/* ===== 基础 ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }
:root {
  --primary: #4f7cff;
  --primary-deep: #3a5fe0;
  --accent: #ff9f43;
  --ink: #1f2d3d;
  --muted: #6b7a90;
  --bg: #f5f7fb;
  --radius: 14px;
}
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  background: #fff;
  line-height: 1.7;
}
img { max-width: 100%; }
a { color: var(--primary); text-decoration: none; }
.container { width: min(1080px, 92%); margin: 0 auto; }
.center { text-align: center; }

/* ===== 导航 ===== */
.navbar {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid #edf0f5;
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { font-weight: 700; font-size: 1.05rem; color: var(--ink); }
.brand-mark { color: var(--primary); }
.nav-links { display: flex; align-items: center; gap: 1.6rem; }
.nav-links a { color: var(--muted); font-size: .95rem; }
.nav-links a.active, .nav-links a.active-btn { color: var(--primary); font-weight: 600; }
.nav-toggle { display: none; border: none; background: none; font-size: 1.5rem; cursor: pointer; color: var(--ink); }

/* ===== 按钮 ===== */
.btn {
  display: inline-block; padding: 12px 28px;
  border-radius: 999px; border: none; cursor: pointer;
  font-size: 1rem; font-weight: 600; color: #fff;
  background: linear-gradient(135deg, var(--primary), #6a5bff);
  box-shadow: 0 6px 18px rgba(79,124,255,.35);
  transition: transform .15s, opacity .15s;
}
.btn:hover { transform: translateY(-2px); opacity: .92; }
.btn-ghost {
  background: #fff; color: var(--primary);
  border: 1.5px solid var(--primary);
  box-shadow: none;
}
.btn-sm { padding: 8px 20px; font-size: .9rem; }
.btn-lg { padding: 15px 44px; font-size: 1.05rem; }
.btn-block { width: 100%; }

/* ===== Hero ===== */
.hero {
  background:
    radial-gradient(900px 400px at 85% -10%, rgba(106,91,255,.18), transparent),
    radial-gradient(700px 380px at 10% 110%, rgba(255,159,67,.16), transparent),
    linear-gradient(160deg, #f5f7fb 0%, #e8edf7 100%);
  padding: 88px 0 72px;
  text-align: center;
}
.hero-tag {
  display: inline-block; padding: 6px 16px; border-radius: 999px;
  background: #fff; color: var(--primary);
  font-size: .85rem; font-weight: 600;
  box-shadow: 0 4px 14px rgba(31,45,61,.08);
}
.hero-title {
  font-size: clamp(2rem, 6vw, 3.4rem);
  line-height: 1.25; margin: 1.2rem 0 .8rem;
  letter-spacing: .02em;
}
.hero-sub { color: var(--muted); font-size: 1.05rem; }
.hero-actions { display: flex; gap: 14px; justify-content: center; margin: 2rem 0 2.6rem; flex-wrap: wrap; }
.hero-stats {
  display: flex; justify-content: center; gap: 3rem; list-style: none; flex-wrap: wrap;
}
.hero-stats strong { display: block; font-size: 1.7rem; color: var(--primary); }
.hero-stats span { color: var(--muted); font-size: .9rem; }

/* ===== 区块 ===== */
.section { padding: 72px 0; }
.section-alt { background: var(--bg); }
.section-title { font-size: 1.8rem; text-align: center; margin-bottom: .4rem; }
.section-desc { text-align: center; color: var(--muted); margin-bottom: 2.6rem; }

.grid { display: grid; gap: 22px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.card {
  background: #fff; border-radius: var(--radius);
  padding: 30px 26px; text-align: center;
  box-shadow: 0 8px 26px rgba(31,45,61,.07);
  border: 1px solid #eef1f6;
  transition: transform .18s;
}
.card:hover { transform: translateY(-4px); }
.card-icon { font-size: 2.4rem; margin-bottom: .8rem; }
.card h3 { margin-bottom: .5rem; }
.card p { color: var(--muted); font-size: .95rem; }

/* ===== 步骤 ===== */
.steps { max-width: 640px; margin: 0 auto 2.4rem; display: grid; gap: 18px; }
.step {
  display: flex; gap: 16px; align-items: flex-start;
  background: #fff; border-radius: var(--radius);
  padding: 20px 24px; box-shadow: 0 6px 20px rgba(31,45,61,.06);
}
.step-num {
  flex: none; width: 34px; height: 34px; line-height: 34px;
  border-radius: 50%; text-align: center;
  background: linear-gradient(135deg, var(--primary), #6a5bff);
  color: #fff; font-weight: 700;
}
.step h4 { font-size: 1.02rem; }
.step p { color: var(--muted); font-size: .92rem; }

/* ===== 日程页 ===== */
.page-head {
  background: linear-gradient(160deg, var(--primary), #6a5bff);
  color: #fff; text-align: center; padding: 56px 0 48px;
}
.page-head h1 { font-size: 2rem; }
.page-head p { opacity: .85; margin-top: .4rem; }
.day-title { font-size: 1.3rem; margin: 2.6rem 0 1.4rem; }
.timeline { display: grid; gap: 14px; }
.tl-item {
  display: flex; gap: 18px; align-items: baseline;
  background: #fff; border: 1px solid #eef1f6;
  border-left: 4px solid var(--primary);
  border-radius: 10px; padding: 16px 20px;
}
.tl-item time { flex: none; font-weight: 700; color: var(--primary); width: 64px; }
.tl-item p { color: var(--muted); font-size: .92rem; }

/* ===== 报名表单 ===== */
.form-wrap { max-width: 620px; }
.signup-form {
  background: #fff; border: 1px solid #eef1f6;
  border-radius: var(--radius);
  padding: 36px 32px;
  box-shadow: 0 10px 32px rgba(31,45,61,.08);
  display: grid; gap: 20px;
}
.form-row label { display: block; font-weight: 600; margin-bottom: .45rem; font-size: .95rem; }
.form-row label em { color: #e74c3c; font-style: normal; }
.form-row input[type="text"],
.form-row input[type="tel"],
.form-row textarea {
  width: 100%; padding: 12px 14px;
  border: 1.5px solid #e0e6ef; border-radius: 10px;
  font-size: .95rem; font-family: inherit; outline: none;
  transition: border-color .15s, box-shadow .15s;
}
.form-row input:focus,
.form-row textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(79,124,255,.15);
}
.check-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.check {
  display: flex; align-items: center; gap: 8px;
  border: 1.5px solid #e0e6ef; border-radius: 10px;
  padding: 10px 14px; cursor: pointer; font-size: .93rem; font-weight: 400;
}
.check:has(input:checked) { border-color: var(--primary); background: #f3f6ff; }
.check input { accent-color: var(--primary); }
.form-tip { color: var(--muted); font-size: .82rem; text-align: center; }

.success-box {
  background: #fff; border-radius: var(--radius);
  padding: 56px 32px; text-align: center;
  box-shadow: 0 10px 32px rgba(31,45,61,.08);
}
.success-icon {
  width: 68px; height: 68px; line-height: 68px; margin: 0 auto 1rem;
  border-radius: 50%; font-size: 2rem; color: #fff;
  background: linear-gradient(135deg, #2ecc71, #27ae60);
}
.success-box p { color: var(--muted); margin: .5rem 0 1.6rem; }

/* ===== 页脚 ===== */
.footer {
  background: #1c2740; color: #d5dbe8;
  text-align: center; padding: 34px 0;
}
.footer-sub { font-size: .85rem; opacity: .7; margin-top: .3rem; }

/* ===== 响应式 ===== */
@media (max-width: 820px) {
  .grid-3 { grid-template-columns: 1fr; }
  .nav-toggle { display: block; }
  .nav-links {
    display: none; position: absolute; top: 64px; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 0;
    background: #fff; border-bottom: 1px solid #edf0f5;
    padding: 8px 0;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 24px; }
  .check-grid { grid-template-columns: 1fr; }
  .tl-item { flex-direction: column; gap: 4px; }
}