/* Camera 课程网站 - 轻量主题 */
* { margin:0; padding:0; box-sizing:border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif; background: #F5F6FA; color: #1A1A2E; line-height: 1.6; }
a { color: #0066CC; text-decoration: none; }
a:hover { color: #004499; }

.nav { display:flex; align-items:center; padding:0 24px; height:64px; border-bottom:1px solid #E8E8EE; background:#fff; position:sticky; top:0; z-index:100; }
.nav-logo { font-size:18px; font-weight:700; color:#1A1A2E; margin-right:32px; }
.nav-logo span { color:#0066CC; }
.nav-links { display:flex; gap:24px; }
.nav-links a { color:#6B7280; font-size:14px; padding:4px 0; border-bottom:2px solid transparent; transition:color .2s,border-color .2s; }
.nav-links a:hover, .nav-links a.active { color:#1A1A2E; border-bottom-color:#0066CC; }
.nav-right { margin-left:auto; display:flex; align-items:center; gap:16px; }
.nav-btn { padding:6px 16px; border-radius:6px; font-size:13px; font-weight:500; background:#F0F0F5; color:#1A1A2E; cursor:pointer; border:none; }
.nav-btn:hover { background:#E5E5EB; }
.nav-user { font-size:14px; color:#6B7280; }

.hero { max-width:960px; margin:0 auto; padding:72px 24px 40px; text-align:center; }
.hero h1 { font-size:40px; font-weight:800; letter-spacing:-1px; line-height:1.2; margin-bottom:16px; color:#1A1A2E; }
.hero h1 span { color:#0066CC; }
.hero p { font-size:17px; color:#6B7280; max-width:560px; margin:0 auto 28px; }
.hero-btns { display:flex; gap:12px; justify-content:center; }
.btn { padding:11px 26px; border-radius:8px; font-size:15px; font-weight:600; cursor:pointer; border:none; transition:all .2s; display:inline-block; }
.btn-primary { background:#0066CC; color:#fff; }
.btn-primary:hover { background:#0052A3; transform:translateY(-1px); }
.btn-secondary { background:#F0F0F5; color:#1A1A2E; }
.btn-secondary:hover { background:#E5E5EB; }

.section { max-width:960px; margin:0 auto; padding:40px 24px; }
.section-title { font-size:22px; font-weight:700; margin-bottom:20px; color:#1A1A2E; }
.section-sub { font-size:14px; color:#6B7280; margin-bottom:24px; }

.grid-3 { display:grid; grid-template-columns:repeat(auto-fill, minmax(280px,1fr)); gap:16px; }

.card { background:#fff; border:1px solid #E8E8EE; border-radius:10px; padding:24px; transition:box-shadow .2s,transform .2s; }
.card:hover { box-shadow:0 4px 12px rgba(0,0,0,.06); transform:translateY(-2px); }
.tag { display:inline-block; padding:2px 10px; border-radius:4px; font-size:11px; font-weight:600; margin-bottom:10px; }
.tag-video { background:#E8F4FF; color:#0066CC; }
.tag-doc { background:#E6F7E6; color:#1A8C3E; }
.tag-free { background:#F0F0F5; color:#6B7280; }
.card h3 { font-size:17px; margin-bottom:6px; color:#1A1A2E; }
.card p { font-size:14px; color:#6B7280; margin-bottom:12px; line-height:1.5; }
.price { font-size:22px; font-weight:700; color:#1A1A2E; }
.price small { font-size:13px; color:#6B7280; font-weight:400; }

/* Detail */
.detail { max-width:800px; margin:0 auto; padding:40px 24px; }
.detail h1 { font-size:28px; margin-bottom:8px; color:#1A1A2E; }
.detail .sub { font-size:15px; color:#6B7280; margin-bottom:20px; }
.price-box { background:#fff; border:1px solid #E8E8EE; border-radius:10px; padding:20px 24px; display:flex; justify-content:space-between; align-items:center; margin-bottom:20px; }
.price-box .price { font-size:26px; }
.buy-btn { padding:10px 36px; border-radius:8px; background:#0066CC; color:#fff; font-size:15px; font-weight:600; cursor:pointer; border:none; }
.buy-btn:hover { background:#0052A3; }
.bought { background:#1A8C3E; }
.bought:hover { background:#15803A; }

.chapters { list-style:none; margin-top:16px; }
.chapters li { padding:12px 16px; border-bottom:1px solid #E8E8EE; display:flex; align-items:center; gap:12px; font-size:14px; }
.chapters li:last-child { border:none; }
.ch-num { width:24px; height:24px; border-radius:50%; background:#F0F0F5; display:flex; align-items:center; justify-content:center; font-size:12px; color:#6B7280; flex-shrink:0; }
.ch-locked { color:#9CA3AF; }
.ch-locked .ch-num { background:#F0F0F5; color:#B0B0C0; }

/* Articles */
.article-item { display:flex; padding:14px 16px; background:#fff; border:1px solid #E8E8EE; border-radius:8px; margin-bottom:6px; gap:12px; transition:box-shadow .2s; }
.article-item:hover { box-shadow:0 2px 8px rgba(0,0,0,.04); }
.article-item .info { flex:1; }
.article-item .info h4 { font-size:15px; color:#1A1A2E; margin:0; }
.article-item .info p { font-size:13px; color:#6B7280; margin-top:2px; }
.article-item .date { font-size:12px; color:#9CA3AF; white-space:nowrap; }

/* Ad */
.ad-placeholder { background:#fff; border:1px dashed #D0D0DA; border-radius:8px; padding:16px; text-align:center; font-size:13px; color:#B0B0C0; margin:20px 0; }

/* Login */
.login-box { max-width:380px; margin:60px auto; background:#fff; border:1px solid #E8E8EE; border-radius:12px; padding:32px; }
.login-box h2 { margin-bottom:16px; font-size:20px; text-align:center; color:#1A1A2E; }
input[type=text], input[type=password] { width:100%; padding:10px 14px; background:#F5F6FA; border:1px solid #D0D0DA; border-radius:8px; color:#1A1A2E; font-size:14px; margin-bottom:10px; outline:none; }
input:focus { border-color:#0066CC; }
.err { color:#DC2626; font-size:13px; margin-top:4px; display:none; }
.submit-btn { width:100%; padding:10px; border-radius:8px; background:#0066CC; color:#fff; font-size:14px; font-weight:600; cursor:pointer; border:none; margin-top:8px; }
.submit-btn:hover { background:#0052A3; }

/* Footer */
.footer { border-top:1px solid #E8E8EE; padding:24px; text-align:center; font-size:13px; color:#9CA3AF; margin-top:40px; }
.footer-links { display:flex; gap:20px; justify-content:center; margin-bottom:6px; }
.footer-links a { color:#6B7280; font-size:13px; }
.footer-links a:hover { color:#1A1A2E; }

/* Mobile */
/* ===== Language Switcher ===== */
.lang-switch { display:flex; align-items:center; gap:2px; margin-right:12px; padding-right:12px; border-right:1px solid #E8E8EE; }
.lang-btn { border:none; background:none; font-size:12px; font-weight:600; color:#9CA3AF; cursor:pointer; padding:2px 4px; border-radius:3px; transition:all .15s; font-family:inherit; }
.lang-btn:hover { color:#6B7280; }
.lang-btn.active { color:#0066CC; background:#E8F4FF; }
.lang-sep { font-size:11px; color:#D0D0DA; }

/* ===== Nav Dropdown ===== */
.nav-dd { position:relative; }
.nav-dd-trigger { cursor:pointer; font-size:14px; color:#6B7280; text-decoration:none; padding:4px 0; border-bottom:2px solid transparent; transition:color .2s,border-color .2s; white-space:nowrap; }
.nav-dd-trigger:hover, .nav-dd-trigger.active { color:#1A1A2E; border-bottom-color:#0066CC; }
.nav-dd-menu { display:none; position:absolute; top:100%; left:-12px; background:#fff; border:1px solid #E8E8EE; border-radius:10px; padding:6px; min-width:220px; box-shadow:0 8px 24px rgba(0,0,0,.08); margin-top:6px; z-index:200; }
.nav-dd:hover .nav-dd-menu { display:block; }
.dd-item { display:flex; align-items:center; gap:10px; padding:10px 12px; border-radius:8px; text-decoration:none; transition:background .15s; }
.dd-item:hover { background:#F0F4FF; }
.dd-icon { font-size:18px; width:32px; height:32px; border-radius:8px; display:flex; align-items:center; justify-content:center; flex-shrink:0; background:#F8F6F3; }
.dd-text { flex:1; min-width:0; }
.dd-title { display:block; font-size:13px; font-weight:600; color:#1A1A2E; }
.dd-desc { display:block; font-size:11px; color:#9CA3AF; margin-top:1px; }
/* Dropdown mobile */
@media (max-width:768px) {
  .nav-dd-menu { position:static; box-shadow:none; border:1px solid #F0EEEA; margin-top:4px; border-radius:8px; }
  .nav-dd:hover .nav-dd-menu { display:none; }
  .nav-dd.nav-dd-open .nav-dd-menu { display:block; }
}

/* ===== Language Display ===== */
body:not(.lang-en) .lang-en { display:none !important; }
body.lang-en .lang-zh { display:none !important; }
body.lang-en .lang-en { display:inline-block !important; }
body.lang-en h1 .lang-en, body.lang-en h2 .lang-en, body.lang-en p .lang-en, body.lang-en li .lang-en, body.lang-en a .lang-en, body.lang-en div .lang-en { display:unset !important; }

@media (max-width:768px) {
  .hero { padding:40px 16px 28px; }
  .hero h1 { font-size:26px; }
  .hero p { font-size:15px; }
  .section { padding:28px 16px; }
  .detail { padding:24px 16px; }
  .detail h1 { font-size:22px; }
  .nav { padding:0 12px; }
  .nav-links { gap:10px; }
  .nav-links a { font-size:13px; }
  .grid-3 { grid-template-columns:1fr; }
  .price-box { flex-direction:column; gap:12px; align-items:stretch; }
  .buy-btn { text-align:center; display:block; }
}