/* C-Sky Photonic FAQ PAGE
   Dedicated page styling. Theme and shared dimensions match the existing site.
*/
:root {
  --dimension-size: 20vh;
  --theme-teal: #008080;
  --theme-teal-hover: #006666;
  --bg-page: #ffffff;
  --text-white: #ffffff;
  --text-dark: #1e293b;
  --border-light: #e2e8f0;
  --font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; }
body { font-family: var(--font-family); background: var(--bg-page); color: var(--text-dark); display: flex; flex-direction: column; min-height: 100vh; }
a { color: inherit; text-decoration: none; transition: opacity .2s ease, background-color .2s ease; }

.navbar { width: 100%; height: var(--dimension-size); background: var(--theme-teal); color: var(--text-white); display: flex; align-items: center; justify-content: space-between; padding: 0 2rem; gap: 1.5rem; flex-shrink: 0; z-index: 10; }
.logo { display: flex; align-items: center; gap: 1rem; font-size: 1.4rem; font-weight: 800; letter-spacing: .1em; color: var(--text-white); white-space: nowrap; }
.companyname { font-size: 1.4rem; font-weight: 700; }
.nav-links { display: flex; align-items: center; gap: 1.5rem; flex-wrap: wrap; justify-content: center; }
.nav-links a { font-size: .95rem; font-weight: 600; color: var(--text-white); position: relative; padding: .25rem 0; }
.nav-links a::after { content: ""; position: absolute; bottom: 0; left: 0; width: 0; height: 2px; background: var(--text-white); transition: width .2s ease; }
.nav-links a:hover::after { width: 100%; }
.search-box { padding: .55rem 1rem; border-radius: 9999px; border: 1px solid rgba(255,255,255,.4); background: rgba(255,255,255,.15); color: var(--text-white); font-size: .9rem; outline: none; min-width: 140px; max-width: 200px; }
.search-box::placeholder { color: rgba(255,255,255,.8); }
.search-box:focus { background: #000; color: var(--text-dark); border-color: #000; }
.mobile-toggle-btn { display: none; background: none; border: 2px solid rgba(255,255,255,.5); border-radius: 6px; color: var(--text-white); font-size: 1.5rem; padding: .3rem .6rem; cursor: pointer; }

.herosection { flex: 1; min-height: 0; display: grid; grid-template-columns: minmax(0,var(--dimension-size)) 1fr; grid-template-areas: "sidebar content"; overflow: hidden; background: var(--bg-page); }
.sidebar { grid-area: sidebar; width: 20vh; min-width: 20vh; max-width: var(--dimension-size); position: sticky; top: 0; height: calc(100vh - (var(--dimension-size) * 2)); align-self: start; background: var(--theme-teal); color: var(--text-white); display: flex; flex-direction: column; padding: 1.5rem .75rem; gap: .75rem; overflow-y: auto; z-index: 10; }
.sidebar a { display: block; width: 100%; color: var(--text-white); padding: .7rem .6rem; border-radius: 5px; font-size: .9rem; font-weight: 600; line-height: 1.25; text-align: left; }
.sidebar a:first-child { text-align: center; }
.sidebar a:hover { background: var(--theme-teal-hover); transform: translateX(3px); }

.content { margin: 5vh; min-width: 0; overflow-y: auto; }
.faq-content { width: min(1000px, 100%); margin: 0 auto; padding: 1rem 0 3rem; }
.faq-heading { margin-bottom: 2rem; }
.faq-heading h1 { font-size: clamp(1.8rem, 3vw, 2.6rem); color: var(--theme-teal); margin-bottom: .7rem; }
.faq-heading p { line-height: 1.75; max-width: 850px; font-size: 1.05rem; color: #475569; }
.faq-intro-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; margin: 0 0 1.5rem; }
.faq-intro-card { background: linear-gradient(180deg, #ffffff, #f8fafc); border: 1px solid var(--border-light); border-radius: 12px; padding: 1rem 1.1rem; min-height: 120px; display: flex; flex-direction: column; gap: .45rem; box-shadow: 0 4px 14px rgba(15,23,42,.05); }
.faq-intro-card strong { color: var(--theme-teal); font-size: 1rem; }
.faq-intro-card span { color: #64748b; line-height: 1.55; font-size: .95rem; }
.faq-list { display: grid; gap: .85rem; }
.faq-list details { border: 1px solid var(--border-light); border-radius: 12px; background: #fff; overflow: hidden; box-shadow: 0 2px 10px rgba(15,23,42,.035); transition: border-color .2s ease, box-shadow .2s ease; }
.faq-list details:hover { border-color: rgba(0,128,128,.35); box-shadow: 0 5px 18px rgba(15,23,42,.07); }
.faq-list summary { cursor: pointer; list-style: none; padding: 1.05rem 1.2rem; font-weight: 700; font-size: 1rem; color: var(--text-dark); position: relative; padding-right: 3rem; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; position: absolute; right: 1.2rem; top: .8rem; font-size: 1.4rem; color: var(--theme-teal); }
.faq-list details[open] summary::after { content: "−"; }
.faq-list details[open] summary { color: var(--theme-teal); }
.faq-list p { padding: 0 1.2rem 1.2rem; line-height: 1.75; font-size: .98rem; color: #475569; }

.footer { width: 100%; min-height: var(--dimension-size); flex: 0 0 auto; background: var(--theme-teal); color: var(--text-white); box-sizing: border-box; display: grid; grid-template-columns: repeat(5,minmax(0,1fr)); gap: 1.75rem; padding: 1.5rem 2.5rem; align-items: start; align-content: center; overflow: hidden; z-index: 20; }
.footer div { display: flex; flex-direction: column; gap: .25rem; min-width: 0; align-items: flex-start; }
.footer h4 { color: var(--text-white); font-size: .85rem; font-weight: 700; text-transform: uppercase; letter-spacing: .06em; margin-bottom: .35rem; padding-bottom: .2rem; width: 100%; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.footer a { color: rgba(255,255,255,.85); font-size: .8rem; line-height: 1.3; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; display: inline-block; }
.footer a:hover { color: var(--text-white); text-decoration: none; transform: translateX(3px); }
.footer p { color: rgba(255,255,255,.85); font-size: .76rem; line-height: 1.3; word-break: break-word; }

@media (max-width: 1024px) { .faq-intro-grid { grid-template-columns: 1fr; } .nav-links { gap: 1rem; } .nav-links a { font-size: .85rem; } .footer { grid-template-columns: repeat(3,1fr); height: auto; min-height: var(--dimension-size); } }
@media (max-width: 768px) {
  :root { --dimension-size: clamp(65px,12vh,85px); }
  body { height: auto; overflow-y: auto; }
  .navbar { height: auto; min-height: var(--dimension-size); padding: .8rem 1rem; flex-wrap: wrap; gap: .5rem; }
  .mobile-toggle-btn { display: block; order: 2; margin-left: auto; }
  .logo { order: 1; }
  .search-box { order: 4; width: 100%; max-width: none; }
  .nav-links { order: 3; width: 100%; display: none; flex-direction: column; gap: 0; background: var(--theme-teal-hover); border-radius: 8px; overflow: hidden; }
  .nav-links.open { display: flex; }
  .nav-links a { flex-shrink: 0; font-size: .95rem; padding: .7rem 1rem; border-bottom: 1px solid rgba(255,255,255,.1); }
  .herosection { display: flex; flex-direction: column; flex: 1; overflow: visible; }
  .sidebar { width: 100%; min-width: 100%; max-width: 100%; height: auto; flex-direction: row; overflow-x: auto; padding: .6rem .8rem; gap: .5rem; white-space: nowrap; scrollbar-width: none; }
  .sidebar::-webkit-scrollbar { display: none; }
  .sidebar a { flex: 1 0 auto; padding: .5rem .85rem; font-size: .8rem; }
  .content { margin: 1.5rem; overflow-y: visible; }
  .footer { grid-template-columns: 1fr; height: auto; min-height: 20vh; padding: 2rem 1.5rem; gap: 1.5rem; text-align: center; }
  .footer div { align-items: center; }
}