/* 囲碁ベース LP — igobase.jp */

:root {
  --color-bg: #ffffff;
  --color-text: #333333;
  --color-text-muted: #5c5c5c;
  --color-accent: #1a4d3e;
  --color-accent-light: #e8f2ef;
  --color-border: #e0e0e0;
  --color-footer-bg: #f7f7f7;
  --font-sans: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", sans-serif;
  --max-width: 960px;
  --section-gap: clamp(3rem, 8vw, 5rem);
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}

a:hover {
  opacity: 0.85;
}

/* Layout */
.container {
  width: min(100% - 2rem, var(--max-width));
  margin-inline: auto;
}

/* Hero */
.hero {
  padding: clamp(2.5rem, 6vw, 4rem) 0 clamp(2rem, 5vw, 3rem);
  text-align: center;
  border-bottom: 1px solid var(--color-border);
}

.hero__logo {
  width: min(200px, 50vw);
  margin: 0 auto clamp(1.5rem, 4vw, 2.5rem);
}

.hero__catch {
  display: flex;
  flex-direction: column;
  gap: 0.15em;
  margin-bottom: 1.25rem;
}

.hero__catch-line {
  font-size: clamp(1.5rem, 4.5vw, 2.25rem);
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--color-accent);
  line-height: 1.35;
}

.hero__catch-line--emphasis {
  font-size: clamp(1.75rem, 5.5vw, 2.75rem);
}

.hero__subtitle {
  font-size: clamp(0.95rem, 2.5vw, 1.125rem);
  color: var(--color-text-muted);
  font-weight: 500;
}

/* Hero video */
.hero__video {
  margin: clamp(1.75rem, 5vw, 2.75rem) auto clamp(1.5rem, 4vw, 2.5rem);
  max-width: min(340px, 82vw);
}

.hero__video-title {
  font-size: clamp(1.05rem, 3vw, 1.35rem);
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  margin-bottom: clamp(1rem, 3vw, 1.5rem);
  position: relative;
  display: inline-block;
}

.hero__video-title::after {
  content: "";
  display: block;
  width: 2.5rem;
  height: 3px;
  margin: 0.6rem auto 0;
  border-radius: 2px;
  background: var(--color-accent);
}

/* Vertical (9:16) player with smartphone-like frame + green glow */
.video-player {
  position: relative;
  aspect-ratio: 9 / 16;
  width: 100%;
  margin-inline: auto;
  border-radius: 28px;
  overflow: hidden;
  cursor: pointer;
  border: 3px solid #0f3a2d;
  background: #0f3a2d;
  box-shadow:
    0 0 0 6px rgba(26, 77, 62, 0.08),
    0 18px 40px -12px rgba(26, 77, 62, 0.55),
    0 0 38px -6px rgba(26, 77, 62, 0.5);
  transition: transform 0.35s ease, box-shadow 0.35s ease;
}

.video-player:hover {
  transform: translateY(-4px);
  box-shadow:
    0 0 0 6px rgba(26, 77, 62, 0.12),
    0 26px 52px -12px rgba(26, 77, 62, 0.65),
    0 0 56px -2px rgba(26, 77, 62, 0.7);
}

.video-player:focus-visible {
  transform: translateY(-4px);
  box-shadow:
    0 0 0 6px rgba(26, 77, 62, 0.12),
    0 26px 52px -12px rgba(26, 77, 62, 0.65),
    0 0 56px -2px rgba(26, 77, 62, 0.7);
  outline: 3px solid #ffffff;
  outline-offset: 4px;
}

.video-player__thumb {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.video-player:hover .video-player__thumb {
  transform: scale(1.04);
}

/* Subtle dark gradient for contrast behind the play button */
.video-player::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(0, 0, 0, 0.25) 0%,
    rgba(0, 0, 0, 0) 35%,
    rgba(0, 0, 0, 0) 60%,
    rgba(0, 0, 0, 0.35) 100%
  );
  z-index: 1;
  pointer-events: none;
  transition: opacity 0.35s ease;
}

.video-player__play {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 2;
  width: clamp(60px, 22%, 84px);
  aspect-ratio: 1;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: rgba(255, 255, 255, 0.92);
  color: var(--color-accent);
  box-shadow: 0 8px 24px -6px rgba(0, 0, 0, 0.5);
  transition: transform 0.3s ease, background 0.3s ease;
}

.video-player:hover .video-player__play {
  transform: translate(-50%, -50%) scale(1.12);
  background: #ffffff;
}

/* Pulsing ring around the play button */
.video-player__play::after {
  content: "";
  position: absolute;
  inset: -10px;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.7);
  animation: video-pulse 2s ease-out infinite;
}

@keyframes video-pulse {
  0% {
    transform: scale(0.85);
    opacity: 0.8;
  }
  100% {
    transform: scale(1.4);
    opacity: 0;
  }
}

.video-player__play svg {
  width: 42%;
  height: 42%;
  margin-left: 8%;
  fill: currentColor;
}

/* When playing, embed fills the frame */
.video-player.is-playing {
  cursor: default;
}

.video-player.is-playing::before,
.video-player.is-playing .video-player__play {
  opacity: 0;
  pointer-events: none;
}

.video-player iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
  z-index: 3;
}

@media (prefers-reduced-motion: reduce) {
  .video-player,
  .video-player__thumb,
  .video-player__play {
    transition: none;
  }
  .video-player__play::after {
    animation: none;
  }
}

/* Sections */
.section {
  padding-block: var(--section-gap);
}

.section__title {
  font-size: clamp(1.25rem, 3vw, 1.5rem);
  font-weight: 700;
  color: var(--color-accent);
  text-align: center;
  margin-bottom: clamp(1.25rem, 3vw, 2rem);
  letter-spacing: 0.02em;
}

.section__lead {
  font-size: clamp(1rem, 2.2vw, 1.0625rem);
  max-width: 42em;
  margin-inline: auto;
  text-align: center;
}

/* Values */
.values {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1rem;
  margin-top: 2rem;
  list-style: none;
}

.values__item {
  background: var(--color-accent-light);
  border-radius: 8px;
  padding: 1rem 0.75rem;
  text-align: center;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-accent);
  line-height: 1.4;
}

/* Tagline */
.tagline {
  background: var(--color-accent);
  color: #fff;
  padding: clamp(2rem, 5vw, 3rem) 0;
  text-align: center;
}

.tagline__text {
  font-size: clamp(1.05rem, 2.8vw, 1.25rem);
  font-weight: 600;
  line-height: 1.7;
  max-width: 36em;
  margin-inline: auto;
}

/* Bridge */
.bridge {
  background: var(--color-footer-bg);
  padding: clamp(2rem, 5vw, 3rem) 0;
  text-align: center;
}

.bridge__text {
  font-size: clamp(0.95rem, 2.5vw, 1.1rem);
  font-weight: 500;
  max-width: 40em;
  margin-inline: auto;
  line-height: 1.8;
}

.bridge__text strong {
  color: var(--color-accent);
  font-weight: 700;
}

/* Features */
.features {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  list-style: none;
}

@media (min-width: 640px) {
  .features {
    grid-template-columns: repeat(3, 1fr);
    gap: 1.25rem;
  }
}

.feature-card {
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 1.5rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  height: 100%;
}

.feature-card__label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--color-accent);
  text-transform: uppercase;
}

.feature-card__title {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-text);
}

.feature-card__list {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  line-height: 1.65;
  flex: 1;
  padding-left: 1.15em;
  list-style: disc;
}

.feature-card__list li + li {
  margin-top: 0.5em;
}

/* Official links */
.official {
  text-align: center;
  padding-block: clamp(2rem, 4vw, 2.5rem);
  border-top: 1px solid var(--color-border);
}

.official__list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem 2rem;
}

.official__link {
  font-weight: 600;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.official__link:hover {
  text-decoration: underline;
}

/* Footer */
.site-footer {
  background: var(--color-footer-bg);
  padding: clamp(2rem, 4vw, 2.5rem) 0;
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  text-align: center;
}

.site-footer__credits {
  margin-bottom: 1rem;
  line-height: 1.8;
}

.site-footer__legal {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem 1.25rem;
  margin-bottom: 1rem;
  list-style: none;
}

.site-footer__legal a {
  color: var(--color-text-muted);
}

.site-footer__copy {
  font-size: 0.75rem;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}