:root {
  --bg: #f7f8fa;
  --bg-alt: #eef1f5;
  --surface: #ffffff;
  --text: #1a1d23;
  --text-muted: #5b6270;
  --border: #dde1e7;
  --accent: #1e6f5c;
  --accent-hover: #17594a;
  --accent-contrast: #ffffff;
  --danger: #c0392b;
  --danger-bg: #fdecea;
  --info-bg: #eef2f7;
  --shadow: 0 2px 10px rgba(20, 24, 30, 0.08);
  --radius: 10px;
  --focus-ring: 0 0 0 3px rgba(30, 111, 92, 0.35);
  --uk-accent: #1d4e89;
  --cz-accent: #1e6f5c;
}

:root[data-theme="dark"] {
  --bg: #14171c;
  --bg-alt: #1a1e25;
  --surface: #1f242c;
  --text: #eef0f3;
  --text-muted: #9aa2b1;
  --border: #2c323c;
  --accent: #35a084;
  --accent-hover: #3fbb99;
  --accent-contrast: #0c1a16;
  --danger: #ff6b5e;
  --danger-bg: #3a1f1c;
  --info-bg: #232a34;
  --shadow: 0 2px 14px rgba(0, 0, 0, 0.4);
  --uk-accent: #6fa3e0;
  --cz-accent: #35a084;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #14171c;
    --bg-alt: #1a1e25;
    --surface: #1f242c;
    --text: #eef0f3;
    --text-muted: #9aa2b1;
    --border: #2c323c;
    --accent: #35a084;
    --accent-hover: #3fbb99;
    --accent-contrast: #0c1a16;
    --danger: #ff6b5e;
    --danger-bg: #3a1f1c;
    --info-bg: #232a34;
    --shadow: 0 2px 14px rgba(0, 0, 0, 0.4);
    --uk-accent: #6fa3e0;
    --cz-accent: #35a084;
  }
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.5;
  overflow-x: hidden;
}

h1, h2, h3 { line-height: 1.25; }

a { color: var(--accent); }

/* ---------- header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0.75rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.site-logo {
  font-weight: 700;
  font-size: 1.05rem;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.flag-switch, .theme-switch {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.25rem 0.35rem;
  border-radius: 999px;
  font-size: 1rem;
}

.flag-switch:hover, .theme-switch:hover { background: var(--bg-alt); }

.flag { width: 22px; height: 15px; border-radius: 2px; display: block; }
.theme-icon { font-size: 0.95rem; line-height: 1; }

.switch-track {
  width: 38px;
  height: 20px;
  border-radius: 999px;
  background: var(--border);
  position: relative;
  display: inline-block;
  transition: background 0.2s ease;
}

.switch-thumb {
  position: absolute;
  top: 2px;
  left: 2px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent);
  transition: transform 0.2s ease;
}

.flag-switch[data-lang="en"] .switch-thumb,
.theme-switch[data-theme-state="dark"] .switch-thumb {
  transform: translateX(18px);
}

/* ---------- layout ---------- */
main { display: block; }

.section { padding: 3rem 0; }
.section-alt { background: var(--bg-alt); }
.section-inner { max-width: 900px; margin: 0 auto; padding: 0 1.25rem; }

.about-text p { color: var(--text-muted); }

/* ---------- form ---------- */
form { display: flex; flex-direction: column; gap: 1.75rem; margin-top: 1.5rem; }

.field { display: flex; flex-direction: column; gap: 0.5rem; }

.field > label { font-weight: 600; }

select, input[type="text"], input[type="number"] {
  font: inherit;
  padding: 0.55rem 0.7rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  min-width: 0;
}

select:focus, input:focus { outline: none; box-shadow: var(--focus-ring); border-color: var(--accent); }

.field-error {
  color: var(--danger);
  font-size: 0.85rem;
  margin: 0;
  min-height: 1em;
}

.field.has-error > label { color: var(--danger); }
.field.has-error select,
.field.has-error input[type="text"] {
  border-color: var(--danger);
  background: var(--danger-bg);
}

/* date field */
.date-field { display: flex; align-items: center; gap: 0.5rem; max-width: 220px; }
.date-text { flex: 1; }
.date-icon-wrap { position: relative; width: 36px; height: 36px; display: flex; align-items: center; justify-content: center; border: 1px solid var(--border); border-radius: 8px; background: var(--surface); }
.date-icon { pointer-events: none; }
.date-native {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  cursor: pointer;
  border: none;
  padding: 0;
}

/* dropdown rows (CZ / UK) */
.dropdown-rows { display: flex; flex-direction: column; gap: 0.75rem; }

.dropdown-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 0.6rem;
  align-items: center;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem;
}

.dropdown-row .row-points {
  font-weight: 600;
  white-space: nowrap;
  color: var(--cz-accent);
  text-align: right;
}

.dropdown-row .row-remove {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 1.1rem;
  justify-self: end;
}
.dropdown-row .row-remove:hover { color: var(--danger); }

.add-row-btn {
  align-self: flex-start;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--accent);
  color: var(--accent-contrast);
  border: none;
  font-size: 1.3rem;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow);
}
.add-row-btn:hover { background: var(--accent-hover); }

.points-sum { margin: 0; color: var(--text-muted); }
.points-sum strong { color: var(--text); }

/* ZSU tree */
.zsu-tree { border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); overflow: hidden; }

.zsu-cat { border-top: 1px solid var(--border); }
.zsu-cat:first-child { border-top: none; }
.zsu-cat-header { padding: 0.6rem 0.9rem; font-weight: 700; background: var(--bg-alt); }
.zsu-sub-header { padding: 0.5rem 0.9rem 0.2rem 1.4rem; font-weight: 600; color: var(--text-muted); font-size: 0.92rem; }

.zsu-row {
  display: grid;
  grid-template-columns: minmax(160px, 2fr) repeat(5, minmax(70px, 1fr));
  gap: 0.5rem;
  align-items: center;
  padding: 0.4rem 0.9rem 0.4rem 1.4rem;
  font-size: 0.9rem;
}
.zsu-row.zsu-head-row {
  font-weight: 600;
  color: var(--text-muted);
  font-size: 0.78rem;
  background: var(--bg-alt);
  padding-top: 0.5rem;
  padding-bottom: 0.5rem;
}
.zsu-row input[type="number"] { width: 100%; padding: 0.35rem 0.4rem; color: var(--text); font-weight: 600; }
.zsu-row input[type="number"].zsu-default { color: var(--text-muted); font-weight: 400; }
.zsu-readonly { color: var(--text-muted); text-align: center; }
.zsu-total-line { margin: 0; font-weight: 600; }

/* validation / submit */
.validation-message {
  background: var(--danger-bg);
  color: var(--danger);
  padding: 0.75rem 1rem;
  border-radius: 8px;
  font-weight: 600;
}

.submit-btn {
  align-self: flex-start;
  background: var(--accent);
  color: var(--accent-contrast);
  border: none;
  padding: 0.85rem 1.8rem;
  border-radius: 999px;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  box-shadow: var(--shadow);
}
.submit-btn:hover { background: var(--accent-hover); }

/* ---------- results ---------- */
.result-section-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin: 1.5rem 0 0.75rem;
  padding-bottom: 0.4rem;
  border-bottom: 3px solid var(--cz-accent);
}
.result-section-title.uk { border-color: var(--uk-accent); }

.result-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  margin-bottom: 0.85rem;
}
.result-card-title { font-weight: 700; margin-bottom: 0.5rem; }
.result-card-sub { color: var(--text-muted); font-size: 0.88rem; margin-bottom: 0.5rem; }

.result-values { display: flex; flex-wrap: wrap; gap: 1rem 2rem; }
.result-value { display: flex; align-items: center; gap: 0.4rem; font-size: 1.05rem; font-weight: 600; }

.bolestne-item {
  padding: 0.6rem 0;
  border-top: 1px solid var(--border);
}
.bolestne-item:first-of-type { border-top: none; padding-top: 0; }
.bolestne-item .result-value { font-size: 0.95rem; font-weight: 500; }

.bolestne-total {
  padding-top: 0.7rem;
  margin-top: 0.4rem;
  border-top: 2px solid var(--cz-accent);
}
.bolestne-total .result-card-sub { font-weight: 700; color: var(--text); text-transform: uppercase; letter-spacing: 0.03em; font-size: 0.8rem; }
.bolestne-total .result-value { font-size: 1.1rem; }

.info-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--text-muted);
  color: var(--surface);
  font-size: 0.72rem;
  font-style: italic;
  font-weight: 700;
  cursor: help;
  position: relative;
  flex-shrink: 0;
}

.info-icon .tooltip-bubble {
  visibility: hidden;
  opacity: 0;
  position: absolute;
  bottom: 130%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--text);
  color: var(--bg);
  padding: 0.5rem 0.7rem;
  border-radius: 6px;
  font-size: 0.78rem;
  font-weight: 400;
  width: 220px;
  text-align: center;
  transition: opacity 0.15s ease;
  z-index: 10;
}

.info-icon:hover .tooltip-bubble,
.info-icon.tapped .tooltip-bubble {
  visibility: visible;
  opacity: 1;
}

.fallback-note {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.4rem;
}

.result-card-total {
  border: 1px solid var(--accent);
}
.result-card-total .result-card-title { color: var(--accent); }

.result-sentence {
  display: flex;
  align-items: flex-start;
  gap: 0.45rem;
  font-size: 0.92rem;
  line-height: 1.5;
  color: var(--text);
  margin: 0;
  padding-top: 0.7rem;
  margin-top: 0.6rem;
  border-top: 1px solid var(--border);
}
.result-sentence .info-icon { margin-top: 0.2rem; }

/* ---------- scroll fab ---------- */
.scroll-fab-group {
  position: fixed;
  right: 1.25rem;
  bottom: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  z-index: 30;
}
.scroll-fab {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  border: none;
  background: var(--accent);
  color: var(--accent-contrast);
  font-size: 1.2rem;
  cursor: pointer;
  box-shadow: var(--shadow);
}
.scroll-fab:hover { background: var(--accent-hover); }

/* ---------- footer ---------- */
.site-footer {
  text-align: center;
  padding: 1.5rem 1rem;
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* ---------- responsive ---------- */
@media (max-width: 640px) {
  .header-inner { flex-wrap: wrap; }
  .zsu-tree { overflow-x: auto; }
  .zsu-row, .zsu-row.zsu-head-row { grid-template-columns: minmax(160px, 2fr) repeat(5, minmax(60px, 1fr)); min-width: 560px; }
  .dropdown-row { grid-template-columns: 1fr; }
  .dropdown-row .row-points { text-align: left; }
}