/* =========================================================
   Base
   ========================================================= */

:root {
  --bg: #f7faf8;
  --bg-soft: #edf4ef;
  --bg-card: #ffffff;

  --text: #203129;
  --text-soft: #5f6f66;
  --text-light: #7a887f;

  --accent: #315d48;
  --accent-dark: #244737;
  --accent-light: #dfece4;

  --border: rgba(34, 72, 53, 0.14);
  --shadow: 0 14px 34px rgba(42, 70, 55, 0.08);

  --radius-lg: 22px;
  --radius-md: 16px;
  --radius-sm: 10px;

  --container: 1080px;
}


/* =========================================================
   Reset
   ========================================================= */

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family:
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    "Helvetica Neue",
    Arial,
    "Noto Sans",
    "Noto Sans JP",
    sans-serif;
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

a {
  color: inherit;
}

p,
h1,
h2,
h3 {
  margin-top: 0;
}

main {
  overflow: hidden;
}


/* =========================================================
   Container
   ========================================================= */

.container {
  width: min(calc(100% - 48px), var(--container));
  margin: 0 auto;
}


/* =========================================================
   Hero
   ========================================================= */

.hero {
  position: relative;
  min-height: 440px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px 24px;
  background:
    linear-gradient(
      135deg,
      #345e4b 0%,
      #5b7d6b 48%,
      #8ba295 100%
    );
  color: #ffffff;
  text-align: center;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(
      circle at top right,
      rgba(255, 255, 255, 0.17),
      transparent 40%
    ),
    linear-gradient(
      to bottom,
      rgba(18, 44, 31, 0.02),
      rgba(18, 44, 31, 0.17)
    );
}

.hero-content {
  position: relative;
  z-index: 1;
  width: min(900px, 100%);
}

.hero h1 {
  margin-bottom: 22px;
  font-size: clamp(2rem, 5vw, 3.7rem);
  font-weight: 650;
  line-height: 1.22;
  letter-spacing: -0.02em;
}

.hero-en {
  margin: 0;
  font-size: clamp(1rem, 2vw, 1.25rem);
  line-height: 1.6;
  letter-spacing: 0.03em;
  opacity: 0.92;
}


/* =========================================================
   Shared sections
   ========================================================= */

.section {
  padding: 88px 0;
}

.section:nth-of-type(even) {
  background: #ffffff;
}

.section-heading {
  margin-bottom: 34px;
}

.section-kicker {
  display: inline-block;
  margin-bottom: 8px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.section-heading h2 {
  margin: 0;
  color: var(--text);
  font-size: clamp(1.7rem, 3vw, 2.35rem);
  font-weight: 650;
  line-height: 1.3;
  letter-spacing: -0.02em;
}


/* =========================================================
   About
   ========================================================= */

.section-about {
  background: var(--bg);
}

.lead {
  max-width: 860px;
}

.lead p {
  margin-bottom: 20px;
}

.lead-ja {
  color: var(--text);
  font-size: 1.08rem;
  line-height: 1.95;
}

.lead-en {
  color: var(--text-soft);
  font-size: 1rem;
  line-height: 1.85;
}


/* =========================================================
   Event information
   ========================================================= */

.section-info {
  background: #ffffff;
}

.info-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
}

.info-card {
  padding: 28px 26px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
}

.info-label {
  margin-bottom: 12px;
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.info-value {
  margin-bottom: 7px;
  color: var(--text);
  font-size: 1.05rem;
  font-weight: 600;
  line-height: 1.55;
}

.info-en {
  color: var(--text-soft);
  font-size: 0.93rem;
  line-height: 1.55;
}


/* =========================================================
   Registration
   ========================================================= */

.section-registration {
  background: var(--bg-soft);
}

.registration-copy {
  max-width: 760px;
}

.registration-copy p {
  margin-bottom: 8px;
}

.registration-copy .en {
  color: var(--text-soft);
}

.registration-link {
  margin: 30px 0 0;
}

.registration-link a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 52px;
  padding: 12px 24px;
  background: var(--accent);
  color: #ffffff;
  border-radius: 999px;
  font-weight: 650;
  line-height: 1.4;
  text-decoration: none;
  box-shadow: 0 8px 20px rgba(49, 93, 72, 0.16);
  transition:
    background-color 0.2s ease,
    transform 0.2s ease,
    box-shadow 0.2s ease;
}

.registration-link a:hover {
  background: var(--accent-dark);
  transform: translateY(-1px);
  box-shadow: 0 11px 25px rgba(49, 93, 72, 0.2);
}

.registration-link a:focus-visible {
  outline: 3px solid rgba(49, 93, 72, 0.28);
  outline-offset: 4px;
}


/* =========================================================
   Program
   ========================================================= */

.section-program {
  background: #ffffff;
}

.program-list {
  margin-top: 10px;
  border-top: 1px solid var(--border);
}

.program-item {
  display: grid;
  grid-template-columns: minmax(230px, 0.85fr) minmax(300px, 1.55fr);
  gap: 52px;
  align-items: start;
  padding: 30px 4px;
  border-bottom: 1px solid var(--border);
}

.program-speaker h3 {
  margin: 0;
  color: var(--text);
  font-size: 1.1rem;
  font-weight: 700;
  line-height: 1.4;
}

.program-affiliation {
  margin: 6px 0 0;
  color: var(--text-soft);
  font-size: 0.93rem;
  line-height: 1.5;
}

.program-title {
  padding-top: 1px;
}

.program-title p {
  margin: 0;
  color: var(--text);
  font-family:
    Georgia,
    "Times New Roman",
    Times,
    serif;
  font-size: 1.06rem;
  font-weight: 500;
  line-height: 1.65;
}

.program-title .program-tba {
  color: var(--text-light);
  font-family:
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    "Helvetica Neue",
    Arial,
    sans-serif;
  font-size: 0.95rem;
  font-weight: 400;
  font-style: italic;
}


/* =========================================================
   Notice box
   ========================================================= */

.notice-box {
  max-width: 820px;
  padding: 26px 28px;
  background: var(--bg-soft);
  border-left: 4px solid var(--accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.notice-box p {
  margin: 0;
}

.notice-en {
  margin-top: 6px !important;
  color: var(--text-soft);
}


/* =========================================================
   Previous workshop
   ========================================================= */

.section-past {
  background: var(--bg);
}

.past-card {
  max-width: 880px;
  padding: 38px 40px;
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.past-label {
  margin-bottom: 10px;
  color: var(--accent);
  font-size: 0.86rem;
  font-weight: 700;
}

.past-card h3 {
  margin-bottom: 6px;
  color: var(--text);
  font-size: clamp(1.35rem, 2.5vw, 1.8rem);
  line-height: 1.4;
}

.past-subtitle {
  margin-bottom: 28px;
  color: var(--text-soft);
  font-size: 1rem;
}

.past-meta {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 30px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}

.past-meta p {
  margin: 0;
  color: var(--text-soft);
  font-size: 0.95rem;
  line-height: 1.7;
}

.past-notice {
  margin-top: 28px;
  padding: 20px 22px;
  background: var(--bg-soft);
  border-radius: var(--radius-sm);
}

.past-notice p {
  margin: 0;
}

.past-notice .en {
  margin-top: 5px;
  color: var(--text-soft);
}


/* =========================================================
   Footer
   ========================================================= */

footer {
  padding: 42px 0 46px;
  background: #243a30;
  color: rgba(255, 255, 255, 0.9);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 30px;
  align-items: flex-start;
}

.footer-title {
  margin: 0;
  font-size: 0.98rem;
  font-weight: 650;
}

.footer-contact {
  margin: 0;
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.88rem;
  line-height: 1.65;
  text-align: right;
}


/* =========================================================
   Responsive: Tablet
   ========================================================= */

@media (max-width: 900px) {

  .section {
    padding: 72px 0;
  }

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

  .program-item {
    grid-template-columns: minmax(200px, 0.9fr) minmax(260px, 1.4fr);
    gap: 32px;
  }

  .past-meta {
    grid-template-columns: 1fr;
    gap: 16px;
  }

}


/* =========================================================
   Responsive: Mobile
   ========================================================= */

@media (max-width: 700px) {

  .container {
    width: min(calc(100% - 32px), var(--container));
  }

  .hero {
    min-height: 360px;
    padding: 64px 20px;
  }

  .hero h1 {
    margin-bottom: 16px;
    font-size: clamp(1.8rem, 8vw, 2.5rem);
  }

  .hero-en {
    font-size: 0.96rem;
  }

  .section {
    padding: 58px 0;
  }

  .section-heading {
    margin-bottom: 28px;
  }

  .section-heading h2 {
    font-size: 1.6rem;
  }

  .lead-ja {
    font-size: 1rem;
  }

  .lead-en {
    font-size: 0.94rem;
  }

  .info-card {
    padding: 24px 22px;
  }

  .registration-link a {
    width: 100%;
    padding: 14px 20px;
    text-align: center;
  }

  .program-item {
    grid-template-columns: 1fr;
    gap: 12px;
    padding: 24px 0;
  }

  .program-speaker h3 {
    font-size: 1.05rem;
  }

  .program-affiliation {
    font-size: 0.9rem;
  }

  .program-title {
    padding-top: 4px;
  }

  .program-title p {
    font-size: 1rem;
    line-height: 1.6;
  }

  .program-title .program-tba {
    font-size: 0.92rem;
  }

  .past-card {
    padding: 28px 24px;
    border-radius: var(--radius-md);
  }

  .footer-inner {
    flex-direction: column;
    gap: 12px;
  }

  .footer-contact {
    text-align: left;
  }

}


/* =========================================================
   Small mobile
   ========================================================= */

@media (max-width: 420px) {

  .container {
    width: min(calc(100% - 24px), var(--container));
  }

  .hero {
    min-height: 330px;
    padding-left: 16px;
    padding-right: 16px;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  .section {
    padding: 50px 0;
  }

  .info-card {
    padding: 22px 18px;
  }

  .past-card {
    padding: 24px 20px;
  }

}


/* =========================================================
   Accessibility
   ========================================================= */

@media (prefers-reduced-motion: reduce) {

  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }

}