/* 序伴官网 · 独立站点样式
   一个地面色、一个墨色、一个玫瑰色；靠字级与色块分层，不用渐变、阴影和细线。 */

:root {
  --ground: #f8f4f2;
  --ink: #2a2124;
  --ink-2: #5f545a;
  --accent: #b2506c;
  --accent-dark: #8d3450;
  --accent-light: #e8a7b8;
  --field: #f1e6e8;
  --field-2: #e9dfe1;
  --rose: #ecd7dd;
  --dark: #241d20;
  --on-dark: #f8f4f2;
  --on-dark-2: #c9bcc0;

  --font-display: "Songti SC", "Noto Serif SC", "Source Han Serif SC", "SimSun", serif;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;

  --page: 1240px;
  --gutter: 24px;
  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
}

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

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

body {
  margin: 0;
  background: var(--ground);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.75;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: inherit;
  text-decoration: none;
}

h1,
h2,
h3,
p,
dl,
dd,
dt,
figure,
blockquote,
ol,
ul {
  margin: 0;
  padding: 0;
}

ol,
ul {
  list-style: none;
}

::selection {
  background: var(--accent);
  color: #fff;
}

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
}

.skip {
  position: absolute;
  top: -100px;
  left: 16px;
  z-index: 100;
  padding: 10px 16px;
  background: var(--ink);
  color: var(--on-dark);
}

.skip:focus {
  top: 16px;
}

.section-inner {
  width: min(var(--page), calc(100% - var(--gutter) * 2));
  margin-inline: auto;
}

/* ---------- 导航：一条素净的横条 ---------- */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  gap: 32px;
  width: min(var(--page), calc(100% - var(--gutter) * 2));
  margin-inline: auto;
  padding: 22px 0;
  background: var(--ground);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.brand img {
  width: 30px;
  height: 30px;
}

.nav-links {
  display: flex;
  gap: 28px;
  margin-left: auto;
  font-size: 15px;
  color: var(--ink-2);
}

.nav-links a {
  padding: 6px 0;
}

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

/* ---------- 按钮与文字链接 ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 15px 26px;
  background: var(--accent);
  color: #fff;
  font-size: 16px;
  font-weight: 600;
  line-height: 1;
  border-radius: 0;
  transition: background 0.25s var(--ease), transform 0.25s var(--ease);
}

.btn:hover {
  background: var(--accent-dark);
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

.btn-small {
  padding: 12px 20px;
  font-size: 15px;
}

.text-link {
  color: var(--accent);
  border-bottom: 2px solid var(--accent-light);
  padding-bottom: 2px;
  transition: border-color 0.25s var(--ease), color 0.25s var(--ease);
}

.text-link:hover {
  color: var(--accent-dark);
  border-color: var(--accent);
}

/* ---------- 首屏 ---------- */

.hero {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 56px;
  align-items: end;
  width: min(var(--page), calc(100% - var(--gutter) * 2));
  margin-inline: auto;
  padding: 72px 0 120px;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(42px, 4.8vw, 69px);
  font-weight: 600;
  line-height: 1.04;
  letter-spacing: -0.02em;
}

.hero .lead {
  max-width: 33em;
  margin-top: 30px;
  font-size: 19px;
  line-height: 1.7;
  color: var(--ink-2);
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 28px;
  margin-top: 38px;
}

.facts {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-top: 64px;
}

.facts dt {
  font-family: var(--font-display);
  font-size: 30px;
  font-weight: 600;
  line-height: 1.2;
}

.facts dd {
  margin-top: 6px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--ink-2);
}

.hero-visual {
  align-self: stretch;
}

.hero-field {
  display: flex;
  justify-content: center;
  align-items: flex-end;
  padding: 44px 40px 0;
  background: var(--rose);
  height: 100%;
  min-height: 560px;
}

.hero-field img {
  width: min(300px, 100%);
  height: auto;
}

.hero-visual figcaption,
.rel-visual figcaption,
.play-visual figcaption {
  margin-top: 14px;
  font-size: 14px;
  color: var(--ink-2);
}

/* 首屏入场 */
.hero-copy > * {
  animation: rise 0.9s var(--ease) both;
}

.hero-copy > :nth-child(2) {
  animation-delay: 0.08s;
}

.hero-copy > :nth-child(3) {
  animation-delay: 0.16s;
}

.hero-copy > :nth-child(4) {
  animation-delay: 0.24s;
}

.hero-visual {
  animation: rise 1.1s var(--ease) 0.18s both;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(28px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

/* ---------- 记忆 ---------- */

.memory {
  padding: 120px 0;
  background: var(--field);
}

.memory-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 72px;
  align-items: start;
}

.memory h2,
.rel-head h2,
.platform-head h2,
.play h2,
.safety h2,
.faq h2,
.cta h2 {
  font-family: var(--font-display);
  font-size: clamp(32px, 4vw, 54px);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.statement {
  max-width: 26em;
  margin-top: 26px;
  font-size: clamp(20px, 2.2vw, 27px);
  line-height: 1.55;
  color: var(--ink);
}

.body {
  max-width: 36em;
  margin-top: 24px;
  font-size: 17px;
  line-height: 1.8;
  color: var(--ink-2);
}

.memory-layers {
  display: grid;
  gap: 24px;
  margin-top: 40px;
}

.memory-layers dt {
  font-size: 17px;
  font-weight: 600;
}

.memory-layers dd {
  margin-top: 4px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink-2);
}

.memory-visual {
  display: grid;
  grid-template-columns: 1fr 168px;
  gap: 36px;
  align-items: start;
}

.ledger {
  display: grid;
  gap: 34px;
  padding-top: 8px;
}

.ledger time {
  display: block;
  font-size: 14px;
  color: var(--ink-2);
}

.ledger p {
  margin-top: 8px;
  font-family: var(--font-display);
  font-size: clamp(20px, 1.9vw, 25px);
  line-height: 1.55;
}

.memory-visual .note {
  grid-column: 1 / -1;
  margin-top: -6px;
}

.memory-shot {
  width: 168px;
  border: 0;
}

.note {
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-2);
}

/* ---------- 关系 ---------- */

.relationship {
  padding: 130px 0;
}

.rel-head {
  max-width: 760px;
}

.rel-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 72px;
  align-items: end;
  margin-top: 64px;
}

.day-label {
  display: block;
  font-size: 20px;
  font-weight: 600;
}

.day-label output {
  font-family: var(--font-display);
  font-size: 40px;
  color: var(--accent);
  line-height: 1;
  margin-inline: 4px;
}

.day-range {
  width: 100%;
  margin: 28px 0 8px;
  accent-color: var(--accent);
  height: 28px;
  cursor: pointer;
}

.rel-state {
  font-family: var(--font-display);
  font-size: clamp(30px, 3.4vw, 46px);
  line-height: 1.2;
  margin-top: 12px;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
  margin-top: 38px;
}

.metrics dt {
  font-size: 15px;
  color: var(--ink-2);
}

.metrics dd {
  font-family: var(--font-display);
  font-size: clamp(38px, 4vw, 58px);
  line-height: 1.1;
  color: var(--accent);
  margin-top: 2px;
}

.metrics p {
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--ink-2);
}

.rel-live .note {
  margin-top: 34px;
}

.rel-visual img {
  width: min(330px, 100%);
  margin-left: auto;
}

.rel-visual figcaption {
  text-align: right;
}

/* ---------- 平台 ---------- */

.platforms {
  padding: 120px 0;
  background: var(--dark);
  color: var(--on-dark);
}

.platforms h2 {
  color: var(--on-dark);
}

.platforms .statement {
  color: var(--on-dark);
}

.platform-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 56px;
  margin-top: 64px;
}

.platform-grid h3 {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 600;
  color: var(--accent-light);
}

.platform-grid p {
  margin-top: 16px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--on-dark-2);
}

.platforms .note {
  margin-top: 56px;
  color: var(--on-dark-2);
}

/* ---------- 玩法 ---------- */

.play {
  padding: 130px 0;
}

.play-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 72px;
  align-items: start;
}

.game-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 30px 32px;
  margin-top: 46px;
}

.game-list h3 {
  font-size: 18px;
  font-weight: 600;
}

.game-list p {
  margin-top: 4px;
  font-size: 15px;
  line-height: 1.65;
  color: var(--ink-2);
}

.play-copy > .body {
  margin-top: 40px;
}

.play-visual {
  position: sticky;
  top: 104px;
}

.play-visual img {
  width: min(330px, 100%);
  margin-left: auto;
}

.play-visual figcaption {
  text-align: right;
}

/* ---------- 安全 ---------- */

.safety {
  padding: 120px 0;
  background: var(--field-2);
}

.safety-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 48px;
  margin-top: 56px;
}

.safety-grid h3 {
  font-size: 19px;
  font-weight: 600;
}

.safety-grid p {
  margin-top: 12px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-2);
}

/* ---------- 问答 ---------- */

.faq {
  padding: 130px 0;
}

.faq-grid {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 72px;
  align-items: start;
}

.faq-head .body {
  margin-top: 28px;
}

.faq-list {
  display: grid;
  gap: 8px;
}

.faq-list details {
  padding: 20px 0;
}

.faq-list summary {
  cursor: pointer;
  font-size: 18px;
  font-weight: 600;
  line-height: 1.5;
  list-style-position: outside;
}

.faq-list summary::marker {
  color: var(--accent);
}

.faq-list details p {
  max-width: 40em;
  margin-top: 12px;
  padding-left: 20px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--ink-2);
}

/* ---------- 收束 ---------- */

.cta {
  padding: 140px 0;
  text-align: center;
}

.cta .section-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.cta h2 {
  font-size: clamp(36px, 5vw, 68px);
}

.cta .statement {
  margin-top: 20px;
  color: var(--ink-2);
}

.cta .btn {
  margin-top: 40px;
}

/* ---------- 页脚 ---------- */

.foot {
  padding: 80px 0 36px;
  background: var(--dark);
  color: var(--on-dark);
  overflow: hidden;
}

.foot-top {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 32px;
}

.foot-top p {
  font-size: 15px;
  color: var(--on-dark-2);
}

.foot-top nav {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  font-size: 15px;
}

.foot-top nav a {
  color: var(--on-dark);
  transition: color 0.25s var(--ease);
}

.foot-top nav a:hover {
  color: var(--accent-light);
}

.wordmark {
  margin-top: 64px;
  font-family: var(--font-display);
  font-size: clamp(110px, 19vw, 280px);
  font-weight: 600;
  line-height: 0.82;
  letter-spacing: -0.05em;
  color: var(--accent-light);
}

.foot-bottom {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  margin-top: 40px;
  font-size: 13px;
  color: var(--on-dark-2);
}

/* ---------- 进场（脚本可用时才隐藏） ---------- */

.js [data-reveal] {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.75s var(--ease), transform 0.75s var(--ease);
}

.js [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 自适应 ---------- */

@media (max-width: 1080px) {
  .hero {
    grid-template-columns: 1.1fr 0.9fr;
    gap: 40px;
  }

  .memory-grid,
  .rel-grid,
  .play-grid,
  .faq-grid {
    gap: 48px;
  }

  .memory-visual {
    grid-template-columns: 1fr 150px;
  }

  .memory-shot {
    width: 150px;
  }
}

@media (max-width: 860px) {
  .nav-links {
    display: none;
  }

  .nav {
    gap: 16px;
  }

  .nav .btn {
    margin-left: auto;
  }

  .hero {
    grid-template-columns: 1fr;
    padding: 48px 0 84px;
  }

  .hero-field {
    min-height: 0;
    padding: 36px 24px 0;
  }

  .hero-field img {
    width: min(270px, 100%);
  }

  .facts {
    margin-top: 48px;
  }

  .memory,
  .relationship,
  .platforms,
  .play,
  .safety,
  .faq,
  .cta {
    padding: 84px 0;
  }

  .memory-grid,
  .rel-grid,
  .play-grid,
  .faq-grid {
    grid-template-columns: 1fr;
  }

  .memory-visual {
    grid-template-columns: 1fr 132px;
    gap: 24px;
  }

  .memory-shot {
    width: 132px;
  }

  .rel-visual img,
  .play-visual img {
    margin-inline: 0;
  }

  .rel-visual figcaption,
  .play-visual figcaption {
    text-align: left;
  }

  .platform-grid,
  .safety-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .play-visual {
    position: static;
  }

  .game-list {
    margin-top: 36px;
  }

  .foot-top {
    flex-direction: column;
    align-items: flex-start;
  }

  .foot-bottom {
    flex-direction: column;
    gap: 8px;
  }
}

@media (max-width: 560px) {
  body {
    font-size: 16px;
  }

  .hero h1 {
    font-size: clamp(32px, 9.2vw, 42px);
  }

  .hero .lead {
    font-size: 17px;
  }

  .hero-actions {
    flex-wrap: wrap;
    gap: 18px;
  }

  .facts {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .facts dt {
    font-size: 26px;
  }

  .metrics {
    grid-template-columns: 1fr;
    gap: 22px;
  }

  .metrics dd {
    font-size: 42px;
  }

  .memory-visual {
    grid-template-columns: 1fr;
  }

  .memory-shot {
    width: 132px;
  }

  .game-list {
    grid-template-columns: 1fr;
  }
}

/* ---------- 减少动效 ---------- */

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

  .hero-copy > *,
  .hero-visual {
    animation: none;
  }

  .js [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .btn,
  .text-link,
  .foot-top nav a {
    transition: none;
  }
}