/* ===== Header ===== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 253, 249, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0,0,0,.06);
  padding: 0;
}
.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 24px;
}
.logo {
  display: flex;
  align-items: baseline;
  gap: 8px;
  text-decoration: none;
  color: var(--text);
  flex-shrink: 0;
}
.logo__zh {
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.logo__sub {
  font-size: 0.85rem;
  font-weight: 400;
  color: var(--text-light);
  font-style: italic;
}
.lang-switch {
  border: 1px solid rgba(0,0,0,.12);
  border-radius: 6px;
  padding: 6px 10px;
  font-size: 0.85rem;
  background: var(--white);
  cursor: pointer;
  color: var(--text);
  flex-shrink: 0;
}
.nav {
  display: flex;
  gap: 8px;
}
.nav a {
  padding: 8px 14px;
  text-decoration: none;
  color: var(--text);
  font-weight: 500;
  font-size: 0.95rem;
  border-radius: 6px;
  transition: all 0.15s;
}
.nav a:hover {
  background: rgba(200,75,49,.08);
  color: var(--primary);
}
.nav-cta {
  flex-shrink: 0;
  font-size: 0.9rem !important;
  padding: 10px 20px !important;
}
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: all 0.25s;
}
.hamburger--open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger--open span:nth-child(2) { opacity: 0; }
.hamburger--open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== Hero ===== */
.hero {
  padding: 100px 0 80px;
  background: linear-gradient(135deg, var(--accent) 0%, #1a2d45 100%);
  color: var(--white);
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 30% 70%, rgba(200,75,49,.15) 0%, transparent 60%),
              radial-gradient(circle at 70% 30%, rgba(255,255,255,.04) 0%, transparent 50%);
  pointer-events: none;
}
.hero__content {
  max-width: 700px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}
.hero h1 {
  font-size: 3.2rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 12px;
  line-height: 1.2;
}
.hero h1 span {
  display: block;
  font-size: 1.5rem;
  font-weight: 400;
  opacity: .85;
  margin-top: 4px;
}
.hero p {
  font-size: 1.1rem;
  opacity: .75;
  margin-bottom: 36px;
}
.hero__btns {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ===== Stats ===== */
.stats {
  max-width: 800px;
  margin: -36px auto 0;
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: rgba(0,0,0,.06);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}
.stat-card {
  background: var(--white);
  padding: 28px 16px;
  text-align: center;
}
.stat-card strong {
  display: block;
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 4px;
}
.stat-card span {
  font-size: 0.85rem;
  color: var(--text-light);
}

/* ===== Why Grid ===== */
.why-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  max-width: 900px;
  margin: 0 auto;
}
.why-card {
  text-align: center;
  padding: 32px 24px;
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 0.2s;
}
.why-card:hover { transform: translateY(-4px); }
.why-card .why-icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
  display: block;
}
.why-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--accent);
}
.why-card p {
  font-size: 0.95rem;
  color: var(--text-light);
  line-height: 1.6;
}

/* ===== Courses Preview / Cards ===== */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
  max-width: 1000px;
  margin: 0 auto;
}
.course-card {
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px;
  border: 1px solid rgba(0,0,0,.05);
  transition: transform 0.2s, box-shadow 0.2s;
  display: flex;
  flex-direction: column;
}
.course-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(0,0,0,.1);
}
.course-card__tag {
  display: inline-block;
  background: rgba(200,75,49,.1);
  color: var(--primary);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 20px;
  margin-bottom: 12px;
  align-self: flex-start;
}
.course-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 6px;
}
.course-card .course-card__duration {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 12px;
}
.course-card p {
  font-size: 0.9rem;
  color: var(--text-light);
  line-height: 1.6;
  margin-bottom: 20px;
  flex: 1;
}
.course-card__price {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 4px;
}
.course-card__price small {
  font-size: 0.8rem;
  color: var(--text-light);
  font-weight: 400;
}
.course-card .btn {
  margin-top: 16px;
  text-align: center;
}

/* ===== Reviews ===== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: 1000px;
  margin: 0 auto;
}
.review-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
}
.review-card .stars {
  color: #f0a500;
  font-size: 1.1rem;
  margin-bottom: 12px;
}
.review-card p {
  font-size: 0.95rem;
  color: var(--text);
  line-height: 1.7;
  margin-bottom: 16px;
  font-style: italic;
}
.review-card .review-author {
  font-size: 0.85rem;
  color: var(--text-light);
  font-weight: 600;
}

/* ===== CTA Block ===== */
.cta-block {
  background: linear-gradient(135deg, var(--accent) 0%, var(--primary) 100%);
  color: var(--white);
  text-align: center;
  padding: 72px 24px;
  border-radius: 12px;
  max-width: 800px;
  margin: 0 auto;
}
.cta-block h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 12px;
}
.cta-block p {
  font-size: 1.1rem;
  opacity: .85;
  margin-bottom: 28px;
}

/* ===== About Page ===== */
.about-intro {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  max-width: 1000px;
  margin: 0 auto;
}
.about-intro__text h2 {
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 20px;
}
.about-intro__text p {
  color: var(--text-light);
  line-height: 1.8;
  margin-bottom: 16px;
  font-size: 1.05rem;
}
.about-intro__img {
  background: var(--gray);
  border-radius: var(--radius);
  aspect-ratio: 3/4;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-light);
  font-size: 0.9rem;
  overflow: hidden;
}
.about-intro__img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* Credentials */
.creds-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  max-width: 1000px;
  margin: 0 auto;
}
.cred-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 28px 20px;
  text-align: center;
  box-shadow: var(--shadow);
  border-top: 3px solid var(--primary);
}
.cred-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--accent);
}
.cred-card p {
  font-size: 0.85rem;
  color: var(--text-light);
  line-height: 1.5;
}

/* Teaching grid */
.teaching-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  max-width: 900px;
  margin: 0 auto;
}
.teaching-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
}
.teaching-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
}
.teaching-card p {
  font-size: 0.9rem;
  color: var(--text-light);
  line-height: 1.6;
}

/* ===== Contact Page ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  max-width: 900px;
  margin: 0 auto;
}
.contact-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.form-group label {
  font-size: 0.9rem;
  font-weight: 600;
}
.form-group input,
.form-group textarea,
.form-group select {
  padding: 12px 14px;
  border: 1px solid rgba(0,0,0,.12);
  border-radius: 6px;
  font-size: 1rem;
  font-family: inherit;
  background: var(--white);
  transition: border-color 0.15s;
}
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(200,75,49,.1);
}
.contact-info {
  background: var(--gray);
  border-radius: var(--radius);
  padding: 32px;
}
.contact-info h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 20px;
}
.contact-info p {
  margin-bottom: 12px;
  color: var(--text-light);
  font-size: 0.95rem;
}

/* ===== Blog ===== */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 28px;
  max-width: 1000px;
  margin: 0 auto;
}
.blog-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform 0.2s;
  text-decoration: none;
  color: inherit;
}
.blog-card:hover { transform: translateY(-3px); }
.blog-card__img {
  background: linear-gradient(135deg, var(--accent) 0%, #3a5a80 100%);
  height: 180px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: 2.5rem;
}
.blog-card__body {
  padding: 24px;
}
.blog-card__tag {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--primary);
  margin-bottom: 8px;
}
.blog-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 8px;
}
.blog-card p {
  font-size: 0.9rem;
  color: var(--text-light);
  line-height: 1.5;
}

/* ===== Checkout Modal ===== */
.checkout-overlay {
  position: fixed;
  inset: 0;
  z-index: 9999;
  background: rgba(0,0,0,.5);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}
.checkout-modal {
  background: var(--white);
  border-radius: 12px;
  padding: 36px;
  max-width: 460px;
  width: 100%;
  position: relative;
  box-shadow: 0 20px 60px rgba(0,0,0,.2);
}
.checkout-close {
  position: absolute;
  top: 12px;
  right: 16px;
  background: none;
  border: none;
  font-size: 1.3rem;
  cursor: pointer;
  color: var(--text-light);
}
.checkout-modal h2 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 20px;
}

/* ===== Toast ===== */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 9999;
  padding: 14px 28px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  animation: toast-in .3s ease;
  box-shadow: 0 8px 24px rgba(0,0,0,.15);
}
.toast--success { background: #2e7d32; color: #fff; }
.toast--error { background: #c62828; color: #fff; }
@keyframes toast-in {
  from { opacity: 0; transform: translateX(-50%) translateY(12px); }
  to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

/* ===== Footer ===== */
.footer {
  background: var(--accent);
  color: rgba(255,255,255,.75);
  padding: 60px 0 30px;
  margin-top: 80px;
  position: relative;
}
.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
}
.footer__logo {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 12px;
}
.footer__logo span {
  font-weight: 400;
  opacity: .6;
  margin-left: 6px;
  font-style: italic;
  font-size: 0.9rem;
}
.footer__col--brand p {
  font-size: 0.9rem;
  line-height: 1.7;
  color: rgba(255,255,255,.5);
  max-width: 340px;
}
.footer__title {
  font-weight: 700;
  color: var(--white);
  margin-bottom: 14px;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.footer__col a {
  display: block;
  color: rgba(255,255,255,.6);
  text-decoration: none;
  font-size: 0.9rem;
  margin-bottom: 8px;
  transition: color 0.15s;
}
.footer__col a:hover { color: var(--white); }
.footer__col p {
  font-size: 0.85rem;
  margin-bottom: 6px;
}
.footer__italki {
  display: inline-block;
  margin-top: 8px;
  padding: 8px 16px;
  border-radius: 6px;
  background: rgba(255,255,255,.1);
  color: var(--white) !important;
  font-weight: 600;
}
.footer__italki:hover { background: rgba(255,255,255,.18); }
.footer__bottom {
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid rgba(255,255,255,.1);
  text-align: center;
  font-size: 0.85rem;
  color: rgba(255,255,255,.4);
}
.sitemap-seo {
  position: absolute;
  bottom: 8px;
  right: 16px;
  font-size: 0.7rem;
  color: rgba(255,255,255,.2);
  text-decoration: none;
}

/* ===== Page Header ===== */
.page-header {
  text-align: center;
  padding: 60px 0 20px;
}
.page-header h1 {
  font-size: 2.4rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}
.page-header p {
  color: var(--text-light);
  font-size: 1.1rem;
}

/* ===== Thank You Page ===== */
.thanks-block {
  text-align: center;
  padding: 100px 24px;
  max-width: 500px;
  margin: 0 auto;
}
.thanks-block h1 {
  font-size: 2rem;
  margin-bottom: 16px;
}
.thanks-block p {
  color: var(--text-light);
  margin-bottom: 32px;
  font-size: 1.05rem;
  line-height: 1.7;
}

/* ===== Mobile ===== */
@media (max-width: 768px) {
  .container { padding: 0 16px; }
  .section { padding: 56px 0; }
  .section__title { font-size: 1.5rem; }

  .header__inner { height: 56px; }
  .nav-cta { display: none; }
  .hamburger { display: flex; z-index: 101; }
  .lang-switch { display: none; }
  .nav {
    position: fixed;
    inset: 0;
    background: var(--bg);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 8px;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.25s;
    z-index: 100;
  }
  .nav--open { opacity: 1; pointer-events: auto; }
  .nav a { font-size: 1.3rem; padding: 12px 20px; }

  .hero { padding: 64px 0 48px; }
  .hero h1 { font-size: 2rem; }
  .hero h1 span { font-size: 1.1rem; }

  .stats { grid-template-columns: repeat(2, 1fr); margin-top: -24px; }
  .why-grid { grid-template-columns: 1fr; gap: 16px; }
  .courses-grid { grid-template-columns: 1fr; gap: 16px; }
  .reviews-grid { grid-template-columns: 1fr; gap: 16px; }
  .about-intro { grid-template-columns: 1fr; gap: 32px; }
  .creds-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .teaching-grid { grid-template-columns: 1fr; gap: 12px; }
  .contact-grid { grid-template-columns: 1fr; gap: 24px; }
  .blog-grid { grid-template-columns: 1fr; gap: 16px; }
  .footer__grid { grid-template-columns: 1fr; gap: 28px; }

  .page-header { padding: 40px 0 12px; }
  .page-header h1 { font-size: 1.8rem; }

  .cta-block { padding: 48px 20px; border-radius: 0; margin: 0 -16px; }
  .cta-block h2 { font-size: 1.5rem; }
}