/* CHEMCALC FX-17 — styles (split out of index.html) */
/* ── Fonts ─────────────────────────────────────────── */
@font-face {
  font-family: 'VT323';
  src: url('fonts/VT323/VT323-Regular.ttf') format('truetype');
  font-weight: normal;
  font-style: normal;
}
@font-face {
  font-family: 'Share Tech Mono';
  src: url('fonts/ShareTechMono/ShareTechMono-Regular.ttf') format('truetype');
  font-weight: normal;
  font-style: normal;
}

/* ── CSS Custom Properties ─────────────────────────── */
:root {
  /* Fonts */
  --font-display: 'VT323', monospace;
  --font-body:    'Share Tech Mono', monospace;
  /* Backgrounds */
  --bg-primary:    #0f1117;
  --bg-secondary:  #1a1d2e;
  --bg-tertiary:   #252838;
  /* Text */
  --text-primary:  #c8cce8;
  --text-secondary:#6b6f8a;
  /* Accent (overridable by user) */
  --accent:        #3b82f6;
  --accent-hover:  #2563eb;
  --accent-subtle: rgba(59,130,246,0.13);
  /* Semantic */
  --border:        #2a2d3e;
  --error:         #ff4444;
  --success:       #33ff66;
  --warning:       #f59e0b;
  /* LCD screen */
  --screen-bg:     #0a1a0a;
  --screen-fg:     #33ff66;
  --screen-dim:    #1a8a33;
  /* Calculate button */
  --btn-calc:      #1e3d1e;
  --btn-calc-fg:   #5dff7a;
  /* Shadow */
  --shadow:        0 8px 32px rgba(0,0,0,0.6);
  /* Small hint text inside forms */
  --label-fg:      var(--text-secondary);
}
[data-theme="light"] {
  --bg-primary:    #d4d8e8;
  --bg-secondary:  #e8eaf6;
  --bg-tertiary:   #d0d4e8;
  --text-primary:  #1a1d3a;
  --text-secondary:#6060a0;
  /* accent stays — user-chosen, no override */
  --border:        #b0b4c8;
  --error:         #cc0000;
  --success:       #1a6a1a;
  --warning:       #d97706;
  --screen-bg:     #c8d4c0;
  --screen-fg:     #1a3a1a;
  --screen-dim:    #4a7a4a;
  --btn-calc:      #b0d4b0;
  --btn-calc-fg:   #1a3a1a;
  --shadow:        0 8px 32px rgba(0,0,0,0.15);
}

/* ── Reset / Base ──────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body {
  background: var(--bg-primary);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  min-height: 100vh;
  padding: 20px 8px 40px;
  font-family: var(--font-body);
  transition: background 0.3s, color 0.3s;
}

/* ── Calculator Shell ──────────────────────────────── */
.calc {
  background: var(--bg-secondary);
  border: 2px solid var(--border);
  border-radius: 18px;
  width: 100%;
  max-width: 460px;
  box-shadow: var(--shadow);
  padding: 16px 14px 20px;
  transition: background 0.3s, border-color 0.3s;
}

/* ── Header ────────────────────────────────────────── */
.calc-header {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-bottom: 10px;
  margin-bottom: 12px;
  border-bottom: 1px solid var(--border);
}
.brand {
  font-family: var(--font-display);
  font-size: 28px;
  letter-spacing: 1px;
  color: var(--text-secondary);
  text-transform: uppercase;
  line-height: 1;
}
.brand span { color: var(--accent); }
.header-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}
.accent-picker {
  display: flex;
  gap: 5px;
  align-items: center;
}
.accent-dot {
  width: 13px;
  height: 13px;
  border-radius: 50%;
  border: 2px solid transparent;
  cursor: pointer;
  padding: 0;
  transition: border-color 0.15s, transform 0.1s;
  outline: none;
}
.accent-dot:hover { transform: scale(1.25); }
.accent-dot.active { border-color: var(--text-primary); }
.theme-btn {
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  color: var(--text-primary);
  border-radius: 8px;
  padding: 4px 10px;
  font-family: var(--font-body);
  font-size: 12px;
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}
.theme-btn:hover { background: var(--accent); color: #fff; }

/* ── LCD Screen ────────────────────────────────────── */
.screen {
  background: var(--bg-tertiary);
  border: 2px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 8px;
  padding: 10px 12px 10px 16px;
  margin-bottom: 12px;
  min-height: 80px;
  position: relative;
  overflow: hidden;
  transition: border-left-color 0.2s;
}
.screen-label {
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: 1.5px;
  color: var(--text-secondary);
  text-transform: uppercase;
  margin-bottom: 2px;
}
.screen-content {
  font-family: var(--font-display);
  font-size: 21px;
  color: var(--accent);
  white-space: pre-wrap;
  word-break: break-all;
  line-height: 1.35;
  min-height: 40px;
}
.screen-content.error { color: var(--error); }
.screen-warnings {
  font-family: var(--font-body);
  font-size: 12px;
  color: var(--warning);
  margin-top: 6px;
  white-space: pre-wrap;
  display: none;
}
.screen-prompt {
  font-family: var(--font-body);
  font-size: 11px;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* ── Module Grid ───────────────────────────────────── */
.mod-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 5px;
  margin-bottom: 12px;
}
.mod-label {
  grid-column: 1 / -1;
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-top: 14px;
  margin-bottom: 3px;
  padding-bottom: 3px;
  border-bottom: 1px solid var(--border);
  line-height: 1;
}
.mod-label:first-child { margin-top: 0; }
.mod-btn {
  background: var(--accent-subtle);
  color: var(--accent);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 8px 4px;
  font-family: var(--font-body);
  font-size: 13px;
  text-align: center;
  cursor: pointer;
  line-height: 1.3;
  transition: background 0.15s, color 0.15s, transform 0.1s;
  user-select: none;
}
.mod-btn:hover { background: var(--accent); color: #fff; }
.mod-btn.active { background: var(--accent); color: #fff; font-weight: 700; }
.mod-btn:active { transform: scale(0.95); }
/* Single-button sections: span 2 of 3 columns (~50-66% width) */
.mod-btn.solo { grid-column: span 2; }

/* ── Input Panel ───────────────────────────────────── */
.input-panel {
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 10px 6px;
  margin-bottom: 10px;
  min-height: 60px;
}
.panel-title {
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: 1px;
  color: var(--text-secondary);
  text-transform: uppercase;
  margin-bottom: 8px;
  line-height: 1;
}
.field-row {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 6px;
  flex-wrap: wrap;
}
.field-row label {
  font-family: var(--font-body);
  font-size: 13px;
  color: var(--text-secondary);
  min-width: 80px;
  flex-shrink: 0;
}
.field-row input,
.field-row select,
.field-row textarea {
  flex: 1;
  min-width: 0;
  background: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 5px 7px;
  font-family: var(--font-body);
  font-size: 13px;
  transition: border-color 0.2s;
  outline: none;
}
.field-row input:focus,
.field-row select:focus,
.field-row textarea:focus { border-color: var(--accent); }
.field-row textarea { resize: vertical; min-height: 32px; font-size: 11px; }

.dynamic-rows { margin-top: 4px; }
.dyn-row {
  display: flex;
  gap: 5px;
  margin-bottom: 5px;
  align-items: center;
  flex-wrap: wrap;
}
.dyn-row input {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 4px 6px;
  font-family: var(--font-body);
  font-size: 12px;
  outline: none;
}
.dyn-row input:focus { border-color: var(--accent); }
.dyn-row input.w-sm { width: 52px; }
.dyn-row input.w-md { width: 80px; }
.dyn-row input.w-lg { width: 110px; }
.dyn-row .dyn-label { font-family: var(--font-body); font-size: 11px; color: var(--text-secondary); }
.add-row-btn, .rem-row-btn {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  border-radius: 4px;
  padding: 2px 6px;
  font-family: var(--font-body);
  font-size: 12px;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}
.add-row-btn:hover { border-color: var(--accent); color: var(--accent); }
.rem-row-btn:hover { border-color: var(--error); color: var(--error); }

.radio-row {
  display: flex;
  gap: 12px;
  margin-bottom: 6px;
}
.radio-row label {
  display: flex;
  align-items: center;
  gap: 4px;
  font-family: var(--font-body);
  font-size: 13px;
  color: var(--text-primary);
  cursor: pointer;
}

/* ── Calculate Button ──────────────────────────────── */
.calc-btn {
  width: 100%;
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  opacity: 0.7;
  cursor: not-allowed;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: normal;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  transition: background 0.2s ease, color 0.2s ease, opacity 0.2s ease, transform 0.1s;
}
.calc-btn.ready {
  background: var(--accent);
  color: var(--bg-primary);
  opacity: 1;
  cursor: pointer;
}
.calc-btn.ready:hover { background: var(--accent-hover); }
.calc-btn.ready:active { transform: scale(0.98); }
.calc-btn.loading {
  background: var(--accent-subtle);
  color: var(--accent);
  opacity: 0.8;
  cursor: wait;
  animation: btn-pulse 1.2s ease-in-out infinite;
}
@keyframes btn-pulse {
  0%, 100% { opacity: 0.8; }
  50%       { opacity: 0.45; }
}

/* ── Tools row, copy, history, examples, chaining ──── */
.header-tools {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 6px;
}
.header-tools label {
  font-family: var(--font-body);
  font-size: 11px;
  color: var(--text-secondary);
}
select.theme-btn { padding: 3px 6px; }
.mini-btn {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  border-radius: 5px;
  padding: 2px 7px;
  font-family: var(--font-body);
  font-size: 11px;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}
.mini-btn:hover { border-color: var(--accent); color: var(--accent); }
.screen-copy { position: absolute; top: 8px; right: 8px; }
.chain-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin-top: 8px;
  padding-top: 6px;
  border-top: 1px dashed var(--border);
  font-family: var(--font-body);
  font-size: 11px;
  color: var(--text-secondary);
}
.chain-bar select {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: 5px;
  font-family: var(--font-body);
  font-size: 11px;
  padding: 2px 4px;
}
.history-panel {
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 10px;
  margin-bottom: 12px;
  max-height: 260px;
  overflow-y: auto;
}
.history-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 6px;
}
.history-item {
  display: block;
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  border-bottom: 1px solid var(--border);
  padding: 5px 2px;
  cursor: pointer;
  font-family: var(--font-body);
  color: var(--text-primary);
}
.history-item:hover { background: var(--accent-subtle); }
.history-item .h-title { font-size: 10px; color: var(--text-secondary); }
.history-item .h-answer { font-size: 12px; color: var(--accent); white-space: pre-wrap; }
.history-empty { font-family: var(--font-body); font-size: 12px; color: var(--text-secondary); }
.panel-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 6px;
  margin-bottom: 8px;
}
.panel-head .panel-title { margin-bottom: 0; }

/* ── Utility ───────────────────────────────────────── */
.hidden { display: none !important; }
.sep { border: none; border-top: 1px solid var(--border); margin: 8px 0; }