/* ===== 基础 ===== */
:root {
  --bg: #fbf6f0;
  --bg-alt: #f3ece3;
  --ink: #211a14;
  --ink-soft: #6b5f52;
  --accent: #e0574f;
  --accent-dark: #c74139;
  --line: #e7ddd1;
  --white: #ffffff;
  --radius: 18px;
  --shadow: 0 20px 50px -20px rgba(33, 26, 20, 0.25);
  --font-display: 'Fraunces', Georgia, serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }

.container { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

.accent { color: var(--accent); }

/* 通用标题 */
.eyebrow {
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}

.section__title {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4vw, 2.8rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.01em;
}

.section__sub {
  color: var(--ink-soft);
  font-size: 1.1rem;
  max-width: 560px;
  margin-top: 16px;
}

.section { padding: 96px 0; }
.section--alt { background: var(--bg-alt); }

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 1rem;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
  cursor: pointer;
  border: none;
}

.btn--primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 10px 26px -10px rgba(224, 87, 79, 0.7);
}
.btn--primary:hover { background: var(--accent-dark); transform: translateY(-2px); }

.btn--ghost {
  background: transparent;
  color: var(--ink);
  border: 1.5px solid var(--line);
}
.btn--ghost:hover { border-color: var(--ink); transform: translateY(-2px); }

.btn--block { width: 100%; }

/* ===== 导航 ===== */
.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 32px;
  background: rgba(251, 246, 240, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s ease, box-shadow .2s ease;
}
.nav.scrolled { border-color: var(--line); box-shadow: 0 8px 30px -20px rgba(33,26,20,.3); }

.nav__brand { display: inline-flex; align-items: center; gap: 10px; }

.nav__brand-mark {
  display: grid; place-items: center;
  width: 40px; height: 40px;
  background: var(--accent);
  color: #fff;
  border-radius: 12px;
  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: 0.02em;
}

.nav__brand-text { font-family: var(--font-display); font-weight: 700; font-size: 1.2rem; }

.nav__links { display: flex; align-items: center; gap: 28px; }

.nav__link {
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--ink-soft);
  transition: color .15s ease;
}
.nav__link:hover, .nav__link.active { color: var(--ink); }

.nav__link--cta {
  background: var(--ink);
  color: #fff;
  padding: 10px 20px;
  border-radius: 999px;
}
.nav__link--cta:hover { background: #000; color: #fff; }

.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}
.nav__toggle span {
  width: 24px; height: 2px;
  background: var(--ink);
  border-radius: 2px;
  transition: transform .2s ease, opacity .2s ease;
}

/* ===== Hero ===== */
.hero { padding: 160px 0 80px; position: relative; overflow: hidden; }

.hero__grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 56px;
  align-items: center;
}

.hero__title {
  font-family: var(--font-display);
  font-size: clamp(2.6rem, 6vw, 4.2rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}
.hero__title em {
  font-style: normal;
  color: var(--accent);
}

.hero__sub {
  color: var(--ink-soft);
  font-size: 1.18rem;
  max-width: 520px;
  margin-bottom: 32px;
}

.hero__actions { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 40px; }

.hero__stats {
  list-style: none;
  display: flex;
  gap: 40px;
  flex-wrap: wrap;
}
.hero__stats li { display: flex; flex-direction: column; }
.hero__stats strong {
  font-family: var(--font-display);
  font-size: 1.9rem;
  font-weight: 700;
}
.hero__stats span { color: var(--ink-soft); font-size: 0.9rem; }

/* Hero 卡片视觉 */
.hero__visual { position: relative; height: 420px; }

.hero__blob {
  position: absolute;
  inset: 8% 4%;
  background: radial-gradient(circle at 30% 30%, #f4a89b, #e0574f);
  border-radius: 42% 58% 55% 45% / 48% 42% 58% 52%;
  opacity: 0.18;
}

.hero__card {
  position: absolute;
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px;
  width: 220px;
}

.hero__card--main {
  top: 50%;
  right: 8%;
  transform: translateY(-50%) rotate(-3deg);
  width: 260px;
  padding: 32px;
  z-index: 2;
}

.hero__card--float {
  bottom: 14%;
  left: 4%;
  transform: rotate(4deg);
  z-index: 3;
}

.hero__card-label {
  display: inline-block;
  font-size: 0.75rem;
  color: var(--ink-soft);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 2px 10px;
  margin-bottom: 14px;
}

.hero__card-word {
  font-family: var(--font-display);
  font-size: 2.1rem;
  font-weight: 700;
  margin-bottom: 4px;
}
.hero__card--main .hero__card-word { font-size: 2.6rem; }

.hero__card-pinyin { color: var(--accent); font-size: 1rem; font-weight: 500; }
.hero__card--float .hero__card-pinyin { color: var(--ink-soft); }

.hero__card-mean { color: var(--ink-soft); font-size: 0.9rem; }

/* ===== 课程卡片 ===== */
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 56px;
}

.card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 32px;
  display: flex;
  flex-direction: column;
  transition: transform .18s ease, box-shadow .18s ease;
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow); }

.card__icon {
  width: 52px; height: 52px;
  display: grid; place-items: center;
  border-radius: 14px;
  background: color-mix(in srgb, var(--c) 14%, white);
  color: var(--c);
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 20px;
}

.card__title { font-size: 1.2rem; font-family: var(--font-display); font-weight: 700; margin-bottom: 6px; }

.card__tag { color: var(--accent); font-size: 0.82rem; font-weight: 600; margin-bottom: 12px; }

.card__desc { color: var(--ink-soft); font-size: 0.95rem; flex: 1; margin-bottom: 20px; }

.card__link { font-weight: 600; color: var(--ink); position: relative; }
.card__link::after { content: "→"; margin-left: 6px; color: var(--accent); transition: margin-left .15s ease; }
.card__link:hover::after { margin-left: 12px; }

/* ===== 步骤 ===== */
.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 56px;
}

.step {
  padding: 28px;
  border-left: 2px solid var(--line);
}
.step__num {
  font-family: var(--font-display);
  color: var(--accent);
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: 0.05em;
}
.step__title { font-size: 1.15rem; font-family: var(--font-display); font-weight: 700; margin: 10px 0 8px; }
.step__desc { color: var(--ink-soft); font-size: 0.95rem; }

/* ===== 关于 ===== */
.about {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 64px;
  align-items: center;
}

.about__portrait {
  aspect-ratio: 1;
  border-radius: 26px;
  background: linear-gradient(150deg, #f4a89b, #e0574f);
  display: grid;
  place-items: center;
  box-shadow: var(--shadow);
}
.about__initial {
  font-family: var(--font-display);
  font-size: 7rem;
  font-weight: 700;
  color: #fff;
}

.about__points { margin-top: 32px; display: flex; flex-direction: column; gap: 18px; }
.about__points div { display: flex; gap: 14px; align-items: baseline; }
.about__points strong { font-family: var(--font-display); font-size: 1.05rem; min-width: 96px; }
.about__points span { color: var(--ink-soft); font-size: 0.95rem; }

/* ===== 联系表单 ===== */
.contact {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}

.contact__perks { list-style: none; margin-top: 28px; display: flex; flex-direction: column; gap: 14px; }
.contact__perks li { position: relative; padding-left: 28px; color: var(--ink-soft); font-size: 1rem; }
.contact__perks li::before {
  content: "✓";
  position: absolute; left: 0; top: 0;
  color: #4aa368;
  font-weight: 700;
}

.form {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 22px;
  padding: 36px;
  box-shadow: var(--shadow);
}

.form__row { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }

.field { margin-bottom: 18px; }
.field label { display: block; font-size: 0.9rem; font-weight: 600; margin-bottom: 8px; }
.field input,
.field select,
.field textarea {
  width: 100%;
  padding: 13px 16px;
  border: 1.5px solid var(--line);
  border-radius: 12px;
  font-family: inherit;
  font-size: 1rem;
  color: var(--ink);
  background: var(--bg);
  transition: border-color .15s ease, box-shadow .15s ease;
}
.field input:focus,
.field select:focus,
.field textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 4px rgba(224, 87, 79, 0.12);
}

.form__status { margin-top: 14px; font-size: 0.9rem; min-height: 20px; }
.form__status.success { color: #2f8a4e; }
.form__status.error { color: var(--accent-dark); }

/* ===== 页脚 ===== */
.footer { background: var(--ink); color: #f5efe8; padding: 56px 0 32px; }
.footer__row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 24px;
}
.nav__brand--footer .nav__brand-mark { background: var(--accent); }
.footer__links { display: flex; gap: 24px; }
.footer__links a { color: #cbb9a8; font-size: 0.95rem; transition: color .15s ease; }
.footer__links a:hover { color: #fff; }
.footer__copy { text-align: center; color: #8f7d6c; font-size: 0.85rem; margin-top: 40px; }

/* ===== 滚动动画 ===== */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .6s ease, transform .6s ease; }
.reveal.visible { opacity: 1; transform: none; }

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .hero__grid, .about, .contact { grid-template-columns: 1fr; }
  .cards { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .hero { padding-top: 130px; }
}

@media (max-width: 640px) {
  .nav { padding: 14px 20px; }
  .nav__links {
    position: fixed;
    top: 0; right: 0;
    height: 100vh;
    width: min(78vw, 320px);
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    gap: 24px;
    background: var(--bg);
    padding: 0 40px;
    transform: translateX(100%);
    transition: transform .25s ease;
    box-shadow: -20px 0 50px rgba(33,26,20,.15);
  }
  .nav__links.open { transform: translateX(0); }
  .nav__toggle { display: flex; z-index: 60; }
  .nav__toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav__toggle.open span:nth-child(2) { opacity: 0; }
  .nav__toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

  .cards { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr; }
  .form__row { grid-template-columns: 1fr; }
  .hero__visual { height: 320px; }
  .hero__stats { gap: 24px; }
}