/* ============================================================
   WordAssistant landing page
   Palette mirrors the desktop app QSS (gui/main_window.py):
     primary   #168A5B   hover #117348   light #EAF6F0
     bg        #F3F4F6   card  #FFFFFF   window #F7F8FA
     text      #202124   secondary #6B7280  muted #9CA3AF
     border    #E5E7EB   control #D1D5DB  error #B3261E
   ============================================================ */

:root {
  --primary: #168A5B;
  --primary-hover: #117348;
  --primary-light: #EAF6F0;
  --primary-border: #A9D8C3;
  --bg: #F3F4F6;
  --bg-window: #F7F8FA;
  --card: #FFFFFF;
  --text: #202124;
  --text-secondary: #6B7280;
  --text-muted: #9CA3AF;
  --border: #E5E7EB;
  --control: #D1D5DB;
  --error: #B3261E;
  --radius: 8px;
  --radius-sm: 6px;
  --font-sans: "Segoe UI", "Segoe UI Variable", "Microsoft YaHei",
              -apple-system, "Helvetica Neue", Arial, sans-serif;
  --font-serif: Georgia, "Times New Roman", "Songti SC", serif;
  --mono: "Cascadia Code", Consolas, "Courier New", monospace;
  --shadow: 0 1px 3px rgba(16, 24, 40, 0.06), 0 8px 24px rgba(16, 24, 40, 0.06);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.6;
  color: var(--text);
  background: var(--card);
  -webkit-font-smoothing: antialiased;
}

.container { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

.mono { font-family: var(--mono); font-size: 0.9em; }

/* ---------------- Navbar ---------------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: var(--card);
  border-bottom: 1px solid var(--border);
}
.nav-inner { display: flex; align-items: center; height: 56px; gap: 24px; }
.brand { display: flex; align-items: center; gap: 9px; text-decoration: none; color: var(--text); }
.brand-mark {
  display: inline-flex; align-items: center; justify-content: center;
  width: 30px; height: 30px; border-radius: var(--radius-sm);
  background: var(--primary); color: #fff;
}
.brand-mark.dark { background: var(--primary); }
.brand-name { font-weight: 600; font-size: 15px; }
.nav-links { display: flex; align-items: center; gap: 22px; margin-left: auto; }
.nav-links a { color: var(--text-secondary); text-decoration: none; font-size: 14px; }
.nav-links a:hover { color: var(--text); }
.nav-gh {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 6px 12px; border: 1px solid var(--control); border-radius: var(--radius-sm);
  color: var(--text) !important; font-weight: 500;
}
.nav-gh:hover { background: var(--bg); }
.nav-toggle {
  display: none; margin-left: auto; background: none; border: none; cursor: pointer;
  flex-direction: column; gap: 4px; padding: 6px;
}
.nav-toggle span { width: 20px; height: 2px; background: var(--text); border-radius: 1px; }

/* ---------------- Hero ---------------- */
.hero { background: var(--bg-window); border-bottom: 1px solid var(--border); }
.hero-inner { padding: 64px 24px 48px; text-align: center; }
.hero-eyebrow {
  display: inline-block; font-size: 12.5px; font-weight: 600; letter-spacing: 0.02em;
  color: var(--primary); background: var(--primary-light);
  border: 1px solid var(--primary-border); border-radius: 999px;
  padding: 4px 14px; margin-bottom: 22px;
}
.hero-title {
  font-size: clamp(32px, 5vw, 52px);
  line-height: 1.15; letter-spacing: -0.02em;
  font-weight: 700; color: var(--text);
  margin-bottom: 18px;
}
.hero-title em {
  font-family: var(--font-serif); font-style: italic; font-weight: 500;
  color: var(--primary);
}
.hero-sub {
  max-width: 620px; margin: 0 auto 30px;
  color: var(--text-secondary); font-size: 17px;
}
.hero-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.hero-hint { margin-top: 22px; font-size: 13px; color: var(--text-muted); }

/* ---------------- Buttons ---------------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 20px; border-radius: var(--radius);
  font-size: 14.5px; font-weight: 600; text-decoration: none;
  transition: background 0.15s ease, border-color 0.15s ease;
  cursor: pointer;
}
.btn-primary { background: var(--primary); color: #fff; border: 1px solid var(--primary); }
.btn-primary:hover { background: var(--primary-hover); border-color: var(--primary-hover); }
.btn-secondary {
  background: var(--card); color: var(--text);
  border: 1px solid var(--control);
}
.btn-secondary:hover { background: var(--bg); }
.btn-dark { background: var(--text); color: #fff; border: 1px solid var(--text); }
.btn-dark:hover { background: #000; }

/* ---------------- Screenshot ---------------- */
.shot { background: var(--bg); padding: 24px 0 80px; }
.shot-img {
  width: 100%; height: auto; display: block;
  max-width: 1080px; margin: 0 auto;
  border-radius: 6px;
  border: 1px solid var(--border);
  box-shadow: 0 1px 2px rgba(16, 24, 40, 0.05), 0 12px 32px rgba(16, 24, 40, 0.08);
}

/* ---------------- Sections ---------------- */
.features { padding: 84px 0; background: var(--card); }
.section-title {
  font-size: 30px; font-weight: 700; letter-spacing: -0.01em;
  text-align: center; margin-bottom: 10px;
}
.section-sub { text-align: center; color: var(--text-secondary); max-width: 560px; margin: 0 auto 48px; }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 26px 24px;
  transition: box-shadow 0.15s ease, border-color 0.15s ease;
}
.card:hover { border-color: var(--control); box-shadow: var(--shadow); }
.card-icon {
  display: flex; align-items: center; justify-content: center;
  width: 44px; height: 44px; border-radius: var(--radius-sm);
  background: var(--primary-light); color: var(--primary);
  border: 1px solid var(--primary-border); margin-bottom: 16px;
}
.card h3 { font-size: 17px; font-weight: 600; margin-bottom: 8px; }
.card p { font-size: 14px; color: var(--text-secondary); }

/* ---------------- Download ---------------- */
.download { padding: 84px 0; background: var(--bg-window); }
.download-card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 12px; box-shadow: var(--shadow);
  padding: 52px 32px; text-align: center;
}
.download-note { margin-top: 20px; font-size: 13px; color: var(--text-muted); }

/* ---------------- Open Source CTA ---------------- */
.oss { padding: 84px 0; background: var(--card); }
.oss-panel {
  display: flex; align-items: center; justify-content: space-between; gap: 32px; flex-wrap: wrap;
  background: var(--primary-light); border: 1px solid var(--primary-border);
  border-radius: 12px; padding: 40px 44px;
}
.oss-panel .section-title { text-align: left; margin-bottom: 8px; }
.oss-panel .section-sub { text-align: left; margin: 0; max-width: 520px; }

/* ---------------- Footer ---------------- */
.footer { background: var(--text); color: #fff; padding: 48px 0 40px; }
.footer-inner { display: flex; flex-wrap: wrap; gap: 18px; align-items: center; }
.footer-brand { display: flex; align-items: center; gap: 9px; font-weight: 600; }
.footer-links { display: flex; gap: 20px; margin-left: auto; }
.footer-links a { color: var(--text-muted); text-decoration: none; font-size: 14px; }
.footer-links a:hover { color: #fff; }
.footer-note { width: 100%; font-size: 13px; color: var(--text-muted); margin-top: 6px; }

/* ---------------- Responsive ---------------- */
@media (max-width: 820px) {
  .nav-toggle { display: flex; }
  .nav-links {
    display: none; position: absolute; top: 56px; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 0;
    background: var(--card); border-bottom: 1px solid var(--border);
    padding: 8px 16px;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 10px 0; border-bottom: 1px solid var(--border); }
  .nav-links a:last-child { border-bottom: none; }
  .feature-grid { grid-template-columns: 1fr; }
  .hero-inner { padding: 40px 16px 32px; }
}