/* ═══════════════════════════════════════════════════
   いつか事ム所 — LP Styles
   ═══════════════════════════════════════════════════ */

/* ---------- Design Tokens ---------- */
:root {
  --ink: #24211d;
  --muted: #756f66;
  --paper: #fbfaf6;
  --soft: #f1ece3;
  --line: #ded6c8;
  --green: #45685a;
  --green-dark: #385548;
  --blue: #3f607d;
  --blue-light: #5a7e9e;
  --red: #a6554d;
  --red-warm: #c76b5f;
  --yellow: #d7a84f;
  --white: #fffefb;
  --shadow-sm: 0 2px 8px rgba(36, 33, 29, 0.06);
  --shadow-md: 0 8px 32px rgba(36, 33, 29, 0.1);
  --shadow-lg: 0 24px 80px rgba(36, 33, 29, 0.14);
  --radius: 6px;
  --radius-lg: 12px;
  --transition: 360ms cubic-bezier(0.4, 0, 0.2, 1);
  --font-serif:
    "Noto Serif JP", "Hiragino Mincho ProN", "Yu Mincho", "YuMincho",
    Georgia, serif;
  --font-sans:
    "Noto Sans JP", "Hiragino Sans", "Yu Gothic", "YuGothic", sans-serif;
}

/* ---------- Reset ---------- */
* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--font-serif);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
}

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

/* ---------- Header ---------- */
.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 72px;
  padding: 16px clamp(18px, 4vw, 56px);
  background: rgba(251, 250, 246, 0.82);
  border-bottom: 1px solid rgba(36, 33, 29, 0.06);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  transition: background var(--transition);
}

.brand {
  text-decoration: none;
  display: flex;
  flex-direction: column;
  gap: 0;
}

.brand-main {
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 900;
  letter-spacing: 0.05em;
  line-height: 1.2;
}

.brand-sub {
  font-family: var(--font-sans);
  font-size: 10px;
  font-weight: 500;
  color: var(--muted);
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.nav {
  display: flex;
  gap: clamp(14px, 3vw, 36px);
  color: var(--muted);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
}

.nav a {
  text-decoration: none;
  position: relative;
  padding-bottom: 4px;
  transition: color var(--transition);
}

.nav a::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--green);
  border-radius: 1px;
  transition: width var(--transition);
}

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

.nav a:hover::after {
  width: 100%;
}

/* ---------- Hero / Slider ---------- */
.hero {
  min-height: 100svh;
  padding-top: 72px;
  background:
    radial-gradient(ellipse at 10% 20%, rgba(69, 104, 90, 0.08) 0%, transparent 50%),
    radial-gradient(ellipse at 90% 80%, rgba(63, 96, 125, 0.06) 0%, transparent 50%),
    linear-gradient(180deg, var(--white), var(--soft));
}

.slider {
  position: relative;
  min-height: calc(100svh - 136px);
  overflow: hidden;
}

.slide {
  position: absolute;
  inset: 0;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.95fr);
  align-items: stretch;
  gap: clamp(24px, 5vw, 72px);
  padding: clamp(28px, 5vw, 72px) clamp(18px, 5vw, 72px);
  opacity: 0;
  pointer-events: none;
  transform: translateY(20px);
  transition: opacity 600ms ease, transform 600ms ease;
}

.slide.is-active {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

/* ---------- Slide Visuals ---------- */
.visual {
  min-height: 420px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  position: relative;
}

.visual::after {
  content: "";
  position: absolute;
  inset: 0;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-lg);
  pointer-events: none;
}

/* Duo portrait (Slide 1) */
.visual-duo {
  display: grid;
  grid-template-columns: 1fr 1fr;
  box-shadow: var(--shadow-lg);
}

.portrait {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.portrait-itsuka {
  background:
    linear-gradient(145deg, rgba(215, 168, 79, 0.4), transparent 50%),
    linear-gradient(320deg, rgba(69, 104, 90, 0.2), transparent 50%),
    var(--green);
}

.portrait-ukiyo {
  background:
    linear-gradient(145deg, rgba(166, 85, 77, 0.45), transparent 50%),
    linear-gradient(320deg, rgba(63, 96, 125, 0.2), transparent 50%),
    var(--blue);
}

.portrait-label {
  font-family: var(--font-serif);
  font-size: clamp(28px, 4vw, 48px);
  font-weight: 900;
  color: rgba(255, 254, 251, 0.9);
  line-height: 1.6;
  text-align: center;
  letter-spacing: 0.15em;
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.15);
}

/* Author visual (Slides 2, 3) */
.author-visual {
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
}

.author-itsuka {
  background:
    radial-gradient(circle at 30% 30%, rgba(215, 168, 79, 0.35), transparent 60%),
    linear-gradient(145deg, #4d7a68, var(--green));
}

.author-ukiyo {
  background:
    radial-gradient(circle at 70% 30%, rgba(166, 85, 77, 0.3), transparent 60%),
    linear-gradient(145deg, #4d729a, var(--blue));
}

.author-visual-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.author-initial {
  display: grid;
  place-items: center;
  width: min(40vw, 240px);
  aspect-ratio: 1;
  border: 2px solid rgba(255, 254, 251, 0.3);
  border-radius: 50%;
  font-family: var(--font-serif);
  font-size: clamp(72px, 14vw, 160px);
  font-weight: 900;
  color: rgba(255, 254, 251, 0.92);
  text-shadow: 0 4px 24px rgba(0, 0, 0, 0.15);
}

.author-name-vertical {
  font-family: var(--font-serif);
  font-size: clamp(18px, 2.5vw, 28px);
  color: rgba(255, 254, 251, 0.8);
  letter-spacing: 0.6em;
  font-weight: 600;
}

/* Books visual (Slide 4) */
.books-visual {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(16px, 3vw, 32px);
  padding: clamp(28px, 5vw, 64px);
  align-items: center;
  justify-items: center;
  background:
    radial-gradient(circle at 40% 60%, rgba(166, 85, 77, 0.08), transparent 50%),
    linear-gradient(135deg, rgba(63, 96, 125, 0.12), transparent),
    var(--soft);
  box-shadow: var(--shadow-lg);
}

.book-cover {
  display: grid;
  place-items: end start;
  width: 100%;
  max-width: 240px;
  aspect-ratio: 0.68;
  padding: 20px;
  border-radius: var(--radius);
  color: var(--white);
  font-family: var(--font-serif);
  box-shadow: 0 18px 36px rgba(36, 33, 29, 0.2);
  transition: transform var(--transition), box-shadow var(--transition);
}

.book-cover:hover {
  transform: translateY(-4px) rotate(-1deg);
  box-shadow: 0 24px 48px rgba(36, 33, 29, 0.26);
}

.cover-one {
  background: linear-gradient(160deg, var(--red), #dfb76a 90%);
}

.cover-two {
  background: linear-gradient(160deg, var(--blue), var(--green) 90%);
}

.cover-title {
  font-weight: 700;
  font-size: 14px;
  opacity: 0.9;
}

/* ---------- Slide Copy ---------- */
.slide-copy {
  align-self: center;
  max-width: 640px;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--red);
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.35;
}

h1 {
  font-size: clamp(32px, 5vw, 64px);
  font-weight: 900;
}

h2 {
  font-size: clamp(28px, 4vw, 48px);
  font-weight: 700;
}

h3 {
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 700;
}

.slide-copy p:not(.eyebrow),
.section-heading + p,
.section-lead,
.author-panel p,
.book-card p,
.contact p {
  color: var(--muted);
}

.slide-copy p:not(.eyebrow) {
  max-width: 36em;
  margin: 24px 0 0;
  font-size: clamp(15px, 1.6vw, 18px);
}

/* ---------- Slider Controls ---------- */
.slider-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  min-height: 64px;
  padding: 0 18px 20px;
}

.control {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 50%;
  color: var(--ink);
  background: var(--white);
  font-size: 28px;
  line-height: 1;
  cursor: pointer;
  transition: background var(--transition), border-color var(--transition);
}

.control:hover {
  background: var(--soft);
  border-color: var(--muted);
}

.dots {
  display: flex;
  gap: 10px;
}

.dot {
  width: 42px;
  height: 3px;
  border: 0;
  border-radius: 999px;
  background: #c9c0b0;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition);
}

.dot.is-active {
  background: var(--ink);
  transform: scaleY(1.5);
}

.dot:hover:not(.is-active) {
  background: var(--muted);
}

/* ---------- Section Common ---------- */
.authors,
.books,
.contact {
  padding: clamp(72px, 10vw, 128px) clamp(18px, 5vw, 72px);
}

.section-heading {
  max-width: 960px;
  margin: 0 auto 48px;
  text-align: center;
}

.section-lead {
  margin: 18px 0 0;
  font-size: clamp(15px, 1.6vw, 18px);
}

/* ---------- Authors Section ---------- */
.authors {
  background:
    radial-gradient(ellipse at 20% 50%, rgba(69, 104, 90, 0.05) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 50%, rgba(63, 96, 125, 0.05) 0%, transparent 50%),
    var(--paper);
}

.author-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2px;
  max-width: 1200px;
  margin: 0 auto;
  background: var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.author-panel {
  display: grid;
  grid-template-rows: auto 1fr;
  gap: 0;
  background: var(--white);
}

.author-photo {
  width: 100%;
  aspect-ratio: 4 / 3;
  display: grid;
  place-items: center;
  position: relative;
  overflow: hidden;
}

.photo-itsuka {
  background:
    radial-gradient(circle at 40% 40%, rgba(215, 168, 79, 0.3), transparent 60%),
    linear-gradient(145deg, #4d7a68, var(--green));
}

.photo-ukiyo {
  background:
    radial-gradient(circle at 60% 40%, rgba(166, 85, 77, 0.3), transparent 60%),
    linear-gradient(145deg, #4d729a, var(--blue));
}

.photo-initial {
  font-family: var(--font-serif);
  font-size: clamp(32px, 6vw, 64px);
  font-weight: 900;
  color: rgba(255, 254, 251, 0.9);
  text-shadow: 0 2px 16px rgba(0, 0, 0, 0.12);
  letter-spacing: 0.1em;
}

.author-info {
  padding: clamp(24px, 4vw, 40px);
}

.author-panel h3 {
  margin-bottom: 4px;
}

.author-panel p {
  margin: 14px 0 18px;
  font-size: clamp(14px, 1.4vw, 16px);
}

.author-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 22px;
}

.tag {
  display: inline-block;
  padding: 4px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 500;
  color: var(--muted);
  background: var(--paper);
  transition: background var(--transition), color var(--transition);
}

.text-link {
  color: var(--green);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  transition: color var(--transition);
}

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

/* ---------- Books Section ---------- */
.books {
  background:
    radial-gradient(ellipse at 50% 0%, rgba(215, 168, 79, 0.06), transparent 50%),
    var(--white);
}

.book-list {
  display: grid;
  gap: 36px;
  max-width: 1080px;
  margin: 0 auto;
}

.book-card {
  display: grid;
  grid-template-columns: minmax(180px, 280px) minmax(0, 1fr);
  gap: clamp(24px, 5vw, 56px);
  align-items: center;
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--paper);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), transform var(--transition);
}

.book-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.book-image {
  width: 100%;
  aspect-ratio: 0.72;
  padding: 20px;
  display: grid;
  place-items: center;
  border-radius: var(--radius);
  box-shadow: 0 18px 36px rgba(36, 33, 29, 0.14);
  transition: transform var(--transition);
}

.book-card:hover .book-image {
  transform: rotate(-1deg);
}

.book-one {
  background: linear-gradient(160deg, var(--red), #dfb76a 90%);
}

.book-two {
  background: linear-gradient(160deg, var(--blue), var(--green) 90%);
}

.book-placeholder-title {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 14px;
  color: rgba(255, 254, 251, 0.8);
}

.book-body p:not(.eyebrow) {
  margin: 12px 0 18px;
}

.book-author-name {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 500;
  color: var(--muted) !important;
  margin: 8px 0 12px !important;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 48px;
  padding: 12px 24px;
  border: 1px solid var(--green);
  border-radius: var(--radius);
  color: var(--green);
  background: transparent;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
  transition: background var(--transition), color var(--transition), transform 200ms ease;
}

.button:hover {
  background: var(--green);
  color: var(--white);
  transform: translateY(-1px);
}

.button-amazon {
  border-color: var(--yellow);
  color: var(--ink);
  background: linear-gradient(180deg, #f5e6c0, #e8d4a2);
}

.button-amazon:hover {
  background: linear-gradient(180deg, #e8d4a2, #dbc48e);
  color: var(--ink);
}

.icon-amazon {
  flex-shrink: 0;
}

/* ---------- Contact Section ---------- */
.contact {
  background:
    radial-gradient(ellipse at 10% 50%, rgba(215, 168, 79, 0.1), transparent 40%),
    radial-gradient(ellipse at 90% 80%, rgba(69, 104, 90, 0.06), transparent 40%),
    var(--soft);
}

.contact-inner {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(320px, 1fr);
  gap: clamp(32px, 6vw, 72px);
  max-width: 1080px;
  margin: 0 auto;
  align-items: start;
}

.contact-text h2 {
  margin-bottom: 18px;
}

.contact-info {
  margin-top: 36px;
  padding: 20px 24px;
  border-left: 3px solid var(--green);
  background: rgba(69, 104, 90, 0.05);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.contact-label {
  font-weight: 700;
  color: var(--ink) !important;
  margin: 0 !important;
}

.contact-note {
  font-family: var(--font-sans);
  font-size: 13px;
  margin: 6px 0 0 !important;
}

.contact-form {
  display: grid;
  gap: 18px;
  padding: clamp(24px, 4vw, 40px);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--white);
  box-shadow: var(--shadow-md);
}

label {
  display: grid;
  gap: 8px;
  color: var(--muted);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
}

.required {
  color: var(--red);
}

input,
textarea,
select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 12px 14px;
  color: var(--ink);
  background: var(--paper);
  font: inherit;
  font-family: var(--font-sans);
  font-size: 15px;
  transition: border-color var(--transition), box-shadow var(--transition);
}

input:focus,
textarea:focus,
select:focus {
  outline: none;
  border-color: var(--green);
  box-shadow: 0 0 0 3px rgba(69, 104, 90, 0.12);
}

select {
  appearance: none;
  background-image: url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 16 16'%3E%3Cpath fill='%23756f66' d='M4.5 6l3.5 4 3.5-4z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 16px;
  padding-right: 36px;
}

textarea {
  resize: vertical;
}

.button-submit {
  width: 100%;
  border: none;
  color: var(--white);
  background: var(--green);
  font-size: 16px;
  min-height: 52px;
}

.button-submit:hover {
  background: var(--green-dark);
  color: var(--white);
}

/* ---------- Footer ---------- */
.site-footer {
  padding: 36px 24px;
  text-align: center;
  color: rgba(255, 254, 251, 0.6);
  background: var(--ink);
}

.footer-inner {
  max-width: 960px;
  margin: 0 auto;
}

.footer-brand {
  font-size: 18px;
  font-weight: 700;
  color: rgba(255, 254, 251, 0.85);
  margin: 0 0 8px;
  letter-spacing: 0.08em;
}

.site-footer small {
  font-family: var(--font-sans);
  font-size: 12px;
}

/* ---------- Animations ---------- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.section-heading {
  animation: fadeInUp 700ms ease both;
}

/* Intersection Observer で付与するクラス */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 650ms ease, transform 650ms ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- Responsive ---------- */
@media (max-width: 820px) {
  .site-header {
    position: sticky;
    min-height: auto;
  }

  .nav {
    gap: 12px;
    font-size: 13px;
  }

  .hero {
    padding-top: 0;
  }

  .slider {
    min-height: 760px;
  }

  .slide {
    grid-template-columns: 1fr;
    align-content: start;
    gap: 28px;
  }

  .visual {
    min-height: 300px;
  }

  .slide-copy {
    align-self: start;
  }

  .author-grid {
    grid-template-columns: 1fr;
  }

  .book-card {
    grid-template-columns: 1fr;
  }

  .book-image {
    max-width: 260px;
    margin: 0 auto;
  }

  .contact-inner {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 520px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 8px;
  }

  .visual-duo,
  .books-visual {
    grid-template-columns: 1fr;
  }

  .slider {
    min-height: 880px;
  }

  .book-cover {
    max-width: none;
    aspect-ratio: 1.4;
  }

  h1 {
    font-size: clamp(26px, 7vw, 38px);
  }

  .author-photo {
    aspect-ratio: 16 / 9;
  }
}