/* ── Tokens ─────────────────────────────────────────────────
   Neutral zinc palette, same as tyaglovsky.com.
   Tense accents (ps / pc / pp / ppc) stay colored for learning. */
:root {
  --bg: #fafafa;
  --fg: #09090b;
  --muted: #71717a;
  --border: #e4e4e7;
  --secondary: #f4f4f5;
  --card: rgba(244,244,245,0.45);
  --card-hover: rgba(244,244,245,0.8);
  --primary: #18181b; --primary-fg: #fafafa;
  --accent-bg: rgba(245,197,24,0.18); --accent-border: rgba(245,197,24,0.45); --accent-fg: #854d0e;
  --nav-bg: rgba(250,250,250,0.8);

  --ps-h: #2563eb; --ps-bg: rgba(37,99,235,0.06);  --ps-border: rgba(37,99,235,0.25);
  --pc-h: #7c3aed; --pc-bg: rgba(124,58,237,0.06); --pc-border: rgba(124,58,237,0.25);
  --pp-h: #0891b2; --pp-bg: rgba(8,145,178,0.06);  --pp-border: rgba(8,145,178,0.25);
  --ppc-h: #059669; --ppc-bg: rgba(5,150,105,0.06); --ppc-border: rgba(5,150,105,0.25);
  --irr-v1: #2563eb; --irr-v2: #7c3aed; --irr-v3: #0891b2; --irr-ua: #059669;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #09090b; --fg: #fafafa; --muted: #a1a1aa; --border: #27272a; --secondary: #27272a;
    --card: rgba(39,39,42,0.35); --card-hover: rgba(39,39,42,0.6);
    --primary: #fafafa; --primary-fg: #18181b;
    --accent-bg: rgba(245,197,24,0.15); --accent-border: rgba(245,197,24,0.35); --accent-fg: #f5c518;
    --nav-bg: rgba(9,9,11,0.8);
    --ps-h: #60a5fa; --ps-bg: rgba(96,165,250,0.08);  --ps-border: rgba(96,165,250,0.25);
    --pc-h: #a78bfa; --pc-bg: rgba(167,139,250,0.08); --pc-border: rgba(167,139,250,0.25);
    --pp-h: #22d3ee; --pp-bg: rgba(34,211,238,0.07);  --pp-border: rgba(34,211,238,0.25);
    --ppc-h: #34d399; --ppc-bg: rgba(52,211,153,0.07); --ppc-border: rgba(52,211,153,0.25);
    --irr-v1: #60a5fa; --irr-v2: #a78bfa; --irr-v3: #22d3ee; --irr-ua: #34d399;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #09090b; --fg: #fafafa; --muted: #a1a1aa; --border: #27272a; --secondary: #27272a;
  --card: rgba(39,39,42,0.35); --card-hover: rgba(39,39,42,0.6);
  --primary: #fafafa; --primary-fg: #18181b;
  --accent-bg: rgba(245,197,24,0.15); --accent-border: rgba(245,197,24,0.35); --accent-fg: #f5c518;
  --nav-bg: rgba(9,9,11,0.8);
  --ps-h: #60a5fa; --ps-bg: rgba(96,165,250,0.08);  --ps-border: rgba(96,165,250,0.25);
  --pc-h: #a78bfa; --pc-bg: rgba(167,139,250,0.08); --pc-border: rgba(167,139,250,0.25);
  --pp-h: #22d3ee; --pp-bg: rgba(34,211,238,0.07);  --pp-border: rgba(34,211,238,0.25);
  --ppc-h: #34d399; --ppc-bg: rgba(52,211,153,0.07); --ppc-border: rgba(52,211,153,0.25);
  --irr-v1: #60a5fa; --irr-v2: #a78bfa; --irr-v3: #22d3ee; --irr-ua: #34d399;
  color-scheme: dark;
}

/* ── Reset & Base ────────────────────────────────────────── */
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.5;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}
.f-code, .p-formula, td.v2, td.v3 { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }

/* ── Nav ─────────────────────────────────────────────────── */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--nav-bg);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid var(--border);
  padding: 10px 16px;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
}
.site-logo {
  font-size: 1rem;
  font-weight: 500;
  color: var(--fg);
  text-decoration: none;
  transition: opacity 0.15s;
}
.site-logo:hover { opacity: 0.8; }
.site-logo span { color: var(--muted); }
.nav-links { display: flex; gap: 2px; flex-wrap: wrap; margin-left: auto; }
.nav-link {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--muted);
  text-decoration: none;
  padding: 5px 12px;
  border-radius: 9999px;
  transition: color 0.15s, background 0.15s;
}
.nav-link:hover { color: var(--fg); }
.nav-link.active { color: var(--fg); background: var(--secondary); }
.theme-btn {
  width: 32px; height: 32px; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  color: var(--fg);
  background: var(--secondary);
  border: none;
  border-radius: 9999px;
  cursor: pointer;
  transition: background 0.3s, color 0.3s;
}
.theme-btn:hover { background: var(--primary); color: var(--primary-fg); }
.theme-btn svg { width: 16px; height: 16px; }
@media (max-width: 520px) {
  .site-logo { margin-right: auto; }
  .theme-btn { order: 2; }
  .nav-links { order: 3; width: 100%; margin-left: -6px; }
}

/* ── Page Content ────────────────────────────────────────── */
.page-content { padding: 32px 16px 48px; }

h1 { font-size: 1.75rem; font-weight: 700; text-align: center; margin-bottom: 6px; letter-spacing: -0.025em; }
.subtitle { text-align: center; color: var(--muted); font-size: 0.95rem; margin-bottom: 28px; }

/* ── Tense Cards Grid ────────────────────────────────────── */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(290px, 1fr));
  gap: 16px;
  max-width: 960px;
  margin: 0 auto;
}
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.card-header { display: flex; align-items: center; gap: 10px; }
.dot { width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0; }
.tense-name { font-size: 1.1rem; font-weight: 600; letter-spacing: -0.01em; }

.ps .dot { background: var(--ps-h); } .ps .tense-name { color: var(--ps-h); }
.ps .formula { background: var(--ps-bg); border-color: var(--ps-border); }
.ps .ex-block { border-left-color: var(--ps-h); }

.pc .dot { background: var(--pc-h); } .pc .tense-name { color: var(--pc-h); }
.pc .formula { background: var(--pc-bg); border-color: var(--pc-border); }
.pc .ex-block { border-left-color: var(--pc-h); }

.pp .dot { background: var(--pp-h); } .pp .tense-name { color: var(--pp-h); }
.pp .formula { background: var(--pp-bg); border-color: var(--pp-border); }
.pp .ex-block { border-left-color: var(--pp-h); }

.ppc .dot { background: var(--ppc-h); } .ppc .tense-name { color: var(--ppc-h); }
.ppc .formula { background: var(--ppc-bg); border-color: var(--ppc-border); }
.ppc .ex-block { border-left-color: var(--ppc-h); }

.when-label { font-size: 0.7rem; font-weight: 500; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); margin-bottom: 6px; }
.when-tags { display: flex; flex-wrap: wrap; gap: 5px; }
.tag { background: var(--secondary); color: var(--fg); font-size: 0.75rem; font-weight: 500; padding: 3px 10px; border-radius: 9999px; }

.formula { border: 1px solid; border-radius: 12px; padding: 10px 12px; }
.formula-row { font-size: 0.8rem; margin-bottom: 5px; display: flex; gap: 8px; align-items: baseline; flex-wrap: wrap; }
.formula-row:last-child { margin-bottom: 0; }
.f-label { font-size: 0.75rem; font-weight: 600; color: var(--muted); min-width: 14px; }
.f-code { color: var(--fg); font-weight: 500; }

.tabs-wrap { display: flex; flex-direction: column; gap: 10px; }
.tab-buttons { display: inline-flex; gap: 2px; padding: 3px; background: var(--secondary); border-radius: 12px; align-self: flex-start; flex-wrap: wrap; }
.tab-btn {
  font-family: inherit; font-size: 0.78rem; font-weight: 500;
  padding: 4px 12px; border-radius: 9px;
  border: none;
  background: transparent; color: var(--muted);
  cursor: pointer; transition: background 0.15s, color 0.15s;
}
.tab-btn:hover { color: var(--fg); }
.tab-btn.active { background: var(--primary); color: var(--primary-fg); }
.tab-pane { display: none; }
.tab-pane.active { display: block; }

.ex-block { border-left: 2px solid; padding-left: 12px; display: flex; flex-direction: column; gap: 8px; }
.example { font-size: 0.88rem; }
.en { font-weight: 600; display: block; }
.ua { font-size: 0.8rem; color: var(--muted); display: block; }

.key-words { font-size: 0.78rem; color: var(--muted); }
.key-words strong { color: var(--fg); font-weight: 600; }

/* ── Passive Voice / info sections ───────────────────────── */
.passive-section {
  max-width: 960px; margin: 16px auto 0;
  background: var(--card); border: 1px solid var(--border); border-radius: 24px; padding: 20px;
}
.passive-title { font-size: 1.1rem; font-weight: 600; letter-spacing: -0.01em; margin-bottom: 12px; }
.passive-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); gap: 8px; }
.passive-row { display: flex; flex-direction: column; gap: 3px; padding: 10px 12px; border-radius: 12px; background: var(--secondary); }
.p-tense { font-size: 0.7rem; font-weight: 500; color: var(--muted); text-transform: uppercase; letter-spacing: 0.06em; }
.p-formula { font-size: 0.8rem; font-weight: 500; color: var(--fg); }
.p-example { font-size: 0.78rem; color: var(--muted); }

/* ── Irregular Verbs ─────────────────────────────────────── */
.irr-section {
  max-width: 960px; margin: 16px auto 0;
  background: var(--card); border: 1px solid var(--border); border-radius: 24px;
  overflow: hidden;
}
.irr-header { padding: 20px 20px 12px; display: flex; flex-direction: column; gap: 12px; }
.irr-title { font-size: 1.1rem; font-weight: 600; letter-spacing: -0.01em; }
.irr-legend { display: flex; gap: 6px 14px; flex-wrap: wrap; }
.irr-legend span { font-size: 0.75rem; font-weight: 500; }
.leg-v1 { color: var(--irr-v1); } .leg-v2 { color: var(--irr-v2); } .leg-v3 { color: var(--irr-v3); } .leg-ua { color: var(--irr-ua); }
.irr-search-wrap { position: relative; }
.irr-search {
  width: 100%; padding: 11px 16px 11px 40px;
  border-radius: 12px; border: 1px solid var(--border); outline: none;
  background: var(--bg); color: var(--fg);
  font-family: inherit; font-size: 16px; /* ≥16px stops iOS zoom on focus */
  transition: box-shadow 0.15s;
}
.irr-search::placeholder { color: var(--muted); }
.irr-search:focus { box-shadow: 0 0 0 3px var(--secondary); border-color: var(--muted); }
.irr-search-icon { position: absolute; left: 14px; top: 50%; transform: translateY(-50%); font-size: 0.85rem; pointer-events: none; }
.irr-count { font-size: 0.75rem; color: var(--muted); text-align: right; }
.irr-table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 0.85rem; }
thead th {
  color: var(--muted);
  font-size: 0.7rem; font-weight: 500; text-transform: uppercase; letter-spacing: 0.08em;
  padding: 8px 12px; text-align: left; white-space: nowrap;
  border-top: 1px solid var(--border); border-bottom: 1px solid var(--border);
}
tbody tr { border-bottom: 1px solid var(--border); transition: background 0.1s; }
tbody tr:last-child { border-bottom: none; }
tbody tr:hover { background: var(--card-hover); }
td { padding: 8px 12px; vertical-align: middle; }
thead th:first-child, td:first-child { padding-left: 20px; }
td.v1 { color: var(--irr-v1); font-weight: 600; }
td.v2 { color: var(--irr-v2); font-weight: 500; font-size: 0.8rem; }
td.v3 { color: var(--irr-v3); font-weight: 500; font-size: 0.8rem; }
td.tua { color: var(--muted); font-size: 0.8rem; }
.no-results { text-align: center; padding: 24px; color: var(--muted); font-size: 0.85rem; display: none; }

/* ── Home Page Cards ─────────────────────────────────────── */
.home-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 16px;
  max-width: 760px;
  margin: 0 auto;
}
.topic-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 22px 20px;
  text-decoration: none;
  color: var(--fg);
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: background 0.2s, transform 0.2s;
}
a.topic-card:hover { background: var(--card-hover); transform: translateY(-2px); }
.topic-icon { font-size: 1.8rem; }
.topic-name { font-size: 1.1rem; font-weight: 600; letter-spacing: -0.01em; }
.topic-desc { font-size: 0.85rem; color: var(--muted); }
.topic-badge {
  display: inline-block;
  font-size: 0.7rem; font-weight: 600; letter-spacing: 0.04em;
  padding: 2px 10px; border-radius: 9999px;
  background: var(--accent-bg); color: var(--accent-fg); border: 1px solid var(--accent-border);
  align-self: flex-start;
}
.topic-badge.soon { background: var(--secondary); color: var(--muted); border-color: transparent; }

@media (max-width: 480px) {
  thead th, td { padding: 8px 6px; }
  thead th:first-child, td:first-child { padding-left: 16px; }
  td.v1 { font-size: 0.8rem; }
  td.v2, td.v3, td.tua { font-size: 0.74rem; }
  td.tua { overflow-wrap: break-word; -webkit-hyphens: auto; hyphens: auto; }
}