body {
    font-family: "Noto Sans JP", "Helvetica Neue", "Helvetica", "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Arial", "Yu Gothic", "Meiryo", sans-serif;
    font-optical-sizing: auto;
    font-weight: 400;
    font-style: normal;
    font-size: 18px;
    line-height: 1.5;
    color: #333;
    background-color: rgb(243, 248, 255);
    margin: 0;
    width: 100vw;
}
footer {
    margin: 20px 10%;
    width: 80%;
    font-weight: bold;
    text-align: center;
}
label,input,textarea,select,button {
    cursor: pointer;
}
h1 {
    margin: 0;
}
h2 {
    padding: 1rem 0rem;
    margin-bottom: 0.2rem;
    border-bottom: 3px solid #b2d5de;
    font-weight: bold;
    font-size: 26px;
}
a {
    text-decoration: none;
    color: black;
}

/* index */
header {
  background: white;
  border-bottom: 1px solid #e2e8f0;
  padding: 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

header .logo {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
}
header .logo-box {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    background: linear-gradient(to bottom right, purple, pink);
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
    font-weight: bold;
}
nav a {
    margin: 0 8px;
    text-decoration: none;
    color: #475569;
}
nav a:hover {
    color: #0f172a;
}
.hero {
    max-width: 1000px;
    margin: auto;
    padding: 2rem;
    display: grid;
    gap: 2rem;
}
.hero-box {
    background: white;
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: 0 2px 6px rgba(0,0,0,0.05);
}
.hero-box h2 {
  font-size: 24px;
}
.hero-box p {
  font-size: 16px;
}
.hero-box input {
    width: 70%;
    padding: 0.5rem;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
}
.articles {
    max-width: 1000px;
    margin: auto;
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 1.5rem;
    padding: 2rem;
}
.article {
    display: block;
    background: white;
    border-radius: 1rem;
    padding: 1rem;
    margin-bottom: 1rem;
    box-shadow: 0 2px 6px rgba(0,0,0,0.05);
}
.article h4 {
  font-size: 20px;
  font-weight: bold;
}
.article.list {
    margin: auto;
    display: grid;
    grid-template-columns: 1fr 2fr;
    align-items: center;
    font-size: 12px;
    margin-bottom: 10px;
}
.article.list:hover {
    box-shadow: 0 4px 12px rgba(0,0,0,0.1); 
    transform: translateY(-2px);
    transition: all 0.2s ease;
}
.article-img {
    width: 100%;
}
.article-txt {
    padding: 10px;

}
.article h3 {
    margin: 0;
}
.article_hot:hover {
    transform: translateY(-2px);
    transition: all 0.2s ease;
}
footer {
    background: white;
    border-top: 1px solid #e2e8f0;
    padding: 1.5rem;
    text-align: center;
    font-size: 0.9rem;
    color: #475569;
}
@media (max-width: 768px) {
  body {
    font-size: 14px;
  }

  header {
    padding: 1rem 0.5rem;
  }

  .hero {
    padding: 1rem;
  }

  .hero-box {
    padding: 1.5rem;
  }

  .articles {
    grid-template-columns: 1fr;
    padding: 1rem;
  }

  nav a {
    font-size: 14px;
  }

  .article_hot {
    font-size: 14px;
  }

  .footer {
    padding: 1rem;
  }
}

@media (max-width: 480px) {
  .hero-box h2 {
    font-size: 20px;
  }

  .hero-box p {
    font-size: 14px;
  }

  .article_hot {
    font-size: 13px;
  }

  footer {
    font-size: 0.8rem;
  }
}


/* form */
.form-title {
    padding: 20px 10px;
}
.form {
    padding-top: 20px;
    padding-bottom: 100px;
    width: 100%;
    font-weight: bold;
}
.form-div {
    width: 80%;
    margin: 10px 10%;
}
.form-btn {
    width: 50%;
    margin: 10px 25%;
    display: inline-block;
    text-align: center;
    padding: 0.8em 1em;
    text-decoration: none;
    background: #668ad8;
    color: #FFF;
    border-bottom: solid 4px #627295;
    border-radius: 3px;
}
.form-input {
    width: 100%;
    border-radius: 5px;
    padding: 12px;
    border:1px solid #ccc;
}
.form-textarea {
    width: 100%;
    border-radius: 5px;
    padding: 12px;
    border:1px solid #ccc;
    min-height: 100px;
}
.sended {
    width: 100%;
    text-align: center;
    margin: 30px 0;
}
@media (min-width :767px) {
    .form-div {
        width: 50%;
        margin: 10px 25%;
    }
    .form-btn {
        width: 15%;
        margin: 10px 42.5%;
    }
}

/* content */
.article-content{
    width: 60%;
    margin: 20px 20%;
}
.article-title {
    margin: 20px 0;
}
.update {
    margin: 10px 15%;
    text-align: right;
}
.article-headerimg {
    width: 70%;
    margin: 0 15%;
}
#tagsbox {
    display: flex;
    flex-wrap: wrap;
    gap: 5px;  
}
.tag {
    padding: 5px 10px;
    margin: 0 10px;
    background-color: #adcfff;
    white-space: nowrap; 
}
.box-toc {
    font-weight: bold;
    position: relative;
    margin: 2em 0;
    padding: 0.5em 1em;
    border: solid 3px #95ccff;
    border-radius: 8px;
    line-height: 2;
}
.box-toc .box-title {
    position: absolute;
    display: inline-block;
    top: -13px;
    left: 10px;
    padding: 0 9px;
    line-height: 1;
    font-size: 19px;
    background: #FFF;
    color: #95ccff;
    font-weight: bold;
}
.box-toc p {
    margin: 0; 
    padding: 0;
}
.box-text {
    padding: 0.5em 1em;
    margin: 2em 0;
    color: #2c2c2f;
    background: #cde4ff;
}
.box-text p {
    margin: 0; 
    padding: 0;
}
.box-placeholder {
    padding: 0.5em 1em;
    margin: 2em 0;
    background: #f0f7ff;
    display: flex;
    border: dashed 2px #5b8bd0;
}
.box-placeholder p {
    margin: 0; 
    padding: 0;
}
.box-stecker{
    padding: 0.5em 1em;
    margin: 1em 0;
    background: #f0f7ff;
    border-left: solid 6px #5b8bd0;
}
.box-stecker p {
    margin: 0; 
    padding: 0;
}
.box-description {
    padding-top: 20px;
    font-size: 20px;
    line-height: 3;
}
@media (max-width :1000px) {
    .article-headerimg {
        width: 100%;
        margin: 0;
    }
    .article-content{
        width: 80%;
        margin: 20px 10%;
    }
    .update {
        margin: 10px 0;
    }
    .box-description {
        font-size: 15px;
        line-height: 2;
    }
}

#toc {
  padding: 1rem;
  border-radius: 0.5rem;
}
#toc li {
  margin-bottom: 0.5rem;
}
#toc a {
  text-decoration: none;
  color: #333;
}
#toc a:hover {
  text-decoration: underline;
}

.button {
    background: #eee;
    position: relative;
    display: flex;
    justify-content: space-around;
    align-items: center;
    margin: 15px auto;
    max-width: 240px;
    padding: 10px 25px;
    color: #313131;
    transition: 0.3s ease-in-out;
    font-weight: 500;
    z-index:0;
    border-left: solid 5px #6bb6ff;
}
.button:before {
    content: "";
    position: absolute;
    top: 0;
    bottom: 0;
    width: 0;
    display: block;
    background: #6bb6ff;
    transition: .3s;
    left:0;
}
.button:hover {
    color: #FFF;
}
.button:hover:before {
    width: 100%;
    z-index: -1;
}