/* ============================================================
 * 课堂通道主题：课程 × 四条服务通道 × 右脑图像力
 * 色系：深海青碧 + 极光薄荷 + 珊瑚橙 + 星紫（比首页更冷、更「通道感」）
 * 作用域：body.brain-courses（仅 courses.html 引入）
 * ============================================================ */

/* ---------- 主题色 ---------- */
.brain-courses {
  --bc-void: #7d0d1a;
  --bc-deep: #9c1424;
  --bc-ink: #fff7f2;
  --bc-ink-2: #ffe6da;
  --bc-ink-3: #ffcdb9;
  --bc-mint: #ffd36e;
  --bc-sky: #ffb347;
  --bc-coral: #ff9a6b;
  --bc-gold: #ffd36e;
  --bc-violet: #ff9f8a;
  --bc-glass: linear-gradient(160deg, rgba(255, 255, 255, .17), rgba(255, 255, 255, .075));
  --bc-line: rgba(255, 255, 255, .24);
  --bc-shadow: 0 14px 32px rgba(78, 4, 14, .34);
  background: var(--bc-void);
  color: var(--bc-ink);
}

/* ---------- 背景：深空舱体 + 通道网格 ---------- */
.bc-bg {
  position: fixed; left: 0; right: 0; top: 0; bottom: 0; z-index: -1; overflow: hidden; pointer-events: none;
  background:
    radial-gradient(1100px 680px at 8% -6%, rgba(255, 138, 88, .3), transparent 62%),
    radial-gradient(940px 600px at 96% 2%, rgba(255, 92, 120, .26), transparent 62%),
    radial-gradient(900px 700px at 52% 104%, rgba(255, 168, 130, .16), transparent 60%),
    linear-gradient(180deg, #7d0d1a 0%, #9c1424 46%, #6b0812 100%);
}
.bc-grid {
  position: absolute; left: -10%; right: -10%; top: -10%; bottom: -10%;
  background-image:
    linear-gradient(rgba(255, 211, 110, .06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 211, 110, .06) 1px, transparent 1px);
  background-size: 64px 64px;
  transform: perspective(700px) rotateX(58deg) translateY(18%);
  transform-origin: center bottom;
  mask-image: radial-gradient(ellipse at 50% 70%, #000 8%, transparent 66%);
  -webkit-mask-image: radial-gradient(ellipse at 50% 70%, #000 8%, transparent 66%);
  opacity: .42;
}
.bc-aurora { position: absolute; border-radius: 50%; filter: blur(68px); opacity: .24; mix-blend-mode: screen; }
.bc-aurora.a1 { width: 640px; height: 430px; left: -10%; top: -8%; background: radial-gradient(circle, #ff7a3c, transparent 68%); animation: bcDrift1 28s ease-in-out infinite; }
.bc-aurora.a2 { width: 560px; height: 400px; right: -8%; top: 2%; background: radial-gradient(circle, #ff2e63, transparent 68%); animation: bcDrift2 34s ease-in-out infinite; }
.bc-aurora.a3 { width: 700px; height: 460px; left: 30%; top: 52%; background: radial-gradient(circle, #ff8a5c, transparent 70%); opacity: .14; animation: bcDrift1 40s ease-in-out infinite reverse; }
.bc-orb {
  position: absolute; border-radius: 50%; filter: blur(1px);
  background: radial-gradient(circle at 32% 28%, #fff8e3, #ffce5c 58%, rgba(255, 155, 60, .12) 100%);
  box-shadow: 0 0 26px 5px rgba(255, 211, 110, .36), inset 0 0 14px rgba(255, 255, 255, .5);
  animation: bcFloat 13s ease-in-out infinite;
}
.bc-orb.o1 { width: 12px; height: 12px; left: 6%; top: 30%; }
.bc-orb.o2 { width: 16px; height: 16px; right: 9%; top: 52%; animation-delay: -4s; background: radial-gradient(circle at 32% 28%, #fff6e3, #ffd36e 58%, rgba(255, 150, 60, .12) 100%); box-shadow: 0 0 30px 7px rgba(255, 211, 110, .3), inset 0 0 14px rgba(255, 255, 255, .5); }
.bc-orb.o3 { width: 10px; height: 10px; left: 46%; top: 78%; animation-delay: -8s; }
.bc-stars {
  position: absolute; left: 0; right: 0; top: 0; bottom: 0; opacity: .34;
  background-image:
    radial-gradient(1.3px 1.3px at 10% 16%, #fff 40%, transparent 42%),
    radial-gradient(1.1px 1.1px at 26% 58%, #ffe9a8 40%, transparent 42%),
    radial-gradient(1.5px 1.5px at 44% 10%, #fff 40%, transparent 42%),
    radial-gradient(1.1px 1.1px at 58% 40%, #ffe9a8 40%, transparent 42%),
    radial-gradient(1.3px 1.3px at 76% 20%, #fff 40%, transparent 42%),
    radial-gradient(1.1px 1.1px at 90% 66%, #ffcdb9 40%, transparent 42%),
    radial-gradient(1.5px 1.5px at 6% 78%, #fff 40%, transparent 42%),
    radial-gradient(1.1px 1.1px at 34% 88%, #ffb347 40%, transparent 42%),
    radial-gradient(1.3px 1.3px at 66% 84%, #fff 40%, transparent 42%),
    radial-gradient(1.1px 1.1px at 96% 34%, #ffd36e 40%, transparent 42%);
  animation: bcTwinkle 7s ease-in-out infinite;
}
@keyframes bcDrift1 { 0%, 100% { transform: translate3d(0, 0, 0) scale(1); } 50% { transform: translate3d(56px, 34px, 0) scale(1.1); } }
@keyframes bcDrift2 { 0%, 100% { transform: translate3d(0, 0, 0) scale(1.04); } 50% { transform: translate3d(-64px, 26px, 0) scale(.93); } }
@keyframes bcFloat { 0%, 100% { transform: translateY(0); opacity: .82; } 50% { transform: translateY(-20px); opacity: 1; } }
@keyframes bcTwinkle { 0%, 100% { opacity: .5; } 50% { opacity: .92; } }

/* ---------- SVG 动画（brain-art.js 输出的通用类名） ---------- */
.brain-courses .bp-svg { width: 100%; height: auto; display: block; overflow: visible; }
.brain-courses .bp-pulse { transform-box: fill-box; transform-origin: center; animation: bcPulse 3.6s ease-in-out infinite; }
.brain-courses .bp-spin { transform-box: fill-box; transform-origin: center; animation: bcSpin 20s linear infinite; }
.brain-courses .bp-spin-slow { transform-box: fill-box; transform-origin: center; animation: bcSpin 50s linear infinite; }
.brain-courses .bp-dot { animation: bcDot 5.2s ease-in-out infinite; }
.brain-courses .bp-link, .brain-courses .bc-link { stroke-dasharray: 7 9; animation: bcDash 2.8s linear infinite; }
.brain-courses .bp-beam { animation: bcPulse 4.4s ease-in-out infinite; transform-box: fill-box; transform-origin: bottom center; }
.brain-courses .bc-node { transition: opacity .3s; }
.brain-courses .bc-node:hover { opacity: .78; }
@keyframes bcPulse { 0%, 100% { opacity: .55; transform: scale(.95); } 50% { opacity: 1; transform: scale(1.05); } }
@keyframes bcSpin { to { transform: rotate(360deg); } }
@keyframes bcDot { 0%, 100% { opacity: .3; } 50% { opacity: 1; } }
@keyframes bcDash { to { stroke-dashoffset: -64; } }

/* ---------- 文字与通用容器 ---------- */
.brain-courses h1, .brain-courses h2, .brain-courses h3, .brain-courses h4 { color: #fff7f2; }
.brain-courses .text-muted { color: var(--bc-ink-3); }
.brain-courses .section-head h2 { position: relative; padding-left: 14px; }
.brain-courses .section-head h2::before {
  content: ""; position: absolute; left: 0; top: 50%; transform: translateY(-50%);
  width: 4px; height: 22px; border-radius: 4px;
  background: linear-gradient(180deg, var(--bc-gold), var(--bc-sky) 55%, var(--bc-violet));
  box-shadow: 0 0 12px rgba(255, 211, 110, .55);
}
.brain-courses .section-head p { color: var(--bc-ink-3); }

.bc-grad {
  background: linear-gradient(100deg, #fff3d6 0%, var(--bc-gold) 30%, var(--bc-sky) 55%, #ffce8a 80%, var(--bc-violet) 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.bc-eyebrow {
  display: inline-flex; align-items: center; gap: 8px; padding: 5px 14px; border-radius: 999px;
  font-size: 12.5px; letter-spacing: 1.2px; color: #ffe2c4;
  background: rgba(255, 211, 110, .1); border: 1px solid rgba(255, 211, 110, .32);
  box-shadow: inset 0 0 22px rgba(255, 211, 110, .16);
}
.bc-eyebrow::before { content: "◈"; color: var(--bc-mint); }

/* 玻璃卡片 */
.brain-courses .card,
.brain-courses .stat,
.brain-courses .svc,
.brain-courses .bc-card {
  background: var(--bc-glass);
  border: 1px solid var(--bc-line);
  box-shadow: var(--bc-shadow), inset 0 1px 0 rgba(255, 255, 255, .09);
  backdrop-filter: blur(10px);
  color: var(--bc-ink);
}
.brain-courses .card-title { border-bottom: 1px dashed var(--bc-line); padding-bottom: 12px; }
.brain-courses .card-title .sub { color: var(--bc-ink-3); }
.brain-courses .btn.gold { box-shadow: 0 10px 26px rgba(255, 170, 60, .28); }
.brain-courses .btn.outline { background: rgba(255, 255, 255, .06); color: #eafaff; border-color: rgba(255, 255, 255, .3); }
.brain-courses .btn.outline:hover { background: rgba(255, 255, 255, .14); border-color: var(--bc-mint); color: #fff; }
.brain-courses .btn.ghost { color: var(--bc-ink-2); border-color: var(--bc-line); background: rgba(255, 255, 255, .05); }
.brain-courses .btn.ghost:hover { background: rgba(255, 255, 255, .12); color: #fff; }
.brain-courses .tip { background: rgba(255, 255, 255, .055); border-left-color: var(--bc-mint); color: var(--bc-ink-2); }
.brain-courses .tip.warn { background: rgba(255, 211, 110, .1); border-left-color: var(--bc-gold); color: #ffe6b0; }
.brain-courses .tag { background: rgba(255, 179, 71, .13); color: #ffd0a8; border: 1px solid rgba(255, 179, 71, .22); }
.brain-courses .tag.gold { background: rgba(255, 211, 110, .15); color: #ffe0a8; border-color: rgba(255, 211, 110, .28); }
.brain-courses .badge { background: rgba(255, 255, 255, .1); color: var(--bc-ink-2); }
.brain-courses .badge.ok { background: rgba(23, 165, 130, .22); color: #8bf0cf; }
.brain-courses .badge.warn { background: rgba(199, 119, 0, .22); color: #ffd88a; }
.brain-courses .badge.info { background: rgba(255, 179, 71, .2); color: #ffd9a8; }
.brain-courses .badge.gold { background: linear-gradient(135deg, rgba(255, 211, 110, .9), rgba(255, 179, 71, .7)); color: #3b2405; }
.brain-courses .artbox {
  background: radial-gradient(circle at 32% 26%, rgba(255, 220, 160, .18), rgba(90, 10, 22, .5));
  box-shadow: inset 0 0 0 1px rgba(255, 211, 110, .22), 0 0 20px rgba(255, 211, 110, .14);
}

/* ---------- 顶部（v22：原主视觉栏目下线，promo 横幅即页面第一屏） ---------- */
.brain-courses .bc-topband { margin-top: 6px; }
.brain-courses .bc-topband .pr-banner { margin: 20px 0 22px; }

/* ---------- 右脑图像力 ---------- */
.bc-right-wrap {
  display: grid; grid-template-columns: 340px 1fr; gap: 22px; align-items: center;
  padding: 20px; border-radius: 22px;
  background:
    radial-gradient(520px 320px at 12% 20%, rgba(255, 190, 90, .12), transparent 64%),
    var(--bc-glass);
  border: 1px solid var(--bc-line); box-shadow: var(--bc-shadow);
}
.bc-right-art { position: relative; }
.bc-right-art::after {
  content: ""; position: absolute; left: -4%; right: -4%; top: -4%; bottom: -4%; border-radius: 50%; pointer-events: none;
  background: radial-gradient(circle, rgba(255, 190, 90, .16), transparent 66%); filter: blur(22px);
}
.bc-right-txt h3 { font-size: 19px; margin: 0 0 8px; }
.bc-right-txt p { color: var(--bc-ink-2); font-size: 14px; line-height: 1.88; margin: 0 0 14px; }
.bc-force { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; }
.bc-force .f {
  padding: 11px 13px; border-radius: 13px; font-size: 13px; color: var(--bc-ink-2);
  background: rgba(255, 255, 255, .05); border: 1px solid rgba(255, 255, 255, .1);
  transition: .2s;
}
.bc-force .f:hover { border-color: rgba(255, 211, 110, .4); background: rgba(255, 255, 255, .085); }
.bc-force .f b { display: block; color: #fff; font-size: 13.6px; margin-bottom: 2px; }
.bc-force .f:nth-child(1) b { color: #ffe0a8; }
.bc-force .f:nth-child(2) b { color: #ffd0a8; }
.bc-force .f:nth-child(3) b { color: #ffb3a0; }
.bc-force .f:nth-child(4) b { color: #8bf0cf; }

/* ---------- 天才教育 · 天赋四阶 ---------- */
.bc-genius {
  position: relative; overflow: hidden; display: grid; grid-template-columns: 320px 1fr;
  gap: 24px; align-items: center; margin-top: 22px; padding: 22px 24px; border-radius: 22px;
  background:
    radial-gradient(560px 300px at 88% 16%, rgba(255, 190, 90, .14), transparent 66%),
    linear-gradient(150deg, rgba(255, 255, 255, .15), rgba(255, 255, 255, .06) 52%, rgba(120, 220, 240, .12));
  border: 1px solid rgba(255, 211, 110, .28);
  box-shadow: var(--bc-shadow), inset 0 0 44px rgba(255, 211, 110, .05);
}
.bc-genius::before {
  content: ""; position: absolute; left: 0; right: 0; top: 0; height: 3px; z-index: 1;
  background: linear-gradient(90deg, rgba(255, 211, 110, 0), var(--bc-gold), #ff9f8a, rgba(255, 180, 140, 0));
  opacity: .85;
}
.bc-genius-art { position: relative; }
.bc-genius-art::after {
  content: ""; position: absolute; left: 0; right: 0; top: 0; bottom: 0; border-radius: 50%; pointer-events: none;
  background: radial-gradient(circle, rgba(255, 200, 100, .16), transparent 68%); filter: blur(20px);
}
.bc-genius-txt { position: relative; z-index: 1; }
.bc-tag {
  display: inline-block; padding: 4px 12px; border-radius: 999px; font-size: 12px; font-weight: 700;
  color: #2b2205; background: linear-gradient(120deg, #ffe9a8, #ffc857);
  box-shadow: 0 4px 14px rgba(150, 100, 10, .3);
}
.bc-genius-txt h3 { font-size: 21px; margin: 10px 0 8px; }
.bc-genius-txt p { color: var(--bc-ink-2); font-size: 14px; line-height: 1.9; margin: 0 0 16px; }
.bc-stairs { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; }
.bc-stairs .st {
  position: relative; padding: 12px 10px 12px 14px; border-radius: 13px;
  background: rgba(255, 255, 255, .055); border: 1px solid rgba(255, 255, 255, .12);
  transition: .2s;
}
.bc-stairs .st:hover { transform: translateY(-3px); border-color: rgba(255, 211, 110, .4); background: rgba(255, 255, 255, .09); }
.bc-stairs .st::before {
  content: ""; position: absolute; left: 0; top: 14px; bottom: 14px; width: 3px; border-radius: 3px;
  background: linear-gradient(180deg, var(--bc-sky), var(--bc-gold));
}
.bc-stairs .st b { display: block; font-size: 14.5px; color: #fff; margin-bottom: 2px; }
.bc-stairs .st span { font-size: 12px; color: var(--bc-ink-3); }
.bc-stairs .st:nth-child(1) b { color: #ffd0a8; }
.bc-stairs .st:nth-child(2) b { color: #ffe0a8; }
.bc-stairs .st:nth-child(3) b { color: #ffb3a0; }
.bc-stairs .st:nth-child(4) b { color: #8bf0cf; }

/* ---------- 课程列表 ---------- */
.bc-course-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.bc-course {
  position: relative; display: flex; gap: 14px; align-items: flex-start; overflow: hidden;
  padding: 16px 18px; border-radius: 18px; color: var(--bc-ink);
  background: var(--bc-glass); border: 1px solid var(--bc-line);
  box-shadow: var(--bc-shadow), inset 0 1px 0 rgba(255, 255, 255, .07);
  backdrop-filter: blur(8px); transition: .22s;
}
.bc-course::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 3px;
  background: linear-gradient(180deg, var(--bc-gold), var(--bc-sky) 45%, var(--bc-violet));
  opacity: .7;
}
.bc-course:hover { transform: translateY(-4px); border-color: rgba(255, 211, 110, .5); box-shadow: 0 20px 42px rgba(78, 4, 14, .4); }
.bc-course .art { flex: 0 0 84px; }
.bc-course .body { flex: 1; min-width: 0; }
.bc-course .top { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; }
.bc-course h4 { margin: 0; font-size: 16.5px; color: #f2fdff; }
.bc-course .hrs { flex: 0 0 auto; font-size: 12px; font-weight: 700; padding: 2px 9px; border-radius: 999px; color: #3b2405; background: linear-gradient(135deg, #ffeec4, var(--bc-mint)); }
.bc-course .hrs.gift { background: linear-gradient(135deg, #ffeec4, var(--bc-gold)); }
.bc-course .sub2 { margin-top: 4px; font-size: 13px; font-weight: 600; color: #ffd8b8; }
.bc-course .desc2 { margin-top: 4px; font-size: 12.8px; line-height: 1.75; color: var(--bc-ink-3); }
.bc-course .rails { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 10px; }
.bc-course .rails i {
  font-style: normal; font-size: 11.6px; padding: 3px 8px; border-radius: 7px;
  background: rgba(255, 211, 110, .09); border: 1px solid rgba(255, 211, 110, .2); color: #ffe4a8;
}
.bc-course .rails i:nth-child(2) { background: rgba(255, 179, 71, .1); border-color: rgba(255, 179, 71, .22); color: #ffd0a8; }
.bc-course .rails i:nth-child(3) { background: rgba(255, 211, 110, .1); border-color: rgba(255, 211, 110, .24); color: #ffe4a8; }
.bc-course .rails i:nth-child(4) { background: rgba(255, 154, 107, .1); border-color: rgba(255, 154, 107, .24); color: #ffc4ab; }
.bc-course .go2 { margin-top: 10px; font-size: 12.6px; font-weight: 600; color: var(--bc-mint); }

/* ---------- CTA ---------- */
.bc-cta {
  position: relative; margin-top: 26px; border-radius: 26px; overflow: hidden; padding: 40px 28px; text-align: center;
  background:
    radial-gradient(700px 380px at 16% 0%, rgba(255, 196, 120, .22), transparent 62%),
    radial-gradient(680px 360px at 86% 100%, rgba(255, 92, 120, .22), transparent 62%),
    radial-gradient(620px 320px at 50% 60%, rgba(255, 154, 107, .14), transparent 64%),
    linear-gradient(140deg, #a01526, #c2412f 58%, #7d0d1a);
  border: 1px solid rgba(255, 255, 255, .24); box-shadow: 0 20px 46px rgba(8, 40, 56, .34);
}
.bc-cta .eye { width: 74px; margin: 0 auto 12px; }
.bc-cta h2 { font-size: 24px; margin-bottom: 10px; }
.bc-cta p { color: var(--bc-ink-2); font-size: 14.5px; line-height: 1.85; max-width: 720px; margin: 0 auto 20px; }
.bc-cta .btn-row { justify-content: center; }
.bc-cta .cta-tip { margin-top: 18px; font-size: 13px; line-height: 1.9; color: var(--bc-ink-3); }
.bc-cta .cta-tip b { color: var(--bc-mint); }
.bc-cta::after {
  content: ""; position: absolute; left: -10%; right: -10%; top: -40%; height: 160%; pointer-events: none;
  background: conic-gradient(from 90deg, transparent 0 68%, rgba(255, 211, 110, .12) 82%, transparent 100%);
  animation: bcSpin 26s linear infinite;
}

/* ---------- 响应式 ---------- */
@media (max-width: 1080px) {
  .bc-course-grid { grid-template-columns: 1fr; }
}
@media (max-width: 980px) {
  .bc-right-wrap { grid-template-columns: 1fr; }
  .bc-right-art { max-width: 320px; margin: 0 auto; }
  .bc-genius { grid-template-columns: 1fr; }
  .bc-genius-art { max-width: 300px; margin: 0 auto; }
}
@media (max-width: 700px) {
  .bc-metrics { grid-template-columns: repeat(2, 1fr); }
  .bc-force { grid-template-columns: 1fr; }
  .bc-course { flex-direction: column; }
  .bc-course .art { flex: 0 0 auto; }
  .bc-stairs { grid-template-columns: repeat(2, 1fr); }
  .bc-genius-txt h3 { font-size: 19px; }
}
@media (prefers-reduced-motion: reduce) {
  .bc-grid, .bc-aurora, .bc-orb, .bc-stars, .brain-courses .bp-pulse, .brain-courses .bp-spin,
  .brain-courses .bp-spin-slow, .brain-courses .bp-dot, .brain-courses .bp-link, .brain-courses .bc-link,
  .brain-courses .bp-beam, .bc-cta::after { animation: none !important; }
}