:root {
  --ink: #111111;
  --sidebar: #eeeeff;
  --line: #9a9a9a;
  --link: #0000ee;
  --visited: #551a8b;
  --alert: #cc0000;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: #ffffff;
  font-family: "MS PGothic", "ＭＳ Ｐゴシック", "Yu Gothic", Meiryo,
    sans-serif;
  font-size: 15px;
  line-height: 1.6;
}

a:link {
  color: var(--link);
  text-decoration: underline;
}

a:visited {
  color: var(--visited);
}

a:hover,
a:focus-visible {
  color: #ff0000;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 4px;
  z-index: 10;
  padding: 3px 6px;
  border: 1px solid #000000;
  background: #ffffff;
}

.skip-link:focus {
  top: 4px;
}

/* 左右フレーム風。実際の frame 要素は使わず、スマートフォンにも対応する。 */
.site-frame {
  display: grid;
  grid-template-columns: 190px minmax(0, 1fr);
  width: min(1040px, 100%);
  min-height: 100vh;
  margin: 0 auto;
  border-right: 1px solid #b5b5b5;
  border-left: 1px solid #b5b5b5;
  background: #ffffff;
}

.sidebar {
  position: sticky;
  top: 0;
  align-self: start;
  min-height: 100vh;
  padding: 22px 16px;
  border-right: 3px double #777777;
  background: var(--sidebar);
}

.retro-mark {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin: 0 auto 18px;
  text-align: center;
}

.retro-mark img {
  order: 3;
  display: block;
  width: 95px;
  height: 90px;
  margin: 7px auto 0;
  image-rendering: auto;
}

.retro-mark strong,
.retro-mark small {
  display: block;
}

.retro-mark strong {
  order: 1;
  font-family: "MS Mincho", "ＭＳ 明朝", serif;
  font-size: 14px;
  line-height: 1.25;
}

.retro-mark small {
  order: 2;
  margin-top: 4px;
  font-size: 11px;
}

.sidebar ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.sidebar li {
  position: relative;
  margin: 0;
  padding: 8px 0 8px 20px;
}

.sidebar li::before {
  content: "";
  position: absolute;
  top: 14px;
  left: 0;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: #ffb6c1;
}

.sidebar li:nth-child(6n + 2)::before { background: #55e678; }
.sidebar li:nth-child(6n + 3)::before { background: #5ce1e6; }
.sidebar li:nth-child(6n + 4)::before { background: #4997e8; }
.sidebar li:nth-child(6n + 5)::before { background: #1515e8; }
.sidebar li:nth-child(6n + 6)::before { background: #a939ba; }

.sidebar a[aria-current="page"] {
  font-weight: bold;
}

.content-pane {
  min-width: 0;
  background: #ffffff;
}

.site-header,
.main-content,
.site-footer {
  width: min(760px, calc(100% - 38px));
  margin-right: auto;
  margin-left: auto;
}

.site-header {
  padding: 18px 0 6px;
  text-align: center;
}

.header-inner {
  padding-bottom: 12px;
  border-bottom: 2px solid #555555;
}

.language-switch {
  margin: 0 0 7px;
  text-align: right;
  font-size: 12px;
}

.site-kicker {
  margin: 0;
  font-size: 14px;
  font-weight: normal;
}

.site-title {
  margin: 3px 0 5px;
  color: #000000;
  font-family: "MS PGothic", "ＭＳ Ｐゴシック", "Yu Gothic", Meiryo,
    sans-serif;
  font-size: 31px;
  line-height: 1.25;
  letter-spacing: 0.04em;
}

.site-subtitle {
  max-width: 680px;
  margin: 0 auto;
  font-size: 14px;
  font-weight: normal;
}

.main-content {
  padding: 0 0 28px;
}

.welcome {
  display: grid;
  justify-items: center;
  gap: 8px;
  margin: 0 0 25px;
  padding: 7px 10px 13px;
  border-bottom: 1px solid var(--line);
  text-align: center;
}

.latest-heading {
  font-size: 17px;
}

section {
  scroll-margin-top: 8px;
  margin: 0 0 28px;
  padding: 4px 4px 10px;
  border: 0;
  background: transparent;
}

.main-content h2 {
  margin: 0 0 10px;
  padding: 0 0 3px;
  border-bottom: 1px solid var(--line);
  color: #000000;
  font-size: 19px;
  line-height: 1.35;
}

.main-content h3 {
  margin: 16px 0 5px;
  font-size: 15px;
}

.main-content p {
  margin-top: 6px;
  margin-bottom: 10px;
}

.main-content ul {
  margin-top: 6px;
}

.info-table {
  width: 100%;
  border-collapse: collapse;
  background: rgba(255, 255, 255, 0.92);
  font-size: 14px;
}

.info-table th,
.info-table td {
  padding: 6px 8px;
  border: 1px solid #999999;
  vertical-align: top;
}

.info-table th {
  width: 118px;
  background: #eeeeee;
  text-align: left;
}

.speaker-list {
  columns: 2;
  column-gap: 30px;
  padding-left: 20px;
}

.speaker-list li {
  break-inside: avoid;
  margin-bottom: 5px;
}

.speaker-links {
  white-space: nowrap;
  font-size: 12px;
}

.under-construction {
  display: table;
  margin: 3px auto;
  padding: 2px 8px;
  border: 2px ridge #bbbbbb;
  color: var(--alert);
  background: #ffff00;
  font-weight: bold;
  letter-spacing: 0.16em;
  text-align: center;
}

.caution {
  padding: 5px 8px;
  border: 1px dashed #aa6600;
  background: #ffffdd;
}

.payment-note {
  margin: 6px 0 16px;
  padding: 8px 10px;
  color: #444444;
  background: #eeeeee;
}

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

.registration-cta-row {
  display: flex;
  align-items: center;
  gap: 14px;
  margin: 12px 0 16px;
}

.registration-cta-row .registration-cta {
  margin: 0;
}

.mascot-registration {
  width: 88px;
}

.template-download-row {
  display: flex;
  align-items: center;
  gap: 16px;
}

.template-download-list {
  flex: 1;
  margin: 6px 0;
}

.mascot-template {
  width: 104px;
}

.mascot-access {
  width: 96px;
  margin: 16px 0 0 auto;
}

.mascot-program {
  width: 108px;
  margin: 18px auto 0;
}

.mascot-speakers {
  width: 112px;
  margin: 18px 0 0 auto;
}

.origin-image {
  display: block;
  width: min(438px, 100%);
  height: auto;
  margin: 0 auto 20px;
}

.origin-quotes,
.origin-quote {
  margin-left: 1.5em;
}

.origin-disclaimer {
  margin-top: 32px;
  text-align: center;
}

.registration-cta {
  margin: 12px 0 16px;
}

.registration-cta a,
.form-button {
  display: inline-block;
  max-width: 100%;
  min-width: 124px;
  padding: 7px 20px;
  border: 2px outset #e8e8e8;
  border-radius: 0;
  color: #000000;
  background: #d4d0c8;
  box-shadow: none;
  font-family: "MS PGothic", "ＭＳ Ｐゴシック", sans-serif;
  font-size: 15px;
  font-weight: bold;
  letter-spacing: 0;
  text-align: center;
  text-shadow: none;
  text-decoration: none;
}

.registration-cta a:visited,
.form-button:link,
.form-button:visited {
  color: #000000;
  text-decoration: none;
}

.registration-cta a:hover,
.registration-cta a:focus-visible,
.form-button:hover,
.form-button:focus-visible {
  color: #000000;
  background: #e4e4e4;
}

.registration-cta a:active,
.form-button:active {
  border-style: inset;
  background: #c4c0b8;
  transform: none;
}

.form-button-list {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 8px;
  margin: 12px 0 16px;
}

.program-table-wrap {
  max-width: 650px;
  margin: 0 auto 10px;
  border: 0;
  box-shadow: none;
}

.program-table {
  width: 100%;
  min-width: 0;
  border-collapse: collapse;
  border: 1px solid #999999;
  background: rgba(255, 255, 255, 0.92);
  font-size: 14px;
}

.program-table th,
.program-table td {
  padding: 6px 8px;
  border: 0;
  vertical-align: middle;
}

.program-table thead th {
  border-bottom: 1px solid #999999;
  color: #777777;
  background: transparent;
  font-size: 12px;
  font-weight: normal;
  letter-spacing: 0;
  text-align: left;
}

.program-table thead th:nth-child(2),
.program-table thead th:nth-child(3) {
  width: 86px;
  text-align: center;
}

.program-table td:nth-child(2),
.program-table td:nth-child(3) {
  white-space: nowrap;
  text-align: center;
}

.program-table tbody tr:not(.program-day) td:first-child {
  padding-left: 30px;
}

.program-day th {
  padding: 7px 8px;
  border-top: 1px solid #999999;
  border-bottom: 0;
  color: inherit;
  background: #eeeeee;
  font-size: 14px;
  text-align: left;
}

.program-day span {
  display: inline-block;
  font-size: 13px;
  font-weight: bold;
  letter-spacing: 0.04em;
}

.program-session td:first-child {
  font-weight: bold;
}

.program-break {
  color: #666666;
  background: #f7f7f7;
  font-style: italic;
}

.program-social {
  background: #f7f7f7;
}

.program-poster {
  background: #f7f7f7;
  font-weight: normal;
}

.program-logistics {
  color: #444444;
  background: #f7f7f7;
}

.program-time-check td:last-child {
  text-decoration: underline dotted;
  text-underline-offset: 3px;
}

.small {
  font-size: 11px;
}

.contact {
  overflow-wrap: anywhere;
}

.site-footer {
  padding: 9px 0 20px;
  border-top: 2px solid #555555;
  font-size: 11px;
  text-align: center;
}

.site-footer p {
  margin: 2px 0;
}

@media (max-width: 700px) {
  .site-frame {
    display: block;
    border: 0;
  }

  .sidebar {
    position: static;
    min-height: 0;
    padding: 8px 12px 10px;
    border-right: 0;
    border-bottom: 3px double #777777;
  }

  .retro-mark {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-bottom: 7px;
  }

  .retro-mark img {
    width: 57px;
    height: 54px;
    margin: 0;
  }

  .retro-mark small {
    margin: 0;
  }

  .sidebar ul {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 2px 14px;
  }

  .sidebar li {
    padding: 3px 0 3px 14px;
  }

  .sidebar li::before {
    top: 10px;
    width: 8px;
    height: 8px;
  }

  .site-header,
  .main-content,
  .site-footer {
    width: min(100% - 24px, 760px);
  }

  .site-title {
    font-size: 27px;
  }

  .speaker-list {
    columns: 1;
  }

  .registration-cta-row {
    gap: 8px;
  }

  .mascot-registration {
    width: 52px;
  }

  .template-download-row {
    gap: 10px;
  }

  .mascot-template {
    width: 66px;
  }

  .mascot-access {
    width: 58px;
    margin-top: 10px;
  }

  .mascot-program {
    width: 70px;
    margin-top: 12px;
  }

  .mascot-speakers {
    width: 72px;
    margin-top: 12px;
  }
}

@media (max-width: 460px) {
  .template-download-row {
    flex-direction: column;
    align-items: flex-start;
  }

  .template-download-list {
    width: 100%;
    margin: 6px 0 0;
  }

  .mascot-template {
    margin-left: auto;
  }

  body {
    font-size: 14px;
  }

  .site-header {
    text-align: left;
  }

  .site-title {
    font-size: 24px;
  }

  .info-table,
  .info-table tbody,
  .info-table tr,
  .info-table th,
  .info-table td {
    display: block;
    width: 100%;
  }

  .info-table tr {
    margin-bottom: 6px;
  }

  .info-table td {
    border-top: 0;
  }

}

/* 2000年代初頭の個人サイト風：あえて少し賑やかに。 */
body {
  background-color: #dbe8ff;
  background-image:
    radial-gradient(circle at 12px 12px, rgba(255, 255, 255, 0.9) 0 1px, transparent 2px),
    radial-gradient(circle at 40px 31px, rgba(255, 255, 255, 0.72) 0 1px, transparent 2px),
    linear-gradient(135deg, #dff3ff 0%, #fff0fa 47%, #eeefff 100%);
  background-size: 52px 52px, 73px 73px, 100% 100%;
}

.site-frame {
  width: min(1080px, calc(100% - 22px));
  margin-top: 11px;
  margin-bottom: 11px;
  overflow: hidden;
  border: 4px ridge #e7d8ff;
  border-radius: 8px;
  box-shadow: 0 0 0 2px #ffffff, 0 7px 20px rgba(65, 69, 154, 0.35);
}

.sidebar {
  position: relative;
  padding: 17px 13px 24px;
  border-right: 4px ridge #cbb4ff;
  background:
    linear-gradient(90deg, rgba(255, 255, 255, 0.28), transparent 28%, rgba(255, 255, 255, 0.3)),
    linear-gradient(#ebe6ff 0%, #d6edff 48%, #fbe2ff 100%);
}

.sidebar::after {
  content: "★ ･ﾟ:* ✦ *:ﾟ･ ★";
  position: absolute;
  right: 0;
  bottom: 7px;
  left: 0;
  color: #ff4f9b;
  font-size: 10px;
  letter-spacing: 1px;
  text-align: center;
  text-shadow: 1px 1px #ffffff;
}

.retro-mark {
  margin-bottom: 13px;
  padding: 8px 4px 6px;
  border: 3px ridge #ffffff;
  border-radius: 8px;
  background: linear-gradient(#ffffff 0%, #fff9cc 100%);
  box-shadow: 0 2px 0 #b7a8e8;
}

.retro-mark img {
  filter: drop-shadow(2px 2px 0 rgba(133, 90, 197, 0.22));
}

.retro-mark strong {
  color: #673098;
  font-family: "MS PGothic", "ＭＳ Ｐゴシック", sans-serif;
  font-size: 15px;
  font-weight: bold;
  text-shadow: 1px 1px #ffffff;
}

.retro-mark small {
  color: #0082a5;
  font-weight: bold;
}

.sidebar li {
  margin: 0 0 3px;
  padding: 0;
}

.sidebar li::before {
  content: "✦";
  top: 7px;
  left: 6px;
  width: auto;
  height: auto;
  border-radius: 0;
  background: transparent;
  color: #ff4b9a;
  font-size: 11px;
  line-height: 1;
  text-shadow: 1px 1px #ffffff;
}

.sidebar li:nth-child(6n + 2)::before { background: transparent; color: #34b859; }
.sidebar li:nth-child(6n + 3)::before { background: transparent; color: #00aeba; }
.sidebar li:nth-child(6n + 4)::before { background: transparent; color: #317bdd; }
.sidebar li:nth-child(6n + 5)::before { background: transparent; color: #7260d9; }
.sidebar li:nth-child(6n + 6)::before { background: transparent; color: #ba4ac4; }

.sidebar a {
  display: block;
  padding: 4px 5px 4px 20px;
  border: 1px solid transparent;
  border-radius: 5px;
  color: #51219a;
  font-weight: bold;
  line-height: 1.28;
  text-decoration: none;
  text-shadow: 1px 1px #ffffff;
}

.sidebar a:visited { color: #51219a; }

.sidebar a:hover,
.sidebar a:focus-visible,
.sidebar a[aria-current="page"] {
  border-color: #cc8ceb;
  color: #c50062;
  background: linear-gradient(#ffffff, #ffe4f2);
  box-shadow: inset 0 1px #ffffff, 1px 1px 0 rgba(140, 86, 180, 0.34);
}

.content-pane {
  background:
    linear-gradient(rgba(255, 255, 255, 0.96), rgba(255, 255, 255, 0.96)),
    repeating-linear-gradient(0deg, transparent 0 25px, rgba(157, 194, 255, 0.12) 26px);
}

.site-header {
  padding-top: 14px;
}

.header-inner {
  position: relative;
  padding: 13px 17px 15px;
  border: 3px ridge #d6c2ff;
  border-radius: 7px;
  background:
    linear-gradient(90deg, rgba(255, 223, 246, 0.78), rgba(255, 255, 255, 0.9) 27%, rgba(220, 251, 255, 0.75)),
    #ffffff;
  box-shadow: 0 3px 0 #e8dcff;
}

.header-inner::before,
.header-inner::after {
  position: absolute;
  top: 6px;
  color: #ff6bab;
  font-size: 17px;
  content: "✦";
}

.header-inner::before { left: 10px; }
.header-inner::after { right: 10px; }

.language-switch {
  position: relative;
  z-index: 1;
  margin-bottom: 4px;
}

.language-switch a {
  display: inline-block;
  padding: 1px 7px;
  border: 1px solid #af70d8;
  border-radius: 10px;
  color: #69258d;
  background: #ffffff;
  font-weight: bold;
  text-decoration: none;
}

.site-kicker {
  color: #a12a72;
  font-weight: bold;
  letter-spacing: 0.07em;
  text-shadow: 1px 1px #ffffff;
}

.site-title {
  color: #f22381;
  background: linear-gradient(90deg, #ef2787, #8d46d3 31%, #0085cb 53%, #8d46d3 75%, #ef2787);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  font-family: "Arial Black", "MS PGothic", "ＭＳ Ｐゴシック", sans-serif;
  font-size: 34px;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-shadow: 2px 2px 0 rgba(255, 255, 255, 0.8), 3px 3px 0 rgba(138, 76, 194, 0.22);
}

.site-subtitle {
  color: #174b98;
  font-weight: bold;
  text-shadow: 1px 1px #ffffff;
}

.main-content {
  padding-top: 8px;
}

.welcome {
  gap: 5px;
  margin-bottom: 20px;
  padding: 8px 12px 10px;
  border: 3px ridge #ffe98c;
  border-radius: 6px;
  background: linear-gradient(90deg, #fff8bb, #fffdf0 45%, #ffdef0);
  box-shadow: 0 2px 0 rgba(220, 168, 42, 0.3);
}

.latest-heading {
  color: #e60068;
  font-size: 18px;
  letter-spacing: 0.05em;
  text-shadow: 1px 1px #ffffff, 2px 2px #ffd7eb;
}

.latest-heading::before,
.latest-heading::after {
  content: "✦";
  color: #ffac00;
  padding: 0 5px;
}

.latest-item-new {
  display: block;
  max-width: 100%;
  color: #a60055;
  font-weight: bold;
  justify-self: stretch;
  text-align: center;
  overflow-wrap: anywhere;
}

.latest-item-new > span {
  white-space: normal;
}

section {
  margin-bottom: 22px;
  padding: 12px 14px 14px;
  border: 2px solid #d9cdf7;
  border-radius: 7px;
  background: rgba(255, 255, 255, 0.88);
  box-shadow: 2px 2px 0 rgba(159, 128, 204, 0.18);
}

.main-content h2 {
  margin: -2px -4px 12px;
  padding: 5px 9px 6px;
  border: 2px ridge #f8d0f0;
  border-radius: 5px;
  color: #652192;
  background: linear-gradient(90deg, #ffd6ee, #f7eaff 48%, #d9f7ff);
  font-size: 20px;
  letter-spacing: 0.05em;
  text-shadow: 1px 1px #ffffff;
}

.main-content h3 {
  padding-left: 8px;
  border-left: 5px solid #ff80bb;
  color: #263e9e;
  font-size: 16px;
  text-shadow: 1px 1px #ffffff;
}

.info-table {
  border: 2px ridge #d2c6e8;
  box-shadow: 1px 1px 0 rgba(137, 111, 174, 0.25);
}

.info-table th,
.info-table td {
  border-color: #d7d0e5;
}

.info-table th {
  color: #5f318e;
  background: linear-gradient(#f5eaff, #e8f7ff);
  font-weight: bold;
}

.caution {
  border: 2px ridge #ffd459;
  border-radius: 5px;
  background: linear-gradient(#fff9ae, #fff5dd);
  box-shadow: 1px 1px 0 rgba(199, 146, 0, 0.25);
}

.payment-note {
  border: 2px ridge #d3ceea;
  border-radius: 5px;
  color: #514c69;
  background: linear-gradient(90deg, #f6f2ff, #e8faff);
  box-shadow: 1px 1px 0 rgba(113, 105, 146, 0.2);
}

.registration-cta a,
.form-button {
  border: 3px outset #ffe9ff;
  border-radius: 7px;
  color: #ffffff;
  background: linear-gradient(#ff87c4 0%, #f14295 48%, #b92072 100%);
  box-shadow: 2px 2px 0 #7d3a9d, inset 1px 1px rgba(255, 255, 255, 0.8);
  font-size: 16px;
  letter-spacing: 0.04em;
  text-shadow: 1px 1px #8d1a64;
}

.registration-cta a:visited,
.form-button:link,
.form-button:visited {
  color: #ffffff;
}

.registration-cta a:hover,
.registration-cta a:focus-visible,
.form-button:hover,
.form-button:focus-visible {
  color: #ffffff;
  background: linear-gradient(#ffa9d5 0%, #ff5aa8 48%, #cf2b8b 100%);
  transform: translate(1px, 1px);
  box-shadow: 1px 1px 0 #7d3a9d, inset 1px 1px rgba(255, 255, 255, 0.8);
}

.registration-cta a:active,
.form-button:active {
  border-style: inset;
  color: #ffffff;
  background: #c3287f;
}

.program-table-wrap {
  border: 3px ridge #d8cff1;
  border-radius: 6px;
  box-shadow: 2px 2px 0 rgba(127, 93, 174, 0.2);
}

.program-table {
  border: 0;
  background: #ffffff;
}

.program-table thead th {
  border-bottom: 2px solid #d2c6e9;
  color: #61358f;
  background: linear-gradient(#f7ecff, #e7f7ff);
  font-weight: bold;
}

.program-day th {
  color: #653496;
  background: linear-gradient(90deg, #f4d9ff, #d9f7ff);
  font-weight: bold;
}

.program-break,
.program-social,
.program-poster,
.program-logistics {
  background: #f6f3fb;
}

.program-break { color: #686078; }

.origin-image {
  padding: 6px;
  border: 3px ridge #ffd7ed;
  border-radius: 6px;
  background: #ffffff;
  box-shadow: 2px 2px 0 rgba(185, 104, 162, 0.24);
}

.origin-disclaimer {
  color: #925091;
  font-weight: bold;
}

.site-footer {
  position: relative;
  margin-top: 4px;
  padding: 14px 0 20px;
  border-top: 3px ridge #d7c7ff;
  color: #5d4c75;
  background: linear-gradient(90deg, #f0eaff, #e8faff, #ffe8f5);
}

.site-footer::before {
  content: "☆ ｡･:*:･ﾟ’★,｡･:*:♪･ﾟ’☆";
  display: block;
  margin-bottom: 3px;
  color: #df5a9b;
  font-size: 10px;
  letter-spacing: 2px;
}

@media (max-width: 700px) {
  .site-frame {
    width: 100%;
    margin: 0;
    border-right: 0;
    border-left: 0;
    border-radius: 0;
  }

  .sidebar {
    padding: 8px 10px 16px;
    border-right: 0;
    border-bottom: 4px ridge #cbb4ff;
  }

  .sidebar::after { display: none; }

  .retro-mark {
    padding: 3px 7px;
  }

  .sidebar li { margin: 0; }

  .sidebar a {
    padding: 3px 3px 3px 14px;
    font-size: 13px;
  }

  .sidebar li::before {
    top: 8px;
    left: 3px;
    font-size: 8px;
  }

  .header-inner {
    padding: 10px 13px 12px;
  }

  .site-title { font-size: 29px; }

  section { padding: 10px 10px 12px; }
}

@media (max-width: 460px) {
  .site-title { font-size: 25px; }
  .header-inner::before,
  .header-inner::after { display: none; }
  .main-content h2 { font-size: 18px; }
}