:root{
  --bg:#0b1220;
  --card:#111a2e;
  --text:#e9eefc;
  --muted:#a9b4d0;
  --copyright:#666666;
  --accent:#5fe1ff;
  --line: rgba(255,255,255,.12);
  --shadow: 0 18px 50px rgba(0,0,0,.35);
  --radius: 18px;
  --max: 1100px;
}

*{ box-sizing:border-box; /*border:2px solid red;*/} /*for debug*/
html,body{ margin:0; padding:0; }
body{
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Hiragino Sans", "Noto Sans JP", sans-serif;
  background: radial-gradient(1200px 600px at 70% -10%, rgba(95,225,255,.18), transparent 60%),
              radial-gradient(900px 500px at 0% 10%, rgba(120,120,255,.14), transparent 55%),
              var(--bg);
  color: var(--text);
  line-height: 1.65;
}

.desktop-only { display: block; }
.mobile-only { display: none; }

a{ color: inherit; text-decoration: none; }
a:hover{ text-decoration: none; color:#e9eefcbe;}

.container{ max-width: var(--max); margin: 0 auto; padding: 20px; min-height:70vh;}

.nav{
  position: sticky; top: 0; z-index: 10;
  backdrop-filter: blur(10px);
  background: rgba(11,18,32,.6);
  border-bottom: 1px solid var(--line);
  box-shadow:0 1px 4px 0 rgba(0,0,0,0.3);
}
.nav-inner{ display:flex; align-items:center; justify-content:space-between; gap:12px; padding: 14px 20px; max-width: var(--max); margin:0 auto; }
@media(max-width:370){
  .nav-top{
    height: 20px;
  }
}
.nav-top{ display:flex; align-items:center; justify-content:space-between; gap:5px;  max-width: var(--max); margin:0 auto;}
.brand{ display:flex; flex-direction:column; }
.brand b{ font-size: 15px; letter-spacing:.3px; white-space: nowrap;}
.brand span{ font-size: 12px; color: var(--muted); }

.nav-links{ display:flex; gap:14px; flex-wrap: wrap; }
.nav-links a{

  margin: 0px 6px 0px 6px;
  padding: 10px 2px 10px 2px;
  border-bottom: 1px solid transparent;
}
.nav-links a:hover{ border-color: var(--text); text-decoration:none; }

.hero{
  height: 105vh;
  background-image: url("../images/top1.jpg");
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;

  margin-top: -95px;

  display: flex;
  align-items: center;
  text-align:center;
  color:white;
  position: relative;
}
.here::before {
  content: "";
  position:absolute;
  inset:0;
  background: rgba(0,0,0,0.4);
}
.hero-content {
  position:relative;
  z-index: 1;
  padding: 28px; /*width: max-content;*/
}
.hero-overlay{
  position:absolute; inset:0;
  z-index: 1;
  background: linear-gradient(
    to bottom,
    rgba(0,0,0,0.6),
    rgba(0,0,0,0.3),
    rgba(0,0,0,0.1)
  );
  justify-content: center;
  display:flex;
  flex-direction: column;
  align-items:center;
}
.h1-hero{ font-size: clamp(20px,2.5vw + 0.5rem,50px);
  font-weight: 500;
  margin: 8px 0 10px 0;
  line-height:1.4;
  letter-spacing: 0.05em;
  text-shadow: 0 1px 2px rgba(0,0,0,0.4);
}

.lead{ color: var(--muted); margin: 0 0 15px;
  font-weight: 400;
  font-size: clamp(14px,1.8vw + 0.5rem,20px);
  white-space: normal;
  text-shadow: 0 1px 1px rgba(0,0,0,0.4);
}
.hero-aboutus-btn{
  color : rgb(219, 232, 244);
  font-size : clamp(14px,3vw,21px);
  font-weight : 500;
  text-shadow: 0 1px 1px rgba(0,0,0,0.4);
  align-items: bottom;
}

.after-hero{
  margin-top: 18px;
}

.scroll-hint{
  position: absolute;
  left: 28px;
  bottom: 18px;
  color: rgba(233,238,252,.8);
  font-size: 12px;
  letter-spacing: .2em;
  text-transform: uppercase;
  opacity: .9;
}

.nav{ position: sticky; top: 0; z-index: 10; }


.btns{ display:flex; gap:10px; flex-wrap:wrap; }
.btn{
  display:inline-flex; align-items:center; justify-content:center;
  padding: 10px 14px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: rgba(17,26,46,.6);
  text-decoration:none;
}
.btn.primary{
  border-color: rgba(95,225,255,.35);
  background: rgba(95,225,255,.10);
}
.btn:hover{ text-decoration:none; transform: translateY(-1px); }

.grid{ display:grid; gap: 14px; }
.grid.two{ grid-template-columns: 1.2fr .8fr; }
@media (max-width: 900px){
  .grid.two{ grid-template-columns: 1fr; }
  .hero img{ height: 460px; }
}

.card{
  border: 1px solid var(--line);
  background: rgba(17,26,46,.55);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow:hidden;
}
.card-pad{ padding: 18px; }
.h2{ font-size: 18px; margin: 0 0 8px; }
.muted{ color: var(--muted); }

.news-list{ display:grid; gap: 12px; }
.news-item{
  display:grid;
  grid-template-columns: 140px 1fr;
  gap: 12px;
  padding: 12px;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: rgba(11,18,32,.35);
}
.news-item img{
  width: 140px; height: 90px; object-fit: cover; border-radius: 12px;
  border: 1px solid var(--line);
}
.news-meta{ font-size: 12px; color: var(--muted); }
.news-title{ font-weight: 700; margin: 2px 0 6px; }
.news-lead{ color: var(--muted); margin:0; font-size:14px; }

/*=============================
  about.html
=============================*/
.hero-about{
  height: 105vh;
  background-image: url("../images/simulation_nocompression.jpg");
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;

  margin-top: -95px;

  display: flex;
  align-items: center;
  text-align:center;
  color:rgb(246, 246, 246);
  position: relative;
}
.here-about::before {
  content: "";
  position:absolute;
  inset:0;
  background: rgba(0,0,0,0.4);
}
.hero-content-about {
  position:relative;
  z-index: 1;
  padding: 28px; /*width: max-content;*/
}
.hero-overlay-about{
  position:absolute; inset:0;
  z-index: 1;
  background: #0e0a06bf;
  justify-content: center;
  display:flex;
  flex-direction: column;
  align-items:bottom;
}
.h1-about{
  margin: 10% 0 0 0;
  align-items: bottom;
  font-size: clamp(25px,4.0vw + 0.7rem,50px);
  font-family: Cambria, Cochin, Georgia, Times, 'Times New Roman', serif;
  font-weight:600;
  text-shadow: 0 1px 2px rgba(0,0,0,0.5);
}
.project-explain{
  height: 105vh;
  background-image: url("../images/creating-hull.jpg");
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;

  display: flex;
  align-items: center;
  text-align:center;
  position: relative;
  box-shadow: 0 1px 3px 0 rgba(0,0,0,0.7);
}
.project-explain::before {
  content: "";
  position:absolute;
  inset:0;
  background: rgba(0,0,0,0.4);
}
.project-explain-content{
  position:relative;
  z-index: 1;
  padding: 28px; /*width: max-content;*/
}
.project-explain-overlay{
  position:absolute; inset:0;
  z-index: 1;
  background: #0e0a069d;
  justify-content: top;
  display:flex;
  flex-direction: column;
  align-items:center;
}
.project-explain-h1{
  margin: 10% 0 0 0;
  font-size: clamp(25px,4.0vw + 0.7rem,50px);
  font-family: "Noto Sans JP",sans-serif;
  font-weight:600;
  text-shadow: 0 1px 2px rgba(0,0,0,0.5);
  color:rgb(247, 247, 247);
  letter-spacing: 0.01em;
}
.project-explain-lead{
  font-size:clamp(16px,3vw,20px);
  font-weight:400;
  color:#cdcdcd;
  margin-top:30px;
  max-width: var(--max);
  text-wrap: pretty;
  letter-spacing: 0.05em;
  text-shadow:0 1px 1px rgba(0,0,0,0.4);
}

.attempt-now{
  margin-top: 50px;
  font-size:clamp(23px,4.0vw + 0.7rem, 30px);
  font-weight: 500;
  color:rgb(228, 228, 228);
  text-shadow: 0 1px 1px rgba(0,0,0,0.5);
}
.attempt-now-list{
  margin-top:10px;
  line-height: 5px;
  display:flex;
  flex-direction: column;
  font-size:clamp(16px,3vw,18px);
  font-weight:400;
  text-shadow: 0 1px 1px rgba(0,0,0,0.5);
}
.about-background{
  width:100%;
  background-color: rgb(241, 241, 241);
  min-height:70vh;
}
.about-container{
  max-width: var(--max);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  color:#333333;
  font-size:30px;
  padding-top:30px;

}
.whats-mbd-title{
  margin-top: 20px;
  margin-left: 3vw;
  padding: 5px 0 5px 10px;
  border-left: 5px solid #2563eb;
  font-weight:700;
}
.mbd-lead{
  margin: 10px auto 30px auto;
  width:90%;
  font-size:clamp(16px,3vw,18px);
}
/*========================
  footer
========================*/
.footer{
  width: 100%;
  height: auto;
  background-color: #0d0e17;
  border-top: 1px solid var(--copyright);
  padding-top: 10px;
}
.footer-inner{
  display:flex;
  flex-direction: row;
  flex-wrap: wrap;
  max-width: var(--max);
  margin:auto;
}
.footer-container{
  padding: 10px 0 5vh 5vw;
}
.footer-navi-heading{
  font-weight:600;
  font-size:clamp(16px,3vw,18px);
  color:#cccccc;
  margin:0 0 3px 0;
}
.footer-navi{
  font-size:clamp(14.5px,2vw,16px);
  display:flex;
  flex-direction: column;
  color:var(--muted);
  gap:5px;
  a{
    display:inline-block;
    width: fit-content;
  }
}
.footer-navi a:hover{
  text-decoration: none;
  color:#dddddd
}
.footer-copyright{
  padding: 15px 0 10px 0;
  color: var(--copyright);
  font-size: clamp(7px,2vw,12px);
  border-top: 1px solid rgba(66,66,66,0.7);
  margin:auto;
  text-align: center;
  width: 95vw;
}
@media(max-width:600px){
  .footer-container{
    width: 50%;
  }
  .footer-navi{
    gap:10px;
  }
}
@media(min-width:601px){
  .footer-container{
    flex:1;
  }
}


.article h1{ font-size: 28px; margin: 0 0 10px; }
.article .meta{ color: var(--muted); font-size: 13px; margin-bottom: 14px; }
.article img{ width:100%; border-radius: 16px; border: 1px solid var(--line); }
.article .body{ margin-top: 14px; color: #d7def6; }
.article .body h2{ margin-top: 22px; }
.article .body a{ color: var(--accent); }

/* =========================================
   Student Voices
========================================= */
.student-voices {
  padding: 100px 24px;
  position: relative;

  background-image:
    linear-gradient(rgba(4, 30, 70, 0.35), rgba(3, 18, 40, 0.6)),
    url("../images/ocean-dark.jpg");
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}

.student-voices::before {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(255,255,255,0.04);
  pointer-events: none;
}

/* 中央だけさらに浮かせる */
.student-voices-inner {
  position: relative;
  z-index: 1;

  max-width: 1240px;
  margin: 0 auto;

  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(10px);

  padding: 48px;
  border-radius: 20px;
}

.student-voices-label {
  margin: 0 0 20px;
  text-align: center;
  color: white;
  text-shadow: 1px 1px 2px rgba(0,0,0,0.6);
  font-size: 30px;
  letter-spacing: 0.08em;
  font-weight: 600;
}

.student-voices-intro {
  margin: 0 auto 56px;
  max-width: 980px;
  text-align: center;
  color: #fffffff7;
  font-size: 17px;
  line-height: 1.9;
  text-shadow: 0 1px 1px rgba(0,0,0,0.6);
}

.voices-slider {
  display: grid;
  grid-template-columns: 72px 1fr 72px;
  gap: 16px;
  align-items: center;
}

.voices-viewport {
  overflow: hidden;
  width: 100%;
}

.voices-track {
  display: flex;
  transition: transform 0.45s ease;
  will-change: transform;
}

.voice-slide {
  min-width: 100%;
  box-sizing: border-box;
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 32px;
  align-items: center;
  padding: 20px 8px;
}

.voice-photo img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  display: block;
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.08);
}

.voice-body {
  max-width: 760px;
}

.voice-title {
  margin: 0 5px 22px 5px;
  color: rgba(255, 255, 255, 0.825);
  font-size: clamp(24px, 5vw, 50px);
  line-height: 1.2;
  font-weight: 500;
  text-shadow: 0 1px 2px rgba(0,0,0,0.5);
  /*text-shadow:1px 1.2px 0 rgba(255,255,255,0.5), -0.5px -0.5px 0 rgba(0,0,0,0.5)*/
}

.voice-subtitle {
  margin: 0 0 6px;
  color: #fffff77c;
  font-size: 20px;
  line-height: 1.6;
}

.voice-name {
  margin: 0 0 24px;
  color: #fffff792;
  font-size: 18px;
  font-weight: 500;
  line-height: 1.6;
}

.voice-text {
  margin: 0 0 34px;
  color: #222;
  font-size: 17px;
  line-height: 2;
  letter-spacing: 0.04em
}

.voice-more-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 220px;
  height: 64px;
  padding: 0 28px;
  border: 2px solid #c5c8cd;
  border-radius: 999px;
  color: #c5c8cd;
  text-decoration: none;
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 0.08em;
  transition: background-color 0.25s ease, color 0.25s ease;
}
/* Hamburger Menu Styles */
.hamburger {
  display: none;
  flex-direction: column;
  background: none;
  border: none;
  cursor: pointer;
  padding: 10px;
}

.hamburger span {
  width: 25px;
  height: 3px;
  background: var(--text);
  margin: 3px 0;
  transition: 0.3s;
}

/* Responsive Design */
@media (max-width: 851px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(11,18,32,.9);
    flex-direction: column;
    padding: 20px;
    border-bottom: 1px solid var(--line);
  }

  .nav-links.active {
    display: flex;
  }

  .hamburger {
    display: flex;
  }

  .news-item {
    grid-template-columns: 1fr;
  }

  .news-item img {
    width: 100%;
    height: auto;
    max-height: 200px;
  }

  .container {
    padding: 10px;
  }
  .nav-inner {
    padding: 10px 20px;
  }

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

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

@media(max-width:370px){
.nav-inner{
  padding: 10px 10px;
}
.nav-top{
  width:100px;
  height:auto;
}
}


.voice-more-btn::after {
  content: "›";
  margin-left: 16px;
  font-size: 32px;
  line-height: 1;
}

.voice-more-btn:hover {
  background: #224b9b;
  color: #fff;
}

.voices-arrow {
  border: none;
  background: transparent;
  color: #111;
  font-size: 84px;
  line-height: 1;
  cursor: pointer;
  padding: 0;
  width: 72px;
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.voices-arrow:hover {
  opacity: 0.65;
}

.voices-dots {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 12px;
  margin-top: 30px;
}

.voices-dots button {
  width: 12px;
  height: 12px;
  border: none;
  border-radius: 50%;
  background: #b9bfd0;
  cursor: pointer;
  padding: 0;
}

.voices-dots button.active {
  background: #224b9b;
}

@media (max-width: 980px) {
  .voices-slider {
    grid-template-columns: 48px 1fr 48px;
    gap: 8px;
  }

  .voice-slide {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .voice-body {
    max-width: 100%;
  }

  .voice-title {
    font-size: clamp(30px, 8vw, 48px);
  }

  .voices-arrow {
    width: 48px;
    height: 48px;
    font-size: 48px;
  }
}

@media (max-width: 640px) {
  .student-voices {
    padding: 72px 16px;
  }

  .student-voices-intro {
    font-size: 15px;
    margin-bottom: 36px;
  }

  .voice-subtitle,
  .voice-name,
  .voice-text {
    font-size: 15px;
  }

  .voice-more-btn {
    min-width: 180px;
    height: 56px;
    font-size: 18px;
  }

  .desktop-only { display: none; }
  .mobile-only { display: flex; }

  .voices-slider {
    display: flex;
    flex-direction: column;
    gap: 16px;
  }

  .voices-viewport {
    order: 1;
  }

  .arrows-container {
    order: 2;
    display: none;
  }
}

.sponsor-grid.single{
  grid-template-columns: 1fr;
  max-width: 420px;
  margin: 0 auto;
}

.sponsor-card.large{
  min-height: 220px;
}

.sponsor-card.large img{
  max-width: 200px;
  max-height: 100px;
}