:root {
  --color-primary: #2B7DB5;
  --color-primary-dark: #165D9A;
  --color-text: #333;
  --color-muted: #666;
  --color-border: #d5dde2;
  --color-bg: #f4f6f7;
  --color-white: #fff;
}

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

html,
body {
  width: 100%;
  min-height: 100%;
  margin: 0;
}

body {
  color: var(--color-text);
  background: var(--color-bg);
  font-family:
    "Noto Sans JP",
    "Hiragino Kaku Gothic ProN",
    "Yu Gothic",
    Meiryo,
    sans-serif;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
}

/* ========================================
   TOP
======================================== */

.top {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: 100vh;
  min-height: 100dvh;
  padding: 40px 24px;
  overflow: hidden;
  background:
    linear-gradient(
      180deg,
      #edf2f5 0,
      var(--color-bg) 260px
    );
}

.top::before {
  position: absolute;
  top: 0;
  right: 0;
  left: 0;
  height: 7px;
  content: "";
  background: var(--color-primary);
}

.top::after {
  position: absolute;
  right: -180px;
  bottom: -180px;
  width: 420px;
  height: 420px;
  content: "";
  border: 1px solid rgba(22, 74, 112, 0.07);
  border-radius: 50%;
  box-shadow:
    0 0 0 70px rgba(22, 74, 112, 0.02),
    0 0 0 140px rgba(22, 74, 112, 0.015);
  pointer-events: none;
}

/* ========================================
   CONTENT
======================================== */

.top__content {
  position: relative;
  z-index: 1;
  width: min(100%, 760px);
}

/* ========================================
   HEADER PANEL
======================================== */

.top__header {
  padding: 56px 64px;
  text-align: center;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-top: 5px solid var(--color-primary);
  box-shadow: 0 8px 30px rgba(30, 50, 65, 0.07);
}

.top__category {
  margin: 0 0 20px;
  color: var(--color-primary);
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.12em;
}

.top__title {
  margin: 0;
  color: var(--color-primary-dark);
  font-size: clamp(2rem, 4vw, 3.4rem);
  font-weight: 700;
  letter-spacing: 0.08em;
  line-height: 1.4;
}

.top__description {
  margin: 26px 0 0;
  padding-top: 24px;
  color: var(--color-muted);
  border-top: 1px solid var(--color-border);
  font-size: 1rem;
  line-height: 2;
  letter-spacing: 0.04em;
}

/* ========================================
   SITE LINKS
======================================== */

.site-links {
  display: grid;
  gap: 12px;
  margin-top: 14px;
}

/* ========================================
   SITE LINK
======================================== */

.site-link {
  display: flex;
  align-items: stretch;
  min-height: 96px;
  overflow: hidden;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  box-shadow: 0 4px 16px rgba(30, 50, 65, 0.05);
  transition:
    border-color 0.2s ease,
    box-shadow 0.2s ease,
    transform 0.2s ease;
}

.site-link::before {
  width: 4px;
  flex: 0 0 auto;
  content: "";
  background: var(--color-primary);
}

.site-link__text {
  display: flex;
  flex: 1;
  flex-direction: column;
  justify-content: center;
  min-width: 0;
  padding: 18px 22px;
}

.site-link__title {
  color: var(--color-primary-dark);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.5;
}

.site-link__description {
  margin-top: 5px;
  color: var(--color-muted);
  font-size: 0.82rem;
  line-height: 1.6;
}

.site-link__arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 50px;
  flex: 0 0 50px;
  color: var(--color-primary);
  font-size: 1.8rem;
  font-weight: 300;
  border-left: 1px solid var(--color-border);
  transition:
    color 0.2s ease,
    background-color 0.2s ease;
}

.site-link:hover {
  border-color: #aebec8;
  box-shadow: 0 6px 20px rgba(30, 50, 65, 0.09);
  transform: translateY(-2px);
}

.site-link:hover .site-link__arrow {
  color: var(--color-white);
  background: var(--color-primary);
}

.site-link:focus-visible {
  outline: 3px solid rgba(22, 74, 112, 0.3);
  outline-offset: 3px;
}

/* ========================================
   MOBILE
======================================== */

@media (max-width: 640px) {
  .top {
    padding: 24px 16px;
  }

  .top__header {
    padding: 40px 24px;
  }

  .top__category {
    margin-bottom: 14px;
    font-size: 0.8rem;
  }

  .top__title {
    letter-spacing: 0.04em;
  }

  .top__description {
    margin-top: 20px;
    padding-top: 20px;
    font-size: 0.9rem;
  }

  .site-link {
    min-height: 90px;
  }

  .site-link__text {
    padding: 16px 18px;
  }

  .site-link__title {
    font-size: 0.92rem;
  }

  .site-link__description {
    font-size: 0.78rem;
  }

  .site-link__arrow {
    width: 44px;
    flex-basis: 44px;
  }
}