:root {
  --primary: #2F7D5C;
  --primary-light: #4FA67E;
  --primary-dark: #245F46;
  --primary-soft: #E8F3ED;
  --text: #1c252e;
  --text-soft: #637381;
  --bg: #FAFCFA;
  --card-bg: #ffffff;
  --line: rgba(145, 158, 171, 0.2);
  --green-deep: var(--primary-dark);
  --ink: var(--text);
  --muted: var(--text-soft);
  --nav-h: 72px;
  --font-display: "Barlow", "Vazirmatn", system-ui, sans-serif;
  --font-body: "Public Sans", "Vazirmatn", system-ui, sans-serif;
}
html[data-theme="dark"] {
  --text: #e8f0ec;
  --text-soft: #9aada3;
  --bg: #0f1613;
  --card-bg: #162019;
  --line: rgba(145, 158, 171, 0.14);
  --primary-soft: rgba(47, 125, 92, 0.18);
}
*, *::before, *::after { box-sizing: border-box; }
body {
  margin: 0;
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.65;
}
html[lang="fa"] body {
  --font-display: "Vazirmatn", "Tahoma", "Arial", sans-serif;
  --font-body: "Vazirmatn", "Tahoma", "Arial", sans-serif;
  line-height: 1.75;
}
[data-lang-block] { display: none !important; }
html[lang="de"] [data-lang-block="de"],
html[lang="fa"] [data-lang-block="fa"] { display: block !important; }
html[lang="de"] span[data-lang-block="de"],
html[lang="fa"] span[data-lang-block="fa"],
html[lang="de"] a[data-lang-block="de"],
html[lang="fa"] a[data-lang-block="fa"] { display: inline !important; }

.subpage-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: var(--nav-h);
  padding: 12px 20px;
  background: color-mix(in srgb, var(--card-bg) 88%, transparent);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}
.subpage-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.05rem;
  color: var(--ink);
  text-decoration: none;
  cursor: pointer;
}
.subpage-brand-mark {
  width: 28px;
  height: 28px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
}
.subpage-nav-actions { display: flex; align-items: center; gap: 12px; }
.subpage-back {
  font-size: 14px;
  font-weight: 700;
  color: var(--primary-dark);
  text-decoration: none;
  cursor: pointer;
}
.subpage-back:hover { color: var(--primary); }
.lang {
  position: relative;
  display: inline-flex;
  padding: 3px;
  border-radius: 999px;
  background: var(--primary-soft);
  border: 1px solid var(--line);
}
.lang button {
  position: relative;
  z-index: 1;
  min-width: 44px;
  min-height: 36px;
  padding: 0 12px;
  border: 0;
  border-radius: 999px;
  background: transparent;
  font-weight: 700;
  font-size: 13px;
  color: var(--text-soft);
  cursor: pointer;
}
.lang button.active { color: var(--ink); }
.lang::before {
  content: "";
  position: absolute;
  top: 3px;
  left: 3px;
  width: calc(50% - 3px);
  height: calc(100% - 6px);
  border-radius: 999px;
  background: var(--card-bg);
  box-shadow: 0 2px 8px rgba(15, 30, 25, 0.08);
  transition: transform 280ms cubic-bezier(0.34, 1.15, 0.64, 1);
}
html[lang="fa"] .lang::before { transform: translateX(100%); }