:root {
  --bg: #f4f6f9;
  --card: #fff;
  --border: #dce1e8;
  --text: #1a2332;
  --text2: #5a6577;
  --accent: #2563eb;
  --accent-light: #dbeafe;
  --green: #16a34a;
  --green-bg: #dcfce7;
  --yellow: #ca8a04;
  --yellow-bg: #fef9c3;
  --orange: #ea580c;
  --orange-bg: #fff7ed;
  --red: #dc2626;
  --red-bg: #fef2f2;
  --blue-bg: #eff6ff;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,.08);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif; background: var(--bg); color: var(--text); font-size: 14px; line-height: 1.5; }

header { background: var(--accent); color: #fff; padding: 12px 24px; display: flex; align-items: center; justify-content: space-between; }
header h1 { font-size: 18px; font-weight: 600; }
.header-controls { display: flex; gap: 8px; align-items: center; }
.header-controls select, .header-controls button { font-size: 13px; padding: 4px 10px; border-radius: 4px; border: 1px solid rgba(255,255,255,.3); background: rgba(255,255,255,.15); color: #fff; cursor: pointer; }
.header-controls button { background: rgba(255,255,255,.2); }
.header-controls button:hover { background: rgba(255,255,255,.35); }

.app-layout { display: grid; grid-template-columns: 340px 1fr 320px; gap: 0; height: calc(100vh - 48px); overflow: hidden; }

/* Left panel - input */
.input-panel { overflow-y: auto; border-right: 1px solid var(--border); background: var(--card); padding: 12px; }
.panel-section { margin-bottom: 16px; }
.panel-section h3 { font-size: 12px; text-transform: uppercase; letter-spacing: .5px; color: var(--text2); margin-bottom: 8px; padding-bottom: 4px; border-bottom: 1px solid var(--border); }

.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; margin-bottom: 6px; }
.form-row.triple { grid-template-columns: 1fr 1fr 1fr; }
.form-group { display: flex; flex-direction: column; }
.form-group label { font-size: 11px; color: var(--text2); margin-bottom: 2px; }
.form-group input, .form-group select { padding: 5px 8px; border: 1px solid var(--border); border-radius: 4px; font-size: 13px; width: 100%; }
.form-group input:focus, .form-group select:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent-light); }
.form-group .unit { font-size: 10px; color: var(--text2); }
.form-row.single { grid-template-columns: 1fr; }

.computed-row { display: flex; justify-content: space-between; padding: 3px 0; font-size: 12px; }
.computed-row .label { color: var(--text2); }
.computed-row .value { font-weight: 600; }

/* Center panel - summary */
.summary-panel { overflow-y: auto; padding: 12px; }

.tabs { display: flex; gap: 4px; margin-bottom: 12px; border-bottom: 2px solid var(--border); padding-bottom: 0; }
.tab-btn { padding: 6px 14px; font-size: 12px; font-weight: 500; border: none; background: none; cursor: pointer; color: var(--text2); border-bottom: 2px solid transparent; margin-bottom: -2px; }
.tab-btn.active { color: var(--accent); border-bottom-color: var(--accent); }
.tab-panel { display: none; }
.tab-panel.active { display: block; }

.summary-card { background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); padding: 14px; margin-bottom: 12px; }
.summary-card h4 { font-size: 13px; font-weight: 600; margin-bottom: 8px; }

.summary-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.summary-item { display: flex; justify-content: space-between; padding: 4px 0; border-bottom: 1px solid #f0f0f0; font-size: 13px; }
.summary-item .si-label { color: var(--text2); }
.summary-item .si-value { font-weight: 600; font-variant-numeric: tabular-nums; }
.summary-item.highlight { background: var(--accent-light); padding: 4px 6px; border-radius: 4px; border: none; }

.dist-bar { display: flex; height: 24px; border-radius: 4px; overflow: hidden; margin: 8px 0; font-size: 11px; font-weight: 600; color: #fff; }
.dist-bar .dist-dex { background: #3b82f6; display: flex; align-items: center; justify-content: center; }
.dist-bar .dist-prot { background: #10b981; display: flex; align-items: center; justify-content: center; }
.dist-bar .dist-lip { background: #f59e0b; display: flex; align-items: center; justify-content: center; }

.sol-badge { padding: 2px 10px; border-radius: 12px; font-size: 12px; font-weight: 600; }
.sol-safe { background: var(--green-bg); color: var(--green); }
.sol-caution { background: var(--yellow-bg); color: var(--yellow); }
.sol-alert { background: var(--orange-bg); color: var(--orange); }
.sol-stop { background: var(--red-bg); color: var(--red); }

.val-ok { color: var(--green); }
.val-alert { color: var(--red); font-weight: 700; }

/* Electrolyte table */
.elec-table { width: 100%; border-collapse: collapse; font-size: 13px; }
.elec-table th { text-align: left; font-size: 11px; color: var(--text2); padding: 4px; border-bottom: 1px solid var(--border); }
.elec-table td { padding: 4px; border-bottom: 1px solid #f5f5f5; }

/* Comparison table */
.comp-table { width: 100%; border-collapse: collapse; font-size: 13px; }
.comp-table th { text-align: left; font-size: 11px; color: var(--text2); padding: 4px 6px; border-bottom: 2px solid var(--border); }
.comp-table td { padding: 4px 6px; border-bottom: 1px solid #f5f5f5; }
.delta-up { color: var(--orange); font-weight: 600; }
.delta-down { color: var(--accent); font-weight: 600; }
.empty-state { color: var(--text2); text-align: center; font-style: italic; padding: 20px; }

/* Right panel - warnings */
.warnings-panel { overflow-y: auto; border-left: 1px solid var(--border); background: var(--card); padding: 12px; }
.warnings-panel h3 { font-size: 12px; text-transform: uppercase; letter-spacing: .5px; color: var(--text2); margin-bottom: 8px; }

.warning-item { padding: 8px 10px; border-radius: 6px; margin-bottom: 6px; font-size: 12px; display: flex; gap: 8px; align-items: flex-start; }
.warning-badge { font-size: 10px; font-weight: 700; padding: 1px 6px; border-radius: 3px; white-space: nowrap; }
.warning-cat { font-weight: 600; white-space: nowrap; }

.warning-stop { background: var(--red-bg); border-left: 3px solid var(--red); }
.warning-stop .warning-badge { background: var(--red); color: #fff; }
.warning-alert { background: var(--orange-bg); border-left: 3px solid var(--orange); }
.warning-alert .warning-badge { background: var(--orange); color: #fff; }
.warning-caution { background: var(--yellow-bg); border-left: 3px solid var(--yellow); }
.warning-caution .warning-badge { background: var(--yellow); color: #fff; }
.warning-info { background: var(--blue-bg); border-left: 3px solid var(--accent); color: var(--accent); }

/* Guideline ranges table */
.guide-table { width: 100%; border-collapse: collapse; font-size: 12px; }
.guide-table th { text-align: left; font-size: 11px; color: var(--text2); padding: 4px 6px; border-bottom: 1px solid var(--border); }
.guide-table td { padding: 4px 6px; border-bottom: 1px solid #f5f5f5; }
.guide-badge { padding: 1px 8px; border-radius: 10px; font-size: 11px; font-weight: 600; white-space: nowrap; }
.guide-ok { background: var(--green-bg); color: var(--green); }
.guide-low { background: var(--yellow-bg); color: var(--yellow); }
.guide-high { background: var(--orange-bg); color: var(--orange); }

/* Inline warnings */
.inline-warning { font-size: 11px; padding: 4px 8px; border-radius: 4px; margin-top: 4px; }
.inline-warning-alert { background: var(--red-bg); color: var(--red); border-left: 3px solid var(--red); }
.inline-warning-caution { background: var(--yellow-bg); color: var(--yellow); border-left: 3px solid var(--yellow); }

/* Fluid range bar */
.fluid-range-bar { position: relative; height: 12px; background: var(--border); border-radius: 6px; overflow: visible; margin: 4px 0; }
.fluid-range-fill { height: 100%; border-radius: 6px; background: var(--green); transition: width .3s; }
.fluid-range-fill.fluid-range-over { background: var(--red); }
.fluid-range-fill.fluid-range-under { background: var(--yellow); }
.fluid-range-marker { position: absolute; top: -3px; width: 4px; height: 18px; background: var(--text); border-radius: 2px; transform: translateX(-2px); transition: left .3s; }

/* SOAP style select */
#soap-style { padding: 6px 14px; border-radius: var(--radius); border: 1px solid var(--border); background: var(--card); color: var(--text); cursor: pointer; font-size: 12px; }

/* Volume target slider */
.volume-target-section { margin-top: 8px; padding-top: 8px; border-top: 1px dashed var(--border); }
.volume-slider-wrapper { display: flex; align-items: center; gap: 6px; }
.volume-slider-wrapper input[type="range"] { flex: 1; height: 6px; -webkit-appearance: none; appearance: none; background: var(--border); border-radius: 3px; outline: none; cursor: pointer; }
.volume-slider-wrapper input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; width: 16px; height: 16px; border-radius: 50%; background: var(--accent); cursor: pointer; border: 2px solid var(--card); box-shadow: 0 1px 3px rgba(0,0,0,.2); }
.volume-slider-wrapper input[type="range"]::-moz-range-thumb { width: 16px; height: 16px; border-radius: 50%; background: var(--accent); cursor: pointer; border: 2px solid var(--card); box-shadow: 0 1px 3px rgba(0,0,0,.2); }
.slider-label-left, .slider-label-right { font-size: 10px; color: var(--text2); white-space: nowrap; }
.slider-value-display { font-size: 11px; color: var(--text2); margin-top: 3px; text-align: center; }
.slider-auto-label { font-size: 10px; color: var(--accent); font-style: italic; }

/* ============================================
   Login Screen
   ============================================ */
.login-overlay {
  position: fixed;
  inset: 0;
  z-index: 10000;
  background: var(--bg, #f4f6f9);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.login-overlay.hidden { display: none; }
.login-card {
  background: var(--card, #fff);
  border-radius: 16px;
  box-shadow: 0 4px 24px rgba(0,0,0,.12);
  padding: 40px 36px;
  width: 100%;
  max-width: 400px;
}
.login-header {
  text-align: center;
  margin-bottom: 28px;
}
.login-icon {
  color: var(--accent, #2563eb);
  margin-bottom: 12px;
}
.login-header h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 4px;
}
.login-subtitle {
  font-size: 13px;
  color: var(--text2, #5a6577);
}
.login-field {
  margin-bottom: 16px;
}
.login-field label {
  display: block;
  font-size: 12px;
  font-weight: 600;
  color: var(--text2, #5a6577);
  margin-bottom: 4px;
}
.login-field input {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border, #dce1e8);
  border-radius: 8px;
  font-size: 14px;
  background: var(--input-bg, #fff);
  color: var(--text, #1a2332);
  transition: border-color .2s, box-shadow .2s;
}
.login-field input:focus {
  outline: none;
  border-color: var(--accent, #2563eb);
  box-shadow: 0 0 0 3px var(--accent-light, #dbeafe);
}
.login-error {
  background: var(--red-bg, #fef2f2);
  color: var(--red, #dc2626);
  font-size: 13px;
  padding: 8px 12px;
  border-radius: 6px;
  margin-bottom: 16px;
  text-align: center;
}
.login-btn {
  width: 100%;
  padding: 12px;
  background: var(--accent, #2563eb);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: opacity .2s;
}
.login-btn:hover { opacity: .9; }
.login-btn:active { opacity: .8; }

/* ============================================
   Mobile Bottom Navigation
   ============================================ */
.mobile-nav {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--card, #fff);
  border-top: 1px solid var(--border, #dce1e8);
  box-shadow: 0 -2px 8px rgba(0,0,0,.08);
  padding: 4px 0;
  padding-bottom: env(safe-area-inset-bottom, 4px);
}
.mobile-nav-btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding: 6px 4px;
  border: none;
  background: none;
  color: var(--text2, #5a6577);
  font-size: 10px;
  cursor: pointer;
  transition: color .2s;
}
.mobile-nav-btn.active {
  color: var(--accent, #2563eb);
}
.mobile-nav-btn svg { stroke: currentColor; }

/* Print styles */
@media print {
  .app-layout { display: block; }
  .input-panel, .warnings-panel, .tabs, header { display: none; }
  .summary-panel { padding: 0; }
  .tab-panel { display: block !important; }
  .summary-card { break-inside: avoid; box-shadow: none; border: 1px solid #ddd; }
}

/* Responsive */
@media (max-width: 1200px) {
  .app-layout { grid-template-columns: 300px 1fr 280px; }
}

@media (max-width: 900px) {
  .app-layout {
    grid-template-columns: 1fr;
    height: auto;
    min-height: calc(100vh - 48px);
    padding-bottom: 64px;
  }
  .input-panel, .warnings-panel { border: none; }

  .mobile-nav {
    display: flex;
  }

  .app-layout > .input-panel,
  .app-layout > .summary-panel,
  .app-layout > .warnings-panel {
    display: none;
  }
  .app-layout > .mobile-active {
    display: block !important;
  }

  header {
    flex-wrap: wrap;
    gap: 8px;
    padding: 10px 12px;
  }
  header h1 { font-size: 16px; }
  .header-controls {
    flex-wrap: wrap;
    gap: 6px;
    width: 100%;
    justify-content: flex-start;
  }
  .header-controls select, .header-controls button {
    font-size: 12px;
    padding: 6px 10px;
  }

  .input-panel, .summary-panel, .warnings-panel {
    overflow-y: auto;
    height: auto;
    max-height: none;
    padding: 12px;
  }

  .tabs {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    white-space: nowrap;
    gap: 0;
  }
  .tab-btn {
    flex-shrink: 0;
    padding: 8px 12px;
    font-size: 12px;
  }

  .summary-grid { grid-template-columns: 1fr 1fr; }

  .form-group input, .form-group select {
    padding: 8px 10px;
    font-size: 14px;
    min-height: 40px;
  }

  .soap-actions {
    flex-wrap: wrap;
  }
  .soap-actions button, .soap-actions select {
    flex: 1;
    min-width: 100px;
  }

  .guide-table, .elec-table, .comp-table {
    display: block;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
}

@media (max-width: 480px) {
  .form-row { grid-template-columns: 1fr; }
  .form-row.triple { grid-template-columns: 1fr; }
  .summary-grid { grid-template-columns: 1fr; }

  .login-card {
    padding: 28px 20px;
  }

  header h1 { font-size: 14px; }
  .header-controls select, .header-controls button {
    font-size: 11px;
    padding: 5px 8px;
  }
}