/* 棋路（chessroad.cn）官网样式 —— 公司门面与产品页共用。
 *
 * 设计口径（见 frontend-skill）：
 *   - 首屏是海报：hero 通铺、品牌名最大、文案克制；
 *   - 默认不用卡片：用整幅分区（band）、留白、字号与对齐来分层；
 *   - 只用一个强调色（中国红），一个中性木色做正文链接；
 *   - 两套字体：标题 Noto Serif SC，正文系统无衬线；
 *   - 动效只做三处：hero 入场、滚动显影、图片轻微位移。
 */

:root {
  --paper: #f7f3ec;
  --paper-deep: #efe8dc;
  --card: #fffdf8;
  --ink: #211a15;
  --ink-soft: #6b5f55;
  --ink-mid: #4c4239;
  --wood: #8b5a2b;
  --red: #b3202a;
  --line: rgba(33, 26, 21, 0.12);
  --serif: "Noto Serif SC", "Songti SC", serif;
  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  --page: min(1180px, 92vw);
}

* { box-sizing: border-box; }

/* 顶栏是固定的：跳锚点时给顶部留出顶栏的位置 */
html { scroll-behavior: smooth; scroll-padding-top: 5rem; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

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

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

.wrap { width: var(--page); margin: 0 auto; }

/* ── 顶部：hero 上透明，滚过首屏后变实底 ───────────────────── */

.topbar {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding: 1.1rem clamp(1rem, 4vw, 3rem);
  color: #fff;
  transition: background 0.35s ease, color 0.35s ease, padding 0.35s ease;
}

.topbar.is-solid {
  background: rgba(247, 243, 236, 0.94);
  color: var(--ink);
  padding-top: 0.7rem;
  padding-bottom: 0.7rem;
  box-shadow: 0 1px 0 var(--line);
  backdrop-filter: saturate(160%) blur(10px);
}

.topbar__brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--serif);
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.topbar__brand span {
  display: grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  border-radius: 8px;
  background: var(--red);
  color: #fff;
  font-size: 1.05rem;
}

.topbar nav { display: flex; gap: clamp(0.9rem, 3vw, 2rem); font-size: 0.95rem; }

.topbar nav a { opacity: 0.88; }

.topbar nav a:hover { opacity: 1; text-decoration: underline; text-underline-offset: 4px; }

/* ── Hero：通铺，文字压在画面的稳区上 ─────────────────────── */

.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: flex-end;
  padding: clamp(2rem, 8vh, 6rem) clamp(1.2rem, 5vw, 4rem);
  color: #fff;
  overflow: hidden;
}

.hero--photo { align-items: center; padding-bottom: clamp(3rem, 12vh, 9rem); }

.hero--photo .hero__media { object-position: center 62%; }

.hero--photo::after {
  background: linear-gradient(180deg, rgba(20, 14, 10, 0.72) 0%, rgba(20, 14, 10, 0.42) 45%, rgba(20, 14, 10, 0.7) 100%);
}

.hero__media {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 30%;
  transform: scale(1.04);
  animation: hero-drift 14s ease-out forwards;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(20, 14, 10, 0.62) 0%, rgba(20, 14, 10, 0.3) 38%, rgba(20, 14, 10, 0.86) 100%);
}

.hero__inner {
  position: relative;
  z-index: 2;
  width: var(--page);
  margin: 0 auto;
  max-width: 40rem;
  animation: rise 0.7s cubic-bezier(0.22, 0.7, 0.2, 1) both;
}

.hero__brand {
  font-family: var(--serif);
  font-size: clamp(3rem, 9vw, 5.4rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: 0.08em;
  margin: 0 0 0.6rem;
  text-shadow: 0 2px 24px rgba(0, 0, 0, 0.45);
}

.hero__kicker {
  font-size: 0.86rem;
  letter-spacing: 0.34em;
  text-transform: uppercase;
  opacity: 0.82;
  margin-bottom: 0.9rem;
}

.hero__line {
  font-size: clamp(1.05rem, 2.4vw, 1.35rem);
  opacity: 0.94;
  margin: 0 0 1.8rem;
  max-width: 30rem;
}

.hero__support {
  font-size: 0.95rem;
  opacity: 0.8;
  margin: -1.1rem 0 1.6rem;
  max-width: 28rem;
}

.hero__actions { display: flex; flex-wrap: wrap; gap: 0.9rem; }

/* 产品页首屏：通铺墨色底 + 右侧设备图。
   （手机截图是竖版 UI，当照片通铺会让文字与界面互相打架；
     所以底色用品牌墨色，截图按"设备"呈现 —— 背景仍是从边到边。） */
.hero--ink {
  background: radial-gradient(120% 90% at 82% 18%, #3a2b22 0%, #241a14 55%, #1b130e 100%);
  align-items: center;
  /* 铺满整屏：底色比正文短一截时，屏幕底部会露出一条纸色，看着像"没铺满" */
  min-height: 100svh;
}

.hero--ink::after { display: none; }

.hero--ink .hero__inner { max-width: 34rem; }

/* 深底这一版字号收一档：三行标题在窄列里会断得难看 */
.hero--ink .hero__brand { font-size: clamp(2.3rem, 6vw, 3.9rem); }

.hero--split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 0.85fr);
  gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
  width: var(--page);
  margin: 0 auto;
  position: relative;
  z-index: 2;
}

.hero__device img {
  border-radius: 26px;
  box-shadow: 0 40px 90px -40px rgba(0, 0, 0, 0.85), 0 0 0 1px rgba(255, 255, 255, 0.06);
  max-height: 74svh;
  width: auto;
  margin: 0 auto;
}

@media (max-width: 860px) {
  .hero--split { grid-template-columns: 1fr; }
  .hero__device { order: -1; }
  .hero__device img { max-height: 46svh; }
}

/* ── 按钮：只有两种（实心 / 描边），描边在深底上也能用 ───── */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.85rem 1.5rem;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.98rem;
  border: 1px solid transparent;
  transition: transform 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

.btn--solid { background: var(--red); color: #fff; }

.btn--solid:hover { background: #9c1b24; transform: translateY(-1px); }

.btn--ghost { border-color: rgba(255, 255, 255, 0.55); color: #fff; }

.btn--ghost:hover { border-color: #fff; transform: translateY(-1px); }

.btn--ink { border-color: var(--line); color: var(--ink); }

.btn--ink:hover { border-color: var(--ink); transform: translateY(-1px); }

/* ── 产品分区：一张卡片装一个产品，卡片贯穿图片，逐行交替 ──── */

.products {
  display: grid;
  gap: clamp(1.1rem, 2.4vh, 2rem);
  padding: clamp(1.6rem, 4vh, 3rem) 0 clamp(3rem, 8vh, 5.5rem);
}

/* 卡片 ≈ 一屏高：内容垂直居中，四边留白给足，整页因此显得大气 */
.band {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  align-items: center;
  gap: clamp(1.8rem, 5vw, 4.5rem);
  min-height: min(88svh, 880px);
  padding: clamp(1.8rem, 4.4vw, 4rem);
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: clamp(22px, 2.6vw, 36px);
  box-shadow: 0 60px 120px -80px rgba(33, 26, 21, 0.55);
}

/* 交替：第二张卡片把图片换到左边，列宽跟着换 */
.band--flip { grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr); }

.band--flip .band__text { order: 2; }

.band__text { display: flex; flex-direction: column; justify-content: center; }

.band__kicker {
  font-size: 0.82rem;
  letter-spacing: 0.3em;
  color: var(--wood);
  margin-bottom: 0.9rem;
}

.band__title {
  font-family: var(--serif);
  font-size: clamp(2rem, 4.4vw, 3.1rem);
  font-weight: 700;
  line-height: 1.25;
  color: var(--red);
  margin: 0 0 1.15rem;
}

.band__lead {
  font-size: clamp(1.02rem, 1.4vw, 1.2rem);
  color: var(--ink-mid);
  margin: 0 0 1.6rem;
  max-width: 32rem;
}

/* 三条要点：给文字栏该有的分量，也让"两个产品各做一件事"看得见 */
.band__list {
  list-style: none;
  margin: 0 0 2.1rem;
  padding: 0;
  max-width: 32rem;
  display: grid;
  gap: 0.85rem;
}

.band__list li {
  position: relative;
  padding-left: 1.05rem;
  font-size: 1rem;
  line-height: 1.6;
  color: var(--ink-soft);
}

.band__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.66em;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--red);
  opacity: 0.85;
}

.band__list strong {
  color: var(--ink);
  font-weight: 600;
  margin-right: 0.5rem;
}

.band__actions { display: flex; flex-wrap: wrap; gap: 0.9rem 1.4rem; align-items: center; }

.band__link { color: var(--wood); font-weight: 600; text-underline-offset: 4px; }

.band__link:hover { text-decoration: underline; }

.band__media { position: relative; display: flex; align-items: center; justify-content: center; }

.band__media img {
  border-radius: 22px;
  box-shadow: 0 30px 70px -34px rgba(33, 26, 21, 0.6), 0 0 0 1px rgba(33, 26, 21, 0.08);
  transition: transform 0.5s cubic-bezier(0.22, 0.7, 0.2, 1);
}

.band__media:hover img { transform: translateY(-6px); }

/* 截图是竖版界面：按"设备"限高，卡片高度由它和文字共同撑起 */
.band__media img { height: clamp(380px, 62vh, 660px); width: auto; }

/* 收尾的两张卡片：标题站左栏，说明站右栏，别再抢产品的戏 */
.band--message {
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  min-height: min(48svh, 460px);
  gap: clamp(1.4rem, 4vw, 3.5rem);
}

.band__message-title {
  font-family: var(--serif);
  font-size: clamp(1.7rem, 3.4vw, 2.5rem);
  line-height: 1.3;
  margin: 0;
}

.band__message-body p { color: var(--ink-mid); margin: 0; max-width: 34rem; }

/* 卡片正文可以多段：段间、链接行给一点间距 */
.band__message-body > p + p { margin-top: 1rem; }

.band__message-body strong { color: var(--ink); }

.band__message-body .band__links { margin: 1.5rem 0 0; color: var(--ink-soft); }

.band--message .band__actions { margin-top: 1.9rem; }

/* ── 页脚 ──────────────────────────────────────────────── */

.footer {
  border-top: 1px solid var(--line);
  padding: 2.6rem 0 3.4rem;
  color: var(--ink-soft);
  font-size: 0.9rem;
}

.footer__inner {
  width: var(--page);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2rem;
  justify-content: space-between;
  align-items: center;
}

.footer__brand { display: grid; gap: 0.35rem; }

.footer__brand p { margin: 0; }

.footer__icp { color: var(--ink-soft); }

.footer nav { display: flex; flex-wrap: wrap; gap: 1.2rem; }

/* 图片来源这类补充说明单独占一行，压在页脚最下面 */
.footer__credit { flex-basis: 100%; margin: 0; opacity: 0.7; font-size: 0.82rem; }

.footer a:hover { text-decoration: underline; text-underline-offset: 4px; }

/* ── 滚动显影（第二处动效）───────────────────────────────── */

.reveal { opacity: 0; transform: translateY(18px); transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.22, 0.7, 0.2, 1); }

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

@keyframes rise {
  from { opacity: 0; transform: translateY(22px); }
  to { opacity: 1; transform: none; }
}

/* 第三处动效：hero 图片缓慢推移（不是循环动画，只走一次） */
@keyframes hero-drift {
  from { transform: scale(1.08) translateY(0); }
  to { transform: scale(1.02) translateY(-1.2%); }
}

/* ── 响应式：窄屏一律单列，hero 收窄文案 ───────────────── */

@media (max-width: 860px) {
  /* 手机上这张实物照的棋子铺满下半屏，文字必须留在画面上方的静区 */
  .hero--photo { align-items: center; padding-bottom: 5rem; }
  .band { grid-template-columns: 1fr; }
  .band--flip .band__text { order: 0; }
  /* 窄屏卡片落到单列：高度交给内容，不再占一屏 */
  .band {
    min-height: auto;
    gap: 1.9rem;
    padding: clamp(1.7rem, 6vw, 2.3rem);
    border-radius: 24px;
  }
  /* 没有并排的两栏可比，改用宽度约束，别让截图撑出一屏 */
  .band__media img { height: auto; width: min(56vw, 230px); }
  .band--message { padding: clamp(2.6rem, 12vw, 3.6rem) clamp(1.7rem, 6vw, 2.3rem); }
  .hero { align-items: flex-end; padding-bottom: 4rem; }
  .hero__brand { letter-spacing: 0.04em; }
  .topbar nav { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  .hero__media, .hero__inner { animation: none; }
  .reveal { opacity: 1; transform: none; transition: none; }
}