/* 介紹頁（/mxvmusic）：沿用 logo 的賽博龐克配色——黃色主體、青紅色差，其餘是深色和白 */
:root {
  color-scheme: dark;
  --bg: #07060b;
  --panel: rgba(255, 255, 255, .04);
  --line: rgba(255, 255, 255, .1);
  --text: #f3f2f8;
  --muted: #a3a2b6;
  --yellow: #fcee0a;
  --cyan: #00f0ff;
  --red: #ff003c;
  --page: 1120px;
  --font: system-ui, -apple-system, "PingFang TC", "Noto Sans TC", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 400 17px/1.6 var(--font);
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
h1, h2, h3 { margin: 0; line-height: 1.1; }

/* ---------- logo（跟首頁同一套動畫） ---------- */
.logo-defs { position: absolute; width: 0; height: 0; overflow: hidden; }
.logo { display: block; height: 30px; overflow: visible; }
.logo-main use, .logo-dot { fill: var(--yellow); }
.logo-ghost { mix-blend-mode: screen; }
.logo-cyan { fill: rgba(0, 240, 255, .55); transform: translateX(-1.2px); animation: logo-cyan 3s steps(1, end) infinite; }
.logo-red { fill: rgba(255, 0, 60, .45); transform: translateX(1.2px); animation: logo-red 3s steps(1, end) infinite; }
.logo-line { fill: none; stroke: rgba(252, 238, 10, .5); stroke-width: 1; }
.logo-slice { animation: logo-slice 3s steps(1, end) infinite; }
@keyframes logo-slice {
  0% { transform: translateX(3px); } 5.5% { transform: translateX(-4px); } 11% { transform: translateX(5px); }
  16.6% { transform: translateX(-3px); } 22% { transform: translateX(4px); } 27.7% { transform: translateX(-2px); }
  33.3%, 100% { transform: none; }
}
@keyframes logo-cyan {
  0% { transform: translateX(-3px); } 11% { transform: translateX(-1px); } 22% { transform: translateX(-4px); }
  33.3%, 100% { transform: translateX(-1.2px); }
}
@keyframes logo-red {
  0% { transform: translateX(3px); } 11% { transform: translateX(1px); } 22% { transform: translateX(4px); }
  33.3%, 100% { transform: translateX(1.2px); }
}

/* ---------- 按鈕：黃色切角，像 2077 的介面 ---------- */
.btn {
  display: inline-block;
  padding: 14px 28px;
  background: var(--yellow);
  color: #0b0a12;
  font-weight: 800;
  letter-spacing: .02em;
  text-decoration: none;
  clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 14px 100%, 0 calc(100% - 14px));
  transition: filter .15s ease, transform .15s ease;
}
.btn:hover { filter: drop-shadow(0 0 12px rgba(252, 238, 10, .6)); transform: translateY(-1px); }
.btn:focus-visible { outline: 2px solid var(--cyan); outline-offset: 4px; }

/* ---------- 版面 ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--page);
  margin: 0 auto;
  padding: 18px 24px;
  background: linear-gradient(var(--bg) 60%, transparent);
}
.nav-logo { display: block; padding: 4px; }

main { max-width: var(--page); margin: 0 auto; padding: 0 24px; }

.hero { padding: 72px 0 40px; text-align: center; }
.eyebrow {
  margin: 0 0 18px;
  color: var(--cyan);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
}
.hero h1 {
  font-size: clamp(48px, 9vw, 104px);
  font-weight: 900;
  font-style: italic;
  letter-spacing: -.02em;
  text-transform: uppercase;
  /* 跟 logo 一樣的青紅色差 */
  text-shadow: -3px 0 rgba(0, 240, 255, .55), 3px 0 rgba(255, 0, 60, .5);
}
.lead { max-width: 640px; margin: 24px auto 0; color: var(--muted); font-size: 19px; }
.cta { display: flex; flex-direction: column; align-items: center; gap: 12px; margin-top: 36px; }
.cta-note { color: var(--muted); font-size: 14px; }

/* 即時預覽：16:9 的「螢幕」 */
.showcase { padding: 24px 0 40px; }
.screen {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: #000;
  box-shadow: 0 30px 120px -40px rgba(252, 238, 10, .25), 0 0 0 1px rgba(0, 240, 255, .08);
}
.screen canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.screen-tag {
  position: absolute;
  left: 16px;
  bottom: 14px;
  padding: 4px 10px;
  border-left: 3px solid var(--yellow);
  background: rgba(0, 0, 0, .55);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
}
.chips { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin-top: 20px; }
.chip {
  padding: 8px 16px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--panel);
  color: var(--muted);
  font: 600 14px var(--font);
  cursor: pointer;
  transition: color .15s ease, border-color .15s ease;
}
.chip:hover { color: var(--text); border-color: rgba(255, 255, 255, .3); }
.chip[aria-selected="true"] { color: #0b0a12; background: var(--yellow); border-color: var(--yellow); }
.chip:focus-visible { outline: 2px solid var(--cyan); outline-offset: 2px; }
.note { margin: 14px 0 0; color: var(--muted); font-size: 14px; text-align: center; }

.block { padding: 72px 0 24px; }
.block h2, .final h2 {
  font-size: clamp(30px, 4.5vw, 46px);
  font-weight: 900;
  font-style: italic;
  text-transform: uppercase;
}
.block h2::after {
  content: "";
  display: block;
  width: 56px;
  height: 4px;
  margin-top: 14px;
  background: var(--yellow);
}

.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin: 36px 0 0; padding: 0; list-style: none; }
.steps li { padding: 28px; border: 1px solid var(--line); border-radius: 16px; background: var(--panel); }
.step-no { color: var(--yellow); font-weight: 900; font-style: italic; font-size: 15px; letter-spacing: .1em; }
.steps h3 { margin-top: 10px; font-size: 22px; }
.steps p, .features p { margin: 10px 0 0; color: var(--muted); font-size: 16px; }

.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 36px; }
.features article { padding: 26px; border-top: 2px solid var(--line); }
.features article:nth-child(3n + 1) { border-top-color: var(--yellow); }
.features article:nth-child(3n + 2) { border-top-color: var(--cyan); }
.features article:nth-child(3n) { border-top-color: var(--red); }
.features h3 { font-size: 19px; }

.faq details { border-bottom: 1px solid var(--line); }
.faq details:first-of-type { margin-top: 28px; }
.faq summary {
  padding: 20px 0;
  font-size: 18px;
  font-weight: 700;
  cursor: pointer;
  list-style: none;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; float: right; color: var(--yellow); font-weight: 400; }
.faq details[open] summary::after { content: "–"; }
.faq summary:focus-visible { outline: 2px solid var(--cyan); outline-offset: 4px; }
.faq details p { margin: -6px 0 20px; color: var(--muted); }
.faq details a { color: var(--yellow); }

.final { padding: 96px 0; text-align: center; }
.final .btn { margin-top: 28px; }

.foot {
  display: flex;
  justify-content: space-between;
  max-width: var(--page);
  margin: 0 auto;
  padding: 28px 24px 40px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
}
.foot a { text-decoration: none; }
.foot a:hover { color: var(--text); }

@media (max-width: 760px) {
  body { font-size: 16px; }
  main, .nav { padding-left: 16px; padding-right: 16px; }
  .hero { padding-top: 40px; }
  .lead { font-size: 17px; }
  .screen { border-radius: 12px; }
  .steps, .features { grid-template-columns: 1fr; }
  .block { padding-top: 56px; }
  .foot { padding-left: 16px; padding-right: 16px; }
}

@media (prefers-reduced-motion: reduce) {
  .logo-slice, .logo-cyan, .logo-red { animation: none; }
  html { scroll-behavior: auto; }
}