:root {
  --font-large: clamp(1.5rem, 2.5vw, 2rem);
  --font-medium: clamp(1rem, 2vw, 1.3rem);
  --font-small: clamp(0.8rem, 1.5vw, 1rem);
  --main-blue: #0069c2
}

body {
  font-family: 'Apple SD Gothic Neo', sans-serif;
  margin: 0;
  padding: 0;
  background: #fff;
  color: #222;
  line-height: 1.4
}

a {
  color: var(--main-blue);
  text-decoration: none
}

a:hover {
  text-decoration: underline
}

.container,
.header-inner {
  display: flex;
  max-width: 1200px;
  margin: 0 auto
}

.header {
  background: #f8f8f8;
  border-bottom: 1px solid #ddd;
  padding: 1rem 0
}

.header-inner {
  padding: 0 2rem;
  align-items: center
}

.logo {
  font-weight: 700;
  font-size: var(--font-medium)
}

.logo img {
  width: 100%;
  max-width: 300px;
  min-width: 150px;
  height: auto;
}

.container {
  flex-direction: row;
  padding: 2rem;
  box-sizing: border-box
}

.left {
  flex: 0 0 250px;
  padding-right: 2rem;
  border-right: 1px solid #e0e0e0;
  position: sticky;
  top: 2rem;
  align-self: flex-start;
  height: fit-content;
}

.left h2 {
  font-size: var(--font-medium);
  margin-bottom: 1rem;
  color: #555
}

.toc-item {
  margin-bottom: .8rem;
  font-size: var(--font-small)
}

.right {
  flex: 1;
  padding-left: 2rem;
  max-width: 800px
}

.title {
  font-weight: 700;
  font-size: var(--font-large);
  margin-bottom: .5rem
}

.date {
  font-size: var(--font-small);
  color: #999;
  margin-bottom: 2rem
}

.text p {
  margin-bottom: 0.8rem;
  line-height: 1.5
}

.text div[id^=tag-],
.text h2[id^=tag-],
.text p[id^=tag-] {
  font-weight: 700;
  font-size: var(--font-medium);
  margin-top: 2rem
}

.text ul {
  line-height: 1.7;
  margin-bottom: 1.2rem;
}

.text li {
  line-height: 1.7;
  margin-bottom: 0.5rem;
}

form label {
  display: block;
  margin: 1rem 0 .5rem;
  font-weight: 700
}

input[type="text"] {
  width: 100%;
  padding: .5rem;
  font-size: 1rem
}

textarea {
  width: 100%;
  height: 400px
}

button {
  margin-top: 1.5rem;
  padding: .75rem 1.5rem;
  font-size: 1rem;
  background: #0069c2;
  color: #fff;
  border: none;
  cursor: pointer
}

button:hover {
  background: #004f94
}

.note {
  font-size: var(--font-small);
  color: #888;
  margin-top: -0.5rem;
  margin-bottom: 1rem;
  display: block;
}

@media (max-width: 768px) {
  .header {
    padding: 0.5rem 0;
  }

  .header-inner {
    padding: 0 1rem;
  }

  .logo img {
    max-width: 150px;
    min-width: 120px;
  }

  .container {
    flex-direction: column;
    padding: 1rem;
    gap: 1rem;
  }

  .left {
    flex: none;
    width: 100%;
    padding-right: 0;
    padding-bottom: 1rem;
    border-right: none;
    border-bottom: 1px solid #eee;
    position: static;
    top: auto;
    align-self: auto;
    height: auto;
    margin-bottom: 0;
  }

  .left h2 {
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
  }

  .toc-item {
    margin-bottom: 0.4rem;
    font-size: 0.8rem;
  }

  .right {
    padding-left: 0;
    margin-top: 0;
  }

  .title {
    font-size: 1.3rem;
  }

  .date {
    font-size: 0.8rem;
  }

  .text {
    font-size: 0.9rem;
  }
}