/* ============================================================
   MetalShield Pro — Common Styles
   Shared across all pages: nav, footer, utilities
============================================================ */

/* ---------- Reset & Base ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: 'Inter', 'Helvetica Neue', Arial, system-ui, sans-serif;
  background: #f2f2f2;
  color: #1a1a1a;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }

/* ---------- CSS Variables ---------- */
:root {
  --accent:    #c8601a;
  --accent-dk: #a84e12;
  --black:     #111111;
  --gray-1:    #f7f7f7;
  --gray-2:    #eeeeee;
  --gray-3:    #d5d5d5;
  --gray-4:    #999999;
  --gray-5:    #555555;
  --red:       #e34234;
  --white:     #ffffff;
  --nav-h:     64px;
  --max-w:     1440px;
  --pad-x:     48px;
  --radius:    8px;
  --shadow-sm: 0 2px 12px rgba(0,0,0,.07);
  --shadow-md: 0 8px 32px rgba(0,0,0,.10);
}

/* ---------- Toast ---------- */
.toast {
  position: fixed; top: 24px; left: 50%;
  transform: translateX(-50%) translateY(-80px);
  background: var(--black); color: #fff;
  padding: 11px 26px; border-radius: 50px;
  font-size: 14px; font-weight: 500; letter-spacing: .3px;
  z-index: 9999; pointer-events: none; white-space: nowrap;
  box-shadow: 0 8px 32px rgba(0,0,0,.2);
  transition: transform .35s cubic-bezier(.34,1.56,.64,1), opacity .35s ease;
  opacity: 0;
}
.toast.show { transform: translateX(-50%) translateY(0); opacity: 1; }

/* ============================================================
   NAVIGATION BAR
============================================================ */
.site-nav {
  position: sticky; top: 0; z-index: 800;
  background: var(--white);
  border-bottom: 1px solid #e8e8e8;
  height: var(--nav-h);
  box-shadow: var(--shadow-sm);
}
.nav-inner {
  max-width: var(--max-w); margin: 0 auto;
  padding: 0 var(--pad-x);
  height: 100%;
  display: flex; align-items: center; justify-content: space-between;
  gap: 32px;
}

/* Logo */
.nav-logo {
  display: flex; align-items: center; gap: 10px;
  font-size: 18px; font-weight: 800; color: var(--black);
  letter-spacing: -.4px; white-space: nowrap;
  text-decoration: none;
}
.nav-logo-icon {
  width: 32px; height: 32px;
  background: var(--black); border-radius: 7px;
  display: flex; align-items: center; justify-content: center;
}
.nav-logo-icon svg { width: 18px; height: 18px; stroke: #fff; fill: none; }
.nav-logo span { color: var(--accent); }

/* Nav links */
.nav-links {
  display: flex; align-items: center; gap: 6px;
  list-style: none;
}
.nav-links a {
  padding: 7px 14px; border-radius: 6px;
  font-size: 14px; font-weight: 500; color: var(--gray-5);
  transition: background .18s, color .18s;
}
.nav-links a:hover { background: var(--gray-2); color: var(--black); }
.nav-links a.active { color: var(--black); font-weight: 700; }

/* Nav right actions */
.nav-actions {
  display: flex; align-items: center; gap: 10px;
}
.nav-cart-btn {
  display: flex; align-items: center; gap: 7px;
  background: var(--black); color: #fff;
  border: none; border-radius: 6px;
  padding: 9px 18px; font-size: 14px; font-weight: 600;
  cursor: pointer; font-family: inherit;
  transition: background .2s;
}
.nav-cart-btn:hover { background: #2a2a2a; }
.nav-cart-btn svg { width: 16px; height: 16px; stroke: #fff; fill: none; }

/* ============================================================
   FOOTER
============================================================ */
.site-footer {
  background: var(--black); color: #ccc;
  padding: 64px var(--pad-x) 32px;
  margin-top: 80px;
}
.footer-inner {
  max-width: var(--max-w); margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
}
.footer-brand .nav-logo { color: #fff; margin-bottom: 16px; }
.footer-brand p { font-size: 13px; line-height: 1.7; color: #888; max-width: 280px; }
.footer-col h4 { font-size: 13px; font-weight: 700; color: #fff; text-transform: uppercase; letter-spacing: 1px; margin-bottom: 16px; }
.footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.footer-col ul li a { font-size: 13px; color: #888; transition: color .18s; }
.footer-col ul li a:hover { color: #fff; }
.footer-bottom {
  max-width: var(--max-w); margin: 48px auto 0;
  padding-top: 24px; border-top: 1px solid #2a2a2a;
  display: flex; align-items: center; justify-content: space-between;
  font-size: 12px; color: #555;
}
.footer-bottom a { color: #777; transition: color .18s; }
.footer-bottom a:hover { color: #ccc; }

/* ============================================================
   INNER PAGE HERO (for about / privacy / shipping)
============================================================ */
.inner-hero {
  background: var(--black); color: #fff;
  padding: 72px var(--pad-x) 64px;
  text-align: center;
}
.inner-hero h1 { font-size: 40px; font-weight: 800; letter-spacing: -.5px; margin-bottom: 12px; }
.inner-hero p { font-size: 16px; color: #aaa; max-width: 520px; margin: 0 auto; line-height: 1.6; }

/* ============================================================
   CONTENT SECTION WRAPPER
============================================================ */
.content-section {
  max-width: 860px; margin: 0 auto;
  padding: 64px var(--pad-x);
}
.content-section h2 {
  font-size: 22px; font-weight: 700; color: var(--black);
  margin-bottom: 14px; margin-top: 40px;
}
.content-section h2:first-child { margin-top: 0; }
.content-section p {
  font-size: 15px; line-height: 1.8; color: #444;
  margin-bottom: 14px;
}
.content-section ul {
  padding-left: 20px; margin-bottom: 14px;
}
.content-section ul li {
  font-size: 15px; line-height: 1.8; color: #444;
  margin-bottom: 6px;
}
.content-section .highlight-box {
  background: var(--gray-1); border-left: 4px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 18px 22px; margin: 24px 0;
}
.content-section .highlight-box p { margin: 0; color: #333; font-weight: 500; }

/* ============================================================
   UTILITY CLASSES
============================================================ */
.page-wrap { max-width: var(--max-w); margin: 0 auto; padding: 0 var(--pad-x); }
.section-title {
  font-size: 32px; font-weight: 800; color: var(--black);
  letter-spacing: -.4px; line-height: 1.2;
}
.section-sub {
  font-size: 15px; color: var(--gray-4); margin-top: 10px; line-height: 1.6;
}
.btn-primary {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--black); color: #fff;
  border: none; border-radius: 6px;
  padding: 14px 28px; font-size: 15px; font-weight: 700;
  cursor: pointer; font-family: inherit;
  transition: background .2s, transform .12s;
  text-decoration: none;
}
.btn-primary:hover { background: #2a2a2a; }
.btn-primary:active { transform: scale(.98); }
.btn-accent {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--accent); color: #fff;
  border: none; border-radius: 6px;
  padding: 14px 28px; font-size: 15px; font-weight: 700;
  cursor: pointer; font-family: inherit;
  transition: background .2s, transform .12s;
  text-decoration: none;
}
.btn-accent:hover { background: var(--accent-dk); }
.btn-accent:active { transform: scale(.98); }
.divider { height: 1px; background: #e8e8e8; margin: 32px 0; }

/* ============================================================
   RESPONSIVE — MOBILE  (≤ 768px / ≤ 480px)
============================================================ */

@media (max-width: 768px) {
  :root { --pad-x: 16px; --nav-h: 56px; }

  /* ---- Nav ---- */
  .site-nav { height: 56px; }
  .nav-inner { height: 56px; padding: 0 16px; gap: 12px; }
  .nav-links {
    display: none;
    position: fixed; top: 56px; left: 0; right: 0;
    background: #fff; flex-direction: column; gap: 0;
    padding: 8px 0 16px;
    box-shadow: 0 8px 24px rgba(0,0,0,.12);
    z-index: 999; list-style: none;
  }
  .nav-links.open { display: flex; }
  .nav-links li { width: 100%; }
  .nav-links a { display: block; padding: 13px 20px; font-size: 15px; border-radius: 0; }
  /* 汉堡按钮（默认隐藏，手机端显示） */
  .nav-hamburger {
    display: flex; flex-direction: column; justify-content: center; gap: 5px;
    width: 36px; height: 36px; background: none; border: none;
    cursor: pointer; padding: 4px; order: -1;
  }
  .nav-hamburger span {
    display: block; width: 22px; height: 2px;
    background: #111; border-radius: 2px;
    transition: transform .2s, opacity .2s;
  }
  .nav-hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav-hamburger.open span:nth-child(2) { opacity: 0; }
  .nav-hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
  .nav-cart-btn { padding: 8px 12px; font-size: 13px; }
  .nav-cart-btn span { display: none; }

  /* ---- Footer ---- */
  .site-footer { padding: 40px 16px 24px; margin-top: 48px; }
  .footer-inner { grid-template-columns: 1fr 1fr; gap: 28px; }
  .footer-brand { grid-column: 1 / -1; }
  .footer-bottom { flex-direction: column; gap: 8px; text-align: center; }

  /* ---- Inner hero ---- */
  .inner-hero { padding: 48px 16px 36px; }
  .inner-hero h1 { font-size: 26px; }
  .inner-hero p { font-size: 14px; }

  /* ---- Content ---- */
  .content-section { padding: 36px 16px; }
  .content-section h2 { font-size: 18px; }

  /* ---- Utilities ---- */
  .section-title { font-size: 22px; }
  .section-sub { font-size: 14px; }
  .btn-primary, .btn-accent { padding: 13px 22px; font-size: 14px; }
}

@media (max-width: 480px) {
  .footer-inner { grid-template-columns: 1fr; }
  .inner-hero h1 { font-size: 22px; }
  .section-title { font-size: 19px; }
}

/* 桌面端隐藏汉堡按钮 */
.nav-hamburger { display: none; }