/* ── Reset & Base ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --color-primary:      #1565C0;
  --color-primary-light:#1976D2;
  --color-primary-bg:   #E3F2FD;
  --color-green:        #2E7D32;
  --color-green-bg:     #E8F5E9;
  --color-green-border: #A5D6A7;
  --color-amber:        #E65100;
  --color-amber-bg:     #FFF3E0;
  --color-amber-border: #FFCC80;
  --color-red:          #C62828;
  --color-red-bg:       #FFEBEE;
  --color-red-border:   #EF9A9A;
  --color-gray:         #546E7A;
  --color-gray-bg:      #ECEFF1;
  --color-gray-border:  #B0BEC5;
  --color-text:         #1A237E;
  --color-text-body:    #263238;
  --color-text-muted:   #546E7A;
  --color-bg:           #F0F4F8;
  --color-card:         #FFFFFF;
  --color-border:       #CFD8DC;
  --radius:             12px;
  --radius-sm:          8px;
  --shadow:             0 2px 8px rgba(0,0,0,.08), 0 0 0 1px rgba(0,0,0,.04);
  --shadow-hover:       0 4px 16px rgba(0,0,0,.12);
  --font-body:          'Noto Sans TC', sans-serif;
  --font-mono:          'DM Mono', monospace;
  --transition:         .18s ease;
}

html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text-body);
  line-height: 1.6;
  min-height: 100vh;
}

/* ── Header ── */
.header {
  background: linear-gradient(135deg, #0D47A1 0%, #1565C0 60%, #1976D2 100%);
  color: #fff;
  padding: 1.5rem 1rem;
  box-shadow: 0 2px 12px rgba(0,0,0,.2);
}
.header__inner {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.header__brand {
  display: flex;
  align-items: center;
  gap: 1rem;
}
.header__formula {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 500;
  opacity: .9;
  letter-spacing: -.02em;
  background: rgba(255,255,255,.12);
  padding: .25rem .75rem;
  border-radius: var(--radius-sm);
}
.header__title {
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.2;
}
.header__subtitle {
  font-size: .8rem;
  opacity: .75;
  margin-top: .2rem;
}
.header__version {
  font-family: var(--font-mono);
  font-size: .75rem;
  background: rgba(255,255,255,.15);
  padding: .25rem .6rem;
  border-radius: 999px;
  white-space: nowrap;
}

/* ── Main Layout ── */
.main {
  max-width: 900px;
  margin: 0 auto;
  padding: 1.5rem 1rem 3rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

/* ── Card ── */
.card {
  background: var(--color-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.5rem;
}
.card--result {
  border-top: 4px solid var(--color-primary);
}
.card--evidence {
  background: #FAFBFD;
}
.card__title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: .6rem;
  margin-bottom: 1.1rem;
}
.card__step {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.6rem;
  height: 1.6rem;
  background: var(--color-primary);
  color: #fff;
  border-radius: 50%;
  font-size: .8rem;
  font-weight: 700;
  flex-shrink: 0;
}

/* ── Badges ── */
.badge {
  display: inline-block;
  font-size: .72rem;
  font-weight: 600;
  padding: .2rem .55rem;
  border-radius: 999px;
  line-height: 1.4;
  white-space: nowrap;
}
.badge--green  { background: var(--color-green-bg);  color: var(--color-green);  border: 1px solid var(--color-green-border); }
.badge--amber  { background: var(--color-amber-bg);  color: var(--color-amber);  border: 1px solid var(--color-amber-border); }
.badge--red    { background: var(--color-red-bg);    color: var(--color-red);    border: 1px solid var(--color-red-border); }
.badge--gray   { background: var(--color-gray-bg);   color: var(--color-gray);   border: 1px solid var(--color-gray-border); }

/* ── Scenario Grid ── */
.scenario-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: .75rem;
}
@media (max-width: 600px) { .scenario-grid { grid-template-columns: 1fr; } }

.scenario {
  display: flex;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: .9rem 1rem;
  cursor: pointer;
  transition: border-color var(--transition), box-shadow var(--transition), background var(--transition);
  gap: .75rem;
  align-items: flex-start;
}
.scenario input[type="radio"] { width: 1.1rem; height: 1.1rem; flex-shrink: 0; margin-top: .1rem; accent-color: var(--color-primary); }
.scenario__body { display: flex; flex-direction: column; gap: .35rem; }
.scenario__name { font-size: .9rem; font-weight: 600; color: var(--color-text); line-height: 1.3; }
.scenario__evidence { font-size: .75rem; color: var(--color-text-muted); line-height: 1.4; }

.scenario:hover { box-shadow: var(--shadow-hover); }
.scenario:has(input:checked) { border-color: var(--color-primary); background: var(--color-primary-bg); }

/* ── Vd Toggle ── */
.vd-toggle { margin-bottom: 1.25rem; }
.vd-toggle__label { display: block; font-size: .85rem; font-weight: 600; color: var(--color-text); margin-bottom: .5rem; }
.vd-toggle__btns { display: flex; gap: .5rem; flex-wrap: wrap; }
.vd-toggle__hint { font-size: .78rem; color: var(--color-text-muted); margin-top: .4rem; }

.vd-btn {
  padding: .45rem 1.1rem;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: #fff;
  color: var(--color-text-muted);
  font-family: var(--font-body);
  font-size: .85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
}
.vd-btn:hover { border-color: var(--color-primary-light); color: var(--color-primary); }
.vd-btn--active { border-color: var(--color-primary); background: var(--color-primary); color: #fff; }

/* ── Inputs ── */
.input-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-bottom: 1.25rem;
}
@media (max-width: 560px) { .input-row { grid-template-columns: 1fr; } }

.field__label {
  display: block;
  font-size: .82rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: .35rem;
}
.field__wrap {
  display: flex;
  align-items: center;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color var(--transition);
}
.field__wrap:focus-within { border-color: var(--color-primary); }
.field__input {
  flex: 1;
  border: none;
  outline: none;
  padding: .55rem .75rem;
  font-family: var(--font-mono);
  font-size: 1rem;
  background: transparent;
  color: var(--color-text);
  min-width: 0;
}
.field__unit {
  padding: 0 .65rem;
  font-size: .78rem;
  color: var(--color-text-muted);
  background: var(--color-gray-bg);
  height: 100%;
  display: flex;
  align-items: center;
  border-left: 1px solid var(--color-border);
  white-space: nowrap;
}
.field__hint { font-size: .75rem; color: var(--color-text-muted); margin-top: .3rem; }

/* ── Input Row 4-col ── */
.input-row--4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 700px) { .input-row--4 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 400px) { .input-row--4 { grid-template-columns: 1fr; } }

/* ── pH Severity Bar ── */
.ph-severity {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: .6rem;
  border-radius: var(--radius-sm);
  padding: .75rem 1rem;
  margin-bottom: 1rem;
  background: var(--color-gray-bg);
  border: 1px solid var(--color-border);
  transition: background var(--transition), border-color var(--transition);
}
.ph-severity__left { display: flex; align-items: baseline; gap: .6rem; }
.ph-severity__label { font-size: .78rem; color: var(--color-text-muted); font-weight: 600; }
.ph-severity__value {
  font-family: var(--font-mono);
  font-size: 1.6rem;
  font-weight: 500;
  color: var(--color-text);
  transition: color var(--transition);
}
.ph-severity__right { display: flex; align-items: center; gap: .6rem; flex-wrap: wrap; }
.ph-severity__badge {
  font-size: .8rem;
  font-weight: 700;
  padding: .25rem .75rem;
  border-radius: 999px;
  white-space: nowrap;
}
.ph-severity__detail { font-size: .78rem; color: var(--color-text-muted); line-height: 1.4; }

.ph-severity[data-level="critical"] { background: var(--color-red-bg);   border-color: var(--color-red-border); }
.ph-severity[data-level="severe"]   { background: var(--color-amber-bg); border-color: var(--color-amber-border); }
.ph-severity[data-level="moderate"] { background: var(--color-amber-bg); border-color: var(--color-amber-border); }

.ph-severity[data-level="critical"] .ph-severity__value { color: var(--color-red); }
.ph-severity[data-level="severe"]   .ph-severity__value { color: var(--color-amber); }
.ph-severity[data-level="moderate"] .ph-severity__value { color: #F57C00; }

.ph-severity[data-level="critical"] .ph-severity__badge { background: var(--color-red);   color: #fff; }
.ph-severity[data-level="severe"]   .ph-severity__badge { background: var(--color-amber); color: #fff; }
.ph-severity[data-level="moderate"] .ph-severity__badge { background: #F57C00;            color: #fff; }
.ph-severity[data-level="mild"]     .ph-severity__badge { background: var(--color-gray);  color: #fff; }

/* ── Calc Button ── */
.calc-btn {
  width: 100%;
  padding: .75rem;
  background: var(--color-primary);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: background var(--transition), box-shadow var(--transition);
  letter-spacing: .02em;
}
.calc-btn:hover { background: var(--color-primary-light); box-shadow: 0 4px 12px rgba(21,101,192,.3); }
.calc-btn:active { transform: translateY(1px); }

/* ── Alerts ── */
.alert {
  border-radius: var(--radius-sm);
  padding: .9rem 1.1rem;
  margin-bottom: 1rem;
  font-size: .88rem;
  line-height: 1.5;
}
.alert--red    { background: var(--color-red-bg);   border-left: 4px solid var(--color-red);   color: var(--color-red); }
.alert--amber  { background: var(--color-amber-bg); border-left: 4px solid var(--color-amber); color: var(--color-amber); }

/* ── Formula ── */
.formula-box {
  background: #1A237E;
  color: #E8EAF6;
  border-radius: var(--radius-sm);
  padding: .75rem 1.1rem;
  font-family: var(--font-mono);
  font-size: .88rem;
  margin-bottom: 1.1rem;
  line-height: 1.7;
}
.formula-box em { color: #90CAF9; font-style: normal; }

/* ── Result Tiles ── */
.result-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: .75rem;
  margin-bottom: 1.25rem;
}
@media (max-width: 540px) { .result-row { grid-template-columns: 1fr; } }

.result-tile {
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: .85rem 1rem;
  text-align: center;
}
.result-tile--primary { border-color: var(--color-primary); background: var(--color-primary-bg); }
.result-tile__label { font-size: .78rem; color: var(--color-text-muted); margin-bottom: .2rem; font-weight: 500; }
.result-tile__value { font-family: var(--font-mono); font-size: 1.9rem; font-weight: 500; color: var(--color-text); line-height: 1; }
.result-tile--primary .result-tile__value { color: var(--color-primary); font-size: 2.2rem; }
.result-tile__unit { font-size: .78rem; color: var(--color-text-muted); margin-top: .15rem; }

/* ── Vial Box ── */
.vial-box {
  background: var(--color-gray-bg);
  border-radius: var(--radius-sm);
  padding: 1rem 1.1rem;
  margin-bottom: 1rem;
}
.vial-box__title {
  font-size: .88rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: .75rem;
  display: flex;
  align-items: baseline;
  gap: .5rem;
  flex-wrap: wrap;
}
.vial-box__spec {
  font-family: var(--font-mono);
  font-size: .78rem;
  color: var(--color-text-muted);
  font-weight: 400;
}
.vial-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: .6rem;
}
@media (max-width: 480px) { .vial-grid { grid-template-columns: 1fr; } }

.vial-tile {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: .7rem .85rem;
  text-align: center;
}
.vial-tile--highlight { border-color: var(--color-primary); background: var(--color-primary-bg); }
.vial-tile__label { font-size: .75rem; color: var(--color-text-muted); margin-bottom: .15rem; font-weight: 500; }
.vial-tile__vials { font-family: var(--font-mono); font-size: 1.4rem; font-weight: 500; color: var(--color-text); }
.vial-tile--highlight .vial-tile__vials { color: var(--color-primary); }
.vial-tile__detail { font-size: .72rem; color: var(--color-text-muted); margin-top: .1rem; font-family: var(--font-mono); }

/* ── Steps ── */
.steps {
  list-style: none;
  counter-reset: step;
  display: flex;
  flex-direction: column;
  gap: .5rem;
  margin-top: 1rem;
}
.steps__item {
  counter-increment: step;
  display: flex;
  gap: .65rem;
  align-items: flex-start;
  font-size: .88rem;
  color: var(--color-text-body);
  padding: .55rem .8rem;
  background: var(--color-gray-bg);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--color-primary);
}
.steps__item::before {
  content: counter(step);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.4rem;
  height: 1.4rem;
  background: var(--color-primary);
  color: #fff;
  border-radius: 50%;
  font-size: .7rem;
  font-weight: 700;
  flex-shrink: 0;
}

/* ── Checklist ── */
.checklist { display: flex; flex-direction: column; gap: 1.1rem; }
.checklist__group {}
.checklist__heading {
  font-size: .85rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: .5rem;
  padding-bottom: .3rem;
  border-bottom: 2px solid var(--color-primary-bg);
}
.checklist__item {
  display: flex;
  align-items: flex-start;
  gap: .55rem;
  padding: .4rem .5rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: .87rem;
  line-height: 1.45;
  transition: background var(--transition);
}
.checklist__item:hover { background: var(--color-primary-bg); }
.checklist__item input { width: 1rem; height: 1rem; flex-shrink: 0; margin-top: .15rem; accent-color: var(--color-primary); }

/* ── Evidence Table ── */
.evidence-wrap { overflow-x: auto; margin-bottom: .75rem; }
.evidence-table {
  width: 100%;
  border-collapse: collapse;
  font-size: .8rem;
  min-width: 600px;
}
.evidence-table th {
  background: var(--color-primary);
  color: #fff;
  padding: .55rem .75rem;
  text-align: left;
  font-weight: 600;
  white-space: nowrap;
}
.evidence-table td {
  padding: .55rem .75rem;
  border-bottom: 1px solid var(--color-border);
  vertical-align: top;
  line-height: 1.4;
}
.evidence-table td em { font-size: .75rem; color: var(--color-text-muted); font-style: normal; }
.ev--green td { background: #F1F8E9; }
.ev--amber td { background: #FFF8E1; }
.ev--red   td { background: #FFF3F3; }
.ev__krt { font-family: var(--font-mono); font-size: .78rem; }
.ev__krt--good { color: var(--color-green); font-weight: 600; }

.evidence-disclaimer {
  font-size: .76rem;
  color: var(--color-text-muted);
  border-top: 1px solid var(--color-border);
  padding-top: .6rem;
  line-height: 1.5;
}

/* ── Footer ── */
.footer {
  text-align: center;
  font-size: .75rem;
  color: var(--color-text-muted);
  padding: 1.5rem 1rem 2rem;
  max-width: 900px;
  margin: 0 auto;
  line-height: 1.5;
}

/* ── Utility ── */
.hidden { display: none !important; }