:root {

  --bg: #f5f7fb;

  --card: #ffffff;

  --text: #111827;

  --muted: #6b7280;

  --primary: #2563eb;

  --primary-light: #eff6ff;

  --border: #e5e7eb;

  --green: #16a34a;

  --warning: #f59e0b;

  --danger: #dc2626;

  --radius: 20px;

  --shadow:
    0 10px 30px rgba(0,0,0,0.05);

}

* {

  margin: 0;

  padding: 0;

  box-sizing: border-box;
}

body {

  font-family: 'Inter', sans-serif;

  background: var(--bg);

  color: var(--text);

  line-height: 1.8;
}

img {

  max-width: 100%;

  display: block;
}

a {

  text-decoration: none;

  color: inherit;
}

.container {

  width: min(1180px, 92%);

  margin: auto;
}

/* HEADER */

.site-header {

  position: sticky;

  top: 0;

  z-index: 1000;

  background: rgba(255,255,255,0.92);

  backdrop-filter: blur(10px);

  border-bottom:
    1px solid var(--border);
}

.header-inner {

  display: flex;

  justify-content: space-between;

  align-items: center;

  padding: 1rem 0;
}

.logo {

  display: flex;

  align-items: center;

  gap: 0.7rem;

  font-size: 1.2rem;

  font-weight: 800;

  color: var(--primary);
}

nav {

  display: flex;

  gap: 1.5rem;
}

nav a {

  color: var(--muted);

  transition: 0.2s;
}

nav a:hover {

  color: var(--primary);
}

/* ARTICLE PAGE */

.article-page {

  padding: 3rem 0 5rem;
}

.article-layout {

  display: grid;

  grid-template-columns: 1fr 320px;

  gap: 2rem;
}

.article-main {

  background: var(--card);

  border-radius: 28px;

  overflow: hidden;

  box-shadow: var(--shadow);

  border: 1px solid var(--border);
}

.article-image {

  width: 100%;

  height: 460px;

  object-fit: cover;
}

.article-header {

  padding: 2.5rem 2.5rem 1rem;
}

.guide-label {

  display: inline-block;

  background: var(--primary-light);

  color: var(--primary);

  padding: 0.45rem 0.9rem;

  border-radius: 999px;

  font-size: 0.75rem;

  font-weight: 700;

  margin-bottom: 1rem;
}

.article-header h1 {

  font-size: clamp(2.2rem, 5vw, 4rem);

  line-height: 1.1;

  margin-bottom: 1.5rem;

  letter-spacing: -1px;
}

.article-meta {

  display: flex;

  flex-wrap: wrap;

  gap: 1.5rem;

  color: var(--muted);

  font-size: 0.95rem;
}

.article-meta span {

  display: flex;

  align-items: center;

  gap: 0.5rem;
}

/* PROBLEM BOX */

.problem-box {

  margin: 2rem 2.5rem;

  padding: 1.4rem;

  border-radius: 18px;

  background: #fff7ed;

  border: 1px solid #fed7aa;

  display: flex;

  gap: 1rem;

  align-items: flex-start;
}

.problem-icon {

  width: 48px;

  height: 48px;

  min-width: 48px;

  border-radius: 50%;

  background: #ffedd5;

  color: var(--warning);

  display: flex;

  align-items: center;

  justify-content: center;

  font-size: 1.1rem;
}

.problem-box h3 {

  margin-bottom: 0.3rem;
}

.problem-box p {

  color: #9a3412;
}

/* CONTENT */

.article-content {

  padding: 0 2.5rem 3rem;

  font-size: 1.08rem;

  color: var(--text);
}

.article-content * {

  max-width: 100%;
}

.article-content h1,
.article-content h2,
.article-content h3 {

  margin-top: 2.5rem;

  margin-bottom: 1rem;

  line-height: 1.3;

  color: #111827;
}

.article-content h2 {

  font-size: 2rem;
}

.article-content p {

  margin-bottom: 1.5rem;

  color: #374151;
}

.article-content a {

  color: var(--primary);

  font-weight: 600;
}

.article-content ul,
.article-content ol {

  padding-left: 1.5rem;

  margin-bottom: 1.5rem;
}

.article-content li {

  margin-bottom: 0.6rem;
}

.article-content blockquote {

  margin: 2rem 0;

  padding: 1.5rem;

  background: #eff6ff;

  border-left: 4px solid var(--primary);

  border-radius: 12px;

  color: #1e40af;
}

.article-content pre {

  background: #111827;

  color: white;

  padding: 1.5rem;

  border-radius: 16px;

  overflow-x: auto;

  margin: 2rem 0;
}

.article-content code {

  background: #f3f4f6;

  padding: 2px 6px;

  border-radius: 6px;

  color: #dc2626;
}

/* SIDEBAR */

.article-sidebar {

  position: sticky;

  top: 100px;

  height: fit-content;
}

.sidebar-box {

  background: white;

  border-radius: 20px;

  border: 1px solid var(--border);

  padding: 1.5rem;

  margin-bottom: 1.5rem;

  box-shadow: var(--shadow);
}

.sidebar-box h3 {

  margin-bottom: 1rem;

  font-size: 1.1rem;
}

.sidebar-box ul {

  list-style: none;
}

.sidebar-box li {

  padding: 0.9rem 0;

  border-bottom:
    1px solid #f3f4f6;

  color: var(--muted);
}

.tip-box {

  background: #ecfdf5;

  border-color: #bbf7d0;
}

.tip-box p {

  color: #166534;
}

.tags {

  display: flex;

  flex-wrap: wrap;

  gap: 0.7rem;
}

.tags span {

  background: #f3f4f6;

  padding: 0.45rem 0.8rem;

  border-radius: 999px;

  font-size: 0.85rem;

  color: #374151;
}

/* FOOTER */

.site-footer {

  margin-top: 3rem;

  padding: 2rem 0;

  text-align: center;

  color: var(--muted);

  border-top:
    1px solid var(--border);
}

/* MOBILE */

@media (max-width: 980px) {

  .article-layout {

    grid-template-columns: 1fr;
  }

  .article-sidebar {

    position: relative;

    top: auto;
  }

}

@media (max-width: 768px) {

  nav {

    display: none;
  }

  .article-image {

    height: 260px;
  }

  .article-header,
  .article-content {

    padding-left: 1.3rem;
    padding-right: 1.3rem;
  }

  .problem-box {

    margin-left: 1.3rem;
    margin-right: 1.3rem;
  }

}