:root{
  --bg: #050509;
  --violet: #7B61FF;
  --violet-dim: #4a3b99;
  --teal: #34E0C4;
  --pink: #FF5FA8;
  --text: #EDEBF7;
  --text-dim: #8D8AA3;
  --line: rgba(123,97,255,0.35);
  --card-bg: rgba(255,255,255,0.03);
  --card-border: rgba(255,255,255,0.08);
}
*{ margin:0; padding:0; box-sizing:border-box; }
html{ scroll-behavior:smooth; }
body{
  background: var(--bg);
  color: var(--text);
  font-family:'Inter', sans-serif;
  position: relative;
  overflow-x:hidden;
  min-height:100vh;
}
#bg-canvas{
  position:absolute;
  top:0; left:0;
  width:100%;
  z-index:-1;
  display:block;
}

nav{
  position: fixed;
  top:0; left:0; right:0;
  display:flex;
  align-items:center;
  justify-content:space-between;
  padding: 22px 48px;
  z-index: 50;
  backdrop-filter: blur(10px);
  background: linear-gradient(to bottom, rgba(5,5,9,0.7), transparent);
}
.logo{
  display:flex; align-items:center; gap:12px;
  font-family:'Space Grotesk', sans-serif;
  font-weight:700;
  letter-spacing: 0.04em;
  font-size: 22px;
  text-transform: uppercase;
}
.logo-dot{
  width:12px; height:12px; border-radius:50%;
  background: radial-gradient(circle at 30% 30%, var(--teal), var(--violet));
  box-shadow: 0 0 12px var(--violet);
}
.nav-links{
  display:flex; gap:10px;
  font-family:'JetBrains Mono', monospace;
  font-size: 12.5px;
  color: var(--text-dim);
  letter-spacing: 0.02em;
}
.nav-pill{
  display:flex; align-items:center; gap:7px;
  padding: 9px 18px;
  border-radius: 999px;
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  color: inherit;
  text-decoration:none;
  transition: color .2s ease, border-color .2s ease, background .2s ease, transform .2s ease;
}
.nav-pill svg{ width:14px; height:14px; flex-shrink:0; }
.nav-pill:hover{
  color: var(--teal);
  border-color: rgba(52,224,196,0.4);
  transform: translateY(-1px);
}
@media(max-width:720px){ .nav-links{ display:none; } }

.theme-toggle{
  width: 38px; height: 38px;
  border-radius: 50%;
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  color: var(--text);
  display:flex; align-items:center; justify-content:center;
  cursor:pointer;
  transition: border-color .25s ease, transform .25s ease, background .25s ease;
  flex-shrink:0;
}
.theme-toggle:hover{ border-color: var(--teal); transform: translateY(-1px); }
.theme-toggle svg{ width:18px; height:18px; }
.theme-toggle .icon-sun{ display:none; }
.theme-toggle .icon-moon{ display:block; }
html.light .theme-toggle .icon-sun{ display:block; }
html.light .theme-toggle .icon-moon{ display:none; }

html.light{
  --bg: #f6f5fb;
  --text: #14121f;
  --text-dim: #605d75;
  --card-bg: rgba(20,18,31,0.035);
  --card-border: rgba(20,18,31,0.1);
  --line: rgba(123,97,255,0.3);
}
html.light body{ background: var(--bg); }
html.light nav{
  background: linear-gradient(to bottom, rgba(246,245,251,0.75), transparent);
}
html.light .btn-primary{ color:#fff; }
html.light .row .node{ background: var(--bg); }

.hero{
  min-height:100vh;
  display:flex;
  flex-direction:column;
  align-items:center;
  justify-content:center;
  text-align:center;
  padding: 0 24px;
  position:relative;
}
.eyebrow{
  font-family:'JetBrains Mono', monospace;
  font-size:12px;
  letter-spacing: 0.3em;
  text-transform:uppercase;
  color: var(--teal);
  margin-bottom: 22px;
  opacity:0.85;
}
.hero h1{
  font-family:'Space Grotesk', sans-serif;
  font-weight: 700;
  font-size: clamp(42px, 8vw, 96px);
  line-height: 1.15;
  letter-spacing: normal;
  max-width: 100%;
  overflow-wrap: break-word;
}
.hero h1 .grad{
  display:inline-block;
  background: linear-gradient(100deg, var(--violet), var(--teal) 70%);
  background-size: 100% 100%;
  background-repeat: no-repeat;
  -webkit-background-clip: text;
  background-clip:text;
  color: transparent;
  -webkit-text-fill-color: transparent;
  padding-right: 0.02em;
}
.hero p{
  margin-top: 26px;
  max-width: 560px;
  font-size: 17px;
  line-height:1.6;
  color: var(--text-dim);
}
.hero-cta{
  margin-top: 40px;
  display:flex;
  gap:16px;
  flex-wrap:wrap;
  justify-content:center;
}
.btn{
  font-family:'JetBrains Mono', monospace;
  font-size: 13px;
  padding: 13px 26px;
  border-radius: 999px;
  text-decoration:none;
  letter-spacing: 0.03em;
  transition: transform .2s ease, box-shadow .2s ease, background .2s ease;
}
.btn-primary{
  background: linear-gradient(100deg, var(--violet), var(--teal));
  color:#050509;
  font-weight:600;
}
.btn-primary:hover{ transform: translateY(-2px); box-shadow: 0 8px 24px rgba(123,97,255,0.35); }
.btn-ghost{
  border: 1px solid var(--card-border);
  color: var(--text);
}
.btn-ghost:hover{ border-color: var(--teal); color: var(--teal); }

.scroll-cue{
  position:absolute;
  bottom: 42px;
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:8px;
  font-family:'JetBrains Mono', monospace;
  font-size: 14px;
  letter-spacing: 0.2em;
  color: var(--text-dim);
  text-transform:uppercase;
  animation: floaty 2.4s ease-in-out infinite;
}
.scroll-cue .stick{
  width:1px; height:26px;
  background: linear-gradient(var(--teal), transparent);
}
@keyframes floaty{ 0%,100%{ transform:translateY(0);} 50%{ transform:translateY(8px);} }

.section-head{
  text-align:center;
  padding: 40px 24px 10px;
}
.section-head .eyebrow{ margin-bottom: 14px; }
.section-head h2{
  font-family:'Space Grotesk', sans-serif;
  font-size: clamp(28px, 4vw, 42px);
  font-weight:600;
}
.section-head p{
  color: var(--text-dim);
  margin-top:12px;
  font-size:15px;
}

.constellation{
  position:relative;
  max-width: 1080px;
  margin: 60px auto 40px;
  padding: 0 24px;
}
.spine{
  position:absolute;
  left:50%;
  top:0;
  bottom:0;
  width:1px;
  transform: translateX(-50%);
  background: linear-gradient(to bottom, transparent, var(--line) 6%, var(--line) 94%, transparent);
}
.row{
  position:relative;
  display:grid;
  grid-template-columns: 1fr 1fr;
  align-items:center;
  padding: 56px 0;
}
.row .node{
  position:absolute;
  left:50%; top:50%;
  transform: translate(-50%,-50%);
  width:12px; height:12px;
  border-radius:50%;
  background: var(--bg);
  border: 2px solid var(--teal);
  box-shadow: 0 0 0 6px rgba(52,224,196,0.08), 0 0 14px rgba(52,224,196,0.5);
  z-index:2;
}
.row .index{
  position:absolute;
  left:50%; top:50%;
  transform: translate(-50%, -50%);
  font-family:'JetBrains Mono', monospace;
  font-size: 10px;
  color: var(--text-dim);
  white-space:nowrap;
  margin-top: 26px;
}
.card{
  width: min(380px, 92%);
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  padding: 26px 26px 24px;
  backdrop-filter: blur(6px);
  transition: transform .35s ease, border-color .35s ease, box-shadow .35s ease;
  opacity:0;
  transform: translateY(24px);
}
.card.in-view{
  opacity:1;
  transform: translateY(0);
}
.card:hover{
  border-color: rgba(123,97,255,0.5);
  box-shadow: 0 12px 40px rgba(123,97,255,0.15);
  transform: translateY(-4px);
}
.row.left .card{ grid-column:1; justify-self:end; margin-right: 46px; }
.row.right .card{ grid-column:2; justify-self:start; margin-left: 46px; }

.card-icon{
  width:44px; height:44px;
  border-radius: 12px;
  display:flex; align-items:center; justify-content:center;
  background: radial-gradient(circle at 30% 20%, rgba(123,97,255,0.25), rgba(52,224,196,0.08));
  border: 1px solid var(--card-border);
  margin-bottom: 18px;
}
.card-icon svg{ width:24px; height:24px; }
.card h3{
  font-family:'Space Grotesk', sans-serif;
  font-size: 19px;
  font-weight:600;
  margin-bottom: 8px;
}
.card .tag{
  font-family:'JetBrains Mono', monospace;
  font-size: 10.5px;
  color: var(--teal);
  letter-spacing:0.05em;
  text-transform:uppercase;
  margin-bottom: 10px;
  display:inline-block;
}
.card p{
  color: var(--text-dim);
  font-size: 14px;
  line-height:1.65;
}
.card .stars{
  margin-top:16px;
  display:flex; align-items:center; gap:6px;
  font-family:'JetBrains Mono', monospace;
  font-size: 11.5px;
  color: var(--text-dim);
}

@media(max-width: 760px){
  .spine{ left:20px; }
  .row{ grid-template-columns: 1fr; padding-left: 44px; }
  .row .node{ left:20px; }
  .row .index{ display:none; }
  .row.left .card, .row.right .card{
    grid-column:1; justify-self:start; margin:0;
    width: 100%;
  }
}

.author-section{
  max-width: 640px;
  margin: 100px auto 60px;
  padding: 0 24px;
  text-align:center;
}
.author-card{
  border: 1px solid var(--card-border);
  background: linear-gradient(160deg, rgba(123,97,255,0.06), rgba(52,224,196,0.03));
  border-radius: 20px;
  padding: 46px 32px;
}
.author-card .eyebrow{ margin-bottom:18px; }
.author-card label{
  display:block;
  font-family:'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--text-dim);
  letter-spacing:0.1em;
  text-transform:uppercase;
  margin-bottom: 14px;
}
.author-input{
  width: 100%;
  max-width: 360px;
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--card-border);
  color: var(--text);
  font-family:'Space Grotesk', sans-serif;
  font-size: 24px;
  text-align:center;
  padding: 8px 4px 12px;
  outline:none;
  transition: border-color .25s ease;
}
.author-input:focus{ border-bottom-color: var(--teal); }
.author-sub{
  margin-top: 16px;
  font-size: 13px;
  color: var(--text-dim);
}

footer{
  text-align:center;
  padding: 40px 24px 60px;
  color: var(--text-dim);
  font-family:'JetBrains Mono', monospace;
  font-size: 11.5px;
  letter-spacing: 0.05em;
}

::view-transition-old(root),
::view-transition-new(root){
  animation: none;
  mix-blend-mode: normal;
}
::view-transition-old(root){ z-index:1; }
::view-transition-new(root){ z-index:2; }


/* Bỏ gạch chân mặc định của link card */
a.card {
  text-decoration: none;
  color: inherit;
  display: block;
}

/* Đặt khung chứa ảnh ôm sát kích thước ảnh gốc */
.card-icon {
  width: fit-content;
  height: auto;
  background: transparent;
  border: 1px solid var(--card-border);
  border-radius: 14px;
  overflow: hidden;
  padding: 0;
  margin-bottom: 18px; /* Giữ khoảng cách với thẻ span bên dưới */
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.3s ease, border-color 0.3s ease;
}

/* Định dạng ảnh TO HƠN, hiển thị sắc nét chuẩn tỉ lệ gốc */
.card-avatar {
  display: block;
  width: auto;
  height: auto;
  max-width: 2000px;  /* Tăng chiều rộng tối đa (cũ là 90px) */
  max-height: 80px; /* Tăng chiều cao tối đa (cũ là 80px) */
  object-fit: contain;
  border-radius: 14px;
}

/* Hiệu ứng ô ảnh nổi lên khi di chuột vào card */
.card:hover .card-icon {
  transform: translateY(-4px) scale(1.05);
  border-color: var(--teal);
  box-shadow: 0 8px 24px rgba(52, 224, 196, 0.4);
}

/* Khung chứa các nút mạng xã hội */
.social-links {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 16px;
  margin-top: 24px;
}

/* Nút dạng Pill giống hệt ảnh mẫu */
.social-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 22px;
  border-radius: 12px;
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  color: var(--text);
  font-family: 'Inter', sans-serif;
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease, background 0.25s ease;
}

/* Kích thước Icon */
.social-btn svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

/* Màu icon GitHub tự thích ứng theo Dark/Light theme */
.social-btn .icon-github {
  fill: var(--text);
}

/* Hiệu ứng nổi lên khi rê chuột vào nút */
.social-btn:hover {
  transform: translateY(-2px);
  border-color: rgba(52, 224, 196, 0.5);
  box-shadow: 0 6px 18px rgba(52, 224, 196, 0.15);
  color: var(--teal);
}