/* ===== Variabel tema ===== */
:root {
  --bg: #f7f8fa;
  --surface: #ffffff;
  --surface-2: #eef1f6;
  --text: #1c2330;
  --muted: #5d6879;
  --border: #dbe0e9;
  --primary: #1f4fd8;
  --primary-soft: #e6edff;
  --accent: #0e9f6e;
  --warn: #c27803;
  --warn-soft: #fff4de;
  --danger: #d03a3a;
  --danger-soft: #fde8e8;
  --ok-soft: #e3f7ee;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(20, 30, 50, 0.08), 0 4px 14px rgba(20, 30, 50, 0.05);
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f141c;
    --surface: #171e29;
    --surface-2: #1f2835;
    --text: #e8ecf3;
    --muted: #9aa6b8;
    --border: #2c3748;
    --primary: #6c93ff;
    --primary-soft: #1c2a4d;
    --accent: #3ccf96;
    --warn: #f0b24a;
    --warn-soft: #3a2f16;
    --danger: #ff7b7b;
    --danger-soft: #3d1f1f;
    --ok-soft: #14352a;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --bg: #0f141c;
  --surface: #171e29;
  --surface-2: #1f2835;
  --text: #e8ecf3;
  --muted: #9aa6b8;
  --border: #2c3748;
  --primary: #6c93ff;
  --primary-soft: #1c2a4d;
  --accent: #3ccf96;
  --warn: #f0b24a;
  --warn-soft: #3a2f16;
  --danger: #ff7b7b;
  --danger-soft: #3d1f1f;
  --ok-soft: #14352a;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
  color-scheme: dark;
}

/* ===== Dasar ===== */
* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, Roboto, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
}

h1, h2, h3, h4 { line-height: 1.25; margin: 1.6em 0 0.5em; }
h1 { font-size: 2rem; margin-top: 0; }
h2 { font-size: 1.4rem; padding-bottom: 0.3em; border-bottom: 2px solid var(--border); }
h3 { font-size: 1.1rem; }

p { margin: 0.6em 0; }
a { color: var(--primary); }
code {
  background: var(--surface-2);
  padding: 0.1em 0.4em;
  border-radius: 5px;
  font-size: 0.92em;
}

.container {
  width: 100%;
  max-width: 980px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== Navbar ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.navbar .container {
  display: flex;
  align-items: center;
  gap: 16px;
  min-height: 58px;
}

.brand {
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  white-space: nowrap;
}

.nav-links {
  display: flex;
  gap: 4px;
  margin-left: auto;
  flex-wrap: wrap;
}

.nav-links a {
  padding: 6px 12px;
  border-radius: 8px;
  color: var(--muted);
  text-decoration: none;
  font-size: 0.93rem;
}

.nav-links a:hover { background: var(--surface-2); color: var(--text); }
.nav-links a.active { background: var(--primary-soft); color: var(--primary); font-weight: 600; }

.icon-btn {
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  border-radius: 8px;
  padding: 6px 10px;
  cursor: pointer;
  font-size: 1rem;
}

.icon-btn:hover { background: var(--surface-2); }
#menuToggle { display: none; }

@media (max-width: 760px) {
  #menuToggle { display: inline-block; margin-left: auto; }
  .nav-links {
    display: none;
    position: absolute;
    top: 58px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 10px 20px;
    margin: 0;
  }
  .nav-links.open { display: flex; }
}

/* ===== Hero & kartu ===== */
.hero { padding: 48px 0 24px; }
.hero p { color: var(--muted); max-width: 640px; font-size: 1.05rem; }

.page-head { padding: 32px 0 8px; }
.page-head .badge { margin-bottom: 8px; }

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
  margin: 20px 0 40px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  text-decoration: none;
  color: var(--text);
  display: block;
  transition: transform 0.15s, border-color 0.15s;
}

a.card:hover { transform: translateY(-3px); border-color: var(--primary); }
.card h3 { margin: 0 0 6px; }
.card p { margin: 0; color: var(--muted); font-size: 0.93rem; }

.badge {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 999px;
  background: var(--primary-soft);
  color: var(--primary);
}

.badge.ok { background: var(--ok-soft); color: var(--accent); }
.badge.warn { background: var(--warn-soft); color: var(--warn); }

/* ===== Tabel ===== */
.table-wrap {
  overflow-x: auto;
  margin: 14px 0;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
}

table { width: 100%; border-collapse: collapse; font-size: 0.93rem; }
th, td { padding: 10px 14px; text-align: left; border-bottom: 1px solid var(--border); vertical-align: top; }
th { background: var(--surface-2); font-weight: 600; white-space: nowrap; }
tr:last-child td { border-bottom: none; }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
tr.total td { font-weight: 700; background: var(--surface-2); }

/* ===== Callout ===== */
.callout {
  border-left: 4px solid var(--primary);
  background: var(--primary-soft);
  padding: 12px 16px;
  border-radius: 0 var(--radius) var(--radius) 0;
  margin: 16px 0;
}

.callout.warn { border-color: var(--warn); background: var(--warn-soft); }
.callout.danger { border-color: var(--danger); background: var(--danger-soft); }
.callout.ok { border-color: var(--accent); background: var(--ok-soft); }
.callout strong:first-child { display: block; margin-bottom: 2px; }

/* ===== Accordion (details) ===== */
details {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin: 10px 0;
  overflow: hidden;
}

summary {
  cursor: pointer;
  padding: 12px 16px;
  font-weight: 600;
  list-style: none;
}

summary::-webkit-details-marker { display: none; }
summary::before { content: "▸"; display: inline-block; margin-right: 8px; transition: transform 0.15s; }
details[open] > summary::before { transform: rotate(90deg); }
details[open] > summary { border-bottom: 1px solid var(--border); background: var(--surface-2); }
details > .detail-body { padding: 4px 16px 14px; }

/* ===== Tab ===== */
.tabs { display: flex; gap: 6px; flex-wrap: wrap; margin: 16px 0 0; }

.tab-btn {
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--muted);
  padding: 8px 14px;
  border-radius: 8px 8px 0 0;
  cursor: pointer;
  font: inherit;
  font-size: 0.93rem;
}

.tab-btn.active { background: var(--primary-soft); color: var(--primary); border-color: var(--primary); font-weight: 600; }

.tab-panel {
  display: none;
  border: 1px solid var(--border);
  border-radius: 0 var(--radius) var(--radius) var(--radius);
  background: var(--surface);
  padding: 4px 18px 16px;
}

.tab-panel.active { display: block; }

/* ===== Diagram ===== */
.diagram {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  margin: 14px 0;
  overflow-x: auto;
  text-align: center;
}

.diagram .caption { font-size: 0.85rem; color: var(--muted); margin-top: 8px; }

/* ===== Form & kalkulator ===== */
.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  margin: 16px 0;
  box-shadow: var(--shadow);
}

.panel h3 { margin-top: 0; }

.form-row { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 12px; }
.field { display: flex; flex-direction: column; gap: 4px; flex: 1 1 140px; }
.field label { font-size: 0.85rem; color: var(--muted); }

input[type="number"], input[type="text"], select {
  font: inherit;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  width: 100%;
}

input:focus, select:focus, button:focus-visible, summary:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 1px;
}

.btn {
  font: inherit;
  border: none;
  background: var(--primary);
  color: #fff;
  padding: 9px 16px;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 600;
}

.btn:hover { opacity: 0.9; }
.btn.secondary { background: var(--surface-2); color: var(--text); border: 1px solid var(--border); }
.btn.danger { background: var(--danger); }
.btn-row { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 8px; }

.result { font-variant-numeric: tabular-nums; }
.pos { color: var(--accent); font-weight: 600; }
.neg { color: var(--danger); font-weight: 600; }

/* ===== Navigasi antar praktikum & footer ===== */
.pager { display: flex; justify-content: space-between; gap: 12px; margin: 40px 0; flex-wrap: wrap; }
.pager a {
  padding: 10px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  text-decoration: none;
  background: var(--surface);
}

.pager a:hover { border-color: var(--primary); }

footer {
  border-top: 1px solid var(--border);
  padding: 20px 0 32px;
  color: var(--muted);
  font-size: 0.88rem;
  text-align: center;
}

ul, ol { padding-left: 1.3em; }
li { margin: 0.25em 0; }

@media print {
  .navbar, .pager, .btn-row { display: none; }
  body { background: #fff; color: #000; }
}