table a {
    white-space: nowrap; /* Không xuống dòng */
    display: inline-block; /* Đảm bảo nó giữ trên 1 dòng */
    text-align: center; /* Căn giữa chữ trong ô */
}

/* ============================ Nút mạng xã hội cố định ============================ */
.social-fixed {
  position: fixed;
  bottom: 20px;
  right: 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  z-index: 1000;
}

.social-fixed a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background-color: white;
  box-shadow: 0 4px 12px rgba(0,0,0,0.2);
  transition: transform 0.2s;
}

.social-fixed a:hover {
  transform: scale(1.1);
}

.social-fixed a img {
  width: 28px;
  height: 28px;
  object-fit: contain;
}

/* ============================ TABLE STYLE FOR KHOA HOC ============================ */
.table-wrap {
    margin-top: 40px;
    background: white;
    padding: 20px;
    border-radius: 16px;
    box-shadow: 0 6px 20px rgba(15, 23, 42, 0.08);
    border: 1px solid rgba(15, 23, 42, 0.06);
}

table.custom-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 15px;
}

/* Header */
.custom-table thead tr {
    background: linear-gradient(90deg, #4f46e5, #6366f1);
    color: white;
}

.custom-table th,
.custom-table td {
    padding: 12px 15px;
    border-bottom: 1px solid #e5e7eb;
}

/* Row styles */
.custom-table tr:nth-child(even) {
    background: #f9fafb;
}

.custom-table tr:hover {
    background: #eef2ff;
    transition: 0.2s;
}

/* Teacher separator row */
.teacher-row {
    background: #e0e7ff !important;
    font-weight: 700;
    color: #3730a3;
    text-transform: uppercase;
}

/* Link style */
.custom-table a {
    color: #4f46e5;
    font-weight: 600;
    text-decoration: none;
}

.custom-table a:hover {
    text-decoration: underline;
}

/* ============================ GENERAL STYLES ============================ */
:root{
  --bg:#f4f7fb;
  --card:#ffffff;
  --muted:#6b7280;
  --accent:#4f46e5;
  --accent-2:#6366f1;
  --maxw:1100px;
  --radius:14px;
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font-family: 'Roboto', system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background:linear-gradient(180deg, #f6f8fb 0%, #eef3f8 100%);
  color:#0f172a;
  padding:40px 20px;
  display:flex;
  justify-content:center;
}
.wrap{width:100%;max-width:var(--maxw)}

header.header-enhanced{
  display:flex;
  align-items:center;
  justify-content:center;
  margin-bottom:32px;
  padding:30px 24px;
  border-radius:16px;
  background:#95bd9f;
  box-shadow:0 8px 28px rgba(0,0,0,0.06);
  backdrop-filter:blur(6px);
}
.brand{
  display:flex;
  align-items:center;
  gap:14px;
  flex-direction:column;
  text-align:center;
}
.logo{
  width:80px;
  height:80px;
  border-radius:16px;
  background:linear-gradient(135deg,var(--accent),var(--accent-2));
  display:flex;
  align-items:center;
  justify-content:center;
  color:white;
  font-weight:700;
  font-size:24px;
  box-shadow:0 6px 20px rgba(3,7,18,0.08);
}
.sitename h1{margin:0;font-size:24px}
.sitename p{margin:0;font-size:14px;color:#000000}
nav{display:flex;gap:14px;justify-content:center;margin-top:14px}
nav a{padding:10px 14px;border-radius:10px;text-decoration:none;color: #8d0202;}
nav a.primary{background-color:#a1b354  ;}

.main{display:grid;grid-template-columns:1fr;gap:24px} /* xóa aside, full width */
.card{background:var(--card);border-radius:12px;padding:16px;box-shadow:0 6px 22px rgba(10,15,25,0.06);border:1px solid rgba(15,23,42,0.04)}

.courses{
  display:grid;
  gap:20px;
  margin-top:30px;
}
.courses-header{
  display:flex;align-items:center;justify-content:space-between;
  padding:12px 16px;
  border-radius:12px;
  background:linear-gradient(90deg, var(--accent), var(--accent-2));
  color:white;
  box-shadow:0 4px 16px rgba(0,0,0,0.1);
}
.courses-content{
  background:var(--card);
  border-radius:12px;
  padding:16px;
  box-shadow:0 6px 22px rgba(10,15,25,0.06);
  border:1px solid rgba(15,23,42,0.04);
}
.courses iframe{
  width:100%;
  height:600px;
  border-radius:12px;
  border:none;
}
footer{margin-top:28px;text-align:center;color:var(--muted);font-size:13px;padding:18px}

@media (max-width:900px){
  .main{grid-template-columns:1fr}
}