:root {
  --primary: #0b5394;
  --primary-dark: #073763;
  --accent: #1c9c6a;
  --bg: #f5f7fa;
  --card-bg: #ffffff;
  --text: #1a1a1a;
  --muted: #5b6470;
  --warning-bg: #fff4e5;
  --warning-text: #8a5300;
  --error-bg: #fdecea;
  --error-text: #b3261e;
  --border: #dde3ea;
  --radius: 14px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

.app-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--primary);
  color: #fff;
  padding: 14px 12px;
}

.app-header h1 {
  font-size: 1.05rem;
  margin: 0;
  text-align: center;
  flex: 1;
  font-weight: 600;
}

.icon-btn {
  background: rgba(255,255,255,0.15);
  border: none;
  color: #fff;
  font-size: 1.3rem;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  cursor: pointer;
}
.icon-btn:active { background: rgba(255,255,255,0.3); }

main#app {
  max-width: 640px;
  margin: 0 auto;
  padding: 20px 16px 40px;
}

.page { display: none; }
.page.active { display: block; animation: fadein .15s ease-in; }

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

h2 {
  font-size: 1.15rem;
  color: var(--primary-dark);
  margin: 0 0 8px;
}

.lead {
  font-size: 1rem;
  line-height: 1.5;
  color: var(--text);
  margin-bottom: 16px;
}

.link-btn {
  -webkit-appearance: none;
  appearance: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: transparent;
  border: none;
  color: var(--muted);
  border-radius: 10px;
  padding: 4px 0;
  font-size: 0.85rem;
  font-weight: 600;
  font-family: inherit;
  text-decoration: underline;
  cursor: pointer;
}
.link-btn:active { color: var(--primary-dark); }
.link-btn::before {
  content: '\1F4C4';
  font-size: 1rem;
}

.link-btn-note {
  font-size: 0.78rem;
  color: var(--muted);
  margin: 8px 0 0;
  line-height: 1.4;
}

.choice-stack {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 16px 0;
}

.big-btn {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 4px;
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  text-align: left;
  cursor: pointer;
  font-size: 1rem;
  color: var(--text);
  transition: border-color .1s ease, transform .05s ease;
}
.big-btn:active { transform: scale(0.99); border-color: var(--primary); }

.big-btn-home { border-color: var(--primary); }

.big-btn-title { font-weight: 700; font-size: 1.05rem; color: var(--primary-dark); }
.big-btn-sub { font-size: 0.88rem; color: var(--muted); }

.disclaimer {
  font-size: 0.82rem;
  color: var(--muted);
  border-top: 1px solid var(--border);
  padding-top: 14px;
  margin-top: 24px;
  line-height: 1.4;
}

.summary-line {
  background: #eaf1f8;
  color: var(--primary-dark);
  border-radius: 10px;
  padding: 10px 14px;
  font-size: 0.92rem;
  font-weight: 600;
  margin-bottom: 18px;
}

.habitus-image-wrap {
  -webkit-appearance: none;
  appearance: none;
  display: block;
  width: 100%;
  background: #fff;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  padding: 8px;
  margin: 0 0 8px;
  cursor: zoom-in;
  position: relative;
}
.habitus-image-wrap img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 8px;
}
.habitus-image-wrap::after {
  content: '\1F50D +';
  position: absolute;
  bottom: 14px;
  right: 14px;
  background: rgba(11,83,148,0.88);
  color: #fff;
  font-size: 0.78rem;
  font-weight: 700;
  padding: 5px 10px;
  border-radius: 20px;
}

.zoom-hint {
  font-size: 0.82rem;
  color: var(--muted);
  margin: 0 0 16px;
  line-height: 1.4;
}

.image-modal {
  position: fixed;
  inset: 0;
  z-index: 200;
  background: #000;
  display: flex;
  flex-direction: column;
}
.image-modal[hidden] { display: none; }
.image-modal-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 12px;
  background: #111;
}
.image-modal-title {
  color: #ccc;
  font-size: 0.78rem;
  line-height: 1.5;
}
.image-modal-close {
  flex-shrink: 0;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 20px;
  padding: 9px 18px;
  font-size: 0.92rem;
  font-weight: 700;
  cursor: pointer;
}
.image-modal-scroll {
  flex: 1;
  overflow: auto;
  -webkit-overflow-scrolling: touch;
  display: flex;
  align-items: flex-start;
  justify-content: center;
}
.image-modal-scroll img {
  width: 100%;
  max-width: 900px;
  height: auto;
  display: block;
  touch-action: pinch-zoom pan-x pan-y;
}

.paper-pages {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 10px;
}
.paper-pages img {
  box-shadow: 0 1px 4px rgba(0,0,0,0.4);
}
.paper-pages-loading {
  color: #ccc;
  padding: 30px 16px;
  font-size: 0.9rem;
  text-align: center;
}

.habitus-btn-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}
@media (min-width: 480px) {
  .habitus-btn-row { grid-template-columns: repeat(7, 1fr); }
}

.habitus-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-radius: 10px;
  padding: 10px 4px;
  cursor: pointer;
}
.habitus-btn:active { border-color: var(--primary); transform: scale(0.97); }
.habitus-num { font-size: 1.3rem; font-weight: 800; color: var(--primary); }
.habitus-label { font-size: 0.68rem; text-align: center; color: var(--muted); line-height: 1.15; }

.field-label {
  display: block;
  font-weight: 600;
  margin: 10px 0 8px;
  color: var(--text);
}

.num-input {
  width: 100%;
  font-size: 1.4rem;
  padding: 14px 16px;
  border-radius: 10px;
  border: 2px solid var(--border);
  margin-bottom: 14px;
}
.num-input:focus { outline: none; border-color: var(--primary); }

.primary-btn {
  width: 100%;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 10px;
  font-size: 1.05rem;
  font-weight: 700;
  padding: 15px;
  cursor: pointer;
}
.primary-btn:active { background: var(--primary-dark); }

.warning-line {
  background: var(--warning-bg);
  color: var(--warning-text);
  border-radius: 10px;
  padding: 10px 14px;
  font-size: 0.88rem;
  margin-top: 12px;
  line-height: 1.4;
  font-weight: 600;
}

.warning-line.warning-blocked {
  background: var(--error-bg);
  color: var(--error-text);
}

.result-box {
  margin-top: 22px;
  background: var(--card-bg);
  border: 2px solid var(--accent);
  border-radius: var(--radius);
  overflow: hidden;
}
.result-primary, .result-secondary {
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.result-primary {
  background: #eafaf2;
}
.result-secondary {
  border-top: 1px solid var(--border);
}
.result-label {
  font-size: 0.82rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}
.result-value {
  font-size: 2rem;
  font-weight: 800;
  color: var(--primary-dark);
}

.app-footer {
  max-width: 640px;
  margin: 0 auto;
  padding: 10px 16px 30px;
  font-size: 0.75rem;
  color: var(--muted);
  line-height: 1.4;
}

.install-hint {
  margin-top: 10px;
  font-weight: 600;
  color: var(--accent);
}