@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500&family=IBM+Plex+Sans:wght@300;400;500;600&display=swap');

:root {
  --bg: #0d0d0d;
  --bg2: #141414;
  --bg3: #1a1a1a;
  --bg4: #1f1f1f;
  --border: #2a2a2a;
  --border2: #333;
  --text: #e8e8e8;
  --text2: #aaa;
  --text3: #666;
  --accent: #00e5a0;
  --blue: #4da6ff;
  --orange: #ff8c42;
  --purple: #b47fff;
  --red: #ff5757;
  --yellow: #ffd166;
  --mono: 'IBM Plex Mono', monospace;
  --sans: 'IBM Plex Sans', sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 14px;
  line-height: 1.7;
  min-height: 100vh;
}

/* ── Nav ── */
.topnav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 48px;
  border-bottom: 1px solid var(--border);
  font-family: var(--mono);
  font-size: 12px;
  height: 48px;
  position: sticky;
  top: 0;
  background: var(--bg);
  z-index: 100;
}

.topnav-left {
  display: flex;
  align-items: center;
  gap: 6px;
}

.topnav-left a {
  color: var(--text3);
  text-decoration: none;
  transition: color .15s;
}

.topnav-left a:hover { color: var(--text); }
.topnav-left .sep { color: var(--border); }
.topnav-left .current { color: var(--text2); }

.topnav-right {
  display: flex;
  align-items: center;
  gap: 24px;
}

.topnav-right a {
  color: var(--text3);
  text-decoration: none;
  font-size: 11px;
  letter-spacing: .04em;
  transition: color .15s;
  padding: 4px 0;
  border-bottom: 1px solid transparent;
}

.topnav-right a:hover { color: var(--text2); }
.topnav-right a.active {
  color: var(--text);
  border-bottom-color: var(--accent);
}

@media (max-width: 600px) {
  .topnav { padding: 0 20px; }
  .topnav-right { gap: 14px; }
  .page-header { padding: 32px 20px 24px; }
  .page-main { padding: 28px 20px; }
  .page-footer { padding: 20px; }
}

/* ── Page header ── */
.page-header {
  padding: 48px 48px 36px;
  max-width: 1100px;
  margin: 0 auto;
  border-bottom: 1px solid var(--border);
}

.phase-tag {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .12em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.page-title {
  font-size: clamp(22px, 3vw, 36px);
  font-weight: 300;
  letter-spacing: -.02em;
  margin-bottom: 12px;
  line-height: 1.25;
}

.page-subtitle {
  font-size: 14px;
  color: var(--text2);
  margin-bottom: 20px;
  max-width: 680px;
}

.meta-row {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
}

.meta-item {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--text3);
}

.meta-item strong {
  color: var(--text2);
  font-weight: 500;
}

/* ── Main layout ── */
.page-main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 40px 48px;
}

/* ── Week nav tabs ── */
.week-tabs {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin-bottom: 28px;
}

.wtab {
  padding: 6px 14px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg2);
  color: var(--text3);
  cursor: pointer;
  font-family: var(--mono);
  font-size: 12px;
  transition: all .15s;
}

.wtab:hover { border-color: var(--border2); color: var(--text2); }
.wtab.active { border-color: var(--border2); color: var(--text); background: var(--bg3); }

.week-panel { display: none; }
.week-panel.active { display: block; }

/* ── Section label ── */
.slabel {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--text3);
  letter-spacing: .1em;
  text-transform: uppercase;
  margin: 24px 0 10px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

/* ── Cards ── */
.card {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 18px 20px;
  margin-bottom: 12px;
}

.card-blue   { border-color: #2a4a6e; background: #0d1826; }
.card-purple { border-color: #3d2a6e; background: #130d26; }
.card-orange { border-color: #6e3a1a; background: #1a0e07; }
.card-green  { border-color: #1a5c3a; background: #071a10; }
.card-red    { border-color: #6e2020; background: #1a0707; }

.grid2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 12px;
}

@media (max-width: 600px) { .grid2 { grid-template-columns: 1fr; } }

/* ── Items ── */
.item {
  padding: 7px 0;
  border-bottom: 1px solid var(--border);
  font-size: 13px;
  line-height: 1.55;
}

.item:last-child { border-bottom: none; }

.item sub, .isub {
  display: block;
  font-size: 12px;
  color: var(--text3);
  margin-top: 3px;
}

/* ── Day badge ── */
.day {
  display: inline-block;
  font-family: var(--mono);
  font-size: 10px;
  padding: 2px 7px;
  border-radius: 3px;
  border: 1px solid var(--border2);
  color: var(--text3);
  margin-right: 6px;
  vertical-align: middle;
}

/* ── Code blocks ── */
pre {
  font-family: var(--mono);
  font-size: 12px;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 16px;
  margin: 12px 0;
  overflow-x: auto;
  line-height: 1.65;
  color: var(--text);
  white-space: pre;
}

code { font-family: var(--mono); }

/* ── Concept chips ── */
.chips { margin-bottom: 14px; }

.chip {
  display: inline-block;
  font-size: 11px;
  padding: 3px 9px;
  border-radius: 4px;
  margin: 2px;
  background: var(--bg3);
  border: 1px solid var(--border);
  color: var(--text3);
  font-family: var(--mono);
}

/* ── Milestone rows ── */
.milestone {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  font-size: 13px;
}

.milestone:last-child { border-bottom: none; }

.ms-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
  margin-top: 5px;
}

.ms-sub {
  display: block;
  font-size: 12px;
  color: var(--text3);
  margin-top: 2px;
}

/* ── Progress bar ── */
.prog-wrap {
  height: 3px;
  background: var(--border);
  border-radius: 2px;
  margin: 10px 0 20px;
  overflow: hidden;
}

.prog-fill {
  height: 100%;
  border-radius: 2px;
  transition: width .3s;
}

/* ── Week header ── */
.week-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 12px;
  gap: 12px;
  flex-wrap: wrap;
}

.week-title {
  font-size: 18px;
  font-weight: 500;
}

.badge {
  font-family: var(--mono);
  font-size: 11px;
  padding: 3px 10px;
  border-radius: 4px;
  border: 1px solid;
  flex-shrink: 0;
}

/* ── Alert boxes ── */
.alert {
  border-left: 3px solid;
  padding: 12px 16px;
  margin: 12px 0;
  border-radius: 0 6px 6px 0;
  font-size: 13px;
  line-height: 1.6;
}

.alert-title {
  font-weight: 500;
  margin-bottom: 6px;
}

/* ── Q&A accordion ── */
.qa {
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-bottom: 8px;
  overflow: hidden;
}

.qa-q {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px;
  background: var(--bg2);
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  user-select: none;
  transition: background .15s;
}

.qa-q:hover { background: var(--bg3); }

.qa-arrow { font-size: 10px; color: var(--text3); transition: transform .2s; }
.qa-arrow.open { transform: rotate(180deg); }

.qa-a {
  display: none;
  padding: 14px 16px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--text2);
  border-top: 1px solid var(--border);
}

.qa-a.open { display: block; }

/* ── Tabs ── */
.tab-nav {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 16px;
}

.tbtn {
  padding: 8px 16px;
  border: none;
  background: transparent;
  color: var(--text3);
  cursor: pointer;
  font-size: 13px;
  font-family: var(--sans);
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  transition: all .15s;
}

.tbtn:hover { color: var(--text2); }
.tbtn.active { color: var(--text); border-bottom-color: var(--text); font-weight: 500; }

.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* ── Back link ── */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--text3);
  text-decoration: none;
  margin-bottom: 24px;
  transition: color .15s;
}

.back-link:hover { color: var(--text2); }

/* ── Footer ── */
.page-footer {
  border-top: 1px solid var(--border);
  padding: 24px 48px;
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--text3);
  flex-wrap: wrap;
  gap: 12px;
}

.page-footer a {
  color: var(--text3);
  text-decoration: none;
}

.page-footer a:hover { color: var(--text2); }