/* ===========================================================
   Website Trung tâm dạy học - Stylesheet
   Tác giả: DHM Bot KienDuong
   Ghi chú: Đổi màu chủ đạo tại khối :root bên dưới.
   =========================================================== */

:root {
  --primary: #1d4ed8;        /* Màu chính (xanh dương) */
  --primary-dark: #1e3a8a;
  --accent: #f97316;         /* Màu nhấn (cam) */
  --text: #1f2937;
  --muted: #6b7280;
  --bg: #ffffff;
  --bg-soft: #f5f7fb;
  --border: #e5e7eb;
  --radius: 12px;
  --shadow: 0 4px 16px rgba(17, 24, 39, .08);
  --container: 1120px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  font-size: 16px;
}

img { max-width: 100%; display: block; }

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 20px;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: #fff;
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 68px;
  gap: 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text);
}
.brand:hover { text-decoration: none; }

.brand-logo {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--primary);
  color: #fff;
  display: grid;
  place-items: center;
  font-size: 1.1rem;
  flex: none;
}

.brand small {
  display: block;
  font-weight: 400;
  font-size: .72rem;
  color: var(--muted);
  letter-spacing: .04em;
  text-transform: uppercase;
}

.main-nav ul {
  list-style: none;
  display: flex;
  gap: 4px;
  margin: 0;
  padding: 0;
}

.main-nav a {
  display: block;
  padding: 9px 14px;
  border-radius: 8px;
  color: var(--text);
  font-weight: 500;
  font-size: .95rem;
}
.main-nav a:hover { background: var(--bg-soft); text-decoration: none; }
.main-nav a.active { color: var(--primary); background: var(--bg-soft); }

.nav-cta {
  background: var(--primary) !important;
  color: #fff !important;
}
.nav-cta:hover { background: var(--primary-dark) !important; }

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 1.25rem;
  padding: 6px 12px;
  cursor: pointer;
  color: var(--text);
}

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(135deg, #1e3a8a 0%, #1d4ed8 55%, #2563eb 100%);
  color: #fff;
  padding: 76px 0 68px;
}
.hero h1 {
  font-size: clamp(1.8rem, 4vw, 2.7rem);
  margin: 0 0 14px;
  line-height: 1.25;
}
.hero p {
  font-size: 1.05rem;
  max-width: 620px;
  color: #dbeafe;
  margin: 0 0 26px;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }

.hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 34px;
  margin-top: 40px;
  padding-top: 26px;
  border-top: 1px solid rgba(255,255,255,.22);
}
.hero-stats strong { display: block; font-size: 1.6rem; }
.hero-stats span { color: #bfdbfe; font-size: .9rem; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: 12px 22px;
  border-radius: 8px;
  font-weight: 600;
  font-size: .95rem;
  border: 2px solid transparent;
  cursor: pointer;
  text-align: center;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-accent { background: var(--accent); color: #fff; }
.btn-accent:hover { background: #ea6a0a; }
.btn-outline { border-color: rgba(255,255,255,.7); color: #fff; }
.btn-outline:hover { background: rgba(255,255,255,.12); }
.btn-ghost { border-color: var(--border); color: var(--text); background: #fff; }
.btn-ghost:hover { background: var(--bg-soft); }
.btn-block { display: block; width: 100%; }

/* ---------- Sections ---------- */
.section { padding: 64px 0; }
.section-soft { background: var(--bg-soft); }

.section-head { max-width: 720px; margin: 0 auto 40px; text-align: center; }
.section-head h2 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin: 0 0 10px;
}
.section-head p { color: var(--muted); margin: 0; }

.eyebrow {
  display: inline-block;
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: 8px;
}

/* ---------- Grid & cards ---------- */
.grid { display: grid; gap: 22px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }

.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
}
.card h3 { margin: 0 0 8px; font-size: 1.1rem; }
.card p { color: var(--muted); margin: 0; font-size: .95rem; }

.icon-badge {
  width: 44px; height: 44px;
  border-radius: 10px;
  background: #e0e7ff;
  color: var(--primary);
  display: grid; place-items: center;
  font-size: 1.25rem;
  margin-bottom: 14px;
}

/* Course card */
.course-card { display: flex; flex-direction: column; }
.course-top {
  display: flex; align-items: center; justify-content: space-between;
  gap: 10px; margin-bottom: 12px;
}
.tag {
  font-size: .75rem; font-weight: 600;
  padding: 4px 10px; border-radius: 999px;
  background: #e0e7ff; color: var(--primary-dark);
}
.tag.hot { background: #ffedd5; color: #c2410c; }

.course-card ul {
  list-style: none; padding: 0; margin: 14px 0 18px;
  font-size: .92rem; color: var(--muted);
}
.course-card ul li { padding-left: 22px; position: relative; margin-bottom: 6px; }
.course-card ul li::before {
  content: "✓"; position: absolute; left: 0; color: var(--primary); font-weight: 700;
}
.course-price {
  margin-top: auto;
  padding-top: 14px;
  border-top: 1px dashed var(--border);
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
}
.course-price strong { font-size: 1.1rem; color: var(--primary-dark); }
.course-price span { font-size: .82rem; color: var(--muted); display: block; }

/* ---------- Table (lịch học) ---------- */
.table-wrap { overflow-x: auto; border-radius: var(--radius); border: 1px solid var(--border); background: #fff; }
table.schedule {
  width: 100%;
  border-collapse: collapse;
  min-width: 720px;
  font-size: .93rem;
}
table.schedule th, table.schedule td {
  padding: 14px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}
table.schedule thead th {
  background: var(--primary-dark);
  color: #fff;
  font-weight: 600;
  white-space: nowrap;
}
table.schedule tbody tr:nth-child(even) { background: #fafbff; }
table.schedule tbody tr:hover { background: #eff4ff; }
table.schedule td strong { display: block; }
table.schedule td small { color: var(--muted); }

/* ---------- Contact / form ---------- */
.contact-layout {
  display: grid;
  grid-template-columns: 1.1fr .9fr;
  gap: 30px;
  align-items: start;
}

.form-group { margin-bottom: 16px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

label {
  display: block;
  font-weight: 600;
  font-size: .9rem;
  margin-bottom: 6px;
}
label .req { color: #dc2626; }

input, select, textarea {
  width: 100%;
  padding: 11px 13px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font: inherit;
  font-size: .95rem;
  color: var(--text);
  background: #fff;
}
input:focus, select:focus, textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(29, 78, 216, .12);
}
textarea { resize: vertical; min-height: 110px; }

.form-note { font-size: .82rem; color: var(--muted); margin-top: 10px; }

.form-alert {
  display: none;
  padding: 12px 14px;
  border-radius: 8px;
  font-size: .92rem;
  margin-bottom: 16px;
}
.form-alert.ok { display: block; background: #dcfce7; color: #166534; }
.form-alert.err { display: block; background: #fee2e2; color: #991b1b; }

.info-list { list-style: none; padding: 0; margin: 0; }
.info-list li {
  display: flex; gap: 12px; padding: 14px 0;
  border-bottom: 1px solid var(--border);
}
.info-list li:last-child { border-bottom: none; }
.info-list .ic {
  width: 36px; height: 36px; flex: none;
  border-radius: 8px; background: #e0e7ff; color: var(--primary);
  display: grid; place-items: center;
}
.info-list b { display: block; font-size: .9rem; }
.info-list span { color: var(--muted); font-size: .9rem; }

.map-embed {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg-soft);
  height: 260px;
  display: grid;
  place-items: center;
  color: var(--muted);
  font-size: .9rem;
  text-align: center;
  padding: 20px;
}

/* ---------- CTA band ---------- */
.cta-band {
  background: var(--primary-dark);
  color: #fff;
  border-radius: var(--radius);
  padding: 40px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}
.cta-band h2 { margin: 0 0 6px; font-size: 1.4rem; }
.cta-band p { margin: 0; color: #bfdbfe; }

/* ---------- Footer ---------- */
.site-footer {
  background: #111827;
  color: #9ca3af;
  padding: 44px 0 26px;
  font-size: .92rem;
  margin-top: 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 30px;
  padding-bottom: 26px;
  border-bottom: 1px solid #1f2937;
}
.site-footer h4 { color: #fff; margin: 0 0 12px; font-size: .95rem; }
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin-bottom: 8px; }
.site-footer a { color: #9ca3af; }
.site-footer a:hover { color: #fff; }
.footer-bottom { padding-top: 20px; text-align: center; font-size: .85rem; color: #6b7280; }

/* ---------- Page banner ---------- */
.page-banner {
  background: var(--primary-dark);
  color: #fff;
  padding: 46px 0;
}
.page-banner h1 { margin: 0 0 6px; font-size: clamp(1.5rem, 3vw, 2.1rem); }
.page-banner p { margin: 0; color: #bfdbfe; }
.breadcrumb { font-size: .85rem; color: #93c5fd; margin-bottom: 8px; }
.breadcrumb a { color: #bfdbfe; }

/* ---------- Liên hệ nhanh (3 phương thức) ---------- */
.contact-methods {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 30px;
}
.method-card {
  text-align: center;
  padding: 24px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: #fff;
  box-shadow: var(--shadow);
}
.method-card .ic-big {
  width: 54px; height: 54px;
  border-radius: 50%;
  display: grid; place-items: center;
  margin: 0 auto 14px;
  font-size: 1.5rem;
  color: #fff;
}
.ic-phone { background: #16a34a; }
.ic-zalo { background: #0068ff; font-size: .95rem; font-weight: 700; }
.ic-mail { background: #dc2626; }
.method-card h3 { margin: 0 0 4px; font-size: 1rem; }
.method-card p { margin: 0 0 16px; color: var(--muted); font-size: .88rem; }

/* Nhúng Google Form */
.form-embed {
  width: 100%;
  border: 0;
  border-radius: var(--radius);
  background: #fff;
  min-height: 980px;
  display: block;
}

.embed-placeholder {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 40px 24px;
  text-align: center;
  color: var(--muted);
  background: #fff;
}

/* ---------- Nút liên hệ nổi (góc phải dưới) ---------- */
.float-contact {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 60;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.float-contact a {
  position: relative;
  width: 54px; height: 54px;
  border-radius: 50%;
  display: grid; place-items: center;
  color: #fff;
  font-size: 1.45rem;
  text-decoration: none;
  box-shadow: 0 6px 18px rgba(0, 0, 0, .22);
  transition: transform .15s ease;
}
.float-contact a:hover { transform: translateY(-3px); text-decoration: none; }
.fc-phone { background: #16a34a; }
.fc-zalo { background: #0068ff; font-size: .95rem; font-weight: 700; }
.fc-label {
  position: absolute;
  right: 64px;
  white-space: nowrap;
  background: #111827;
  color: #fff;
  font-size: .8rem;
  padding: 6px 10px;
  border-radius: 6px;
  opacity: 0;
  pointer-events: none;
  transition: opacity .15s ease;
}
.float-contact a:hover .fc-label { opacity: 1; }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .contact-layout { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .contact-methods { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 640px) {
  .nav-toggle { display: block; }
  .main-nav {
    display: none;
    position: absolute;
    top: 68px; left: 0; right: 0;
    background: #fff;
    border-bottom: 1px solid var(--border);
    padding: 10px 20px 18px;
    box-shadow: var(--shadow);
  }
  .main-nav.open { display: block; }
  .main-nav ul { flex-direction: column; gap: 2px; }
  .main-nav a { padding: 12px 10px; }

  .grid-3, .grid-2 { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero { padding: 52px 0 46px; }
  .section { padding: 44px 0; }
  .hero-stats { gap: 22px; }
  .cta-band { padding: 28px; }
  .contact-methods { grid-template-columns: 1fr; }
  .float-contact { right: 12px; bottom: 12px; }
  .float-contact a { width: 48px; height: 48px; font-size: 1.25rem; }
  .fc-label { display: none; }
  .form-embed { min-height: 1100px; }
}