:root {
  --paper: #F3F7F4;
  --white: #FFFFFF;
  --ink: #1D2B36;
  --ink-soft: #4A5A66;
  --grid: #DDE8DF;
  --grass: #5BAA5F;
  --grass-deep: #2E6B35;
  --dirt: #9A6A48;
  --gold: #F5C243;
  --gold-deep: #C8921C;
  --line: #CFDCD2;

  --serif: "Songti SC", "STSong", "Noto Serif CJK SC", "Noto Serif SC", "Source Han Serif SC", serif;
  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "HarmonyOS Sans SC", "MiSans", "Microsoft YaHei", "Noto Sans CJK SC", "Noto Sans SC", sans-serif;

  --gutter: 16px;
  --max: 1080px;
  color-scheme: light;
}

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

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--white);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  overflow-x: hidden;
}

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

h1, h2, h3 { margin: 0; line-height: 1.3; }
h1, h2 { font-family: var(--serif); font-weight: 900; letter-spacing: 0.01em; }
p { margin: 0; }

a { color: var(--grass-deep); }
a:focus-visible,
summary:focus-visible,
.btn:focus-visible {
  outline: 3px solid var(--gold-deep);
  outline-offset: 3px;
}

.wrap {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--gutter);
}
.narrow { max-width: 760px; }

.skip {
  position: absolute;
  left: -999px;
  top: 8px;
  background: var(--ink);
  color: var(--white);
  padding: 8px 12px;
  z-index: 10;
}
.skip:focus { left: 8px; }

/* 按钮：像一块方块，按下去会沉一格 */
.btn {
  display: inline-block;
  background: var(--gold);
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
  padding: 12px 22px;
  border: 2px solid var(--ink);
  box-shadow: 4px 4px 0 var(--ink);
  transition: transform 80ms steps(2), box-shadow 80ms steps(2);
}
.btn:hover { background: #FFD25C; }
.btn:active { transform: translate(4px, 4px); box-shadow: 0 0 0 var(--ink); }
.btn-small { padding: 6px 14px; font-size: 15px; box-shadow: 3px 3px 0 var(--ink); }
.btn-small:active { transform: translate(3px, 3px); }
.btn-ghost { background: var(--white); }
.btn-ghost:hover { background: var(--paper); }

.link { font-weight: 600; }

/* 顶栏 */
.top {
  position: sticky;
  top: 0;
  z-index: 5;
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: saturate(1.2) blur(6px);
}
.top-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 56px;
  gap: 12px;
}
.mark {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
  font-weight: 800;
  font-size: 17px;
  white-space: nowrap;
}
.mark-block {
  width: 18px;
  height: 18px;
  background: linear-gradient(var(--grass) 0 33%, var(--dirt) 33% 100%);
  box-shadow: inset -3px -3px 0 rgba(0, 0, 0, 0.12);
}
.top-nav { display: flex; align-items: center; gap: 20px; }
.top-nav a:not(.btn) {
  color: var(--ink-soft);
  text-decoration: none;
  font-size: 15px;
}
.top-nav a:not(.btn):hover { color: var(--ink); }
@media (max-width: 720px) {
  .top-nav a:not(.btn) { display: none; }
}

/* 首屏：方格纸背景 */
.hero {
  background-color: var(--paper);
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 20px 20px;
  border-bottom: 1px solid var(--line);
  padding: 40px 0 44px;
}
.hero-grid { display: grid; gap: 32px; align-items: center; }
.hero h1 { font-size: clamp(30px, 8vw, 46px); }
.lead {
  margin-top: 18px;
  font-size: 17px;
  color: var(--ink-soft);
  max-width: 34em;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px 24px;
  margin-top: 28px;
}
.hero-art { margin: 0; }
.scene {
  width: 100%;
  height: auto;
  border: 2px solid var(--ink);
  box-shadow: 6px 6px 0 var(--ink);
  image-rendering: pixelated;
}
.hero-art figcaption {
  margin-top: 14px;
  font-size: 13px;
  color: var(--ink-soft);
}

/* 首屏唯一的动效：一块金色方块落到草地上 */
.drop { animation: drop 900ms steps(6, end) 400ms both; }
@keyframes drop {
  from { transform: translateY(-60px); }
  to { transform: translateY(0); }
}
@media (prefers-reduced-motion: reduce) {
  .drop { animation: none; }
}

@media (min-width: 880px) {
  .hero { padding: 72px 0 80px; }
  .hero-grid { grid-template-columns: 1.1fr 1fr; gap: 56px; }
}

/* 区块 */
.block { padding: 56px 0; }
.block-tint { background: var(--paper); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.block h2 { font-size: clamp(24px, 5.6vw, 34px); }
.section-lead {
  margin-top: 10px;
  color: var(--ink-soft);
  max-width: 36em;
}
@media (min-width: 880px) { .block { padding: 80px 0; } }

/* 收获：术语 + 解释 */
.gains { margin: 28px 0 0; display: grid; gap: 0; }
.gains > div {
  display: grid;
  gap: 4px;
  padding: 18px 0;
  border-top: 1px solid var(--line);
}
.gains > div:last-child { border-bottom: 1px solid var(--line); }
.gains dt { font-weight: 800; font-size: 18px; }
.gains dd { margin: 0; color: var(--ink-soft); max-width: 40em; }
@media (min-width: 720px) {
  .gains > div { grid-template-columns: 9em 1fr; gap: 24px; padding: 22px 0; }
}

/* 四步：真正有先后顺序，所以用编号方块 */
.steps {
  list-style: none;
  counter-reset: step;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}
.steps li {
  counter-increment: step;
  position: relative;
  background: var(--white);
  border: 2px solid var(--ink);
  padding: 18px 18px 18px 70px;
}
.steps li::before {
  content: counter(step);
  position: absolute;
  left: 16px;
  top: 18px;
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  background: var(--gold);
  border: 2px solid var(--ink);
  font-weight: 900;
  font-size: 18px;
}
.steps h3 { font-size: 18px; }
.steps p { margin-top: 4px; color: var(--ink-soft); }
@media (min-width: 880px) {
  .steps { grid-template-columns: repeat(4, 1fr); }
  .steps li { padding: 70px 18px 20px; }
  .steps li::before { top: 18px; }
}

/* 作品 */
.works {
  margin-top: 28px;
  display: grid;
  gap: 20px;
}
@media (min-width: 640px) { .works { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 960px) { .works { grid-template-columns: repeat(3, 1fr); } }
.empty {
  grid-column: 1 / -1;
  border: 2px dashed var(--line);
  padding: 28px 20px;
  color: var(--ink-soft);
  text-align: center;
  background: var(--paper);
}
.work {
  border: 2px solid var(--ink);
  background: var(--white);
  display: flex;
  flex-direction: column;
}
.work-cover {
  display: block;
  aspect-ratio: 4 / 3;
  border-bottom: 2px solid var(--ink);
  overflow: hidden;
  background: var(--paper);
}
.work-cover img { width: 100%; height: 100%; object-fit: cover; image-rendering: pixelated; }
.work-cover-tile {
  background-color: var(--tile);
  background-image:
    linear-gradient(rgba(0, 0, 0, 0.08) 2px, transparent 2px),
    linear-gradient(90deg, rgba(0, 0, 0, 0.08) 2px, transparent 2px);
  background-size: 24px 24px;
}
.work-body { padding: 16px 18px 20px; display: flex; flex-direction: column; gap: 6px; flex: 1; }
.work-track { font-size: 13px; color: var(--grass-deep); font-weight: 700; }
.work h3 { font-size: 19px; }
.work h3 a { color: var(--ink); text-decoration: none; }
.work h3 a:hover { text-decoration: underline; }
.work-meta { font-size: 14px; color: var(--ink-soft); }
.work-body > :nth-last-child(2) { margin-bottom: 12px; }
.work .btn { align-self: flex-start; margin-top: auto; }

/* 五天：时间线 */
.days { list-style: none; margin: 28px 0 0; padding: 0; }
.days li {
  display: grid;
  grid-template-columns: 4.5em 1fr;
  gap: 14px;
  padding: 18px 0;
  border-top: 1px solid var(--line);
}
.days li:last-child { border-bottom: 1px solid var(--line); }
.day {
  font-weight: 800;
  color: var(--grass-deep);
  white-space: nowrap;
}
.days h3 { font-size: 18px; }
.days p { margin-top: 2px; color: var(--ink-soft); max-width: 40em; }
@media (min-width: 720px) {
  .days li { grid-template-columns: 7em 1fr; padding: 22px 0; }
}

/* 常见问题 */
.faq { margin-top: 24px; border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary {
  cursor: pointer;
  list-style: none;
  padding: 18px 36px 18px 0;
  font-weight: 700;
  font-size: 17px;
  position: relative;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "";
  position: absolute;
  right: 6px;
  top: 50%;
  width: 12px;
  height: 12px;
  margin-top: -6px;
  background:
    linear-gradient(var(--ink), var(--ink)) center / 12px 2px no-repeat,
    linear-gradient(var(--ink), var(--ink)) center / 2px 12px no-repeat;
}
.faq details[open] summary::after {
  background: linear-gradient(var(--ink), var(--ink)) center / 12px 2px no-repeat;
}
.faq details p { color: var(--ink-soft); padding-bottom: 14px; }
.faq details p:last-child { padding-bottom: 20px; }

/* 咨询 */
.contact-grid { display: grid; gap: 28px; }
@media (min-width: 880px) { .contact-grid { grid-template-columns: 1.3fr 1fr; gap: 56px; align-items: start; } }
.facts { margin: 24px 0 0; }
.facts > div {
  display: grid;
  grid-template-columns: 3.5em 1fr;
  gap: 12px;
  padding: 12px 0;
  border-top: 1px solid var(--line);
}
.facts > div:last-child { border-bottom: 1px solid var(--line); }
.facts dt { font-weight: 800; }
.facts dd { margin: 0; color: var(--ink-soft); }
.contact-card {
  background: var(--white);
  border: 2px solid var(--ink);
  box-shadow: 6px 6px 0 var(--ink);
  padding: 24px;
  display: grid;
  justify-items: center;
  gap: 10px;
  text-align: center;
}
.contact-card .empty { border: 0; background: none; padding: 12px 0; }
.contact-card img { width: 200px; height: 200px; image-rendering: auto; }
.contact-hint { font-size: 14px; color: var(--ink-soft); }
.contact-line { display: flex; gap: 10px; align-items: baseline; font-size: 17px; }
.contact-line span { color: var(--ink-soft); font-size: 14px; }

/* 页脚 */
.foot {
  padding: 28px 0 40px;
  font-size: 13px;
  color: var(--ink-soft);
}

.beian { margin-top: 8px; }
.beian a { color: var(--ink-soft); text-decoration: none; }
.beian a:hover { text-decoration: underline; }