-events: none;
}
.ucc-orb-1 { width: 400px; height: 400px; background: radial-gradient(circle, #6366f1, transparent); top: -120px; left: -80px; }
.ucc-orb-2 { width: 300px; height: 300px; background: radial-gradient(circle, #8b5cf6, transparent); top: -60px; right: -60px; }
.ucc-orb-3 { width: 200px; height: 200px; background: radial-gradient(circle, #06b6d4, transparent); bottom: -40px; left: 50%; transform: translateX(-50%); opacity: 0.2; }

.ucc-hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--ucc-font-display);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--ucc-gold);
  background: rgba(245,158,11,0.1);
  border: 1px solid rgba(245,158,11,0.25);
  padding: 6px 16px;
  border-radius: 100px;
  margin-bottom: 20px;
}

.ucc-hero-title {
  font-family: var(--ucc-font-display);
  font-size: clamp(32px, 5vw, 54px);
  font-weight: 800;
  line-height: 1.1;
  color: var(--ucc-text);
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.ucc-gradient-text {
  background: linear-gradient(135deg, var(--ucc-accent), var(--ucc-accent-2), var(--ucc-accent-3));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.ucc-hero-subtitle {
  font-size: 17px;
  color: var(--ucc-text-muted);
  max-width: 520px;
  margin: 0 auto 32px;
  font-weight: 400;
}

.ucc-stats-row {
  display: inline-flex;
  align-items: center;
  gap: 0;
  background: var(--ucc-surface);
  border: 1px solid var(--ucc-border);
  border-radius: 100px;
  padding: 12px 28px;
  gap: 24px;
}

.ucc-stat { display: flex; flex-direction: column; align-items: center; }
.ucc-stat strong { font-family: var(--ucc-font-display); font-size: 22px; font-weight: 800; color: var(--ucc-accent); }
.ucc-stat span { font-size: 11px; color: var(--ucc-text-muted); text-transform: uppercase; letter-spacing: 0.1em; margin-top: 2px; }
.ucc-stat-divider { width: 1px; height: 36px; background: var(--ucc-border); }

/* ── Tabs ── */
.ucc-tabs-wrapper {
  background: var(--ucc-surface);
  padding: 0 24px;
  border-bottom: 1px solid var(--ucc-border);
  overflow-x: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--ucc-border) transparent;
}

.ucc-tabs {
  display: flex;
  gap: 4px;
  min-width: max-content;
  padding: 12px 0;
}

.ucc-tab {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border: 1px solid transparent;
  border-radius: var(--ucc-radius-sm);
  background: transparent;
  color: var(--ucc-text-muted);
  font-family: var(--ucc-font-body);
  font-size: 13.5px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--ucc-transition);
  white-space: nowrap;
  position: relative;
}

.ucc-tab-icon { font-size: 16px; }
.ucc-tab-label { }

.ucc-tab:hover {
  background: var(--ucc-surface-2);
  color: var(--ucc-text);
  border-color: var(--ucc-border);
}

.ucc-tab.active {
  background: linear-gradient(135deg, rgba(99,102,241,0.15), rgba(139,92,246,0.1));
  color: var(--ucc-text);
  border-color: rgba(99,102,241,0.35);
  font-weight: 600;
}
.ucc-tab.active .ucc-tab-icon { filter: drop-shadow(0 0 6px rgba(99,102,241,0.6)); }

/* ── Panels ── */
.ucc-panels { padding: 32px 32px 0; }

.ucc-panel { display: none; }
.ucc-panel.active { display: block; animation: ucc-fadein 0.3s ease; }

@keyframes ucc-fadein {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ── Converter Card ── */
.ucc-converter-card {
  background: var(--ucc-surface);
  border: 1px solid var(--ucc-border);
  border-radius: var(--ucc-radius-lg);
  padding: 32px;
  margin-bottom: 24px;
  position: relative;
  overflow: hidden;
}

.ucc-converter-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--ucc-accent), var(--ucc-accent-2), var(--ucc-accent-3));
  border-radius: var(--ucc-radius-lg) var(--ucc-radius-lg) 0 0;
}

.ucc-card-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 28px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--ucc-border);
}

.ucc-cat-icon { font-size: 28px; }
.ucc-card-title {
  font-family: var(--ucc-font-display);
  font-size: 20px;
  font-weight: 700;
  margin: 0;
  flex: 1;
  color: var(--ucc-text);
}
.ucc-unit-count {
  font-size: 12px;
  background: rgba(99,102,241,0.12);
  color: var(--ucc-accent);
  border: 1px solid rgba(99,102,241,0.2);
  padding: 4px 12px;
  border-radius: 100px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

/* ── Input Row ── */
.ucc-input-row {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 20px;
  align-items: center;
  margin-bottom: 24px;
}

.ucc-input-group { display: flex; flex-direction: column; gap: 6px; }

.ucc-label {
  font-size: 11.5px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ucc-text-muted);
}
.ucc-label-mt { margin-top: 14px; }

.ucc-field-wrap { position: relative; }

.ucc-input {
  width: 100%;
  padding: 14px 18px;
  background: var(--ucc-surface-2);
  border: 1.5px solid var(--ucc-border);
  border-radius: var(--ucc-radius-sm);
  color: var(--ucc-text);
  font-family: var(--ucc-font-body);
  font-size: 16px;
  font-weight: 500;
  transition: var(--ucc-transition);
  outline: none;
  appearance: none;
  -moz-appearance: textfield;
}
.ucc-input::-webkit-outer-spin-button,
.ucc-input::-webkit-inner-spin-button { -webkit-appearance: none; }

.ucc-input:focus {
  border-color: var(--ucc-accent);
  box-shadow: 0 0 0 3px rgba(99,102,241,0.15);
  background: var(--ucc-surface-3);
}
.ucc-input[readonly] {
  background: var(--ucc-surface-3);
  color: var(--ucc-accent);
  font-weight: 600;
  font-size: 17px;
  letter-spacing: 0.01em;
}

.ucc-result-wrap { position: relative; }
.ucc-result-wrap .ucc-input { padding-right: 52px; }

.ucc-copy-btn {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  width: 32px;
  height: 32px;
  border-radius: 6px;
  border: 1px solid var(--ucc-border);
  background: var(--ucc-surface-2);
  color: var(--ucc-text-muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--ucc-transition);
}
.ucc-copy-btn svg { width: 14px; height: 14px; }
.ucc-copy-btn:hover { background: var(--ucc-accent); color: #fff; border-color: var(--ucc-accent); }
.ucc-copy-btn.copied { background: var(--ucc-success); color: #fff; border-color: var(--ucc-success); }

.ucc-select-wrap { position: relative; }
.ucc-select {
  width: 100%;
  padding: 13px 40px 13px 16px;
  background: var(--ucc-surface-2);
  border: 1.5px solid var(--ucc-border);
  border-radius: var(--ucc-radius-sm);
  color: var(--ucc-text);
  font-family: var(--ucc-font-body);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  outline: none;
  appearance: none;
  -webkit-appearance: none;
  transition: var(--ucc-transition);
}
.ucc-select:focus {
  border-color: var(--ucc-accent);
  box-shadow: 0 0 0 3px rgba(99,102,241,0.15);
}
.ucc-select option { background: #1c1c28; color: var(--ucc-text); }
.ucc-select-arrow {
  position: absolute;
  right: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--ucc-text-muted);
  font-size: 14px;
  pointer-events: none;
}

/* ── Swap Button ── */
.ucc-swap-col { display: flex; justify-content: center; align-items: flex-end; padding-bottom: 4px; }

.ucc-swap-btn {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 1.5px solid var(--ucc-border);
  background: var(--ucc-surface-2);
  color: var(--ucc-text-muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--ucc-transition);
  flex-shrink: 0;
}
.ucc-swap-btn svg { width: 20px; height: 20px; }
.ucc-swap-btn:hover {
  background: linear-gradient(135deg, var(--ucc-accent), var(--ucc-accent-2));
  border-color: var(--ucc-accent);
  color: #fff;
  transform: rotate(180deg);
}

/* ── Buttons Row ── */
.ucc-btn-row {
  display: flex;
  gap: 12px;
  align-items: center;
}

.ucc-convert-btn {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 15px 28px;
  background: linear-gradient(135deg, var(--ucc-accent), var(--ucc-accent-2));
  border: none;
  border-radius: var(--ucc-radius-sm);
  color: #fff;
  font-family: var(--ucc-font-display);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: var(--ucc-transition);
  position: relative;
  overflow: hidden;
}

.ucc-convert-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--ucc-accent-2), var(--ucc-accent-3));
  opacity: 0;
  transition: var(--ucc-transition);
}
.ucc-convert-btn:hover::before { opacity: 1; }
.ucc-convert-btn:hover { transform: translateY(-1px); box-shadow: 0 8px 24px rgba(99,102,241,0.4); }
.ucc-convert-btn:active { transform: translateY(0); }
.ucc-btn-text, .ucc-btn-icon { position: relative; }
.ucc-btn-icon { font-size: 18px; font-weight: 800; }

.ucc-clear-btn {
  padding: 15px 22px;
  background: transparent;
  border: 1.5px solid var(--ucc-border);
  border-radius: var(--ucc-radius-sm);
  color: var(--ucc-text-muted);
  font-family: var(--ucc-font-body);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--ucc-transition);
}
.ucc-clear-btn:hover { border-color: #ef4444; color: #ef4444; background: rgba(239,68,68,0.06); }

/* ── Formula Box ── */
.ucc-formula-box {
  margin-top: 16px;
  padding: 14px 20px;
  background: var(--ucc-surface-2);
  border: 1px solid var(--ucc-border);
  border-radius: var(--ucc-radius-sm);
  font-size: 13.5px;
  color: var(--ucc-text-muted);
  min-height: 48px;
  display: flex;
  align-items: center;
  font-family: 'Courier New', monospace;
}
.ucc-formula-box:empty::before {
  content: 'Enter a value and press Convert to see the formula.';
  opacity: 0.5;
}
.ucc-formula-box .ucc-formula-result { color: var(--ucc-accent); font-weight: 600; }

/* ── Reference Section ── */
.ucc-ref-section {
  margin-bottom: 24px;
}

.ucc-ref-title {
  font-family: var(--ucc-font-display);
  font-size: 15px;
  font-weight: 700;
  color: var(--ucc-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 14px;
}

.ucc-ref-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 10px;
}

.ucc-ref-item {
  background: var(--ucc-surface);
  border: 1px solid var(--ucc-border);
  border-radius: var(--ucc-radius-sm);
  padding: 12px 16px;
  display: flex;
  flex-direction: column;
  gap: 3px;
  transition: var(--ucc-transition);
}
.ucc-ref-item:hover { border-color: rgba(99,102,241,0.3); background: var(--ucc-surface-2); }
.ucc-ref-from { font-size: 12px; color: var(--ucc-text-muted); }
.ucc-ref-eq { font-size: 14px; color: var(--ucc-text); }
.ucc-ref-eq strong { color: var(--ucc-accent-3); }
.ucc-ref-to { font-size: 12px; color: var(--ucc-text-muted); }

/* ── SEO Block ── */
.ucc-seo-block {
  background: var(--ucc-surface);
  border: 1px solid var(--ucc-border);
  border-radius: var(--ucc-radius);
  padding: 28px 32px;
  margin-bottom: 32px;
}
.ucc-seo-block h3 {
  font-family: var(--ucc-font-display);
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--ucc-text);
}
.ucc-seo-block p {
  font-size: 14.5px;
  color: var(--ucc-text-muted);
  line-height: 1.75;
}

/* ── Footer ── */
.ucc-footer {
  background: var(--ucc-surface);
  border-top: 1px solid var(--ucc-border);
  padding: 16px 32px;
  text-align: center;
}
.ucc-footer p {
  font-size: 12px;
  color: var(--ucc-text-dim);
}

/* ── Animations ── */
@keyframes ucc-spin { to { transform: rotate(360deg); } }
.ucc-loading { opacity: 0.5; pointer-events: none; }

/* ── Responsive ── */
@media (max-width: 768px) {
  .ucc-hero { padding: 40px 24px 32px; }
  .ucc-hero-title { font-size: 28px; }
  .ucc-hero-subtitle { font-size: 14px; }
  .ucc-stats-row { gap: 16px; padding: 10px 20px; }
  .ucc-stat strong { font-size: 18px; }

  .ucc-panels { padding: 20px 16px 0; }
  .ucc-converter-card { padding: 20px 18px; }

  .ucc-input-row {
    grid-template-columns: 1fr;
    gap: 0;
  }
  .ucc-swap-col {
    align-items: center;
    padding: 14px 0;
  }
  .ucc-swap-btn { transform: rotate(90deg); }
  .ucc-swap-btn:hover { transform: rotate(270deg); }

  .ucc-btn-row { flex-direction: column; }
  .ucc-convert-btn, .ucc-clear-btn { width: 100%; }

  .ucc-ref-grid { grid-template-columns: 1fr 1fr; }

  .ucc-seo-block { padding: 20px; }
  .ucc-tabs-wrapper { padding: 0 12px; }
  .ucc-tab { padding: 8px 12px; font-size: 12.5px; }
}

@media (max-width: 480px) {
  .ucc-ref-grid { grid-template-columns: 1fr; }
  .ucc-card-header { flex-wrap: wrap; gap: 8px; }
}