/* ══════════════════════════════════════════════════════
   abinScience Molarity & Dilution Calculator Widget
   Version: 2.0  |  Brand: Blue #0052CC + Orange #FF6600
   Zero-dependency  |  Embeddable in product detail pages
   ══════════════════════════════════════════════════════ */

:root {
  --abin-brand: #0052CC;
  --abin-brand-dark: #003D99;
  --abin-brand-light: #EDF3FC;
  --abin-brand-muted: #D6E4F7;
  --abin-accent: #FF6600;
  --abin-accent-dark: #E55A00;
  --abin-accent-light: #FFF4EB;
  --abin-text: #1A1A2E;
  --abin-text-sec: #5A6778;
  --abin-bg: #FFFFFF;
  --abin-border: #D6E0EB;
  --abin-error: #D94F4F;
  --abin-success: #4CAF7D;
  --abin-radius: 8px;
}

.abin-calc-widget * { box-sizing: border-box; margin: 0; padding: 0; }

.abin-calc-widget {
  font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, 'Helvetica Neue', sans-serif;
  max-width: 720px;
  margin: 0 auto;
  background: var(--abin-bg);
  border-radius: 12px;
  border: 1px solid var(--abin-border);
  box-shadow: 0 2px 16px rgba(0,82,204,0.08);
  overflow: hidden;
  color: var(--abin-text);
  line-height: 1.5;
  font-size: 14px;
}

/* ── Tabs ── */
.abin-calc-tabs { display: flex; background: var(--abin-brand-light); border-bottom: 1px solid var(--abin-border); }
.abin-calc-tab {
  flex: 1; padding: 13px 0; text-align: center; font-size: 14px; font-weight: 600;
  cursor: pointer; border: none; background: transparent; color: var(--abin-brand);
  transition: all 0.25s ease; letter-spacing: 0.3px; font-family: inherit; position: relative;
}
.abin-calc-tab:hover { background: rgba(0,82,204,0.08); }
.abin-calc-tab.active { background: var(--abin-brand); color: #fff; }

/* ── Body ── */
.abin-calc-body { padding: 24px 28px 28px; }
.abin-calc-panel { display: none; }
.abin-calc-panel.active { display: block; }

/* ── Formula ── */
.abin-calc-formula {
  background: var(--abin-brand-light); border-left: 3px solid var(--abin-brand);
  padding: 12px 16px; border-radius: 0 6px 6px 0; margin-bottom: 20px;
}
.abin-calc-formula-label { font-size: 11px; font-weight: 600; color: var(--abin-brand); text-transform: uppercase; letter-spacing: 0.8px; margin-bottom: 4px; }
.abin-calc-formula-text { font-size: 13px; color: var(--abin-text); font-weight: 500; }

.abin-calc-hint { font-size: 12px; color: var(--abin-text-sec); margin-bottom: 18px; }
.abin-calc-hint strong { color: var(--abin-text); }

/* ── Section Titles & Operators ── */
.abin-calc-section-title { font-size: 11px; font-weight: 700; color: var(--abin-brand); text-transform: uppercase; letter-spacing: 1px; margin-bottom: 10px; }
.abin-calc-eq-sign { text-align: center; color: var(--abin-text-sec); font-size: 16px; font-weight: 700; margin: 8px 0 14px; letter-spacing: 2px; }

/* ── Fields ── */
.abin-calc-row { display: flex; align-items: flex-end; gap: 8px; flex-wrap: wrap; margin-bottom: 20px; }
.abin-calc-field { display: flex; flex-direction: column; flex: 1 1 120px; min-width: 100px; }
.abin-calc-label { font-size: 12px; font-weight: 600; color: var(--abin-text); margin-bottom: 6px; display: flex; align-items: center; gap: 4px; }
.abin-calc-label .req { color: var(--abin-error); font-size: 13px; font-weight: 700; }

/* ── Input Groups ── */
.abin-calc-input-group {
  display: flex; align-items: stretch; border: 1.5px solid var(--abin-border);
  border-radius: var(--abin-radius); overflow: hidden; transition: border-color 0.2s, box-shadow 0.2s; background: #fff;
}
.abin-calc-input-group:focus-within { border-color: var(--abin-brand); box-shadow: 0 0 0 3px rgba(0,82,204,0.1); }
.abin-calc-input-group.highlighted { border-color: var(--abin-success); background: #F0FFF5; }

.abin-calc-input {
  flex: 1; border: none; outline: none; padding: 10px 12px; font-size: 14px;
  font-family: inherit; color: var(--abin-text); background: transparent; min-width: 0;
}
.abin-calc-input::placeholder { color: #B8B8C8; }

.abin-calc-select {
  border: none; border-left: 1px solid var(--abin-border); padding: 10px 8px;
  font-size: 13px; font-family: inherit; color: var(--abin-text-sec);
  background: var(--abin-brand-light); cursor: pointer; outline: none;
}

.abin-calc-operator { display: flex; align-items: center; justify-content: center; font-size: 18px; font-weight: 600; color: var(--abin-text-sec); width: 28px; flex-shrink: 0; padding-bottom: 2px; }

/* ── Buttons ── */
.abin-calc-btns { display: flex; gap: 10px; margin-top: 8px; }
.abin-calc-btn { flex: 1; padding: 12px 0; border-radius: var(--abin-radius); font-size: 14px; font-weight: 600; font-family: inherit; cursor: pointer; transition: all 0.2s; letter-spacing: 0.3px; border: none; }
.abin-calc-btn-primary { background: var(--abin-accent); color: #fff; }
.abin-calc-btn-primary:hover { background: var(--abin-accent-dark); }
.abin-calc-btn-secondary { background: var(--abin-brand-muted); color: var(--abin-brand); border: 1.5px solid var(--abin-border); }
.abin-calc-btn-secondary:hover { background: var(--abin-brand-light); }

/* ── Result ── */
.abin-calc-result { margin-top: 20px; padding: 14px 18px; background: linear-gradient(135deg, var(--abin-brand-light), #E0ECFA); border-radius: var(--abin-radius); border: 1px solid var(--abin-brand-muted); display: none; }
.abin-calc-result.visible { display: block; animation: abin-fadeIn 0.3s ease; }
.abin-calc-result-label { font-size: 11px; font-weight: 600; color: var(--abin-brand); text-transform: uppercase; letter-spacing: 0.8px; }
.abin-calc-result-value { font-size: 22px; font-weight: 700; color: var(--abin-accent); margin-top: 4px; }

/* ── Error ── */
.abin-calc-error { margin-top: 14px; padding: 10px 14px; background: #FFF5F5; border: 1px solid #FFE0E0; border-radius: var(--abin-radius); color: var(--abin-error); font-size: 13px; display: none; }
.abin-calc-error.visible { display: block; animation: abin-fadeIn 0.2s ease; }

@keyframes abin-fadeIn { from { opacity: 0; transform: translateY(-4px); } to { opacity: 1; transform: translateY(0); } }

/* ── Mobile ── */
@media (max-width: 520px) {
  .abin-calc-body { padding: 16px; }
  .abin-calc-row { gap: 6px; }
  .abin-calc-field { flex: 1 1 100px; min-width: 80px; }
  .abin-calc-operator { width: 20px; font-size: 14px; }
  .abin-calc-result-value { font-size: 18px; }
}