/* ==========================================================
   HPLS&A 2026 top page
   Prepared as static HTML/CSS package for BrandConcept.
   Assets:
   - assets/images/hplsa2026_logo.png
   - assets/images/okazaki_panorama.png

   Note:
   The hero photo is intentionally displayed without a blue color overlay.
   Only a subtle dark text-shadow is used for readability.
   ========================================================== */

:root {
  --color-bg: #ffffff;
  --color-text: #1d2633;
  --color-muted: #5d6978;
  --color-primary: #123c69;
  --color-primary-dark: #0b2849;
  --color-accent: #00b8e6;
  --color-section: #f5f8fc;
  --color-border: #d9e0ea;
  --shadow: 0 16px 40px rgba(18, 60, 105, 0.14);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.65;
}

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

a {
  color: var(--color-primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

/* Header */

.site-header {
  background: #fff;
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 20;
}

.header-inner {
  min-height: 92px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.site-logo {
  display: inline-flex;
  align-items: center;
  flex: 0 0 auto;
}

.site-logo img {
  display: block;
  width: 190px;
  height: auto;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 10px 18px;
  font-size: 0.92rem;
  letter-spacing: 0.02em;
}

.site-nav a {
  color: var(--color-primary-dark);
  font-weight: 700;
}

.nav-toggle {
  display: none;
}

/* Hero */

.hero {
  min-height: 600px;
  display: flex;
  align-items: center;
  background-image: url("../images/okazaki_panorama.png");
  background-position: center center;
  background-size: cover;
  background-repeat: no-repeat;
  color: #fff;
}

.hero-content {
  padding: 90px 0;
}

.eyebrow {
  margin: 0 0 14px;
  font-size: clamp(1rem, 2vw, 1.55rem);
  color: #fff;
  font-weight: 700;
  text-shadow: 0 3px 8px rgba(0,0,0,0.72);
}

h1 {
  margin: 0;
  max-width: 960px;
  font-size: clamp(2.3rem, 5vw, 4.6rem);
  line-height: 1.08;
  letter-spacing: -0.045em;
  color: #fff;
  text-shadow: 0 3px 10px rgba(0,0,0,0.72);
}

.hero-date {
  margin: 28px 0 4px;
  font-size: clamp(1.35rem, 2.5vw, 2rem);
  font-weight: 700;
  text-shadow: 0 3px 8px rgba(0,0,0,0.72);
}

.hero-location {
  margin: 0 0 32px;
  color: #fff;
  font-size: clamp(1.05rem, 2vw, 1.45rem);
  font-weight: 700;
  text-shadow: 0 3px 8px rgba(0,0,0,0.72);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 52px;
  padding: 0 28px;
  border-radius: 6px;
  font-weight: 700;
  border: 2px solid transparent;
  transition: transform .16s ease, box-shadow .16s ease, background .16s ease;
}

.button.primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 8px 22px rgba(0,0,0,0.22);
}

.button.secondary {
  background: rgba(255,255,255,0.12);
  border-color: rgba(255,255,255,0.86);
  color: #fff;
}

.button:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

/* Sections */

.section {
  padding: 76px 0;
}

.section-muted {
  background: var(--color-section);
}

.section-label {
  margin: 0 0 8px;
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-accent);
}

h2 {
  margin: 0 0 18px;
  font-size: clamp(1.6rem, 3vw, 2.25rem);
  color: var(--color-primary-dark);
  line-height: 1.2;
}

h3 {
  margin: 0 0 12px;
  color: var(--color-primary-dark);
  font-size: 1.35rem;
}

p {
  margin: 0 0 18px;
}

.subheading {
  margin-top: 38px;
}

.narrow {
  max-width: 840px;
}

.two-column {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 390px;
  gap: 48px;
  align-items: start;
}

.card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: 16px;
  padding: 30px;
  box-shadow: var(--shadow);
}

.key-dates ul,
.plain-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.key-dates li {
  padding: 15px 0;
  border-top: 1px solid var(--color-border);
}

.key-dates li:first-child {
  border-top: 0;
}

.key-dates span {
  display: block;
  color: var(--color-muted);
  font-size: 0.95rem;
}

.key-dates strong {
  display: block;
  color: var(--color-text);
  font-size: 1.08rem;
}

.link-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-top: 28px;
}

.link-grid a {
  display: block;
  padding: 22px;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: 14px;
  font-weight: 700;
  box-shadow: 0 8px 22px rgba(18,60,105,0.07);
}

.link-grid a span {
  display: block;
}

.link-grid a small {
  display: block;
  color: var(--color-muted);
  margin-top: 4px;
  font-weight: 400;
}

.committee-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.committee-card {
  background: #fff;
  border-left: 5px solid var(--color-accent);
  border-radius: 12px;
  padding: 26px;
  box-shadow: 0 8px 24px rgba(18,60,105,0.08);
}

.committee-card span {
  color: var(--color-muted);
}

.plain-list li {
  padding: 11px 0;
  border-bottom: 1px solid var(--color-border);
}

.contact-section {
  text-align: center;
}

.contact-email a {
  font-size: 1.25rem;
  font-weight: 700;
}

/* Footer */

.site-footer {
  padding: 28px 0;
  background: var(--color-primary-dark);
  color: #dfeaf7;
  font-size: 0.92rem;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.site-footer p {
  margin: 0;
}

/* Responsive */

@media (max-width: 960px) {
  .header-inner {
    min-height: auto;
    align-items: flex-start;
    flex-direction: column;
    padding: 18px 0;
  }

  .site-logo img {
    width: 160px;
  }

  .site-nav {
    justify-content: flex-start;
  }

  .hero {
    min-height: 520px;
  }

  .two-column {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 700px) {
  .container {
    width: min(100% - 28px, 1180px);
  }

  .site-nav {
    gap: 8px 12px;
    font-size: 0.82rem;
  }

  .hero {
    min-height: 470px;
    background-position: center center;
  }

  .hero-content {
    padding: 56px 0;
  }

  .hero-actions {
    flex-direction: column;
    align-items: flex-start;
  }

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

  .section {
    padding: 56px 0;
  }
}