/* 介紹頁(landing):hero、光暈、漂浮星星、進場動畫 */
/* 進場柔焦:從模糊淡入(這是喜歡的「模糊效果」)。只在進場一次性播放,
   一次性 blur 動畫成本可接受;真正會拖垮的是「大面積模糊層持續逐幀重算」。 */
@keyframes fadeSlideIn { 0% { opacity: 0; transform: translate3d(0,22px,0); filter: blur(8px); } 100% { opacity: 1; transform: translate3d(0,0,0); filter: blur(0); } }
@keyframes cptoGlow { 0%,100% { filter: drop-shadow(0 0 16px rgba(90,160,255,.45)); } 50% { filter: drop-shadow(0 0 30px rgba(130,195,255,.75)); } }
/* logo 儀式登場:從深處極小尺寸、大膽螺旋旋轉飛出,弧線衝到定位、微過衝後溫柔煞停。
   全程只用 transform + opacity(GPU 合成),不碰 filter/blur,絲滑不掉幀。 */
@keyframes starFlyIn {
  0%   { opacity: 0; transform: translate3d(-130px,-200px,0) scale(0.04) rotate(-340deg); animation-timing-function: cubic-bezier(0.16,1,0.3,1); }
  28%  { opacity: 1; }
  62%  { transform: translate3d(16px,-12px,0) scale(1.09) rotate(14deg); animation-timing-function: cubic-bezier(0.45,0,0.25,1); }
  100% { opacity: 1; transform: translate3d(0,0,0) scale(1) rotate(0deg); }
}
@keyframes cptoFloat { 0%,100% { transform: translate3d(0,0,0) rotate(var(--spark-rot, 45deg)); } 50% { transform: translate3d(0,-22px,0) rotate(var(--spark-rot, 45deg)); } }

/* 順滑用的自訂緩動:比 ease-in-out 更柔和的呼吸感 */
:root { --ease-soft: cubic-bezier(0.37, 0, 0.63, 1); }

#landing.active { display: flex; }
/* 基底大氣層:頂部極淡提亮的藍一路平滑收到 --bg(收邊拉到 100%,不留亮暗交界) */
#landing { position: relative; overflow: hidden; min-height: 100vh; flex-direction: column; background: radial-gradient(140% 100% at 50% -20%, oklch(0.155 0.026 262), var(--bg) 72%); }
.l-glow { position: absolute; inset: 0; z-index: 0; pointer-events: none; background: radial-gradient(ellipse 82% 55% at 50% -8%, rgba(92,134,210,.10), transparent 66%); }
/* 大光暈一律靜止:模糊質感來自「存在」而非移動。靜態模糊只光柵化一次、
   之後零成本;動它才會逐幀重算整片模糊 → 卡。動感交給下方輕量小星星。
   三片色相全部收到近乎同一靛藍、透明度再降,像淡淡氛圍染色而非可辨色塊。 */
.l-orb { position: absolute; z-index: 0; top: -14%; left: 50%; transform: translateX(-50%); width: 920px; height: 560px; border-radius: 50%; background: radial-gradient(closest-side, rgba(84,126,206,.20), transparent 74%); filter: blur(64px); opacity: .7; pointer-events: none; }

/* 背景極光與漂浮星星 */
.l-aurora { position: absolute; z-index: 0; border-radius: 50%; pointer-events: none; }
.l-aurora-1 { top: 6%; left: 5%; width: 520px; height: 520px; background: radial-gradient(closest-side, rgba(96,116,208,.13), transparent 72%); filter: blur(76px); }
.l-aurora-2 { bottom: -8%; right: 3%; width: 560px; height: 560px; background: radial-gradient(closest-side, rgba(86,132,206,.11), transparent 72%); filter: blur(80px); }
.l-spark { position: absolute; z-index: 0; transform: rotate(var(--spark-rot, 45deg)); will-change: transform; animation: cptoFloat 8s var(--ease-soft) infinite; } /* 角度由 js/landing.js 每次載入隨機指定 */
.l-spark-1 { top: 22%; left: 23%; opacity: .5; }
.l-spark-2 { top: 32%; right: 22%; opacity: .45; animation-duration: 9s; animation-delay: 1s; }
.l-spark-3 { bottom: 24%; left: 31%; opacity: .4; animation-duration: 8s; animation-delay: .6s; }
.l-spark-4 { bottom: 30%; right: 28%; opacity: .4; animation-duration: 6.5s; animation-delay: 1.4s; }

.l-nav { position: relative; z-index: 2; display: flex; align-items: center; justify-content: space-between; padding: 24px 32px; }
/* 介紹頁的玻璃按鈕改用半透明底、不用 backdrop-filter:它疊在會飄動的光暈上,
   backdrop 模糊每幀都得重算,是掉幀來源。改成純色玻璃,外觀幾乎一致但零成本。 */
#landing .ghost-btn { backdrop-filter: none; background: rgba(255,255,255,.07); }
.l-brand { display: flex; align-items: center; gap: 10px; font-weight: 600; font-size: 16px; letter-spacing: -.01em; color: var(--ink); }
.l-brand svg { display: block; transform: translateY(1px); } /* 光學對齊:中英混排字墨中心比行框低 1px */
.l-hero { position: relative; z-index: 1; flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; text-align: center; padding: 20px 24px 80px; }
/* 外層負責「螺旋飛出+放大」;緩動已寫進 keyframes 分段(衝出快、煞停柔) */
.l-star { transform-origin: center; will-change: transform; animation: starFlyIn 1.7s both; }
/* 內層 svg 負責發光呼吸;延後至星星就位那刻才亮起,與飛出不衝突 */
.l-star svg { display: block; will-change: filter; animation: cptoGlow 5s var(--ease-soft) 1.6s infinite; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; margin-top: 26px; padding: 6px 14px; border: 1px solid var(--line); border-radius: 999px; background: var(--glass); font-size: 12.5px; color: var(--muted); }
.eyebrow span { width: 6px; height: 6px; border-radius: 50%; background: #5aa0ff; }
#landing h1 { font-family: var(--font-display); font-weight: 600; font-size: 52px; letter-spacing: -.03em; line-height: 1.05; margin-top: 22px; background: linear-gradient(100deg,#ffffff,#bcd4ff 52%,#6aa0ff); -webkit-background-clip: text; background-clip: text; color: transparent; }
.l-sub { font-family: var(--font-display); font-size: 16px; color: oklch(0.74 0.02 250); margin-top: 16px; max-width: 480px; line-height: 1.65; }
.l-sub em { font-style: normal; color: #8fb8ff; font-weight: 500; }
.l-cta { margin-top: 32px; }
.chips { display: flex; gap: 12px; flex-wrap: wrap; justify-content: center; margin-top: 44px; }
.chip { display: flex; align-items: center; gap: 9px; padding: 10px 16px; border: 1px solid var(--line); border-radius: 999px; background: var(--glass); backdrop-filter: blur(8px); font-size: 13px; color: oklch(0.82 0.02 250); }
.feat { display: flex; gap: 28px; flex-wrap: wrap; justify-content: center; margin-top: 38px; font-size: 14px; color: oklch(0.62 0.02 250); }
.feat span { display: flex; align-items: center; gap: 8px; }
.feat svg { transform: translateY(1px); } /* 光學對齊,同 .l-brand */
/* 進場:預先分層避免首幀卡頓(已不含 filter,不再動 blur) */
.a1, .a2, .a3, .a4, .a5, .a6 { will-change: transform, opacity; }
.a1 { animation: fadeSlideIn 1.1s var(--ease-out) .05s both; }
.a2 { animation: fadeSlideIn 1.1s var(--ease-out) .14s both; }
.a3 { animation: fadeSlideIn 1.1s var(--ease-out) .24s both; }
.a4 { animation: fadeSlideIn 1.1s var(--ease-out) .36s both; }
.a5 { animation: fadeSlideIn 1.1s var(--ease-out) .5s both; }
.a6 { animation: fadeSlideIn 1.1s var(--ease-out) .64s both; }