:root{
  --bg:#f6f7fb;--card:#fff;--text:#101828;--muted:#667085;--line:#e5e7eb;
  --blue:#2563eb;--cyan:#06b6d4;--shadow:0 18px 48px rgba(16,24,40,.08)
}
*{box-sizing:border-box}
body{
  margin:0;background:radial-gradient(circle at 18% 0%,rgba(37,99,235,.13),transparent 30%),radial-gradient(circle at 90% 8%,rgba(6,182,212,.12),transparent 28%),var(--bg);
  color:var(--text);font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",Arial,sans-serif
}
a{text-decoration:none;color:inherit}
.header{position:sticky;top:0;z-index:20;background:rgba(246,247,251,.84);backdrop-filter:blur(18px);-webkit-backdrop-filter:blur(18px);border-bottom:1px solid rgba(229,231,235,.75)}
.header-inner{max-width:920px;margin:auto;padding:12px 16px;display:flex;align-items:center;justify-content:space-between}
.brand{display:flex;align-items:center;gap:10px;font-weight:1000;letter-spacing:-.02em}.brand small{display:block;color:var(--muted);font-size:12px;font-weight:800;margin-top:2px}
.logo{width:42px;height:42px;border-radius:15px;display:grid;place-items:center;color:white;background:linear-gradient(135deg,var(--blue),var(--cyan));box-shadow:0 12px 28px rgba(37,99,235,.24)}
.back{border:1px solid var(--line);background:white;border-radius:999px;padding:10px 14px;font-weight:900}
.wrap{max-width:920px;margin:auto;padding:20px 16px 88px}
.hero{padding:34px 0 18px}.kicker{display:inline-flex;padding:8px 12px;border-radius:999px;background:#eef6ff;color:var(--blue);font-size:13px;font-weight:1000}
h1{font-size:clamp(38px,8vw,68px);line-height:1.02;margin:16px 0 12px;letter-spacing:-.06em}
.lead{font-size:17px;line-height:1.75;color:var(--muted);margin:0;max-width:620px}
.grid{display:grid;gap:16px}.home-grid{grid-template-columns:repeat(2,minmax(0,1fr));margin-top:22px}
.card{background:rgba(255,255,255,.94);border:1px solid rgba(229,231,235,.92);border-radius:28px;padding:22px;box-shadow:var(--shadow)}
.course-card{min-height:210px;display:flex;flex-direction:column;justify-content:space-between;transition:.16s}.course-card:active{transform:scale(.985)}
.course-card .emoji{font-size:42px}.course-card h2{font-size:30px;margin:16px 0 8px;letter-spacing:-.04em}.course-card p{color:var(--muted);line-height:1.65;margin:0}.go{margin-top:18px;color:var(--blue);font-weight:1000}
.day-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;margin-top:16px}
.day{min-height:86px;border:1px solid var(--line);background:#fff;border-radius:22px;display:flex;flex-direction:column;align-items:center;justify-content:center;font-weight:1000;box-shadow:0 10px 26px rgba(16,24,40,.05)}
.day small{font-size:12px;color:var(--muted);margin-top:6px}.day:active{transform:scale(.985)}
.bottom{position:fixed;left:50%;bottom:12px;transform:translateX(-50%);width:min(520px,calc(100% - 24px));display:grid;grid-template-columns:repeat(3,1fr);gap:8px;padding:8px;background:rgba(255,255,255,.86);border:1px solid rgba(229,231,235,.9);border-radius:24px;box-shadow:var(--shadow);backdrop-filter:blur(18px);-webkit-backdrop-filter:blur(18px)}
.bottom a{text-align:center;border-radius:17px;padding:9px 4px;color:var(--muted);font-size:12px;font-weight:1000}.bottom a.active{background:#eef6ff;color:var(--blue)}
@media(max-width:720px){.home-grid{grid-template-columns:1fr}.day-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.card{padding:18px;border-radius:24px}.course-card{min-height:170px}}