/* ============================================================
   沐鸣娱乐 · SNAKE CIRCUIT —— core.css
   设计系统：蛇形回路（PCB 蛇形等长布线 + 贪吃蛇格子）
   分层：tokens → reset → 排版 → 外壳(rail/head/nav/foot) → 按钮 → 动效
   命名：mm- 前缀 + BEM
   ============================================================ */

:root {
  /* 基板 */
  --void: #150e1f;
  --void-2: #1a1129;
  --panel: #211738;
  --panel-2: #2a1d45;
  --panel-3: #33224f;

  /* 信号色 */
  --lime: #c6f24b;
  --lime-2: #e3ff8f;
  --grape: #8b5cf6;
  --pink: #ff5d8f;
  --cyan: #4fd6e0;

  /* 文本 */
  --bone: #f3efe7;
  --bone-2: #cfc7d8;
  --bone-3: #9d94ad;

  /* 线 */
  --line: rgba(198, 242, 75, 0.16);
  --line-2: rgba(198, 242, 75, 0.34);
  --line-3: rgba(243, 239, 231, 0.12);

  /* 结构 */
  --wrap: 1240px;
  --rail: 68px;
  --r-s: 6px;
  --r-m: 12px;
  --r-l: 20px;
  --shadow: 0 22px 60px rgba(6, 3, 12, 0.55);
  --mono: "SFMono-Regular", "JetBrains Mono", Consolas, "Courier New", monospace;
  --sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --ease: cubic-bezier(0.22, 0.68, 0, 1);
}

/* ---------- reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 96px;
}

body {
  margin: 0;
  background: var(--void);
  color: var(--bone);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* 方格底纹：模拟贪吃蛇棋盘的 32px 单元格 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 100% 32px, 32px 100%;
  opacity: 0.55;
  -webkit-mask-image: radial-gradient(ellipse 90% 70% at 60% 0%, #000 10%, transparent 78%);
  mask-image: radial-gradient(ellipse 90% 70% at 60% 0%, #000 10%, transparent 78%);
}

img,
svg { max-width: 100%; display: block; }

a { color: var(--lime); text-decoration: none; }
a:hover { color: var(--lime-2); }

button { font: inherit; color: inherit; }

h1, h2, h3, h4 {
  margin: 0;
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.02em;
}

p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

ul, ol { margin: 0 0 1em; padding-left: 1.2em; }
li { margin: 0.3em 0; }

::selection { background: var(--lime); color: #150e1f; }

/* ---------- 排版 ---------- */
.mm-wrap {
  width: 100%;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 28px;
  position: relative;
  z-index: 1;
}

.mm-kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--lime);
  margin-bottom: 16px;
}
.mm-kicker::before {
  content: "";
  width: 8px;
  height: 8px;
  background: var(--lime);
  box-shadow: 0 0 0 3px rgba(198, 242, 75, 0.16);
}
.mm-kicker--pink { color: var(--pink); }
.mm-kicker--pink::before { background: var(--pink); box-shadow: 0 0 0 3px rgba(255, 93, 143, 0.16); }
.mm-kicker--grape { color: #b79cff; }
.mm-kicker--grape::before { background: var(--grape); box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.2); }

.mm-h1 {
  font-size: clamp(2.05rem, 4.6vw, 3.7rem);
  margin-bottom: 22px;
}
.mm-h1 em {
  font-style: normal;
  color: var(--lime);
  background: linear-gradient(transparent 62%, rgba(198, 242, 75, 0.18) 62%);
}
.mm-h2 {
  font-size: clamp(1.5rem, 2.9vw, 2.35rem);
  margin-bottom: 16px;
}
.mm-h3 {
  font-size: clamp(1.08rem, 1.6vw, 1.3rem);
  margin-bottom: 10px;
}
.mm-h4 { font-size: 1rem; margin-bottom: 8px; }

.mm-lead {
  font-size: clamp(1rem, 1.3vw, 1.12rem);
  color: var(--bone-2);
  max-width: 62ch;
  margin-bottom: 26px;
}

.mm-mono {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--bone-3);
}

.mm-dim { color: var(--bone-3); }
.mm-lime { color: var(--lime); }
.mm-pink { color: var(--pink); }

.mm-skip {
  position: absolute;
  left: -999px;
  top: 0;
  z-index: 200;
  background: var(--lime);
  color: #150e1f;
  padding: 10px 18px;
  font-weight: 700;
}
.mm-skip:focus { left: 12px; top: 12px; }

/* ---------- 左侧走线导轨 ---------- */
.mm-rail {
  display: none;
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  width: var(--rail);
  z-index: 55;
  border-right: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(26, 17, 41, 0.9), rgba(21, 14, 31, 0.9));
  padding: 26px 0;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
}
.mm-rail__txt {
  writing-mode: vertical-rl;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.32em;
  color: var(--bone-3);
  text-transform: uppercase;
}
.mm-rail__dots {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 10px 0;
}
.mm-rail__dots i {
  width: 6px;
  height: 6px;
  background: var(--line-2);
  display: block;
}
.mm-rail__dots i:nth-child(3n) { background: var(--lime); }
.mm-rail__dots i:nth-child(5n) { background: var(--pink); }

/* ---------- 顶栏 ---------- */
.mm-head {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(21, 14, 31, 0.88);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line);
}
.mm-head.is-stuck { box-shadow: 0 12px 32px rgba(6, 3, 12, 0.5); }
.mm-head__in {
  max-width: 1320px;
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  gap: 18px;
}

.mm-logo {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--bone);
  flex: none;
}
.mm-logo:hover { color: var(--bone); }
.mm-logo__mark {
  display: grid;
  grid-template-columns: repeat(3, 8px);
  grid-template-rows: repeat(3, 8px);
  gap: 3px;
  padding: 5px;
  border: 1px solid var(--line-2);
  background: rgba(198, 242, 75, 0.05);
}
.mm-logo__mark i { background: rgba(198, 242, 75, 0.16); display: block; }
.mm-logo__mark i:nth-child(1),
.mm-logo__mark i:nth-child(2),
.mm-logo__mark i:nth-child(5),
.mm-logo__mark i:nth-child(8),
.mm-logo__mark i:nth-child(9) { background: var(--lime); }
.mm-logo__txt { display: flex; flex-direction: column; line-height: 1.15; }
.mm-logo__txt b { font-size: 17px; letter-spacing: 0.04em; }
.mm-logo__txt em {
  font-style: normal;
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.22em;
  color: var(--lime);
  text-transform: uppercase;
}

.mm-nav {
  display: flex;
  align-items: center;
  gap: 2px;
  margin-left: auto;
  flex-wrap: wrap;
}
.mm-nav a {
  position: relative;
  padding: 8px 10px;
  color: var(--bone-2);
  font-size: 14px;
  white-space: nowrap;
  border-radius: var(--r-s);
}
.mm-nav a:hover { color: var(--bone); background: rgba(198, 242, 75, 0.07); }
.mm-nav a.is-here { color: var(--lime); }
.mm-nav a.is-here::after {
  content: "";
  position: absolute;
  left: 10px;
  right: 10px;
  bottom: 2px;
  height: 2px;
  background: var(--lime);
}

.mm-head__cta { display: flex; align-items: center; gap: 8px; flex: none; }

.mm-burger {
  display: none;
  width: 40px;
  height: 38px;
  border: 1px solid var(--line-2);
  background: rgba(198, 242, 75, 0.06);
  cursor: pointer;
  padding: 0;
  align-items: center;
  justify-content: center;
  gap: 4px;
  flex-direction: column;
}
.mm-burger span { width: 16px; height: 2px; background: var(--lime); }
.mm-burger[aria-expanded="true"] span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.mm-burger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.mm-burger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }
.mm-burger span { transition: transform 0.25s var(--ease), opacity 0.2s; }

/* ---------- 按钮 ---------- */
.mm-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border: 1px solid var(--line-2);
  border-radius: var(--r-s);
  background: rgba(198, 242, 75, 0.05);
  color: var(--bone);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s var(--ease), background 0.2s, border-color 0.2s, color 0.2s;
}
.mm-btn:hover {
  transform: translateY(-2px);
  border-color: var(--lime);
  color: var(--lime-2);
}
.mm-btn--solid {
  background: var(--lime);
  border-color: var(--lime);
  color: #150e1f;
  font-weight: 800;
  box-shadow: 0 10px 26px rgba(198, 242, 75, 0.18);
}
.mm-btn--solid:hover { background: var(--lime-2); color: #150e1f; }
.mm-btn--ghost { background: transparent; border-color: var(--line-3); color: var(--bone-2); }
.mm-btn--ghost:hover { color: var(--bone); border-color: var(--line-2); }
.mm-btn--sm { padding: 8px 14px; font-size: 13px; }
.mm-btn--block { width: 100%; justify-content: center; }

.mm-actions { display: flex; flex-wrap: wrap; gap: 12px; }

/* ---------- 通用区块 ---------- */
.mm-sec {
  position: relative;
  padding: clamp(56px, 7vw, 96px) 0;
  z-index: 1;
}
.mm-sec--band {
  background: linear-gradient(180deg, rgba(33, 23, 56, 0.72), rgba(21, 14, 31, 0.2));
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.mm-sec--tight { padding: clamp(40px, 5vw, 64px) 0; }

.mm-sec__head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 28px;
  margin-bottom: clamp(26px, 3.4vw, 44px);
}
.mm-sec__head > div { max-width: 68ch; }
.mm-sec__head p { color: var(--bone-2); margin-bottom: 0; }

.mm-crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--bone-3);
  padding-top: 22px;
}
.mm-crumb a { color: var(--bone-3); }
.mm-crumb a:hover { color: var(--lime); }
.mm-crumb span[aria-current] { color: var(--lime); }

/* ---------- 页脚 ---------- */
.mm-foot {
  position: relative;
  z-index: 1;
  margin-top: 40px;
  border-top: 1px solid var(--line-2);
  background: linear-gradient(180deg, rgba(33, 23, 56, 0.55), rgba(15, 9, 22, 0.95));
}
.mm-foot__top {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.2fr;
  gap: 34px;
  padding: clamp(36px, 5vw, 60px) 0 34px;
}
.mm-foot__brand p { color: var(--bone-3); font-size: 13.5px; max-width: 40ch; }
.mm-foot h4 {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--lime);
  margin-bottom: 14px;
}
.mm-foot ul { list-style: none; padding: 0; margin: 0; }
.mm-foot li { margin: 0 0 9px; }
.mm-foot li a,
.mm-foot address a { color: var(--bone-2); font-size: 13.5px; }
.mm-foot li a:hover,
.mm-foot address a:hover { color: var(--lime); }
.mm-foot address {
  font-style: normal;
  color: var(--bone-3);
  font-size: 13.5px;
  line-height: 1.9;
}
.mm-foot__note {
  border-top: 1px solid var(--line-3);
  padding: 18px 0;
  font-size: 12.5px;
  color: var(--bone-3);
  line-height: 1.85;
}
.mm-foot__note b { color: var(--bone-2); }
.mm-foot__bar {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
  padding: 16px 0 26px;
  border-top: 1px solid var(--line-3);
  font-size: 12.5px;
  color: var(--bone-3);
}
.mm-foot__bar a { color: var(--bone-3); }
.mm-foot__bar a:hover { color: var(--lime); }

/* ---------- 动效 ---------- */
.mm-js [data-signal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.65s var(--ease), transform 0.65s var(--ease);
}
.mm-js [data-signal].is-on { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .mm-js [data-signal] { opacity: 1; transform: none; transition: none; }
  * { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
}

/* ---------- 响应式外壳 ---------- */
@media (min-width: 1280px) {
  .mm-rail { display: flex; }
  body { padding-left: var(--rail); }
  .mm-head { margin-left: 0; }
}

@media (max-width: 1180px) {
  .mm-nav { display: none; }
  .mm-burger { display: flex; }
  .mm-nav.is-open {
    display: flex;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 12px 24px 20px;
    background: rgba(21, 14, 31, 0.98);
    border-bottom: 1px solid var(--line-2);
    box-shadow: var(--shadow);
  }
  .mm-nav.is-open a { padding: 11px 8px; font-size: 15px; }
  .mm-foot__top { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 720px) {
  .mm-wrap { padding: 0 18px; }
  .mm-head__in { padding: 10px 18px; gap: 10px; }
  .mm-head__cta .mm-btn--ghost { display: none; }
  .mm-sec__head { flex-direction: column; align-items: flex-start; gap: 16px; }
  .mm-foot__top { grid-template-columns: 1fr; gap: 26px; }
  .mm-btn { padding: 11px 16px; }
}