/* 進場動畫的兩項整合約束:
   1. 沒有 @font-face、:root、* / html / body 重置、button,a 與 .sr-only ——
      fonts.css 與 style.css 已經全部提供,重寫一次只會互相打架。
   2. class 名用 .intro-skip 與 .intro-door*,不用 .skip / .vault-door ——
      .skip 是跳到主內容的鍵盤捷徑,.vault-door 是啟動彈窗的左右門,撞名會互相污染。 */

body.intro-running { overflow: hidden; }
/* 動畫一開演焦點就落在這個對話框上(intro.js 的 play()),它只是焦點的落腳處,
   不是使用者要操作的東西 —— 畫一圈框只會多一塊東西跟動畫搶注意力。 */
.intro:focus { outline: none; }
.intro-skip:focus-visible {
  outline: 2px solid var(--gold-hi);
  outline-offset: 4px;
}

.intro {
  --brand-alpha: .12;
  --ghost-alpha: .22;
  --brand-scale: 1.1;
  --echo-alpha: 0;
  --rail-alpha: 0;
  --sweep-alpha: 0;
  --sweep-x: -15%;
  --signal-alpha: 0;
  --signal-body-x: 0px;
  --signal-body-y: 0px;
  --signal-slice-a: 0px;
  --signal-slice-b: 0px;
  --signal-slice-y: 0px;
  --signal-skew: 0deg;
  --signal-scan-y: 50%;
  --signal-flash-alpha: 0;
  position: fixed;
  z-index: 100;
  inset: 0;
  isolation: isolate;
  overflow: hidden;
  background:
    radial-gradient(circle at 50% 50%, rgba(138,109,31,.13), transparent 33%),
    #070604;
  opacity: 1;
  touch-action: manipulation;
}
.intro[hidden] { display: none !important; }
.intro::before {
  content: "";
  position: absolute;
  z-index: 0;
  inset: -20%;
  pointer-events: none;
  background:
    repeating-conic-gradient(from 0deg at 50% 50%, rgba(212,175,55,.05) 0 1deg, transparent 1deg 8deg),
    radial-gradient(circle at 50% 50%, transparent 0 20%, rgba(0,0,0,.48) 65%, #030201 100%);
}
.intro-canvas { position: absolute; z-index: 5; inset: 0; width: 100%; height: 100%; pointer-events: none; }
.intro-canvas-front { z-index: 7; top: 33%; bottom: auto; height: 44%; }

.intro-door {
  position: absolute;
  z-index: 3;
  top: -4%;
  bottom: -4%;
  width: 51.5%;
  overflow: hidden;
  will-change: transform;
  background:
    linear-gradient(90deg, rgba(255,255,255,.018), transparent 12% 88%, rgba(255,255,255,.018)),
    repeating-linear-gradient(90deg, transparent 0 66px, rgba(212,175,55,.055) 67px 68px),
    radial-gradient(circle at 100% 50%, rgba(212,175,55,.075), transparent 34%),
    linear-gradient(120deg, #090704, #110d07 55%, #080604);
  box-shadow: inset 0 0 100px rgba(0,0,0,.8);
}
.intro-door::before {
  content: "";
  position: absolute;
  top: 50%;
  width: min(72vh, 72vw);
  aspect-ratio: 1;
  border: 1px solid rgba(212,175,55,.14);
  border-radius: 50%;
  box-shadow:
    0 0 0 12px rgba(212,175,55,.025),
    0 0 0 32px rgba(212,175,55,.018),
    inset 0 0 70px rgba(0,0,0,.8);
  transform: translateY(-50%);
}
.intro-door span {
  position: absolute;
  top: 50%;
  width: 34%;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(243,223,154,.7));
  box-shadow: 0 0 12px rgba(212,175,55,.42);
}
.intro-door-left { left: 0; transform: translate3d(0,0,0); border-right: 1px solid rgba(243,223,154,.54); }
.intro-door-left::before { right: -36vh; }
.intro-door-left span { right: 0; }
.intro-door-right { right: 0; transform: translate3d(0,0,0); border-left: 1px solid rgba(243,223,154,.54); }
.intro-door-right::before { left: -36vh; }
.intro-door-right span { left: 0; transform: scaleX(-1); }

.brand-echo {
  position: absolute;
  z-index: 4;
  top: 50%;
  right: -6vw;
  width: min(52vw, 900px);
  height: min(45vh, 500px);
  overflow: hidden;
  opacity: var(--echo-alpha);
  transform: translateY(-50%) scale(1.35);
  filter: blur(1.5px) saturate(.65);
  pointer-events: none;
}
.brand-echo img { position: absolute; top: 50%; right: 0; width: min(145vw, 2100px); max-width: none; height: auto; transform: translateY(-50%); opacity: .14; }

.brand-stage {
  position: absolute;
  z-index: 6;
  top: 50%;
  left: 50%;
  width: min(90vw, 1560px);
  aspect-ratio: 1176.31 / 156.25;
  transform: translate3d(-50%,-50%,0) scale(var(--brand-scale));
  transform-origin: center;
  will-change: transform, opacity;
}
.brand-stage::before, .brand-stage::after {
  content: "";
  position: absolute;
  pointer-events: none;
  opacity: 0;
  will-change: transform, opacity;
}
.brand-stage::before {
  z-index: 5;
  inset: 0;
  background: url("logo/v2-porta-303/assets/lockup-horizontal.svg") center / contain no-repeat;
  transform: translate3d(var(--signal-slice-b),calc(0px - var(--signal-slice-y)),0) skewX(calc(0deg - var(--signal-skew)));
  -webkit-mask-image: repeating-linear-gradient(184deg, #000 0 1.2%, transparent 1.2% 3.3%, #000 3.3% 5.6%, transparent 5.6% 10%);
  mask-image: repeating-linear-gradient(184deg, #000 0 1.2%, transparent 1.2% 3.3%, #000 3.3% 5.6%, transparent 5.6% 10%);
  mix-blend-mode: screen;
  filter: brightness(1.55) contrast(1.3) saturate(.25);
}
.brand-stage::after {
  z-index: 6;
  top: var(--signal-scan-y);
  left: -1.5%;
  right: -1.5%;
  height: 6%;
  background: linear-gradient(90deg,
    transparent 0 3%, rgba(255,255,255,.96) 3% 9%, transparent 9% 13%,
    rgba(230,199,93,.88) 13% 24%, transparent 24% 33%,
    rgba(255,255,255,.9) 33% 38%, transparent 38% 52%,
    rgba(255,255,255,.75) 52% 66%, transparent 66% 73%,
    rgba(212,175,55,.88) 73% 91%, transparent 91%);
  transform: translate3d(var(--signal-slice-a),-50%,0) skewX(var(--signal-skew));
  box-shadow: 0 -1px rgba(255,255,255,.62), 0 2px rgba(212,175,55,.35);
  mix-blend-mode: screen;
}
.brand-main, .brand-ghost, .brand-mask { position: absolute; inset: 0; width: 100%; height: 100%; }
/* 閃光經過時整組字標一起被提亮,不只是被閃光蓋到的那一小條。字標本身是
   #e9e2d0 的暖白,乘上 1.55 之後三個通道都撞頂,也就是在閃光最亮的那一瞬間
   整個字標讀成純白 —— 「更耀眼、更接近白光」就是這麼來的,而不是把遮罩裡那道
   白條再畫白一點(它本來就已經是 #fff,畫不上去了)。
   用 brightness 不用 drop-shadow:brightness 是一支色彩矩陣,GPU 直接算;
   drop-shadow 每一格都要重新做一次模糊,而這一層每一格都在動。 */
.brand-main {
  z-index: 2;
  opacity: var(--brand-alpha);
  filter: brightness(calc(1 + var(--sweep-alpha) * .55));
  will-change: transform, opacity, filter;
}
.brand-ghost { z-index: 1; opacity: var(--ghost-alpha); }
.intro.logo-glitching .brand-main {
  transform: translate3d(var(--signal-body-x),var(--signal-body-y),0) skewX(var(--signal-skew));
}
.intro.logo-glitching .brand-ghost {
  z-index: 4;
  opacity: var(--signal-alpha);
  transform: translate3d(var(--signal-slice-a),var(--signal-slice-y),0) skewX(var(--signal-skew));
  -webkit-mask-image: repeating-linear-gradient(176deg, #000 0 1.5%, transparent 1.5% 3.8%, #000 3.8% 6%, transparent 6% 11%);
  mask-image: repeating-linear-gradient(176deg, #000 0 1.5%, transparent 1.5% 3.8%, #000 3.8% 6%, transparent 6% 11%);
  mix-blend-mode: screen;
  filter: brightness(1.4) contrast(1.25) saturate(.35);
}
.intro.logo-glitching .brand-stage::before { opacity: var(--signal-alpha); }
.intro.logo-glitching .brand-stage::after { opacity: var(--signal-flash-alpha); }
.intro.logo-glitching-minor .brand-stage::after {
  height: 4%;
  box-shadow: 0 1px rgba(255,255,255,.48);
}
.brand-mask {
  z-index: 3;
  overflow: hidden;
  opacity: var(--sweep-alpha);
  pointer-events: none;
  -webkit-mask: url("logo/v2-porta-303/assets/lockup-horizontal.svg") center / contain no-repeat;
  mask: url("logo/v2-porta-303/assets/lockup-horizontal.svg") center / contain no-repeat;
}
.brand-glint {
  position: absolute;
  top: -55%;
  bottom: -55%;
  left: var(--sweep-x);
  width: clamp(74px, 10.5vw, 178px);
  background: linear-gradient(90deg,
    transparent 0 28%,
    rgba(255,255,255,.42) 36%,
    rgba(255,255,255,.94) 43%,
    #fff 46% 58%,
    rgba(255,255,255,.9) 64%,
    rgba(255,255,255,.38) 72%,
    transparent 80% 100%);
  transform: translate3d(-50%,0,0) skewX(-12deg);
  will-change: transform;
}
.light-rail {
  position: absolute;
  z-index: 5;
  top: 50%;
  left: 5vw;
  right: 5vw;
  height: 1px;
  opacity: var(--rail-alpha);
  background: linear-gradient(90deg, transparent, var(--gold-dim) 20%, var(--gold-hi) 50%, var(--gold-dim) 80%, transparent);
  box-shadow: 0 0 18px rgba(212,175,55,.55);
  transform: scaleX(.96);
  pointer-events: none;
}
/* 光帶正中那一點是整條線的來源,所以它得比線本身亮。外發光鋪成三層:貼著點的
   一圈近白、中圈偏金、外圈散在黑幕上,由白到金再到透明,看起來是一顆會發光的
   燈珠而不是一個塗了顏色的小圓。 */
.light-rail i {
  position: absolute;
  left: 50%;
  top: -3.5px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #fffdf2;
  box-shadow:
    0 0 9px 3px rgba(255,251,230,.9),
    0 0 26px 9px rgba(243,223,154,.6),
    0 0 60px 20px rgba(212,175,55,.34);
}

/* 只留字。原本那顆有底色、金框加毛玻璃的鈕在一片黑幕上是全畫面最亮的東西,
   五秒鐘一直跟動畫搶眼睛。框跟底一起拿掉,顏色降到 --ink-dim ——
   在最亮的一幀(t=3000ms 的背景)量到 6.01:1,還在 AA 之上,看得見但不搶戲。
   min-width / min-height / padding 一格不動:可點範圍還是 44x44。
   forced-colors 那段自己有一整套邊框與底色,是系統高對比的需求,不受這裡影響。 */
.intro-skip {
  position: absolute;
  z-index: 10;
  right: max(18px, env(safe-area-inset-right));
  bottom: max(18px, env(safe-area-inset-bottom));
  min-width: 44px;
  min-height: 44px;
  padding: 0 18px;
  color: var(--ink-dim);
  background: none;
  border: 0;
  cursor: pointer;
  font-size: 12px;
  letter-spacing: .16em;
  transition: color var(--t-fast) var(--ease);
}
.intro-skip:hover { color: var(--gold-hi); }

@media (orientation: portrait) {
  .brand-stage { width: 94vw; }
  .brand-stage::after { left: 0; right: 0; }
  .brand-echo { right: -38vw; width: 95vw; }
  .intro-door::before { width: 84vh; }
  .intro-door-left { border-right-color: rgba(243,223,154,.36); }
  .intro-door-right { border-left-color: rgba(243,223,154,.36); }
}
@media (max-width: 600px) {
  .intro-skip { font-size: 11px; }
}
@media (max-width: 380px) {
  .brand-stage { width: 96vw; }
  .brand-echo { right: -44vw; }
  .intro-skip {
    right: max(12px, env(safe-area-inset-right));
    bottom: max(12px, env(safe-area-inset-bottom));
    padding-inline: 14px;
    font-size: 10px;
  }
}
@media (max-height: 460px) and (orientation: landscape) {
  .brand-stage { width: min(78vw, 1050px); }
  .intro-skip { bottom: max(10px, env(safe-area-inset-bottom)); }
}

/* 減動版的樣子。intro.js 現在預設把 .motion-full 掛上,所以這一段平常不作數 ——
   只有網址帶 ?motion=reduce 時那個 class 才會拿掉,這幾條才生效。
   規則本身一個字沒改:留著是為了那條退路仍然完整,不是死碼。 */
@media (prefers-reduced-motion: reduce) {
  html:not(.motion-full) .intro-canvas,
  html:not(.motion-full) .brand-echo,
  html:not(.motion-full) .brand-mask,
  html:not(.motion-full) .light-rail { display: none; }
  html:not(.motion-full) .brand-stage { transform: translate3d(-50%,-50%,0); }
  html:not(.motion-full) .brand-main { filter: none; }
}

/* Windows 高對比:整片帘幕改成不受系統換色影響。原本這裡是把畫布、門、標誌全部
   display: none,只留一行純系統色的 .forced-title —— 那等於高對比的機器看不到這支動畫。
   forced-color-adjust: none 是規範給「配色本身就是內容」的出口,一張全螢幕的
   開場片正是那種東西:燙金標誌換成 CanvasText 之後根本認不出是同一個商標。
   只有跳過鈕留在系統色裡(forced-color-adjust: auto):那是真正要按的控制項,
   高對比使用者得認得出它是一顆鈕,而且它蓋在自己畫的深色底上,對比是我們自己保證的。
   帘幕散場之後全站其餘的 forced-colors 調整照舊,那些是為了讀字,跟這裡不衝突。 */
@media (forced-colors: active) {
  .intro { forced-color-adjust: none; }
  .intro-skip { forced-color-adjust: auto; color: ButtonText; background: ButtonFace; border: 1px solid ButtonText; }
  .intro-skip:focus-visible { outline: 2px solid Highlight; }
}