/* 路径：/app/static/home/math_intro.css */
:root{
  --mi-bg:#0b1020;
  --mi-bg-2:#111a33;
  --mi-text:#eef3ff;
  --mi-muted:rgba(238,243,255,.74);
  --mi-line:rgba(255,255,255,.12);
  --mi-accent:#7aa2ff;
  --mi-accent-2:#9be7ff;
  --mi-card:rgba(255,255,255,.06);
}

html, body {
  margin: 0;
  padding: 0;
  overflow-x: hidden;
  background:
    radial-gradient(1200px 560px at 50% -120px, rgba(122,162,255,.22), transparent 60%),
    radial-gradient(900px 520px at 15% 20%, rgba(155,231,255,.12), transparent 55%),
    radial-gradient(900px 520px at 85% 30%, rgba(120,120,255,.10), transparent 55%),
    linear-gradient(180deg, var(--mi-bg) 0%, var(--mi-bg-2) 100%);
  color: var(--mi-text);
}

body > .container{
  width:100% !important;
  max-width:none !important;
  margin:0 !important;
  padding:0 !important;
}

.mi-page{
  min-height:100vh;
  min-height:100svh;
}

.mi-topbar{
  position: sticky;
  top: 0;
  z-index: 20;
  display:flex;
  align-items:center;
  justify-content:space-between;
  padding:16px 20px;
  background:rgba(8,12,24,.55);
  backdrop-filter: blur(10px);
  border-bottom:1px solid var(--mi-line);
}

.mi-topbar a{
  color:var(--mi-text);
  text-decoration:none;
  font-weight:700;
}

.mi-topbar .mi-back{
  font-weight:600;
  opacity:.92;
}

.mi-hero{
  max-width:1100px;
  margin:0 auto;
  padding:72px 20px 48px;
  text-align:center;
}

.mi-desc{
  max-width:760px;
  margin:0 auto;
  color:var(--mi-muted);
  font-size:clamp(16px, 2vw, 20px);
  line-height:1.75;
}

.mi-tabbar{
  display:flex;
  gap:18px;
  justify-content:center;
  flex-wrap:wrap;
  margin-top:28px;
}
.mi-tab{
  appearance:none;
  border:1px solid rgba(255,255,255,.12);
  background:rgba(255,255,255,.04);
  color:var(--mi-text);
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-width:240px;
  padding:16px 28px;
  border-radius:999px;
  font-weight:800;
  font-size:clamp(18px, 2.2vw, 22px);
  cursor:pointer;
  transition:
    transform .2s ease,
    background .2s ease,
    border-color .2s ease,
    box-shadow .2s ease,
    color .2s ease;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.02);
}

.mi-tab:hover{
  transform:translateY(-1px);
  border-color:rgba(255,255,255,.22);
  background:rgba(255,255,255,.06);
}

.mi-tab:focus-visible{
  outline:none;
  box-shadow:
    0 0 0 3px rgba(122,162,255,.26),
    inset 0 0 0 1px rgba(255,255,255,.02);
}

.mi-tab.is-active,
.mi-tab[aria-selected="true"]{
  color:#08111f;
  border-color:transparent;
  background:linear-gradient(135deg, var(--mi-accent) 0%, var(--mi-accent-2) 100%);
  box-shadow:0 12px 32px rgba(122,162,255,.24);
}

.mi-section{
  max-width:1100px;
  margin:0 auto;
  padding:18px 20px 80px;
}

.mi-tab-panel{
  animation:miPanelFade .18s ease;
}

.mi-tab-panel[hidden]{
  display:none !important;
}

@keyframes miPanelFade{
  from{
    opacity:0;
    transform:translateY(6px);
  }
  to{
    opacity:1;
    transform:translateY(0);
  }
}

.mi-panel-intro{
  text-align:center;
  margin-bottom:24px;
}

.mi-panel-intro h2{
  margin:0 0 10px;
  font-size:clamp(28px, 4vw, 40px);
}

.mi-panel-intro p{
  margin:0 auto;
  max-width:760px;
  color:var(--mi-muted);
  line-height:1.8;
  font-size:clamp(15px, 1.8vw, 18px);
}

.mi-btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-width:148px;
  padding:12px 20px;
  border-radius:999px;
  text-decoration:none;
  font-weight:700;
  border:1px solid var(--mi-line);
  transition:transform .2s ease, border-color .2s ease, background .2s ease;
}

.mi-btn:hover{
  transform:translateY(-1px);
}

.mi-btn--primary{
  color:#08111f;
  background:linear-gradient(135deg, var(--mi-accent) 0%, var(--mi-accent-2) 100%);
  border:none;
}

.mi-btn--ghost{
  color:var(--mi-text);
  background:rgba(255,255,255,.04);
}

.mi-btn--disabled{
  color:rgba(238,243,255,.52);
  background:rgba(255,255,255,.03);
  border-color:rgba(255,255,255,.08);
  cursor:not-allowed;
  pointer-events:none;
}

.mi-panel-actions{
  display:flex;
  gap:14px;
  justify-content:center;
  flex-wrap:wrap;
  margin-top:24px;
}

.mi-grid{
  display:grid;
  grid-template-columns:repeat(3, minmax(0, 1fr));
  gap:18px;
}

.mi-card{
  padding:24px;
  border-radius:20px;
  background:var(--mi-card);
  border:1px solid var(--mi-line);
  box-shadow:0 20px 60px rgba(0,0,0,.20);
}

.mi-card h3{
  margin:0 0 10px;
  font-size:20px;
}

.mi-card p{
  margin:0;
  color:var(--mi-muted);
  line-height:1.75;
}

.mi-note{
  margin-top:18px;
  padding:16px 18px;
  border-radius:16px;
  border:1px dashed rgba(255,255,255,.18);
  color:var(--mi-muted);
  background:rgba(255,255,255,.03);
  text-align:center;
}

@media (max-width: 900px){
  .mi-tab{
    width:min(100%, 420px);
    min-width:0;
    padding:14px 22px;
    font-size:18px;
  }

  .mi-grid{
    grid-template-columns:1fr;
  }
}

@media (max-width: 640px){
  .mi-hero{
    padding:56px 16px 40px;
  }

  .mi-section{
    padding:12px 16px 64px;
  }

  .mi-tabbar{
    gap:12px;
  }

  .mi-panel-actions{
    gap:12px;
  }

  .mi-btn{
    width:100%;
    max-width:420px;
  }
}