/* ===== Base ===== */
:root{
  --bg:#0b1a33;
  --bg-2:#0f2548;
  --bg-3:#152e54;
  --ink:#e8eef9;
  --ink-dim:#a9b6cf;
  --gold:#d6b56a;
  --gold-2:#e9c98a;
  --line:rgba(255,255,255,.08);
  --card:#13284a;
  --card-2:#16315a;
  --shadow:0 10px 30px rgba(0,0,0,.35);
  --radius:14px;
}

*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background:var(--bg);
  color:var(--ink);
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
}
a{color:var(--gold-2);text-decoration:none}
a:hover{color:var(--gold)}
img{max-width:100%;display:block}
code{
  background:rgba(255,255,255,.08);
  padding:2px 6px;border-radius:4px;
  font-size:.9em;
}

.container{
  width:min(1100px, 92%);
  margin:0 auto;
}

/* ===== Header ===== */
.site-header{
  position:sticky;top:0;z-index:40;
  background:rgba(11,26,51,.85);
  backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line);
}
.nav-wrap{display:flex;align-items:center;justify-content:space-between;height:60px}
.brand{
  font-size:1.25rem;font-weight:700;color:var(--gold);
  letter-spacing:.15em;
}
.nav-menu{display:flex;gap:28px}
.nav-menu a{color:var(--ink);font-size:.95rem}
.nav-menu a:hover{color:var(--gold)}
.nav-toggle{
  display:none;
  background:transparent;border:none;color:var(--ink);
  font-size:1.4rem;cursor:pointer;
}

/* ===== Hero ===== */
.hero{
  position:relative;
  min-height:560px;
  display:flex;align-items:center;
  overflow:hidden;
}
.hero-bg{
  position:absolute;inset:0;
  background:
    linear-gradient(180deg, rgba(11,26,51,.25), rgba(11,26,51,.65)),
    url('https://images.unsplash.com/photo-1601297183305-6df142704ea2?auto=format&fit=crop&w=1600&q=70') center/cover no-repeat;
}
.hero-inner{position:relative;z-index:2;padding:80px 0}
.hero-title{
  font-size:clamp(1.6rem, 3.2vw, 2.6rem);
  line-height:1.6;
  font-weight:600;
  margin:0 0 18px;
  letter-spacing:.08em;
}
.hero-sub{color:var(--ink-dim);margin:0 0 28px;font-size:1.05rem}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap}
.btn{
  display:inline-block;
  padding:11px 22px;
  border-radius:999px;
  font-size:.95rem;
  transition:transform .15s ease, background .2s ease;
  border:1px solid transparent;
}
.btn:hover{transform:translateY(-1px)}
.btn-primary{background:var(--gold);color:#1a1408}
.btn-primary:hover{background:var(--gold-2);color:#1a1408}
.btn-ghost{border-color:var(--ink-dim);color:var(--ink)}
.btn-ghost:hover{border-color:var(--gold);color:var(--gold)}

/* ===== Section ===== */
.section{padding:72px 0}
.section-alt{background:var(--bg-2)}
.section-title{
  text-align:center;
  font-size:1.6rem;
  margin:0 0 8px;
  letter-spacing:.2em;
  color:var(--gold);
  position:relative;
  padding-bottom:14px;
}
.section-title::after{
  content:"";display:block;width:48px;height:2px;
  background:var(--gold);
  margin:12px auto 0;
  opacity:.7;
}
.section-desc{text-align:center;color:var(--ink-dim);margin:0 0 36px;font-size:.95rem}

/* ===== About ===== */
.about-grid{
  display:grid;grid-template-columns:1fr 1fr;gap:36px;align-items:center;
}
.about-img img{
  width:100%;border-radius:var(--radius);
  box-shadow:var(--shadow);
}
.about-text h3{margin:0 0 10px;color:var(--gold-2)}
.about-text p{color:var(--ink-dim)}

/* ===== Videos ===== */
.video-grid{
  display:grid;
  grid-template-columns:repeat(3, 1fr);
  gap:22px;
}
.video-card{
  background:var(--card);
  border-radius:var(--radius);
  overflow:hidden;
  box-shadow:var(--shadow);
  cursor:pointer;
  transition:transform .2s ease, background .2s;
  border:1px solid var(--line);
}
.video-card:hover{transform:translateY(-3px);background:var(--card-2)}
.video-thumb{
  position:relative;
  aspect-ratio:16/9;
  background:#0a1730;
  overflow:hidden;
}
.video-cover{
  position:absolute;inset:0;width:100%;height:100%;
  object-fit:cover;display:block;z-index:1;
}
.video-fallback{
  position:absolute;inset:0;
  display:flex;align-items:center;justify-content:center;
  font-size:2.4rem;letter-spacing:.1em;
  color:rgba(214,181,106,.6);
  background:linear-gradient(135deg, #16315a 0%, #0a1730 100%);
  z-index:0;
  font-weight:700;
}
.video-thumb::after{
  content:"";position:absolute;inset:0;z-index:2;
  background:radial-gradient(circle at center, rgba(0,0,0,.0), rgba(0,0,0,.45));
  pointer-events:none;
}
.video-play{
  position:absolute;left:50%;top:50%;
  width:56px;height:56px;
  border-radius:50%;
  background:rgba(214,181,106,.92);
  color:#1a1408;
  display:flex;align-items:center;justify-content:center;
  font-size:1.4rem;
  transform:translate(-50%,-50%);
  z-index:3;
}
.video-tag{
  position:absolute;right:10px;top:10px;z-index:3;
  background:rgba(0,0,0,.6);
  color:var(--gold-2);
  font-size:.75rem;
  padding:3px 9px;border-radius:999px;
  border:1px solid rgba(214,181,106,.4);
}
.video-meta{padding:14px 16px}
.video-title{margin:0 0 4px;font-size:1rem;color:var(--ink)}
.video-desc{margin:0;font-size:.85rem;color:var(--ink-dim)}

/* ===== Notes ===== */
.notes-layout{
  display:grid;
  grid-template-columns:280px 1fr;
  gap:24px;
  align-items:start;
}
.note-list{
  background:var(--card);
  border-radius:var(--radius);
  padding:10px;
  border:1px solid var(--line);
  max-height:560px;
  overflow:auto;
}
.note-item{
  display:block;
  padding:12px 14px;
  border-radius:10px;
  cursor:pointer;
  color:var(--ink);
  transition:background .15s;
}
.note-item:hover{background:var(--card-2)}
.note-item.active{background:rgba(214,181,106,.15);color:var(--gold-2)}
.note-item .t{display:block;font-size:.98rem;margin-bottom:2px}
.note-item .d{font-size:.78rem;color:var(--ink-dim)}

.note-view{
  background:var(--card);
  border-radius:var(--radius);
  border:1px solid var(--line);
  padding:28px 32px;
  min-height:300px;
}
.note-placeholder{color:var(--ink-dim);text-align:center;padding:40px 0}
.note-view h1, .note-view h2, .note-view h3{color:var(--gold-2)}
.note-view h1{font-size:1.6rem;border-bottom:1px solid var(--line);padding-bottom:8px}
.note-view h2{font-size:1.3rem;margin-top:1.6em}
.note-view p{color:var(--ink)}
.note-view blockquote{
  border-left:3px solid var(--gold);
  padding:6px 14px;color:var(--ink-dim);
  background:rgba(214,181,106,.06);
  border-radius:0 8px 8px 0;
  margin:1em 0;
}
.note-view pre{
  background:#0a1730;border-radius:8px;
  padding:14px;overflow:auto;font-size:.88rem;
}
.note-view code{background:rgba(255,255,255,.08)}
.note-view ul, .note-view ol{padding-left:1.4em}
.note-view img{border-radius:8px;margin:1em 0}
.note-view a{color:var(--gold-2);text-decoration:underline}

/* ===== Contact ===== */
.contact-wrap{text-align:center}
.contact-links{
  display:flex;justify-content:center;gap:22px;flex-wrap:wrap;margin-top:18px;
}
.contact-links a{
  color:var(--ink);font-size:.95rem;
  border:1px solid var(--line);padding:8px 18px;border-radius:999px;
  transition:border-color .2s, color .2s;
}
.contact-links a:hover{border-color:var(--gold);color:var(--gold)}

/* ===== Footer ===== */
.site-footer{
  border-top:1px solid var(--line);
  padding:24px 0;
  text-align:center;
  color:var(--ink-dim);
  font-size:.85rem;
}

/* ===== Modal ===== */
.modal{
  position:fixed;inset:0;z-index:80;
  display:flex;align-items:center;justify-content:center;
}
.modal[hidden]{display:none}
.modal-backdrop{
  position:absolute;inset:0;background:rgba(4,10,22,.85);
}
.modal-body{
  position:relative;z-index:2;
  width:min(900px, 92%);
  background:var(--card);
  border-radius:var(--radius);
  padding:18px;
  box-shadow:var(--shadow);
}
.modal-body video{width:100%;border-radius:8px;background:#000;display:block}
.modal-player{
  width:100%;border-radius:8px;background:#000;overflow:hidden;
  aspect-ratio:16/9;
}
.modal-player iframe{width:100%;height:100%;border:0;display:block}
.modal-player video{width:100%;height:100%;object-fit:contain}
.modal-body h3{margin:14px 0 4px;color:var(--gold-2)}
.modal-body p{margin:0;color:var(--ink-dim)}
.modal-link{margin-top:6px;font-size:.85rem}
.modal-link a{color:var(--gold-2);text-decoration:underline}
.modal-close{
  position:absolute;right:10px;top:6px;
  width:36px;height:36px;border:none;border-radius:50%;
  background:transparent;color:var(--ink);font-size:1.6rem;cursor:pointer;
}
.modal-close:hover{color:var(--gold)}

/* ===== Responsive ===== */
@media (max-width: 900px){
  .video-grid{grid-template-columns:repeat(2, 1fr)}
  .about-grid{grid-template-columns:1fr;gap:22px}
  .notes-layout{grid-template-columns:1fr}
  .note-list{max-height:260px}
}

@media (max-width: 640px){
  .nav-menu{
    position:absolute;top:60px;right:0;left:0;
    flex-direction:column;
    background:var(--bg-2);
    border-bottom:1px solid var(--line);
    padding:10px 0;
    gap:0;
    display:none;
  }
  .nav-menu.open{display:flex}
  .nav-menu a{padding:12px 22px;border-bottom:1px solid var(--line)}
  .nav-toggle{display:block}

  .hero{min-height:460px}
  .hero-inner{padding:60px 0}
  .hero-title{letter-spacing:.05em;line-height:1.7}

  .section{padding:48px 0}
  .section-title{font-size:1.3rem}
  .video-grid{grid-template-columns:1fr;gap:16px}
  .note-view{padding:20px}
}