:root {
  --green: #2d6a5f;
  --green-dark: #1f5148;
  --green-pale: #edf4f2;
  --ink: #333333;
  --muted: #68706e;
  --line: #d8dddb;
  --paper: #faf8f5;
  --white: #ffffff;
  --radius: 14px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Yu Gothic",
    "YuGothic", "Meiryo", sans-serif;
  font-size: 15px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
}

button,
input,
textarea {
  font: inherit;
}

.site-shell {
  width: min(100%, 800px);
  min-height: 100vh;
  margin: 0 auto;
  padding: 0 18px 24px;
  background: var(--white);
}

.site-header {
  display: flex;
  align-items: center;
  min-height: 84px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  color: var(--green);
  text-decoration: none;
}

.brand-letters {
  font-family: Georgia, "Times New Roman", serif;
  font-size: 34px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.13em;
}

.brand-icon {
  position: relative;
  display: inline-block;
  width: 54px;
  height: 54px;
  overflow: hidden;
  border: 2px solid var(--green);
  border-radius: 50%;
  background: #f4f7f6;
}

.brand-icon-person::before {
  position: absolute;
  z-index: 2;
  top: 12px;
  left: 22px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--green);
  content: "";
}

.brand-icon-person::after {
  position: absolute;
  z-index: 2;
  top: 21px;
  left: 18px;
  width: 17px;
  height: 28px;
  border-radius: 7px 7px 2px 2px;
  background: var(--green);
  clip-path: polygon(28% 0, 72% 0, 100% 100%, 59% 100%, 50% 63%, 41% 100%, 0 100%);
  content: "";
}

.brand-icon-lines::before,
.brand-icon-lines::after {
  position: absolute;
  bottom: -4px;
  width: 1px;
  height: 58px;
  background: rgba(45, 106, 95, 0.42);
  content: "";
  transform-origin: bottom;
}

.brand-icon-lines::before {
  left: 5px;
  transform: rotate(24deg);
}

.brand-icon-lines::after {
  right: 5px;
  transform: rotate(-24deg);
}

.hero {
  margin-bottom: 25px;
}

.hero-player {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  padding: 0;
  border: 0;
  border-radius: 12px;
  color: var(--white);
  background: #2b2f2b;
  cursor: pointer;
  text-align: left;
  box-shadow: 0 2px 7px rgba(30, 44, 39, 0.13);
}

.hero-player:focus-visible,
.channel-link:focus-visible,
.video-card:focus-visible {
  outline: 3px solid rgba(45, 106, 95, 0.35);
  outline-offset: 4px;
}

.hero-player iframe,
.hero-iframe {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  height: 100%;
  border: 0;
  border-radius: 12px;
}

.hero-placeholder {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(0, 0, 0, 0.08) 42%, rgba(0, 0, 0, 0.52)),
    linear-gradient(180deg, #807b69 0 31%, #aba78f 31% 64%, #817862 64% 67%, #b6ae92 67%);
}

.hero-placeholder::before {
  position: absolute;
  inset: 60% 0 0;
  background:
    repeating-linear-gradient(93deg, transparent 0 9%, rgba(50, 45, 36, 0.35) 9.4% 10%),
    linear-gradient(170deg, transparent 0 49%, rgba(255, 255, 255, 0.11) 50% 51%, transparent 52%);
  content: "";
}

.ceiling {
  position: absolute;
  top: 19%;
  height: 6px;
  background: #e9e6d8;
  box-shadow: 0 0 9px #fff;
}

.ceiling-one {
  left: 3%;
  width: 30%;
}

.ceiling-two {
  right: 2%;
  width: 31%;
}

.direction-sign {
  position: absolute;
  top: 28%;
  right: 3%;
  padding: 6px 9px;
  border: 1px solid rgba(255, 255, 255, 0.8);
  border-radius: 5px;
  color: #f5f7f6;
  background: rgba(30, 79, 75, 0.9);
  font-size: clamp(8px, 2.2vw, 14px);
  line-height: 1.5;
}

.hero-crowd {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 47%;
  opacity: 0.78;
  background:
    radial-gradient(circle at 11% 31%, #1d211e 0 2.5%, transparent 2.8%),
    linear-gradient(84deg, transparent 7%, #34372f 7.5% 13%, transparent 13.5%),
    radial-gradient(circle at 27% 42%, #31342e 0 2.7%, transparent 3%),
    linear-gradient(91deg, transparent 23%, #4b4a3c 23.5% 30%, transparent 30.5%),
    radial-gradient(circle at 48% 25%, #242823 0 2.8%, transparent 3.2%),
    linear-gradient(87deg, transparent 44%, #363933 44.5% 52%, transparent 52.5%),
    radial-gradient(circle at 70% 39%, #222720 0 2.6%, transparent 2.9%),
    linear-gradient(91deg, transparent 66%, #45453b 66.5% 73%, transparent 73.5%),
    radial-gradient(circle at 87% 27%, #2f322c 0 2.5%, transparent 2.8%),
    linear-gradient(86deg, transparent 83%, #393b35 83.5% 90%, transparent 90.5%);
}

.hero-channel {
  position: absolute;
  top: 12px;
  left: 14px;
  z-index: 2;
  max-width: 76%;
  overflow: hidden;
  font-size: clamp(9px, 2.6vw, 14px);
  white-space: nowrap;
  text-overflow: ellipsis;
  text-shadow: 0 1px 4px #000;
}

.hero-title {
  position: absolute;
  top: 27%;
  left: 5%;
  z-index: 2;
  font-size: clamp(26px, 8vw, 58px);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: 0.02em;
  text-shadow: 0 2px 9px rgba(0, 0, 0, 0.38);
}

.play-button {
  position: absolute;
  z-index: 3;
  top: 58%;
  left: 50%;
  width: clamp(54px, 14vw, 82px);
  height: clamp(37px, 9.5vw, 56px);
  border-radius: 12px;
  background: #ff0033;
  transform: translate(-50%, -50%);
  box-shadow: 0 2px 7px rgba(0, 0, 0, 0.28);
}

.play-button span {
  position: absolute;
  top: 50%;
  left: 54%;
  width: 0;
  height: 0;
  border-top: 9px solid transparent;
  border-bottom: 9px solid transparent;
  border-left: 15px solid white;
  transform: translate(-50%, -50%);
}

.hero-watch {
  position: absolute;
  z-index: 2;
  bottom: 0;
  left: 0;
  padding: 7px 10px;
  background: rgba(0, 0, 0, 0.62);
  font-size: 11px;
}

.introduction {
  margin-bottom: 30px;
}

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

h1 {
  margin-bottom: 10px;
  font-size: clamp(24px, 5.2vw, 35px);
  line-height: 1.45;
  letter-spacing: 0.015em;
}

.introduction p {
  margin-bottom: 8px;
}

.introduction .lead {
  margin-bottom: 14px;
  font-size: 16px;
}

.contribution-grid {
  display: grid;
  gap: 32px;
  margin-bottom: 28px;
}

.section-title {
  margin-bottom: 16px;
  padding-left: 11px;
  border-left: 4px solid var(--green);
  font-size: 21px;
  line-height: 1.4;
  letter-spacing: 0.02em;
}

.section-title small {
  display: block;
  margin-top: 3px;
  font-size: 12px;
  font-weight: 600;
}

.topic-list {
  display: grid;
  gap: 11px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.topic-list li {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 50px;
  padding: 10px 15px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--white);
  font-weight: 600;
}

.check {
  display: inline-grid;
  flex: 0 0 auto;
  width: 19px;
  height: 19px;
  place-items: center;
  border-radius: 50%;
  color: var(--white);
  background: var(--green);
  font-size: 12px;
  font-weight: 800;
  line-height: 1;
}

.form-notes {
  margin: -4px 0 14px;
  font-size: 12px;
  line-height: 1.75;
}

.form-notes span {
  color: var(--muted);
}

.form-embed iframe {
  display: block;
  width: 100%;
  height: 354px;
  border: 0;
  background: var(--white);
}

.channel-link {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  width: 100%;
  min-height: 58px;
  margin: 0 0 30px;
  padding: 10px 44px;
  border: 2px solid var(--green);
  border-radius: 999px;
  color: var(--green-dark);
  background: var(--white);
  font-size: 16px;
  font-weight: 700;
  line-height: 1.45;
  text-align: center;
  text-decoration: none;
  transition: color 0.15s ease, background-color 0.15s ease;
}

.channel-link:hover {
  color: var(--white);
  background: var(--green);
}

.youtube-mark {
  position: relative;
  display: inline-block;
  flex: 0 0 auto;
  width: 30px;
  height: 20px;
  border-radius: 5px;
  background: currentColor;
}

.youtube-mark span {
  position: absolute;
  top: 50%;
  left: 53%;
  width: 0;
  height: 0;
  border-top: 5px solid transparent;
  border-bottom: 5px solid transparent;
  border-left: 8px solid var(--white);
  transform: translate(-50%, -50%);
}

.link-arrow {
  position: absolute;
  right: 22px;
  font-size: 33px;
  font-weight: 300;
  line-height: 1;
}

.recommended {
  margin-bottom: 28px;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px 12px;
}

.video-card {
  display: flex;
  min-width: 0;
  flex-direction: column;
  color: var(--ink);
  text-decoration: none;
}

.video-thumb {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border-radius: 9px;
  background-color: #817d6d;
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, 0.12);
}

.video-thumb::before,
.video-thumb::after {
  position: absolute;
  content: "";
}

.video-thumb::before {
  inset: 0;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.34), transparent 12% 67%, rgba(0, 0, 0, 0.28)),
    repeating-linear-gradient(90deg, transparent 0 17%, rgba(255, 255, 255, 0.12) 18% 19%);
}

.video-thumb::after {
  right: 0;
  bottom: 0;
  left: 0;
  height: 44%;
  background:
    radial-gradient(circle at 18% 28%, #30332e 0 4%, transparent 4.5%),
    linear-gradient(88deg, transparent 13%, #46443d 14% 23%, transparent 24%),
    radial-gradient(circle at 49% 34%, #292d28 0 4%, transparent 4.5%),
    linear-gradient(91deg, transparent 44%, #3c3d37 45% 55%, transparent 56%),
    radial-gradient(circle at 78% 28%, #343630 0 4%, transparent 4.5%),
    linear-gradient(87deg, transparent 73%, #4c4940 74% 84%, transparent 85%);
}

.thumb-one {
  background: linear-gradient(180deg, #777366 0 48%, #b6aa8d 49%);
}

.thumb-two {
  background: linear-gradient(110deg, #b7af96 0 35%, #817d70 36% 70%, #c7c2ae 71%);
}

.thumb-three {
  background: linear-gradient(95deg, #8e8978 0 57%, #273d43 58% 82%, #aca58c 83%);
}

.thumb-four {
  background:
    linear-gradient(30deg, transparent 46%, rgba(236, 193, 100, 0.78) 47% 49%, transparent 50%),
    linear-gradient(150deg, transparent 46%, rgba(84, 162, 151, 0.8) 47% 49%, transparent 50%),
    #25464b;
}

.time {
  position: absolute;
  z-index: 2;
  right: 4px;
  bottom: 4px;
  padding: 1px 4px;
  border-radius: 3px;
  color: #fff;
  background: rgba(0, 0, 0, 0.78);
  font-size: 10px;
  line-height: 1.4;
}

.video-card h3 {
  margin: 8px 0 4px;
  font-size: 14px;
  line-height: 1.55;
}

.video-card p {
  flex: 1;
  margin-bottom: 9px;
  color: #505653;
  font-size: 12px;
  line-height: 1.65;
}

.tag {
  align-self: flex-start;
  padding: 2px 7px;
  border: 1px solid var(--green);
  border-radius: 4px;
  color: var(--green);
  font-size: 11px;
  font-weight: 700;
  line-height: 1.4;
}

.site-footer {
  padding-top: 4px;
  color: #535957;
  text-align: center;
}

.site-footer p {
  margin-bottom: 0;
  font-size: 12px;
  line-height: 1.7;
}

.site-footer a {
  text-underline-offset: 3px;
}

@media (min-width: 640px) {
  body {
    padding: 20px 0;
  }

  .site-shell {
    padding: 0 34px 28px;
    box-shadow: 0 7px 30px rgba(35, 49, 44, 0.08);
  }

  .site-header {
    min-height: 104px;
  }

  .contribution-grid {
    grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
    gap: 36px;
  }

  .section-title small {
    display: inline;
  }

  .video-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 15px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  * {
    transition: none !important;
  }
}