/* =========================================================
   青春三册 · 门户
   深色书脊 / 三块并列的相册
   ========================================================= */

:root {
  --bg: #0b0b0c;
  --ink: #f3eee2;
  --muted: rgba(243, 238, 226, 0.56);
  --line: rgba(243, 238, 226, 0.12);
  --gold: #d9b26f;
  --serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "STSong", "SimSun", Georgia, serif;
  --sans: "Inter", "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100svh;
  color: var(--ink);
  font-family: var(--sans);
  line-height: 1.8;
  background:
    radial-gradient(1100px 600px at 50% -18%, #2a2119 0%, transparent 62%),
    radial-gradient(700px 500px at 100% 100%, #151a23 0%, transparent 60%),
    var(--bg);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
}

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

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

p {
  margin: 0;
}

.page {
  display: flex;
  flex-direction: column;
  min-height: 100svh;
  max-width: 1360px;
  margin-inline: auto;
  padding: clamp(1rem, 2.6vw, 1.8rem) clamp(1.1rem, 4vw, 3rem) 1.6rem;
}

/* ---------------- 头部 ---------------- */

.head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-bottom: 0.9rem;
  border-bottom: 1px solid var(--line);
}

.mark {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--serif);
  font-size: 1rem;
  letter-spacing: 0.14em;
}

.mark__dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 16px 3px rgba(217, 178, 111, 0.55);
}

.head__range {
  font-size: 0.62rem;
  letter-spacing: 0.32em;
  color: var(--muted);
}

/* ---------------- 引言 ---------------- */

.intro {
  margin-top: clamp(1.6rem, 4vw, 3rem);
}

.eyebrow {
  font-size: 0.64rem;
  letter-spacing: 0.34em;
  color: var(--gold);
}

.intro h1 {
  margin: 0.5rem 0 0.9rem;
  font-family: var(--serif);
  font-size: clamp(2.3rem, 5.8vw, 4.4rem);
  font-weight: 600;
  line-height: 1.08;
  letter-spacing: 0.02em;
}

.intro h1 em {
  font-style: normal;
  background: linear-gradient(100deg, #fff4dc, var(--gold) 60%, #b8894a);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.intro p {
  max-width: 46ch;
  color: var(--muted);
  font-size: 0.95rem;
}

/* ---------------- 三本“书” ---------------- */

.books {
  display: flex;
  gap: 10px;
  flex: 1;
  min-height: min(52vh, 520px);
  margin-top: clamp(1.4rem, 3vw, 2.2rem);
}

.book {
  position: relative;
  flex: 1 1 0;
  min-width: 0;
  overflow: hidden;
  border-radius: 3px;
  border: 1px solid var(--line);
  background: #141414;
  transition: flex-grow 0.75s var(--ease), border-color 0.5s;
}

.book:hover,
.book:focus-visible {
  flex-grow: 1.55;
  border-color: var(--accent, var(--gold));
  outline: none;
}

.book__media {
  position: absolute;
  inset: 0;
  display: block;
}

.book__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: grayscale(0.55) brightness(0.5) contrast(1.02);
  transform: scale(1.02);
  transition: filter 0.8s var(--ease), transform 1.1s var(--ease);
}

.book:hover .book__media img,
.book:focus-visible .book__media img {
  filter: grayscale(0) brightness(0.72);
  transform: scale(1.06);
}

.book__shade {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(6, 6, 8, 0.1) 0%, rgba(6, 6, 8, 0.35) 45%, rgba(6, 6, 8, 0.88) 100%),
    linear-gradient(90deg, rgba(6, 6, 8, 0.4), transparent 30%);
}

.book__body {
  position: absolute;
  inset: auto 0 0 0;
  display: grid;
  gap: 0.3rem;
  padding: clamp(0.9rem, 1.8vw, 1.4rem);
}

.book__no {
  font-family: var(--sans);
  font-size: 0.64rem;
  letter-spacing: 0.3em;
  color: var(--accent, var(--gold));
}

.book__title {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(1.4rem, 2.4vw, 2rem);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: 0.04em;
}

.book__title em {
  display: block;
  margin-top: 0.45em;
  font-style: normal;
  font-family: var(--sans);
  font-size: 0.56rem;
  letter-spacing: 0.32em;
  color: var(--muted);
}

.book__count {
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--muted);
}

.book__more {
  margin-top: 0.2rem;
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  color: var(--accent, var(--gold));
  opacity: 0;
  transform: translateY(6px);
  transition: opacity 0.45s var(--ease), transform 0.45s var(--ease);
}

.book:hover .book__more,
.book:focus-visible .book__more {
  opacity: 1;
  transform: none;
}

/* ---------------- 页脚 ---------------- */

.foot {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.8rem 1.4rem;
  margin-top: clamp(1.4rem, 3vw, 2rem);
  padding-top: 1.1rem;
  border-top: 1px solid var(--line);
  font-size: 0.74rem;
  color: var(--muted);
}

.foot__links {
  display: flex;
  gap: 1.2rem;
  letter-spacing: 0.14em;
}

.foot__links a:hover {
  color: var(--gold);
}

.foot__legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem 0.8rem;
}

.foot a {
  transition: color 0.3s;
}

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

.police {
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
}

.police img {
  height: 18px;
  width: auto;
}

/* ---------------- 响应式 ---------------- */

@media (max-width: 900px) {
  .books {
    flex-direction: column;
    min-height: 0;
  }
  .book {
    flex: none;
    height: min(34vh, 300px);
    border-radius: 4px;
  }
  .book:hover,
  .book:focus-visible {
    flex-grow: 1;
  }
  .book__more {
    opacity: 1;
    transform: none;
  }
}

@media (max-width: 640px) {
  .head__range {
    display: none;
  }
  .intro h1 {
    font-size: clamp(2rem, 9vw, 2.8rem);
  }
  .book {
    height: 240px;
  }
  .foot {
    flex-direction: column;
    align-items: flex-start;
  }
}