:root {
  --bg: #f4f6f9;
  --text: #111827;
  --card: #ffffff;
  --primary: #2563eb;
  --header: #2563eb;
  --footer: #1e3a8a;
}

body.dark {
  --bg: #0f172a;
  --text: #e5e7eb;
  --card: #1e293b;
  --primary: #3b82f6;
  --header: #0f172a;
  --footer: #0f172a;
}

* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
  margin: 0;
  font-family: system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  transition: 0.3s ease;
}

/* LAYOUT FLEX SUPAYA FOOTER DI BAWAH */
.wrapper {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* HEADER FIXED */
header {
  position: fixed;
  top: 0;
  width: 100%;
  background: var(--header);
  color: white;
  padding: 15px 0;
  z-index: 1000;
  transition: 0.3s;
}

.header-container {
  width: 90%;
  max-width: 1100px;
  margin: auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* CONTENT */
.content {
  flex: 1;
  margin-top: 80px;
  width: 90%;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

/* CARD */
.card {
  background: var(--card);
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 5px 20px rgba(0,0,0,0.05);
  margin-bottom: 20px;
  transition: 0.3s;
}

/* FOOTER */
footer {
  background: var(--footer);
  color: white;
  text-align: center;
  padding: 20px;
  margin-top: auto;
  transition: 0.3s;
}

/* ARTICLE */
.article-content img {
  max-width: 100%;
  border-radius: 12px;
  margin-bottom: 15px;
}

.article-content h1 {
  margin-bottom: 10px;
}

.article-content p {
  line-height: 1.8;
}

/* BUTTON */
.btn {
  background: var(--primary);
  color: white;
  padding: 8px 14px;
  border-radius: 8px;
  border: none;
  cursor: pointer;
}

/* TOGGLE BUTTON ON/OFF */
.toggle-btn {
  width: 60px;
  height: 30px;
  border-radius: 30px;
  background: #ccc;
  position: relative;
  cursor: pointer;
  transition: 0.3s;
}

.toggle-btn::after {
  content: "";
  width: 24px;
  height: 24px;
  background: white;
  position: absolute;
  top: 3px;
  left: 3px;
  border-radius: 50%;
  transition: 0.3s;
}

body.dark .toggle-btn {
  background: #3b82f6;
}

body.dark .toggle-btn::after {
  transform: translateX(30px);
}

/* RESPONSIVE */
@media(max-width:768px){
  .header-container {
    flex-direction: column;
    gap: 10px;
  }
}