/* =====================================================
   ChemEngg Tools v2 — Frontend CSS
   Colors/fonts are injected as CSS vars by PHP
   ===================================================== */

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

.cet-wrap {
  font-family: var(--font-body, 'DM Sans', sans-serif);
  background: var(--c-bg, #0f1117);
  color: var(--c-text, #e8ecf4);
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid var(--c-border2);
  max-width: 980px;
  margin: 2rem auto;
}

/* Tool title */
.cet-tool-title {
  text-align: center;
  font-size: 20px;
  font-weight: 600;
  color: var(--c-text);
  padding: 1.25rem 1.5rem 0;
  letter-spacing: -0.01em;
}

/* Tabs */
.cet-tabs { display: flex; background: var(--c-surface); border-bottom: 1px solid var(--c-border); padding: 0 1.5rem; gap: 4px; }
.cet-tab { display: flex; align-items: center; gap: 8px; padding: 1rem 1.25rem; border: none; background: transparent; color: var(--c-muted); font-family: var(--font-body); font-size: 14px; font-weight: 500; cursor: pointer; border-bottom: 2px solid transparent; margin-bottom: -1px; transition: color 0.2s; }
.cet-tab svg { opacity: 0.6; transition: opacity 0.2s; }
.cet-tab:hover { color: var(--c-text); }
.cet-tab:hover svg { opacity: 1; }
.cet-tab.cet-tab--active { color: var(--c-accent); border-bottom-color: var(--c-accent); }
.cet-tab.cet-tab--active svg { opacity: 1; }

/* Panels */
.cet-panel { display: none; padding: 1.75rem; }
.cet-panel.cet-panel--active { display: block; }

/* Converter layout */
.cet-converter-layout { display: grid; grid-template-columns: 180px 1fr; gap: 1.5rem; }
@media (max-width: 680px) { .cet-converter-layout { grid-template-columns: 1fr; } }

/* Category buttons */
.cet-cat-list { display: flex; flex-direction: column; gap: 4px; }
.cet-cat-btn { display: flex; align-items: center; gap: 10px; padding: 10px 12px; border: 1px solid transparent; border-radius: calc(var(--radius, 10px) - 2px); background: transparent; color: var(--c-muted); font-family: var(--font-body); font-size: 13px; cursor: pointer; text-align: left; transition: all 0.15s; }
.cet-cat-btn:hover { background: var(--c-surface2); color: var(--c-text); }
.cet-cat-btn.active { background: color-mix(in srgb, var(--c-accent) 12%, transparent); border-color: color-mix(in srgb, var(--c-accent) 35%, transparent); color: var(--c-accent); font-weight: 500; }
.cet-cat-icon { font-size: 15px; min-width: 20px; text-align: center; }

/* Inputs */
.cet-converter-panel { display: flex; flex-direction: column; gap: 1.25rem; }
.cet-conv-row { display: grid; grid-template-columns: 1fr auto 1fr; gap: 1rem; align-items: end; }
@media (max-width: 520px) { .cet-conv-row { grid-template-columns: 1fr; } .cet-swap-btn { margin: 0 auto; } }
.cet-conv-field { display: flex; flex-direction: column; gap: 6px; }
.cet-label { font-size: 11px; font-weight: 600; color: var(--c-muted); letter-spacing: 0.07em; text-transform: uppercase; }

.cet-input { width: 100%; padding: 10px 14px; background: var(--c-input-bg, var(--c-surface2)); border: 1px solid var(--c-border2); border-radius: calc(var(--radius, 10px) - 2px); color: var(--c-text); font-family: var(--font-mono, monospace); font-size: 15px; outline: none; transition: border-color 0.15s; -moz-appearance: textfield; }
.cet-input::-webkit-outer-spin-button, .cet-input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.cet-input:focus { border-color: var(--c-accent); }
.cet-input--result { color: var(--c-accent); font-weight: 500; }

.cet-select { width: 100%; padding: 9px 14px; background: var(--c-surface); border: 1px solid var(--c-border2); border-radius: calc(var(--radius, 10px) - 2px); color: var(--c-text); font-family: var(--font-body); font-size: 13px; outline: none; cursor: pointer; transition: border-color 0.15s; }
.cet-select:focus { border-color: var(--c-accent); }

.cet-swap-btn { width: 40px; height: 40px; border-radius: 50%; border: 1px solid var(--c-border2); background: var(--c-surface2); color: var(--c-muted); cursor: pointer; display: flex; align-items: center; justify-content: center; transition: all 0.2s; align-self: center; margin-top: 18px; }
.cet-swap-btn:hover { border-color: var(--c-accent); color: var(--c-accent); transform: rotate(180deg); }

/* Result card */
.cet-result-card { background: color-mix(in srgb, var(--c-accent) 8%, transparent); border: 1px solid color-mix(in srgb, var(--c-accent) 25%, transparent); border-radius: var(--radius, 10px); padding: 1rem 1.25rem; }
.cet-result-equation { font-family: var(--font-mono); font-size: 16px; font-weight: 500; color: var(--c-accent); }
.cet-result-note { font-size: 12px; color: var(--c-muted); margin-top: 4px; }

/* All conversions */
.cet-all-conversions { background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius, 10px); overflow: hidden; }
.cet-all-conversions-title { font-size: 11px; font-weight: 600; color: var(--c-muted); letter-spacing: 0.07em; text-transform: uppercase; padding: 10px 14px; border-bottom: 1px solid var(--c-border); }
.cet-conv-row-item { display: flex; justify-content: space-between; align-items: center; padding: 8px 14px; border-bottom: 1px solid var(--c-border); font-size: 13px; transition: background 0.1s; }
.cet-conv-row-item:last-child { border-bottom: none; }
.cet-conv-row-item:hover { background: var(--c-surface2); }
.cet-conv-row-item .unit-name { color: var(--c-muted); }
.cet-conv-row-item .unit-val { font-family: var(--font-mono); font-size: 13px; font-weight: 500; color: var(--c-text); }
.cet-conv-row-item .unit-val.highlight { color: var(--c-accent); }

/* Equipment sizing */
.cet-eq-tabs { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 1.5rem; }
.cet-eq-tab { padding: 7px 16px; border: 1px solid var(--c-border2); border-radius: 20px; background: transparent; color: var(--c-muted); font-family: var(--font-body); font-size: 13px; cursor: pointer; transition: all 0.15s; }
.cet-eq-tab:hover { color: var(--c-text); }
.cet-eq-tab.active { background: color-mix(in srgb, var(--c-accent) 12%, transparent); border-color: var(--c-accent); color: var(--c-accent); font-weight: 500; }

.cet-eq-panel { display: none; }
.cet-eq-panel.active { display: block; }

.cet-eq-desc { font-size: 14px; color: var(--c-muted); margin-bottom: 1.25rem; line-height: 1.6; padding: 12px 16px; background: var(--c-surface); border-radius: calc(var(--radius, 10px) - 2px); border-left: 3px solid var(--c-accent2); }
.cet-eq-desc strong { color: var(--c-text); }

.cet-form-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1rem; margin-bottom: 1.25rem; }
.cet-form-group { display: flex; flex-direction: column; gap: 6px; }

.cet-calc-btn { padding: 11px 28px; background: var(--c-accent); color: #0f1117; border: none; border-radius: calc(var(--radius, 10px) - 2px); font-family: var(--font-body); font-size: 14px; font-weight: 600; cursor: pointer; transition: opacity 0.15s, transform 0.1s; }
.cet-calc-btn:hover { opacity: 0.85; }
.cet-calc-btn:active { transform: scale(0.98); }

.cet-result-box { margin-top: 1.25rem; padding: 1.25rem; background: var(--c-card); border: 1px solid var(--c-border); border-radius: var(--radius, 10px); display: none; }
.cet-result-box.visible { display: block; }
.cet-result-box.error { border-color: color-mix(in srgb, #ff5f5f 35%, transparent); background: color-mix(in srgb, #ff5f5f 6%, transparent); }
.cet-result-error { color: #ff5f5f; font-size: 14px; }

.cet-result-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 12px; }
.cet-metric { background: var(--c-surface2); border: 1px solid var(--c-border); border-radius: calc(var(--radius, 10px) - 2px); padding: 12px 16px; }
.cet-metric.highlight { border-color: color-mix(in srgb, var(--c-accent) 35%, transparent); background: color-mix(in srgb, var(--c-accent) 7%, transparent); }
.cet-metric-label { font-size: 11px; color: var(--c-muted); margin-bottom: 4px; text-transform: uppercase; letter-spacing: 0.05em; }
.cet-metric-val { font-family: var(--font-mono); font-size: 20px; font-weight: 500; color: var(--c-accent); line-height: 1.2; }
.cet-metric-unit { font-size: 12px; color: var(--c-muted); margin-top: 2px; }

.cet-formula-box { margin-top: 1.25rem; padding: 1rem 1.25rem; background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius, 10px); font-size: 13px; line-height: 1.8; }
.cet-formula-title { font-size: 11px; font-weight: 600; color: var(--c-muted); letter-spacing: 0.07em; text-transform: uppercase; margin-bottom: 8px; }
.cet-formula-box code { display: block; font-family: var(--font-mono); font-size: 12px; color: var(--c-accent2); background: none; border: none; padding: 0; }

/* Footer */
.cet-footer { text-align: center; padding: 1rem; font-size: 12px; color: var(--c-muted); border-top: 1px solid var(--c-border); }
.cet-footer a { color: var(--c-accent); text-decoration: none; }
.cet-footer a:hover { text-decoration: underline; }

@media (max-width: 480px) { .cet-panel { padding: 1.25rem 1rem; } .cet-metric-val { font-size: 16px; } }