/* ==========================================================================
   倒班助手 Pro — 官网
   黑场 + 极大字 + 一台发光的机器。唯一的视觉母题是「地平线」：
   倒班的人一整天都在等那条线亮起来。
   ========================================================================== */

:root {
  color-scheme: dark;

  --bg: #000;
  --lift: #0a0a0e;
  --ink: #f5f5f7;
  --muted: #86868b;
  --dim: #5b5b61;
  --line: rgba(255, 255, 255, 0.11);
  --line-strong: rgba(255, 255, 255, 0.2);

  --accent: #5b6cff;
  --accent-soft: #8f9bff;

  --wide: 1120px;
  --narrow: 760px;

  --sans: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI Variable Display",
          "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
          "Noto Sans SC", sans-serif;

  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

img { display: block; max-width: 100%; height: auto; }

a { color: inherit; }

:focus-visible {
  outline: 2px solid var(--accent-soft);
  outline-offset: 3px;
  border-radius: 6px;
}

::selection { background: rgba(91, 108, 255, 0.45); }

/* ---------- 导航 ---------- */

.nav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 50;
  border-bottom: 1px solid transparent;
  transition: background 0.35s var(--ease), border-color 0.35s var(--ease),
              backdrop-filter 0.35s var(--ease);
}

.nav.is-scrolled {
  background: rgba(0, 0, 0, 0.72);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  backdrop-filter: saturate(180%) blur(20px);
  border-bottom-color: var(--line);
}

.nav-inner {
  display: flex;
  align-items: center;
  gap: 20px;
  height: 52px;
  max-width: var(--wide);
  margin: 0 auto;
  padding: 0 24px;
}

.wordmark {
  flex: none;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.01em;
  text-decoration: none;
  white-space: nowrap;
}

.wordmark span {
  margin-left: 2px;
  font-weight: 400;
  color: var(--muted);
}

.nav-links {
  display: flex;
  gap: 26px;
  margin-left: auto;
}

.nav-links a {
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
  transition: color 0.2s;
}

.nav-links a:hover { color: var(--ink); }

.nav-cta {
  flex: none;
  padding: 6px 14px;
  border-radius: 980px;
  background: var(--accent);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  transition: background 0.2s;
}

.nav-cta:hover { background: #6d7dff; }

/* ---------- 首屏 ---------- */

.hero {
  position: relative;
  padding: clamp(120px, 18vh, 180px) 24px 0;
  text-align: center;
  overflow: hidden;
}

.hero-glow {
  position: absolute;
  top: -30vh;
  left: 50%;
  width: min(1500px, 150vw);
  height: 120vh;
  transform: translateX(-50%);
  background:
    radial-gradient(50% 46% at 50% 46%, rgba(91, 108, 255, 0.30), transparent 68%),
    radial-gradient(34% 30% at 50% 60%, rgba(160, 108, 255, 0.18), transparent 70%);
  pointer-events: none;
}

.hero-kicker,
.hero-title,
.hero-lede,
.hero-cta,
.platform-note,
.beta-line {
  position: relative;
  z-index: 2;
}

.hero-kicker {
  margin: 0 0 18px;
  color: var(--muted);
  font-size: 15px;
  letter-spacing: 0.02em;
}

.hero-title {
  margin: 0;
  font-size: clamp(44px, 8.4vw, 104px);
  font-weight: 700;
  line-height: 1.04;
  letter-spacing: -0.03em;
  font-feature-settings: "palt" 1;
}

.hero-title-pro {
  font-weight: 300;
  color: var(--accent-soft);
}

.hero-lede {
  margin: 26px auto 0;
  max-width: 22em;
  color: var(--muted);
  font-size: clamp(17px, 1.55vw, 21px);
  line-height: 1.5;
}

.hero-cta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-top: 34px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 30px;
  border-radius: 980px;
  background: var(--accent);
  color: #fff;
  font-size: 17px;
  font-weight: 600;
  text-decoration: none;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.22);
  transition: background 0.2s, transform 0.2s var(--ease);
}

.btn:hover { background: #6d7dff; transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn-icon { width: 19px; height: 19px; fill: currentColor; flex: none; }

.version {
  color: var(--muted);
  font-size: 14px;
  font-variant-numeric: tabular-nums;
}

.platform-note {
  margin: 20px auto 0;
  max-width: 30em;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
}

.beta-line {
  margin: 12px 0 0;
  font-size: 15px;
}

.beta-line a {
  color: var(--accent-soft);
  text-underline-offset: 3px;
}

/* ---------- 首屏的机器 ---------- */

.hero-stage {
  position: relative;
  isolation: isolate;
  margin-top: clamp(44px, 7vw, 76px);
  padding-bottom: 40px;
  z-index: 1;
}

.hour-rail {
  position: absolute;
  z-index: 0;
  left: 50%;
  bottom: 16%;
  width: min(1180px, 94vw);
  height: 170px;
  transform: translateX(-50%);
  background-image: repeating-linear-gradient(
    to right,
    rgba(255, 255, 255, 0.30) 0 1px,
    transparent 1px 4.1667%
  );
  -webkit-mask-image: linear-gradient(to bottom, transparent, #000 42%, transparent);
  mask-image: linear-gradient(to bottom, transparent, #000 42%, transparent);
  opacity: 0.6;
  pointer-events: none;
}

.phones {
  --dy: 0px;
  position: relative;
  z-index: 2;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  transform: translateY(var(--dy));
  -webkit-mask-image: linear-gradient(to bottom, #000 78%, transparent 100%);
  mask-image: linear-gradient(to bottom, #000 78%, transparent 100%);
}

.phone {
  width: clamp(128px, 20vw, 292px);
  filter: drop-shadow(0 40px 70px rgba(0, 0, 0, 0.85));
}

.phone-left {
  transform: rotate(-7deg) translate(16%, 40px);
  opacity: 0.72;
}

.phone-mid {
  position: relative;
  z-index: 2;
  width: clamp(168px, 25vw, 372px);
}

.phone-right {
  transform: rotate(7deg) translate(-16%, 40px);
  opacity: 0.72;
}

.horizon {
  position: absolute;
  z-index: 1;
  left: 50%;
  bottom: 96px;
  width: min(1120px, 94vw);
  height: 1px;
  transform: translateX(-50%);
  background: linear-gradient(90deg, transparent, rgba(160, 172, 255, 0.9), transparent);
  box-shadow: 0 0 24px 2px rgba(120, 135, 255, 0.55);
  pointer-events: none;
}

.horizon::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 380px;
  background: radial-gradient(54% 100% at 50% 0%, rgba(91, 108, 255, 0.30), transparent 72%);
}

/* ---------- 章节 ---------- */

.chapter {
  padding: clamp(92px, 13vw, 176px) 24px;
  max-width: var(--wide);
  margin: 0 auto;
}

.chapter-head {
  max-width: var(--narrow);
  margin: 0 auto;
  text-align: center;
}

.chapter-kicker {
  margin: 0 0 14px;
  color: var(--accent-soft);
  font-size: 14px;
  font-weight: 600;
}

.chapter-title {
  margin: 0;
  font-size: clamp(32px, 4.6vw, 62px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.025em;
  font-feature-settings: "palt" 1;
  text-wrap: balance;
}

.hero-title,
.promise-title,
.closer-title { text-wrap: balance; }

.chapter-lede {
  margin: 24px auto 0;
  max-width: 30em;
  color: var(--muted);
  font-size: clamp(16px, 1.45vw, 19px);
  line-height: 1.62;
}

/* 四条要点 */
.facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px 40px;
  max-width: 900px;
  margin: clamp(52px, 7vw, 84px) auto 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.facts li {
  padding: 26px 2px;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font-size: 15px;
  line-height: 1.6;
}

.facts b {
  display: block;
  margin-bottom: 6px;
  color: var(--ink);
  font-size: 17px;
  font-weight: 600;
}

/* 单机舞台 */
.stage {
  margin: clamp(56px, 8vw, 96px) auto 0;
  width: min(320px, 74vw);
  position: relative;
}

.stage img {
  width: 100%;
  filter: drop-shadow(0 50px 90px rgba(0, 0, 0, 0.9));
}

.stage::before {
  content: "";
  position: absolute;
  inset: -18% -60% -10%;
  z-index: -1;
  background: radial-gradient(50% 50% at 50% 50%, rgba(91, 108, 255, 0.16), transparent 70%);
  pointer-events: none;
}

/* 左右分栏：让页面不至于每一章都是「居中标题 + 居中手机」 */
.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  align-items: center;
  gap: clamp(40px, 6vw, 88px);
  max-width: var(--wide);
  margin: 0 auto;
}

.split-copy { text-align: left; }

.split-copy .chapter-kicker,
.split-copy .chapter-title,
.split-copy .chapter-lede {
  margin-left: 0;
  margin-right: 0;
  text-align: left;
}

.split-copy .chapter-lede { max-width: 26em; }

/* 分栏里标题只能占半幅，字号要收一点，否则中文会在词中间断行 */
.split-copy .chapter-title { font-size: clamp(30px, 3.6vw, 52px); }

.split-copy .callout { margin-top: 32px; }

.split-media {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  gap: clamp(16px, 3vw, 34px);
}

.split-media figure { margin: 0; width: 50%; }

.split-media img {
  width: 100%;
  filter: drop-shadow(0 40px 70px rgba(0, 0, 0, 0.9));
}

.split-media figcaption {
  margin-top: 18px;
  color: var(--dim);
  font-size: 13.5px;
  text-align: center;
}

.split-media-single figure { width: min(286px, 100%); }

.split-reverse .split-media { order: -1; }

.callout {
  max-width: 34em;
  margin: clamp(40px, 5vw, 64px) auto 0;
  padding: 22px 26px;
  border-left: 2px solid var(--accent);
  color: var(--muted);
  font-size: clamp(15px, 1.35vw, 17px);
  line-height: 1.65;
  text-align: left;
}

.callout strong { color: var(--ink); font-weight: 600; }

/* 安静的一章 */
.chapter-quiet .chapter-title { max-width: 14em; margin-inline: auto; }

/* 承诺 */
.chapter-promise {
  max-width: none;
  padding-inline: 24px;
  background: var(--lift);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.promise-title {
  max-width: var(--wide);
  margin: 0 auto clamp(56px, 8vw, 88px);
  font-size: clamp(34px, 5.2vw, 72px);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.028em;
  text-align: center;
  font-feature-settings: "palt" 1;
}

.promises {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 44px 64px;
  max-width: 900px;
  margin: 0 auto;
  padding: 0;
  list-style: none;
}

.promises b {
  display: block;
  margin-bottom: 8px;
  font-size: clamp(19px, 1.9vw, 24px);
  font-weight: 600;
}

.promises span {
  color: var(--muted);
  font-size: 15.5px;
  line-height: 1.6;
}

/* 更新日志 */
.log {
  max-width: 760px;
  margin: clamp(52px, 7vw, 80px) auto 0;
  padding: 0;
  list-style: none;
}

.log li {
  padding: 26px 0;
  border-top: 1px solid var(--line);
}

.log h3 {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.log h3 em {
  font-style: normal;
  color: var(--accent-soft);
  font-size: 12px;
  font-weight: 500;
}

.log p {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.65;
}

.log-more {
  margin: 30px 0 0;
  text-align: center;
  font-size: 15px;
}

.log-more a {
  color: var(--accent-soft);
  text-underline-offset: 3px;
}

/* ---------- 结尾 ---------- */

.closer {
  padding: clamp(96px, 13vw, 172px) 24px clamp(80px, 10vw, 130px);
  text-align: center;
  background:
    radial-gradient(46% 60% at 50% 0%, rgba(91, 108, 255, 0.16), transparent 70%);
  border-top: 1px solid var(--line);
}

.closer-title {
  margin: 0;
  font-size: clamp(34px, 5vw, 66px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.028em;
  font-feature-settings: "palt" 1;
}

.closer .hero-cta { margin-top: 40px; }

/* ---------- 页脚 ---------- */

.foot {
  padding: 46px 24px 60px;
  border-top: 1px solid var(--line);
  color: var(--dim);
  font-size: 13px;
  text-align: center;
}

.foot-name {
  margin: 0 0 6px;
  color: var(--muted);
  font-size: 15px;
  font-weight: 600;
}

.foot-name span { font-weight: 400; color: var(--dim); }

.foot-meta { margin: 0 0 14px; font-variant-numeric: tabular-nums; }

.foot-links {
  display: flex;
  justify-content: center;
  gap: 22px;
}

.foot-links a {
  color: var(--dim);
  text-decoration: none;
  transition: color 0.2s;
}

.foot-links a:hover { color: var(--ink); }

/* ---------- 入场 ---------- */

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 1s var(--ease), transform 1s var(--ease);
}

.reveal.is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 窄屏 ---------- */

@media (max-width: 900px) {
  .nav-links { gap: 18px; }
  .nav-links a:nth-child(3) { display: none; }

  .split { grid-template-columns: 1fr; gap: 46px; }

  .split-copy,
  .split-copy .chapter-kicker,
  .split-copy .chapter-title,
  .split-copy .chapter-lede {
    text-align: center;
  }

  .split-copy .chapter-title,
  .split-copy .chapter-lede { margin-inline: auto; }

  .split-copy .callout { max-width: 34em; margin-inline: auto; }

  .split-reverse .split-media { order: 0; }

  .facts,
  .promises {
    grid-template-columns: 1fr;
    gap: 1px 0;
  }

  .promises { gap: 30px; }

  .facts { border-top: 0; }
  .facts li { padding: 20px 0; }
}

@media (max-width: 620px) {
  .nav-inner { padding: 0 18px; gap: 12px; }
  .nav-links { gap: 14px; }
  .nav-links a:nth-child(2) { display: none; }

  .hero { padding-top: 108px; }
  .hero-lede br { display: none; }

  .phones { --dy: 0px; }
  .phone-left { transform: rotate(-9deg) translate(22%, 26px); }
  .phone-right { transform: rotate(9deg) translate(-22%, 26px); }

  .split-media { gap: 14px; }
  .split-media figcaption { font-size: 12.5px; }

  /* 手机上两张机并排只剩 150px 宽，看不清；竖着放反而舒展 */
  .split-media { flex-direction: column; align-items: center; gap: 34px; }
  .split-media figure { width: min(258px, 76vw); }

  .chapter { padding-inline: 20px; }
  .callout { padding: 18px 20px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .btn,
  .nav-cta,
  .nav { transition: none; }
}