:root {
  --paper: #FAF9F6;
  --grid: #E1DED5;
  --grid-strong: #CFCBC0;
  --ink: #16241C;
  --ink-soft: #5B6B60;
  --ink-faint: #97A199;

  --green: #0F5C46;
  --green-bright: #1B8F6B;
  --green-pale: #E7F3EE;
  --amber: #E8A23D;
  --amber-pale: #FBF0DD;

  --blue-deep: #0B3B5C;
  --blue-mid: #0F4E76;
  --blue-line: #1C5480;
  --blue-line-strong: #2B6699;
  --on-blue: #FFFFFF;
  --on-blue-soft: #BFD9EC;
  --on-blue-faint: #7FA6C4;
  --green-on-blue: #4FD8A8;

  --stamp: #C0483A;
  --stamp-soft: #F7E5E2;

  --font-display: 'Space Grotesk', system-ui, sans-serif;
  --font-body: 'Inter', system-ui, sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0; padding: 0;
  background: var(--blue-deep);
  color: var(--on-blue);
  font-family: var(--font-body);
  -webkit-font-smoothing: antialiased;
}
body {
  background-image:
    linear-gradient(var(--blue-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--blue-line) 1px, transparent 1px);
  background-size: 64px 40px;
  min-height: 100vh;
}
.mono { font-family: var(--font-mono); }
a { color: var(--green-on-blue); }

/* ---------- chrome / top bar ---------- */
.chrome {
  position: sticky; top: 0; z-index: 20;
  background: var(--blue-deep);
  border-bottom: 1px solid var(--blue-line-strong);
}
.chrome-inner {
  max-width: 1180px; margin: 0 auto;
  padding: 12px 24px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; }
.brand-logo { height: 30px; background: #fff; border-radius: 4px; padding: 3px 6px; }
.brand-name { font-family: var(--font-display); font-weight: 600; font-size: 15px; color: var(--on-blue); }
.chrome-nav { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.nav-link {
  color: var(--on-blue-soft); text-decoration: none; font-size: 13.5px; font-weight: 600;
  padding: 7px 12px; border-radius: 7px;
}
.nav-link:hover { background: rgba(255,255,255,0.08); color: #fff; }
.nav-user { font-size: 13px; color: var(--on-blue-faint); padding: 0 4px; }
.nav-cta { background: var(--green-bright); color: #fff; }
.nav-cta:hover { background: var(--green); color: #fff; }
.nav-logout { color: var(--on-blue-faint); }

/* ---------- buttons ---------- */
.btn {
  font-family: var(--font-body); font-size: 13.5px; font-weight: 600;
  padding: 9px 16px; border-radius: 8px; border: 1px solid transparent;
  cursor: pointer; text-decoration: none; display: inline-block; text-align: center;
}
.btn-primary { background: var(--green-bright); border-color: var(--green-bright); color: #fff; }
.btn-primary:hover { background: var(--green); }
.btn-ghost { background: transparent; border-color: var(--blue-line-strong); color: var(--on-blue); }
.btn-ghost:hover { background: rgba(255,255,255,0.06); }
.btn-block { width: 100%; }
.btn-tiny { font-size: 11.5px; padding: 5px 9px; }

/* ---------- hero ---------- */
.hero { padding: 56px 24px 20px; }
.hero-inner { max-width: 760px; margin: 0 auto; text-align: center; }
.badge-row { display: flex; justify-content: center; gap: 8px; margin-bottom: 18px; }
.badge {
  display: inline-flex; align-items: center; gap: 7px;
  font-family: var(--font-mono); font-size: 11.5px; font-weight: 600; letter-spacing: 0.06em;
  padding: 5px 12px; border-radius: 20px;
}
.badge-outline { color: var(--green-on-blue); background: rgba(79,216,168,0.1); border: 1px solid var(--green-on-blue); }
.kicker { font-family: var(--font-mono); font-size: 12.5px; color: var(--green-on-blue); font-weight: 600; margin: 0 0 6px; letter-spacing: 0.04em; }
h1 { font-family: var(--font-display); font-size: 38px; line-height: 1.15; font-weight: 700; margin: 0 0 14px; letter-spacing: -0.01em; color: var(--on-blue); }
.lede { font-size: 16px; color: var(--on-blue-soft); line-height: 1.6; max-width: 620px; margin: 0 auto; }

.progress-summary { margin: 28px auto 0; max-width: 440px; }
.progress-track { height: 9px; background: var(--blue-mid); border: 1px solid var(--blue-line-strong); border-radius: 6px; overflow: hidden; }
.progress-fill { height: 100%; background: var(--green-on-blue); transition: width 0.3s ease; }
.progress-text { display: block; margin-top: 8px; font-family: var(--font-mono); font-size: 12px; color: var(--on-blue-soft); }

.hero-cta { margin-top: 28px; display: flex; flex-direction: column; align-items: center; gap: 10px; }
.hero-cta .btn { min-width: 200px; }
.hero-cta-note { font-size: 12.5px; color: var(--on-blue-faint); margin: 4px 0 0; }

/* ---------- lesson grid ---------- */
.lesson-grid-wrap { max-width: 1180px; margin: 0 auto; padding: 24px; }
.lesson-grid {
  display: grid; grid-template-columns: repeat(4, 1fr);
  background: var(--paper);
  border-top: 1px solid var(--grid-strong);
  border-left: 1px solid var(--grid-strong);
  box-shadow: 0 18px 40px rgba(3,20,34,0.35);
}
.lesson-card {
  position: relative;
  border-right: 1px solid var(--grid-strong);
  border-bottom: 1px solid var(--grid-strong);
  padding: 18px 18px 20px;
  text-decoration: none; color: var(--ink);
  display: flex; flex-direction: column;
  transition: background 0.12s ease, box-shadow 0.12s ease;
}
.lesson-card:hover { background: #fff; box-shadow: inset 0 0 0 2px var(--green-bright); z-index: 1; }
.lesson-card-top { display: flex; justify-content: space-between; align-items: center; }
.lesson-no { font-family: var(--font-mono); font-size: 10px; color: var(--ink-faint); letter-spacing: 0.04em; }
.lesson-duration { font-family: var(--font-mono); font-size: 10px; color: var(--ink-faint); }
.lesson-icon { font-size: 22px; height: 30px; display: flex; align-items: center; margin: 14px 0 10px; color: var(--ink); }
.lesson-icon .chip { font-family: var(--font-mono); font-size: 12px; font-weight: 600; color: var(--green); background: var(--green-pale); border: 1px solid var(--green-bright); border-radius: 4px; padding: 2px 7px; }
.lesson-card h3 { font-family: var(--font-display); font-size: 14.5px; font-weight: 600; margin: 0 0 8px; line-height: 1.3; color: var(--ink); }
.lesson-card p { font-size: 12.5px; color: var(--ink-soft); line-height: 1.5; margin: 0 0 14px; flex: 1; }
.lesson-card-foot { margin-top: auto; }
.start-tag { font-size: 12px; font-weight: 600; color: var(--green); }
.done-tag { font-size: 12px; font-weight: 700; color: var(--green-bright); }
.lesson-card.is-done { background: var(--green-pale); }
.lesson-card.is-done:hover { background: #ddefe7; }

/* ---------- lesson detail page ---------- */
.lesson-main { max-width: 1180px; margin: 0 auto; padding: 28px 24px 10px; }
.lesson-layout { display: grid; grid-template-columns: 1fr 340px; gap: 28px; align-items: start; }
.back-link { color: var(--on-blue-soft); text-decoration: none; font-size: 13px; }
.back-link:hover { color: #fff; }
.back-link-inline { display: inline-block; margin-bottom: 14px; }
.lesson-title { font-family: var(--font-display); font-size: 28px; margin: 0 0 6px; color: var(--on-blue); }
.lesson-subtitle { font-size: 15px; color: var(--on-blue-soft); margin: 0 0 20px; }

.video-frame { position: relative; width: 100%; padding-top: 56.25%; background: #000; border-radius: 10px; overflow: hidden; border: 1px solid var(--blue-line-strong); }
.video-frame iframe { position: absolute; inset: 0; width: 100%; height: 100%; }

.complete-bar { display: flex; align-items: center; gap: 12px; margin-top: 18px; flex-wrap: wrap; }
.btn-complete {
  display: inline-flex; align-items: center; gap: 9px;
  font-family: var(--font-body); font-size: 14px; font-weight: 600;
  padding: 10px 18px; border-radius: 8px; cursor: pointer;
  background: transparent; border: 1.5px solid var(--green-on-blue); color: var(--green-on-blue);
}
.btn-complete:hover { background: rgba(79,216,168,0.1); }
.btn-complete .complete-icon { display: inline-flex; width: 18px; height: 18px; align-items: center; justify-content: center; border: 1.5px solid currentColor; border-radius: 50%; font-size: 11px; }
.btn-complete.is-done { background: var(--green-bright); border-color: var(--green-bright); color: #fff; }
.btn-complete.is-done:hover { background: var(--green); }

.signin-prompt { margin-top: 18px; padding: 14px 16px; background: var(--blue-mid); border: 1px solid var(--blue-line-strong); border-radius: 8px; font-size: 13.5px; color: var(--on-blue-soft); }

/* lesson sidebar */
.lesson-side { display: flex; flex-direction: column; gap: 16px; }
.side-card { background: var(--paper); border-radius: 10px; padding: 18px; color: var(--ink); box-shadow: 0 12px 30px rgba(3,20,34,0.3); }
.side-card h2 { font-family: var(--font-display); font-size: 14px; margin: 0 0 12px; color: var(--ink); text-transform: uppercase; letter-spacing: 0.04em; }
.objectives { margin: 0; padding: 0; list-style: none; }
.objectives li { position: relative; padding-left: 22px; margin-bottom: 10px; font-size: 13px; color: var(--ink-soft); line-height: 1.45; }
.objectives li:before { content: "✓"; position: absolute; left: 0; top: 0; color: var(--green-bright); font-weight: 700; }
.side-card-accent { border-top: 3px solid var(--amber); }
.side-note { font-size: 12.5px; color: var(--ink-soft); line-height: 1.5; margin: 0 0 14px; }
.side-note strong { color: var(--green); font-family: var(--font-mono); font-size: 12px; }
.side-filename { font-family: var(--font-mono); font-size: 10.5px; color: var(--ink-faint); text-align: center; margin: 8px 0 0; }

.side-nav { display: flex; flex-direction: column; gap: 8px; }
.side-nav-link { background: var(--blue-mid); border: 1px solid var(--blue-line-strong); border-radius: 8px; padding: 12px 14px; text-decoration: none; display: block; }
.side-nav-link:hover { background: #12567f; }
.side-nav-dir { display: block; font-family: var(--font-mono); font-size: 10.5px; color: var(--green-on-blue); margin-bottom: 3px; }
.side-nav-title { display: block; font-size: 13px; color: var(--on-blue); font-weight: 500; }

/* ---------- auth pages ---------- */
.auth-main { max-width: 420px; margin: 0 auto; padding: 50px 24px; }
.auth-card { background: var(--paper); border-radius: 12px; padding: 32px 28px; color: var(--ink); box-shadow: 0 18px 44px rgba(3,20,34,0.4); }
.auth-card h1 { font-family: var(--font-display); font-size: 24px; margin: 0 0 6px; color: var(--ink); }
.auth-sub { font-size: 13.5px; color: var(--ink-soft); margin: 0 0 22px; }
.auth-form { display: flex; flex-direction: column; gap: 14px; }
.auth-form label { font-size: 12.5px; font-weight: 600; color: var(--ink-soft); display: flex; flex-direction: column; gap: 5px; }
.auth-form input { font-family: var(--font-body); font-size: 14px; padding: 10px 12px; border: 1px solid var(--grid-strong); border-radius: 8px; background: #fff; color: var(--ink); }
.auth-form input:focus { outline: none; border-color: var(--green-bright); }
.optional { font-weight: 400; color: var(--ink-faint); }
.auth-alt { text-align: center; font-size: 13px; color: var(--ink-soft); margin: 18px 0 0; }
.auth-alt a { color: var(--green); font-weight: 600; }
.auth-form .btn-primary { margin-top: 4px; }

.alert { padding: 10px 14px; border-radius: 8px; font-size: 13px; margin-bottom: 16px; }
.alert-error { background: var(--stamp-soft); color: var(--stamp); }
.notice { background: var(--paper); color: var(--ink); border-radius: 10px; padding: 20px; max-width: 500px; margin: 40px auto; text-align: center; }
.wrap-narrow { max-width: 700px; margin: 0 auto; padding: 24px; }

/* ---------- admin ---------- */
.wrap { max-width: 1180px; margin: 0 auto; padding: 28px 24px 50px; }
.admin-h1 { font-family: var(--font-display); font-size: 26px; color: var(--on-blue); margin: 0 0 22px; }
.cards { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin-bottom: 26px; }
.card { background: var(--paper); border-radius: 10px; border-left: 4px solid var(--green-bright); padding: 16px 18px; color: var(--ink); display: flex; flex-direction: column; gap: 6px; }
.card-label { font-size: 11px; text-transform: uppercase; letter-spacing: 0.06em; color: var(--ink-faint); font-weight: 600; }
.card-value { font-size: 26px; font-weight: 600; color: var(--ink); }

.admin-block { background: var(--paper); border-radius: 10px; padding: 20px 22px; color: var(--ink); margin-bottom: 20px; }
.admin-block h2 { font-family: var(--font-display); font-size: 16px; margin: 0 0 16px; color: var(--ink); }
.admin-block-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 16px; }
.admin-block-head h2 { margin: 0; }

.lesson-bars { display: flex; flex-direction: column; gap: 10px; }
.lesson-bar-row { display: grid; grid-template-columns: 1fr 160px 34px; align-items: center; gap: 12px; }
.lesson-bar-label { font-size: 12.5px; color: var(--ink-soft); }
.lesson-bar-track { height: 8px; background: var(--grid); border-radius: 4px; overflow: hidden; }
.lesson-bar-fill { height: 100%; background: var(--green-bright); }
.lesson-bar-count { font-size: 12px; color: var(--ink-soft); text-align: right; }

.table-scroll { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 13px; color: var(--ink); }
thead th { text-align: left; font-size: 10.5px; text-transform: uppercase; letter-spacing: 0.05em; color: var(--ink-faint); font-weight: 600; padding: 8px 10px; border-bottom: 2px solid var(--grid-strong); white-space: nowrap; }
tbody td { padding: 9px 10px; border-bottom: 1px solid var(--grid); }
tbody tr:hover { background: #fff; }
.empty-row { text-align: center; color: var(--ink-faint); padding: 24px; }
.row-actions { display: flex; gap: 8px; align-items: center; }
.btn-reset { background: #fff; border: 1px solid var(--grid-strong); color: var(--ink); }
.btn-reset:hover { background: var(--paper); }
.row-delete { background: none; border: none; color: var(--ink-faint); cursor: pointer; font-size: 15px; }
.row-delete:hover { color: var(--stamp); }

.mini-progress { display: flex; align-items: center; gap: 8px; min-width: 120px; }
.mini-track { flex: 1; height: 6px; background: var(--grid); border-radius: 3px; overflow: hidden; }
.mini-fill { height: 100%; background: var(--green-bright); }
.mini-label { font-size: 11px; color: var(--ink-soft); }

/* ---------- modals ---------- */
.modal-backdrop { display: none; position: fixed; inset: 0; background: rgba(11,36,54,0.55); align-items: center; justify-content: center; z-index: 60; }
.modal-backdrop.open { display: flex; }
.modal { background: #fff; border-radius: 12px; padding: 24px; width: 340px; color: var(--ink); display: flex; flex-direction: column; gap: 12px; }
.modal h3 { font-family: var(--font-display); margin: 0 0 4px; font-size: 17px; }
.modal-note { font-size: 12.5px; color: var(--ink-soft); margin: 0; }
.modal label { font-size: 12.5px; color: var(--ink-soft); font-weight: 600; display: flex; flex-direction: column; gap: 4px; }
.modal input { font-family: var(--font-body); font-size: 13.5px; padding: 9px 11px; border: 1px solid var(--grid-strong); border-radius: 7px; }
.modal-actions { display: flex; justify-content: flex-end; gap: 8px; margin-top: 6px; }
.modal .btn { border: 1px solid var(--grid-strong); background: #fff; color: var(--ink); }
.modal .btn-primary { background: var(--green-bright); border-color: var(--green-bright); color: #fff; }

/* ---------- footer ---------- */
.page-footer { text-align: center; padding: 36px 24px 50px; }
.page-footer p { font-family: var(--font-mono); font-size: 11.5px; color: var(--on-blue-faint); margin: 0; }

/* ---------- responsive ---------- */
@media (max-width: 1000px) {
  .lesson-grid { grid-template-columns: repeat(2, 1fr); }
  .lesson-layout { grid-template-columns: 1fr; }
  .cards { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 560px) {
  .lesson-grid { grid-template-columns: 1fr; }
  h1 { font-size: 28px; }
  .lesson-bar-row { grid-template-columns: 1fr 90px 28px; }
}

/* ---------- in-lesson reading text ---------- */
.reading { margin-top: 32px; background: var(--paper); border-radius: 12px; color: var(--ink); box-shadow: 0 14px 34px rgba(3,20,34,0.32); overflow: hidden; }
.reading-tabs { display: flex; gap: 0; background: var(--blue-mid); border-bottom: 1px solid var(--blue-line-strong); }
.reading-tab { flex: 0 0 auto; font-family: var(--font-body); font-size: 13.5px; font-weight: 600; color: var(--on-blue-soft); background: transparent; border: none; padding: 13px 22px; cursor: pointer; border-bottom: 3px solid transparent; }
.reading-tab:hover { color: #fff; }
.reading-tab.is-active { color: #fff; background: var(--paper); color: var(--blue-deep); border-bottom-color: var(--amber); }
.reading-panel { display: none; padding: 28px 30px 30px; }
.reading-panel.is-active { display: block; }
.reading-intro { font-size: 15px; font-style: italic; color: var(--ink-soft); line-height: 1.6; margin: 0 0 20px; }
.reading-h { font-family: var(--font-display); font-size: 16px; color: var(--blue-deep); margin: 24px 0 10px; padding-left: 12px; border-left: 4px solid var(--green-bright); }
.reading-panel p { font-size: 14px; line-height: 1.65; color: var(--ink); margin: 0 0 12px; }
.reading-panel code { font-family: var(--font-mono); font-size: 12.5px; color: var(--green); background: var(--green-pale); border-radius: 3px; padding: 1px 5px; }
.reading-callout { background: #fff; border-left: 5px solid var(--blue-mid); border-radius: 6px; padding: 16px 18px; margin: 20px 0; box-shadow: 0 2px 8px rgba(0,0,0,0.04); }
.reading-callout-label { font-family: var(--font-mono); font-size: 11px; font-weight: 600; letter-spacing: 0.08em; color: var(--blue-mid); text-transform: uppercase; }
.reading-callout p { margin: 6px 0 0; font-size: 14px; }
.reading-tips { margin: 8px 0 0; padding: 0; list-style: none; }
.reading-tips li { position: relative; padding-left: 26px; margin-bottom: 10px; font-size: 14px; line-height: 1.55; color: var(--ink); }
.reading-tips li:before { content: "✓"; position: absolute; left: 0; top: 0; color: var(--green-bright); font-weight: 700; }
.reading-dl { margin-top: 22px; }
.reading-dl-note { margin-top: 20px; font-size: 13px; color: var(--ink-soft); }

/* how-to panel specifics */
.howto-goal { background: var(--amber-pale); border-left: 5px solid var(--amber); border-radius: 6px; padding: 14px 18px; margin-bottom: 20px; }
.howto-goal-label { font-family: var(--font-mono); font-size: 11px; font-weight: 600; letter-spacing: 0.08em; color: #93650E; text-transform: uppercase; }
.howto-goal p { margin: 5px 0 0; font-size: 14px; }
.howto-workbook { font-size: 12.5px !important; color: var(--ink-soft) !important; }
.howto-workbook strong { font-family: var(--font-mono); color: var(--green); }
.howto-steps { margin: 0; padding: 0; counter-reset: step; list-style: none; }
.howto-steps li { position: relative; padding: 12px 0 12px 46px; border-bottom: 1px solid var(--grid); min-height: 30px; }
.howto-steps li:before { counter-increment: step; content: counter(step); position: absolute; left: 0; top: 12px; width: 28px; height: 28px; background: var(--blue-deep); color: #fff; font-family: var(--font-display); font-weight: 600; font-size: 14px; border-radius: 6px; display: flex; align-items: center; justify-content: center; }
.howto-step-text { display: block; font-size: 14px; line-height: 1.55; color: var(--ink); }
.howto-step-note { display: block; font-size: 13px; font-style: italic; color: var(--ink-soft); margin-top: 4px; }
.howto-ref { width: 100%; border-collapse: collapse; margin-top: 6px; font-size: 13px; }
.howto-ref thead th { background: var(--blue-deep); color: #fff; text-align: left; padding: 8px 12px; font-size: 11px; text-transform: uppercase; letter-spacing: 0.04em; }
.howto-ref tbody td { padding: 8px 12px; border-bottom: 1px solid var(--grid); color: var(--ink); }
.howto-ref tbody tr:nth-child(even) { background: #fff; }
.howto-ref .mono { font-family: var(--font-mono); font-size: 12px; color: var(--green); }
.howto-check { margin: 8px 0 0; padding: 0; list-style: none; }
.howto-check li { position: relative; padding-left: 28px; margin-bottom: 9px; font-size: 14px; color: var(--ink); }
.howto-check li:before { content: "☐"; position: absolute; left: 0; top: -1px; color: var(--green-bright); font-size: 16px; }

/* sidebar handout links */
.handout-link { display: flex; align-items: center; gap: 11px; padding: 10px; border: 1px solid var(--grid-strong); border-radius: 8px; text-decoration: none; margin-bottom: 8px; transition: border-color 0.12s, background 0.12s; }
.handout-link:hover { border-color: var(--green-bright); background: var(--green-pale); }
.handout-icon { font-size: 20px; }
.handout-text { display: flex; flex-direction: column; }
.handout-name { font-size: 13px; font-weight: 600; color: var(--ink); }
.handout-meta { font-size: 11px; color: var(--ink-faint); }

/* ---------- account page ---------- */
.alert-success { background: var(--green-pale); color: var(--green); }
.auth-section { font-family: var(--font-display); font-size: 15px; color: var(--blue-deep); margin: 22px 0 14px; padding-bottom: 8px; border-bottom: 1px solid var(--grid-strong); }
.nav-link[href$="account.php"] { color: var(--on-blue); }