/* ===== Hero (Fixed Background) ===== */
.hero {
  position: relative;
  min-height: 92vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  color: #fff;
  text-align: center;
  isolation: isolate;
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(circle at 20% 20%, color-mix(in srgb, var(--c-primary) 90%, transparent) 0%, transparent 55%),
    radial-gradient(circle at 80% 30%, color-mix(in srgb, var(--c-secondary) 85%, transparent) 0%, transparent 55%),
    radial-gradient(circle at 50% 90%, color-mix(in srgb, var(--c-accent)   85%, transparent) 0%, transparent 55%),
    linear-gradient(135deg, #74d0ff 0%, #ffa1c8 60%, #c5b3f7 100%);
  background-size: cover;
  animation: heroShift 18s ease-in-out infinite alternate;
}
@keyframes heroShift {
  0%   { filter: hue-rotate(0deg)   saturate(1); }
  100% { filter: hue-rotate(20deg)  saturate(1.15); }
}
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(circle at 50% 100%, rgba(255,255,255,.35), transparent 60%),
    linear-gradient(180deg, transparent 60%, rgba(255,255,255,.1));
  pointer-events: none;
}

/* floating blobs —— 放大 + 只做极轻微的缩放呼吸，不再上下位移，避免视觉晕感 */
.hero-blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: .38;
  z-index: -1;
  animation: heroBlobBreath 14s ease-in-out infinite;
  will-change: transform, opacity;
}
.hero-blob.b1 { width: 420px; height: 420px; background: #ffffffcc; top: 6%; left: 4%; }
.hero-blob.b2 { width: 360px; height: 360px; background: #fff2a8cc; bottom: 4%; right: 6%; animation-delay: -7s; }
@keyframes heroBlobBreath {
  0%,100% { transform: scale(1);    opacity: .34; }
  50%     { transform: scale(1.06); opacity: .42; }
}
@media (max-width: 720px) {
  .hero-blob.b1 { width: 260px; height: 260px; }
  .hero-blob.b2 { width: 220px; height: 220px; }
}

.hero-content {
  max-width: 820px;
  padding: 0 20px;
  animation: fadeUp .9s ease both;
}
/* 主标题：暖色系流光（在冷色 hero 背景上高对比）
 * 说明：
 *  - 去掉 filter:drop-shadow —— 与 background-clip:text 同用会亚像素抖动
 *  - 动画由 6s linear 改为 12s ease-in-out —— 消除匀速冲刷带来的"文字在晃"错觉
 *  - 阴影改成 text-shadow（不会引起重绘抖动）
 */
.hero-content h1 {
  display: inline-block;
  font-weight: 800;
  font-size: clamp(2.4rem, 6vw, 4.4rem);
  letter-spacing: 2px;
  margin-bottom: 20px;
  background: linear-gradient(
    90deg,
    #7cffcb,   /* 极光青 */
    #4fc3f7,   /* 湖水蓝 */
    #a78bfa,   /* 星耀紫 */
    #4fc3f7,   /* 湖水蓝 */
    #7cffcb    /* 回到极光青 */
  );
  background-size: 300% 100%;
  -webkit-background-clip: text;
          background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  text-shadow: 0 2px 10px rgba(0, 0, 0, .12);
  animation: heroTitleFlow 12s ease-in-out infinite;
}
@keyframes heroTitleFlow {
  0%   { background-position: 300% 50%; }
  100% { background-position:   0% 50%; }
}
/* 副标题：柔和淡入（去掉呼吸，避免和背景光斑叠加产生晕感） */
.hero-content p {
  font-size: 1.15rem;
  opacity: .95;
  margin-bottom: 30px;
  animation: subFadeIn 1.6s .3s ease both;
}
@keyframes subFadeIn {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: .95; transform: translateY(0); }
}
.hero-actions { display: inline-flex; gap: 14px; flex-wrap: wrap; justify-content: center; }
.hero-actions .btn-primary {
  background: #fff;
  color: var(--c-primary);
  box-shadow: 0 12px 28px -12px rgba(0,0,0,.25);
}
.hero-actions .btn-ghost {
  background: transparent;
  color: #fff;
  border-color: #ffffffaa;
}
.hero-actions .btn-ghost:hover { background: #ffffff22; }

/* scroll indicator */
.hero-scroll {
  position: absolute;
  left: 50%; bottom: 26px;
  transform: translateX(-50%);
  color: #fff;
  font-size: .85rem;
  letter-spacing: 2px;
  opacity: .8;
}
.hero-scroll::after {
  content: "";
  display: block;
  width: 2px; height: 34px;
  margin: 10px auto 0;
  background: linear-gradient(180deg, #fff, transparent);
  animation: scrollHint 1.6s ease-in-out infinite;
}
@keyframes scrollHint {
  0%   { transform: scaleY(0); transform-origin: top; }
  50%  { transform: scaleY(1); transform-origin: top; }
  100% { transform: scaleY(0); transform-origin: bottom; }
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(28px); }
  to   { opacity: 1; transform: translateY(0); }
}