:root {
  --ink: #07102b;
  --muted: #52607f;
  --line: #dfe6f2;
  --blue: #075cff;
  --navy: #020b1f;
  --panel: #ffffff;
  --soft: #f5f8fc;
  --green: #059669;
  --purple: #7c3aed;
  --red: #ef4444;
}
* { box-sizing: border-box; }
body { margin: 0; font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; color: var(--ink); background: #f8fafc; }
a { color: inherit; text-decoration: none; }
button, input, textarea, select { font: inherit; }
label { color: #111936; }
input:not([type="checkbox"]):not([type="radio"]):not([type="hidden"]):not([type="submit"]):not([type="button"]),
textarea,
select,
.input {
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 11px 12px;
  background: white;
  color: var(--ink);
  width: 100%;
  min-height: 44px;
  display: block;
  outline: none;
  transition: border-color .15s ease, box-shadow .15s ease, background-color .15s ease;
}
input:not([type="checkbox"]):not([type="radio"]):not([type="hidden"]):not([type="submit"]):not([type="button"]):focus,
textarea:focus,
select:focus,
.input:focus {
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(7, 92, 255, .12);
}
input::placeholder, textarea::placeholder { color: #8a95ad; }
input[type="file"] { padding: 9px 12px; }
.topbar { height: 72px; background: var(--navy); color: white; display: flex; align-items: center; gap: 24px; padding: 0 28px; position: sticky; top: 0; z-index: 20; }
.brand { flex: 0 0 auto; font-size: 28px; font-weight: 800; letter-spacing: 0; line-height: 1; margin-right: auto; white-space: nowrap; }
.brand span { color: #1683ff; }
.brand small { font-size: .68em; }
.nav { display: flex; align-items: center; flex: 0 1 auto; gap: 22px; font-weight: 650; }
.notification-nav-link { display: inline-flex; align-items: center; gap: 7px; }
.notification-count { min-width: 20px; height: 20px; border-radius: 999px; display: inline-grid; place-items: center; padding: 0 6px; background: #ef4444; color: white; font-size: 12px; font-weight: 900; line-height: 1; }
.user-pill { display: flex; align-items: center; flex: 0 0 auto; gap: 12px; }
.avatar { width: 38px; height: 38px; border-radius: 999px; background: #1683ff; display: grid; place-items: center; font-weight: 800; color: white; }
.app-shell { display: grid; grid-template-columns: 300px 1fr; min-height: calc(100vh - 72px); }
.sidebar { border-right: 1px solid var(--line); background: white; padding: 28px 18px; }
.side-link { display: flex; gap: 14px; align-items: center; padding: 14px 16px; border-radius: 6px; color: #111936; margin-bottom: 6px; }
.side-link.active, .side-link:hover { background: #eef5ff; color: var(--blue); }
.side-heading { font-size: 12px; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); margin: 28px 14px 10px; }
.main { padding: 36px 44px; }
.grid { display: grid; gap: 24px; }
.dashboard-grid { grid-template-columns: minmax(0, 1.45fr) minmax(360px, .95fr); }
.dashboard-header { display: grid; grid-template-columns: minmax(0, 1fr) minmax(430px, 560px); gap: 24px; align-items: start; margin-bottom: 28px; }
.dashboard-welcome { min-width: 0; }
.dashboard-welcome h1 { font-size: clamp(28px, 3vw, 34px); line-height: 1.14; margin: 0; }
.dashboard-card-header { display: flex; justify-content: space-between; align-items: flex-start; gap: 16px; margin-bottom: 18px; }
.dashboard-card-header h2, .dashboard-card-header h3 { margin: 0; }
.dashboard-card-header a { color: var(--blue); font-weight: 750; white-space: nowrap; }
.dashboard-split { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
.dashboard-course-code { border-color: white; color: white; padding: 6px 10px; }
.dashboard-course-title { font-size: 32px; margin-top: 28px; }
.continue-footer { display: flex; justify-content: space-between; align-items: center; gap: 18px; padding-top: 18px; }
.card { background: var(--panel); border: 1px solid var(--line); border-radius: 8px; padding: 22px; }
.card h2, .card h3 { margin: 0 0 18px; }
.hero-card { background: #062858; color: white; padding: 28px; border-radius: 8px; overflow: hidden; position: relative; }
.hero-card:before { content: ""; position: absolute; inset: 0; background: radial-gradient(circle at 70% 20%, rgba(22,131,255,.45), transparent 35%), linear-gradient(135deg, rgba(255,255,255,.06), transparent); }
.hero-card > * { position: relative; }
.status { display: inline-flex; align-items: center; border-radius: 999px; padding: 6px 10px; background: #dff7ea; color: #047857; font-size: 12px; font-weight: 800; }
.progress { height: 8px; background: rgba(255,255,255,.15); border-radius: 99px; overflow: hidden; }
.progress span { display: block; height: 100%; background: #5aa2ff; }
.btn { border: 1px solid var(--line); background: white; color: var(--ink); border-radius: 6px; padding: 11px 16px; display: inline-flex; gap: 8px; align-items: center; justify-content: center; cursor: pointer; font-weight: 700; }
.btn.primary { background: var(--blue); border-color: var(--blue); color: white; }
.btn.danger { border-color: #fecaca; color: #dc2626; }
.btn.ghost { background: transparent; }
.hero-card .dashboard-course-code { border-color: rgba(255,255,255,.82); color: white; }
.btn.compact { padding: 8px 12px; min-height: 38px; font-size: 14px; }
.muted { color: var(--muted); }
.metric-row { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.dashboard-metrics { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.metric { display: flex; align-items: center; gap: 18px; }
.metric-icon { flex: 0 0 auto; font-size: 28px; line-height: 1; }
.metric strong { font-size: 24px; display: block; }
.activity-list, .achievement-list { display: grid; gap: 12px; }
.activity-item { display: grid; grid-template-columns: 38px minmax(0, 1fr); gap: 12px; align-items: start; padding: 10px 0; border-bottom: 1px solid var(--line); }
.activity-item:last-child { border-bottom: 0; }
.activity-icon { width: 38px; height: 38px; border-radius: 8px; display: grid; place-items: center; background: #eef5ff; color: var(--blue); font-weight: 900; }
.activity-item strong, .achievement-item strong { display: block; line-height: 1.3; overflow-wrap: anywhere; }
.activity-item small, .achievement-item small { display: block; margin-top: 3px; line-height: 1.35; }
.achievement-item { display: grid; grid-template-columns: 48px minmax(0, 1fr); gap: 12px; align-items: center; padding: 10px; border: 1px solid var(--line); border-radius: 8px; background: #fbfdff; min-width: 0; }
.achievement-item img, .achievement-fallback { width: 48px; height: 48px; border-radius: 999px; }
.achievement-item img { display: block; object-fit: cover; border: 1px solid #bfdbfe; background: white; max-width: 48px; max-height: 48px; }
.achievement-fallback { display: grid; place-items: center; background: #eef5ff; color: var(--blue); font-size: 24px; font-weight: 900; }
.achievement-item.locked { opacity: .74; filter: grayscale(.25); }
.weekly-chart { height: 176px; display: grid; grid-template-columns: repeat(7, minmax(0, 1fr)); gap: 10px; align-items: end; padding-top: 12px; }
.weekly-day { display: grid; gap: 6px; justify-items: center; align-items: end; color: var(--muted); font-size: 12px; }
.weekly-bar { width: 100%; max-width: 34px; min-height: 8px; background: #9fc6ff; border-radius: 4px 4px 0 0; }
.weekly-bar.today { background: var(--blue); }
.weekly-day strong { color: #33415f; font-size: 12px; }
.weekly-day small { font-size: 11px; }
.list-item { display: grid; grid-template-columns: 54px 1fr 24px; gap: 16px; align-items: center; padding: 16px 0; border-bottom: 1px solid var(--line); }
.icon-tile { width: 54px; height: 54px; border-radius: 8px; background: #eef5ff; color: var(--blue); display: grid; place-items: center; font-size: 24px; }
.course-layout { display: grid; grid-template-columns: 300px minmax(0, 1fr) 560px; min-height: calc(100vh - 72px); }
.course-layout.lesson-focus { grid-template-columns: 300px minmax(0, 1fr); }
.course-nav { background: #06264c; color: white; padding: 24px 14px; overflow-y: auto; }
.course-nav .lesson-link { display: block; padding: 10px 14px; border-radius: 6px; color: #dbeafe; font-size: 14px; }
.course-nav .lesson-link.active { background: #10498e; color: white; }
.topic-nav { margin: 4px 0 8px 14px; }
.topic-nav summary { color: #bfdbfe; cursor: pointer; font-size: 13px; line-height: 1.35; padding: 7px 10px; }
.course-content { background: white; padding: 32px; overflow-y: auto; }
.lab-panel { background: #fbfcff; border-left: 1px solid var(--line); padding: 26px 22px; overflow-y: auto; }
.tabs { display: flex; gap: 24px; border-bottom: 1px solid var(--line); margin: 24px 0; }
.tabs a { padding: 0 0 14px; color: var(--muted); font-weight: 700; }
.tabs a.active { color: var(--blue); border-bottom: 2px solid var(--blue); }
.tabs .router-tab { border: 0; border-bottom: 2px solid transparent; background: transparent; color: var(--muted); cursor: pointer; padding: 0 0 14px; font-weight: 700; }
.tabs .router-tab.active, .tabs .router-tab:hover { color: var(--blue); border-bottom-color: var(--blue); }
.objective li { margin: 10px 0; }
.lesson-reader-grid { display: grid; grid-template-columns: minmax(0, 1fr) 230px; gap: 28px; align-items: start; }
.lesson-article { min-width: 0; }
.lesson-outline { position: sticky; top: 22px; border-left: 1px solid var(--line); padding-left: 18px; max-height: calc(100vh - 130px); overflow-y: auto; }
.lesson-outline strong { display: block; margin-bottom: 12px; color: var(--ink); }
.lesson-outline nav, .lesson-outline-mobile nav { display: grid; gap: 4px; }
.lesson-outline-link { display: block; border-radius: 6px; color: var(--muted); font-size: 13px; line-height: 1.35; padding: 7px 8px; }
.lesson-outline-link.level-3 { padding-left: 18px; font-size: 12px; }
.lesson-outline-link:hover, .lesson-outline-link.active { background: #eef5ff; color: var(--blue); }
.lesson-outline-mobile { display: none; border: 1px solid var(--line); border-radius: 8px; padding: 12px; margin-bottom: 20px; background: #fbfdff; }
.lesson-outline-mobile summary { cursor: pointer; font-weight: 800; color: var(--ink); }
.lesson-outline-mobile nav { margin-top: 10px; }
.lesson-body { color: #111936; line-height: 1.65; font-size: 16px; }
.lesson-body > *:first-child { margin-top: 0; }
.lesson-body h1, .lesson-body h2, .lesson-body h3, .lesson-body h4 { color: var(--ink); line-height: 1.25; margin: 28px 0 12px; }
.lesson-body h1 { font-size: 32px; }
.lesson-body h2 { font-size: 25px; }
.lesson-body h3 { font-size: 20px; }
.lesson-body h4 { font-size: 17px; }
.lesson-body p { margin: 0 0 16px; }
.lesson-body ul, .lesson-body ol { margin: 0 0 18px; padding-left: 26px; }
.lesson-body li { margin: 7px 0; }
.lesson-body a { color: var(--blue); font-weight: 700; text-decoration: underline; text-underline-offset: 3px; }
.lesson-body blockquote { margin: 20px 0; padding: 16px 18px; border-left: 4px solid var(--blue); background: #f1f6ff; border-radius: 0 6px 6px 0; color: #30415f; }
.lesson-body code { border: 1px solid #d8e2f3; background: #f8fafc; border-radius: 4px; padding: 2px 5px; font: 14px/1.4 ui-monospace, SFMono-Regular, Menlo, monospace; color: #183153; }
.lesson-body pre { background: #111827; color: #d1fae5; border-radius: 6px; padding: 16px; overflow-x: auto; margin: 18px 0; }
.lesson-body pre code { border: 0; background: transparent; color: inherit; padding: 0; }
.lesson-body table { display: block; width: 100%; max-width: 100%; border-collapse: collapse; margin: 20px 0; border: 1px solid var(--line); overflow-x: auto; }
.lesson-body th, .lesson-body td { border: 1px solid var(--line); padding: 10px 12px; text-align: left; vertical-align: top; }
.lesson-body th { background: #f8fafc; color: #33415f; }
.lesson-body hr { border: 0; border-top: 1px solid var(--line); margin: 26px 0; }
.lesson-body img { display: block; max-width: 100%; height: auto; border: 1px solid var(--line); border-radius: 8px; margin: 20px auto; background: white; }
.lesson-callout { margin: 20px 0; padding: 16px 18px; border-radius: 8px; border: 1px solid var(--line); background: #f8fafc; color: #30415f; }
.lesson-callout strong { display: block; margin-bottom: 8px; color: var(--ink); }
.lesson-callout p:last-child { margin-bottom: 0; }
.lesson-callout-note { border-color: #9dbbff; background: #f1f6ff; }
.lesson-callout-tip { border-color: #8fd7b5; background: #f0fdf6; }
.lesson-callout-warning { border-color: #fdba74; background: #fff7ed; }
.lesson-body .lesson-step-heading { display: grid; grid-template-columns: auto minmax(0, 1fr); align-items: center; gap: 10px; border: 1px solid #bfdbfe; background: #f8fbff; border-radius: 8px; padding: 12px 14px; margin-top: 30px; }
.lesson-step-number { color: var(--blue); background: #dbeafe; border-radius: 999px; padding: 4px 9px; font-size: 12px; font-weight: 900; text-transform: uppercase; }
.lesson-step-title { min-width: 0; }
.inline-knowledge-check { margin: 24px 0; padding: 18px; border: 1px solid #bfdbfe; border-radius: 8px; background: #f8fbff; }
.inline-knowledge-check-header { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-bottom: 10px; color: var(--muted); font-size: 12px; font-weight: 900; text-transform: uppercase; letter-spacing: .04em; }
.inline-knowledge-check-header strong { border-radius: 999px; padding: 4px 9px; background: #eef5ff; color: var(--blue); }
.inline-knowledge-check-header strong.correct { background: #ecfdf5; color: #047857; }
.inline-knowledge-check-header strong.incorrect { background: #fff7ed; color: #c2410c; }
.inline-knowledge-check-prompt { margin: 0 0 14px; color: var(--ink); font-size: 17px; font-weight: 800; line-height: 1.4; }
.inline-knowledge-check-choices { display: grid; gap: 9px; margin-bottom: 14px; }
.inline-knowledge-check-choice { display: flex; align-items: flex-start; gap: 10px; padding: 11px 12px; border: 1px solid var(--line); border-radius: 7px; background: white; cursor: pointer; }
.inline-knowledge-check-choice.selected { border-color: #9dbbff; background: #eef5ff; }
.inline-knowledge-check-choice input { margin-top: 3px; }
.inline-knowledge-check-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }
.inline-knowledge-check-feedback { margin-top: 14px; padding: 13px 14px; border-left: 4px solid #9dbbff; border-radius: 0 6px 6px 0; background: white; }
.inline-knowledge-check-feedback strong { display: block; margin-bottom: 5px; color: var(--ink); }
.inline-knowledge-check-feedback p { margin-bottom: 0; }
.text-success { color: #047857; font-weight: 800; }
.text-warning { color: #c2410c; font-weight: 800; }
.form-message { margin: 9px 0 0; font-size: 13px; font-weight: 800; }
.form-message.error { color: #b91c1c; }
.note-box { border: 1px solid #9dbbff; background: #f1f6ff; border-radius: 6px; padding: 18px; }
.code-box { background: #f8fafc; border: 1px solid var(--line); border-radius: 6px; padding: 18px; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; color: #30415f; }
.topology { border: 1px solid var(--line); background: white; border-radius: 6px; padding: 18px 14px; margin: 14px 0 16px; overflow-x: auto; }
.lab-topology-diagram { margin: 0; min-height: 150px; display: grid; place-items: center; background: transparent; color: var(--ink); }
.lab-topology-diagram svg { max-width: 100%; height: auto; display: block; margin: 0 auto; }
.lab-topology-diagram .node rect,
.lab-topology-diagram .node circle,
.lab-topology-diagram .node ellipse,
.lab-topology-diagram .node polygon,
.lab-topology-diagram .node path { rx: 7px; ry: 7px; }
.lab-topology-diagram .edgeLabel { font-weight: 800; color: #33415f; }
.lab-topology-diagram .edgeLabel .labelBkg { fill: white; stroke: #c7d2fe; stroke-width: 1px; }
.lab-topology-diagram .edgeLabel text,
.lab-topology-diagram .edgeLabel span { fill: #33415f; color: #33415f; }
.terminal { min-height: 310px; background: #151719; color: #80ff40; padding: 18px; border-radius: 6px; font: 14px/1.55 ui-monospace, SFMono-Regular, Menlo, monospace; white-space: pre-wrap; overflow-y: auto; cursor: text; outline: none; }
.terminal:focus { box-shadow: 0 0 0 3px rgba(7, 92, 255, .55); background: #10243a; }
.split-actions { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-top: 26px; padding-top: 18px; border-top: 1px solid var(--line); }
.inline-next-form { margin: 0; }
.inline-next-form .btn { display: inline-flex; align-items: center; justify-content: center; }
.practice-launches { display: grid; gap: 12px; margin: 28px 0; padding: 16px; border: 1px solid #bfdbfe; background: #f8fbff; border-radius: 8px; }
.practice-launches form { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }
.lab-drawer-backdrop { position: fixed; inset: 0; z-index: 60; background: rgba(2, 11, 31, .32); display: flex; justify-content: flex-end; }
.lab-drawer { width: min(620px, 100vw); height: 100vh; background: #fbfcff; border-left: 1px solid var(--line); box-shadow: -18px 0 50px rgba(15, 23, 42, .22); overflow-y: auto; padding: 22px; }
.drawer-toolbar { display: flex; justify-content: space-between; align-items: flex-start; gap: 14px; margin-bottom: 12px; }
.drawer-toolbar p { margin: 6px 0 0; }
.drawer-close { font-size: 24px; line-height: 1; min-width: 42px; }
.pricing { max-width: 980px; margin: 0 auto; display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.auth-page { max-width: 460px; margin: 60px auto; }
.auth-card { padding: 30px 24px 24px; }
.auth-card h1 { margin: 0 0 14px; font-size: 34px; }
.auth-form { display: grid; gap: 18px; margin-top: 28px; }
.auth-field { margin: 0; }
.auth-field label { display: block; font-weight: 750; margin-bottom: 8px; }
.auth-form .btn { width: 100%; min-height: 44px; margin-top: 4px; }
.studio-shell { display: grid; grid-template-columns: 250px minmax(0, 1fr); min-height: calc(100vh - 72px); }
.studio-sidebar { background: #071936; color: white; padding: 24px 16px; }
.studio-sidebar a { display: block; padding: 12px 14px; border-radius: 6px; color: #dbeafe; margin-bottom: 4px; }
.studio-sidebar a.active, .studio-sidebar a:hover { background: #123d73; color: white; }
.studio-main { padding: 32px 40px; }
.toolbar { display: flex; gap: 10px; align-items: center; justify-content: space-between; margin-bottom: 22px; }
.studio-course-header { align-items: flex-start; }
.studio-header-actions, .studio-toolbar-actions { display: flex; flex-wrap: wrap; gap: 10px; justify-content: flex-end; }
.studio-course-grid { display: grid; grid-template-columns: minmax(0, 1fr) 300px; align-items: start; gap: 24px; }
.studio-course-builder { min-width: 0; }
.studio-section-toolbar { align-items: flex-start; gap: 18px; }
.studio-section-toolbar h2 { max-width: 360px; }
.studio-domain { border-top: 1px solid var(--line); padding-top: 18px; margin-top: 18px; }
.studio-domain-header, .studio-topic-header { gap: 16px; align-items: flex-start; }
.studio-domain-header h3 { margin: 0; line-height: 1.25; }
.studio-topic { margin: 18px 0; }
.studio-topic-header { display: flex; justify-content: space-between; margin-bottom: 10px; }
.studio-topic-header strong { line-height: 1.35; max-width: 720px; }
.studio-lesson-list { border: 1px solid var(--line); border-radius: 8px; overflow: hidden; background: white; }
.studio-lesson-row { display: grid; grid-template-columns: minmax(240px, 1fr) minmax(140px, .45fr) minmax(220px, auto); gap: 14px; align-items: start; padding: 14px; border-top: 1px solid var(--line); }
.studio-lesson-row:first-child { border-top: 0; }
.studio-lesson-row:hover { background: #fbfdff; }
.studio-lesson-main { min-width: 0; }
.studio-lesson-main strong { display: block; line-height: 1.3; overflow-wrap: anywhere; }
.studio-lesson-main .muted { display: block; margin-top: 5px; font-size: 13px; }
.studio-lesson-meta { display: grid; gap: 8px; justify-items: start; min-width: 0; }
.studio-lab-pills { display: flex; flex-wrap: wrap; gap: 6px; min-width: 0; }
.studio-lab-pills .pill { max-width: 150px; white-space: normal; line-height: 1.2; }
.studio-lesson-actions { display: flex; flex-wrap: wrap; gap: 6px; justify-content: flex-end; }
.studio-lesson-actions .btn { min-width: 68px; }
.studio-empty { padding: 14px; margin: 0; }
.studio-side-panel { display: flex; flex-direction: column; gap: 18px; align-self: start; min-width: 0; }
.studio-side-card { padding: 18px; }
.studio-side-card h2 { font-size: 24px; margin-bottom: 12px; }
.studio-side-card-header { margin-bottom: 12px; align-items: flex-start; }
.studio-compact-list { display: grid; gap: 10px; }
.studio-compact-item { display: block; border: 1px solid var(--line); border-radius: 8px; padding: 12px; background: #fbfdff; }
.studio-compact-item:hover { border-color: #b9c8e6; background: white; }
.studio-compact-item strong, .studio-compact-item span { display: block; line-height: 1.35; }
.studio-compact-item span { margin-top: 3px; font-size: 14px; }
.knowledge-check-studio-item { border: 1px solid var(--line); border-radius: 8px; padding: 16px; margin-top: 18px; background: #fbfdff; }
.knowledge-check-studio-header { display: flex; justify-content: space-between; align-items: center; gap: 14px; margin-bottom: 14px; }
.knowledge-check-studio-header strong, .knowledge-check-studio-header code { display: block; }
.knowledge-check-studio-header code { width: fit-content; margin-top: 6px; border: 1px solid #d8e2f3; background: white; border-radius: 4px; padding: 4px 7px; color: #30415f; font: 12px/1.3 ui-monospace, SFMono-Regular, Menlo, monospace; }
.studio-status-row { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 12px; }
.studio-side-card-title { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; margin-bottom: 14px; }
.studio-side-card-title h2 { margin: 0; }
.studio-metadata-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.studio-metadata-item { border: 1px solid var(--line); border-radius: 8px; padding: 12px; background: #fbfdff; min-width: 0; }
.studio-metadata-item span, .studio-metadata-item small { display: block; color: var(--muted); line-height: 1.3; }
.studio-metadata-item span { font-size: 12px; font-weight: 850; text-transform: uppercase; letter-spacing: .04em; }
.studio-metadata-item strong { display: block; margin: 6px 0 3px; font-size: 22px; line-height: 1.05; overflow-wrap: anywhere; }
.studio-metadata-item small { font-size: 12px; }
.studio-filter-form { display: flex; align-items: end; gap: 10px; }
.studio-filter-form label { font-weight: 800; }
.studio-filter-form select { min-width: 180px; }
.studio-badge-group { border-top: 1px solid var(--line); margin-top: 20px; padding-top: 18px; }
.studio-badge-group:first-of-type { border-top: 0; margin-top: 0; padding-top: 0; }
.studio-badge-group h3 { margin: 0 0 12px; }
.studio-badge-list { display: grid; gap: 10px; }
.studio-badge-row { display: grid; grid-template-columns: 58px minmax(0, 1fr) minmax(130px, auto) auto; gap: 14px; align-items: center; border: 1px solid var(--line); border-radius: 8px; background: #fbfdff; padding: 12px; min-width: 0; }
.studio-badge-preview img, .studio-badge-preview .achievement-fallback { width: 52px; height: 52px; border-radius: 999px; }
.studio-badge-preview img { display: block; object-fit: cover; border: 1px solid #bfdbfe; background: white; }
.studio-badge-main, .studio-badge-meta { min-width: 0; }
.studio-badge-main strong, .studio-badge-main span, .studio-badge-main small, .studio-badge-meta small { display: block; line-height: 1.35; overflow-wrap: anywhere; }
.studio-badge-main span { margin-top: 3px; }
.studio-badge-main small, .studio-badge-meta small { margin-top: 5px; }
.studio-badge-actions { display: flex; justify-content: flex-end; }
.studio-badge-edit-grid { display: grid; grid-template-columns: 280px minmax(0, 1fr); gap: 26px; align-items: start; }
.studio-badge-image-panel, .studio-badge-fields { min-width: 0; }
.studio-badge-image-panel h2, .studio-badge-fields h2 { margin-top: 0; }
.studio-badge-large-preview { width: 160px; height: 160px; border: 1px solid var(--line); border-radius: 8px; display: grid; place-items: center; background: #fbfdff; margin-bottom: 14px; }
.studio-badge-large-preview img, .studio-badge-large-preview .achievement-fallback { width: 120px; height: 120px; border-radius: 999px; }
.studio-badge-large-preview img { object-fit: cover; border: 1px solid #bfdbfe; background: white; }
.studio-checkbox-row { display: flex; align-items: center; gap: 10px; margin-top: 12px; font-weight: 700; }
.studio-checkbox-row input { width: 18px; height: 18px; }
.studio-ticket-filters { display: grid; grid-template-columns: minmax(220px, 1.4fr) repeat(5, minmax(150px, 1fr)); gap: 14px; align-items: end; margin-bottom: 18px; }
.studio-filter-actions { display: flex; gap: 8px; align-items: center; grid-column: 1 / -1; }
.studio-ticket-list { display: grid; gap: 12px; }
.studio-ticket-row { display: grid; grid-template-columns: minmax(0, 1fr) 170px; align-items: start; gap: 16px; }
.studio-ticket-title { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin-bottom: 8px; }
.studio-ticket-title h2 { margin: 0; }
.studio-ticket-title strong { font-size: 18px; line-height: 1.35; }
.studio-ticket-main p { margin: 8px 0; line-height: 1.45; }
.studio-ticket-meta { display: flex; flex-wrap: wrap; gap: 8px 14px; color: var(--muted); font-size: 13px; }
.studio-ticket-side { display: grid; gap: 7px; justify-items: end; text-align: right; }
.ticket-status-new { background: #eef5ff; color: var(--blue); }
.ticket-status-triaged { background: #f3e8ff; color: #6d28d9; }
.ticket-status-in_progress { background: #ecfdf5; color: #047857; }
.ticket-status-waiting_for_info { background: #fff7ed; color: #c2410c; }
.ticket-status-resolved, .ticket-status-closed { background: #f1f5f9; color: #475569; }
.ticket-priority-high, .ticket-priority-urgent { background: #fff1f2; color: #be123c; }
.studio-ticket-detail-grid { display: grid; grid-template-columns: minmax(0, 1fr) 420px; align-items: start; gap: 24px; }
.studio-ticket-message { white-space: pre-wrap; line-height: 1.6; color: #111936; }
.studio-ticket-screenshot { margin-top: 24px; }
.studio-ticket-screenshot img { display: block; max-width: 100%; border: 1px solid var(--line); border-radius: 8px; background: white; }
.studio-ticket-notes { margin-top: 26px; padding-top: 20px; border-top: 1px solid var(--line); }
.studio-ticket-note-form { display: grid; gap: 10px; margin-bottom: 16px; }
.studio-ticket-note-form .btn { justify-self: start; }
.studio-ticket-note-list { display: grid; gap: 10px; }
.studio-ticket-note { border: 1px solid var(--line); border-radius: 8px; background: #fbfdff; padding: 12px; }
.studio-ticket-note p { margin: 8px 0 0; white-space: pre-wrap; line-height: 1.45; }
.studio-ticket-url { color: var(--blue); overflow-wrap: anywhere; }
.studio-ticket-context { display: grid; grid-template-columns: 92px minmax(0, 1fr); gap: 7px 12px; margin: 0; }
.studio-ticket-context dt { color: var(--muted); font-weight: 850; }
.studio-ticket-context dd { margin: 0; min-width: 0; overflow-wrap: anywhere; }
.studio-ticket-json { max-height: 220px; overflow: auto; border: 1px solid var(--line); border-radius: 6px; background: #f8fafc; padding: 12px; white-space: pre-wrap; color: #30415f; font-size: 12px; }
.inline-form { margin: 0; }
.table { width: 100%; border-collapse: collapse; background: white; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; }
.table th, .table td { border-bottom: 1px solid var(--line); padding: 13px 14px; text-align: left; vertical-align: top; }
.table th { background: #f8fafc; color: var(--muted); font-size: 12px; text-transform: uppercase; letter-spacing: .04em; }
.form-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.form-grid .full { grid-column: 1 / -1; }
.form-row label { display: block; font-weight: 750; margin-bottom: 6px; }
.quill-markdown-source-hidden { position: absolute !important; left: -10000px !important; width: 1px !important; height: 1px !important; opacity: 0 !important; pointer-events: none !important; }
.quill-markdown-editor { margin-top: 8px; border: 1px solid var(--line); border-radius: 6px; overflow: hidden; background: white; }
.quill-markdown-editor + .muted, .form-row small.muted { display: block; margin-top: 7px; }
.quill-lesson-toolbar.ql-toolbar.ql-snow { display: flex; flex-wrap: wrap; align-items: center; gap: 0; min-height: 44px; padding: 6px 10px; border: 0; border-bottom: 1px solid var(--line); background: #f8fafc; }
.quill-lesson-toolbar .ql-formats { display: inline-flex; align-items: center; margin: 0 8px 0 0; padding-right: 8px; border-right: 1px solid #e2e8f0; }
.quill-lesson-toolbar .ql-formats:last-child { border-right: 0; }
.quill-lesson-toolbar.ql-snow .ql-picker,
.quill-lesson-toolbar.ql-snow button { align-self: center; }
.quill-lesson-toolbar.ql-snow button { display: inline-flex; align-items: center; justify-content: center; width: 32px; height: 32px; padding: 0; border: 0; border-radius: 4px; background: transparent; }
.quill-lesson-toolbar.ql-snow button:hover,
.quill-lesson-toolbar.ql-snow button:focus { background: #e9edf5; color: var(--blue); outline: none; }
.quill-lesson-toolbar .ql-picker-label { display: inline-flex; align-items: center; height: 32px; }
.quill-lesson-toolbar .quill-callout-group { gap: 4px; }
.quill-lesson-toolbar button.lesson-callout-toolbar-button { appearance: none; display: inline-flex; align-items: center; justify-content: center; width: 32px; min-width: 32px; height: 32px; margin: 0; padding: 0; background: transparent; border: 0; box-shadow: none; outline: none; border-radius: 4px; color: #4b5563; font-size: 12px; font-weight: 900; line-height: 1; text-align: center; }
.quill-lesson-toolbar button.lesson-callout-toolbar-button:hover { background: #e9edf5; color: var(--blue); }
.quill-lesson-toolbar button.lesson-callout-toolbar-tip:hover { background: #e8f6ef; color: #047857; }
.quill-lesson-toolbar button.lesson-callout-toolbar-warning:hover { background: #fff2df; color: #c2410c; }
.quill-markdown-editor .ql-container.ql-snow { border: 0; font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; color: var(--ink); }
.quill-markdown-editor .ql-editor { min-height: inherit; padding: 22px 26px; font-size: 15px; line-height: 1.65; }
.quill-markdown-editor .ql-editor h2 { margin: 24px 0 10px; padding-bottom: 8px; border-bottom: 1px solid var(--line); font-size: 24px; line-height: 1.2; }
.quill-markdown-editor .ql-editor h3 { margin: 20px 0 8px; font-size: 19px; line-height: 1.25; }
.quill-markdown-editor .ql-editor pre.ql-syntax { padding: 13px 15px; border-radius: 6px; background: #111827; color: #e5e7eb; overflow-x: auto; }
.quill-markdown-editor .ql-editor blockquote.lesson-editor-callout { margin: 16px 0; padding: 12px 14px; border-left: 4px solid #9dbbff; border-radius: 6px; background: #f1f6ff; color: #30415f; }
.quill-markdown-editor .ql-editor blockquote.lesson-editor-callout::before { content: "Note"; display: block; margin-bottom: 6px; color: var(--ink); font-weight: 850; }
.quill-markdown-editor .ql-editor blockquote.lesson-editor-callout-tip { border-left-color: #8fd7b5; background: #f0fdf6; }
.quill-markdown-editor .ql-editor blockquote.lesson-editor-callout-tip::before { content: "Tip"; }
.quill-markdown-editor .ql-editor blockquote.lesson-editor-callout-warning { border-left-color: #fdba74; background: #fff7ed; }
.quill-markdown-editor .ql-editor blockquote.lesson-editor-callout-warning::before { content: "Warning"; }
.quill-markdown-editor .ql-editor img { max-width: 100%; height: auto; border-radius: 6px; }
.errorlist { color: #b91c1c; margin: 6px 0; padding-left: 18px; }
.pill { display:inline-flex; padding: 4px 9px; border-radius: 99px; font-size: 12px; font-weight: 800; background:#eef5ff; color:var(--blue); }
.pill.draft { background:#fff7ed; color:#c2410c; }
.notification-page { max-width: 1040px; margin: 0 auto; width: 100%; }
.notification-header { align-items: flex-start; }
.notification-header p { margin: 7px 0 0; }
.notification-filters { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 18px; }
.notification-filters a { display: inline-flex; align-items: center; gap: 8px; border: 1px solid var(--line); background: white; border-radius: 999px; padding: 8px 12px; color: #33415f; font-weight: 800; }
.notification-filters a.active, .notification-filters a:hover { border-color: #9dbbff; background: #eef5ff; color: var(--blue); }
.notification-filters span { min-width: 20px; height: 20px; display: inline-grid; place-items: center; border-radius: 999px; background: #eef2f7; color: #33415f; font-size: 12px; }
.notification-list { display: grid; gap: 12px; }
.notification-card { display: grid; grid-template-columns: 58px minmax(0, 1fr) auto; align-items: center; gap: 16px; border: 1px solid var(--line); background: white; border-radius: 8px; padding: 14px; min-width: 0; }
.notification-card.unread { border-color: #9dbbff; background: #f8fbff; box-shadow: inset 3px 0 0 var(--blue); }
.notification-card.celebration { border-color: #fbbf24; background: #fffdf4; }
.notification-card-icon { width: 58px; height: 58px; border-radius: 14px; display: grid; place-items: center; background: #eef5ff; color: var(--blue); font-size: 28px; overflow: hidden; }
.notification-card-icon img { width: 48px; height: 48px; object-fit: cover; border-radius: 999px; display: block; }
.notification-card-title { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.notification-card-title h2 { margin: 0; font-size: 18px; line-height: 1.25; }
.notification-card-main { min-width: 0; }
.notification-card-main p { margin: 5px 0 0; color: var(--muted); line-height: 1.45; }
.notification-card-meta { display: flex; flex-wrap: wrap; gap: 8px 12px; margin-top: 8px; color: var(--muted); font-size: 13px; }
.notification-card-meta strong { color: #047857; }
.reward-toast-root { position: fixed; right: 20px; top: 88px; z-index: 90; display: grid; gap: 10px; width: min(390px, calc(100vw - 32px)); pointer-events: none; }
.reward-toast { pointer-events: auto; display: grid; grid-template-columns: 50px minmax(0, 1fr) auto auto; gap: 12px; align-items: center; padding: 14px; border-radius: 8px; border: 1px solid #9dbbff; background: white; box-shadow: 0 18px 55px rgba(15, 23, 42, .18); animation: rewardToastIn .24s ease-out; }
.reward-toast.celebration { border-color: #f59e0b; background: #fff9ec; }
.reward-toast.leaving { animation: rewardToastOut .22s ease-in forwards; }
.reward-toast-icon { width: 50px; height: 50px; border-radius: 999px; display: grid; place-items: center; background: #eef5ff; font-size: 26px; overflow: hidden; }
.reward-toast.celebration .reward-toast-icon { background: #fef3c7; }
.reward-toast-icon img { width: 46px; height: 46px; border-radius: 999px; object-fit: cover; display: block; }
.reward-toast-main { min-width: 0; }
.reward-toast-main strong { display: block; line-height: 1.25; }
.reward-toast-main p { margin: 3px 0 0; color: var(--muted); line-height: 1.35; font-size: 14px; }
.reward-toast-main small { display: inline-block; margin-top: 5px; color: #047857; font-weight: 900; }
.reward-toast a { color: var(--blue); font-weight: 850; white-space: nowrap; }
.reward-toast button { width: 30px; height: 30px; border: 0; background: transparent; border-radius: 999px; color: #52607f; cursor: pointer; font-size: 22px; line-height: 1; }
.reward-toast button:hover { background: #eef2f7; color: var(--ink); }
.reward-confetti-root { position: fixed; inset: 0; z-index: 80; overflow: hidden; pointer-events: none; }
.confetti-piece { position: absolute; top: -18px; width: 9px; height: 16px; border-radius: 3px; opacity: .95; animation-name: confettiFall; animation-timing-function: cubic-bezier(.2,.75,.45,1); animation-fill-mode: forwards; }
@keyframes rewardToastIn { from { opacity: 0; transform: translateY(-10px) scale(.98); } to { opacity: 1; transform: translateY(0) scale(1); } }
@keyframes rewardToastOut { from { opacity: 1; transform: translateY(0); } to { opacity: 0; transform: translateY(-8px); } }
@keyframes confettiFall { to { transform: translateY(105vh) rotate(720deg); opacity: 0; } }
.report-issue-root { position: fixed; right: 22px; bottom: 22px; z-index: 95; }
.report-issue-fab { width: 58px; height: 58px; border: 0; border-radius: 999px; display: grid; place-items: center; color: white; background: var(--blue); box-shadow: 0 16px 36px rgba(7, 92, 255, .32); cursor: pointer; }
.report-issue-fab span { width: 26px; height: 26px; display: grid; place-items: center; border: 3px solid white; border-radius: 7px; font-size: 19px; font-weight: 950; line-height: 1; }
.report-issue-fab:hover, .report-issue-fab:focus { background: #004de0; outline: 3px solid rgba(7, 92, 255, .2); outline-offset: 3px; }
.report-issue-tooltip { position: absolute; right: 0; bottom: 68px; white-space: nowrap; color: white; background: #07102b; border-radius: 6px; padding: 7px 10px; font-size: 12px; font-weight: 850; opacity: 0; transform: translateY(6px); pointer-events: none; transition: opacity .15s ease, transform .15s ease; }
.report-issue-fab:hover + .report-issue-tooltip, .report-issue-fab:focus + .report-issue-tooltip { opacity: 1; transform: translateY(0); }
.report-issue-backdrop { position: fixed; inset: 0; z-index: 100; display: grid; place-items: center; padding: 20px; background: rgba(2, 11, 31, .42); }
.report-issue-backdrop[hidden] { display: none !important; }
.report-issue-modal { width: min(720px, 100%); max-height: min(780px, calc(100vh - 40px)); overflow-y: auto; border: 1px solid var(--line); border-radius: 8px; background: white; padding: 26px 28px; box-shadow: 0 24px 80px rgba(15, 23, 42, .24); }
.report-issue-header { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; margin-bottom: 22px; }
.report-issue-header h2 { margin: 0 0 8px; font-size: 28px; }
.report-issue-header p { margin: 0; }
.report-issue-close { width: 38px; height: 38px; border: 0; border-radius: 999px; background: transparent; color: #52607f; cursor: pointer; font-size: 34px; line-height: 1; }
.report-issue-close:hover, .report-issue-close:focus { background: #eef2f7; color: var(--ink); outline: none; }
.report-issue-form { display: grid; gap: 16px; }
.report-issue-form .form-row { margin: 0; }
.report-issue-form small { line-height: 1.35; }
.report-upload-box { min-height: 78px; border: 1px dashed #c9d4e6; border-radius: 8px; display: grid; place-items: center; gap: 2px; padding: 14px; color: var(--blue); cursor: pointer; background: #fbfdff; text-align: center; }
.report-upload-box:hover { border-color: #9dbbff; background: #f8fbff; }
.report-upload-box span { font-weight: 850; }
.report-upload-box small { color: var(--muted); }
.report-issue-form input[type="file"] { position: absolute; width: 1px; height: 1px; opacity: 0; pointer-events: none; }
.report-issue-message { margin: 0; min-height: 20px; font-weight: 850; }
.report-issue-message.success { color: #047857; }
.report-issue-message.error { color: #b91c1c; }
.report-issue-actions { display: flex; justify-content: flex-end; align-items: center; gap: 10px; margin-top: 4px; }
.report-issue-open { overflow: hidden; }
.danger-zone { border-color: #fecaca; background: #fff7f7; }
.public-wrap { max-width: 1180px; margin-left: auto; margin-right: auto; }
.public-hero { background: #f8fbff; border-bottom: 1px solid var(--line); }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1fr) 520px; gap: 54px; align-items: center; min-height: calc(100vh - 72px); padding: 64px 44px; }
.eyebrow { color: var(--blue); display: inline-block; font-size: 12px; font-weight: 850; letter-spacing: .08em; text-transform: uppercase; }
.public-hero h1 { font-size: 58px; line-height: 1.02; letter-spacing: 0; margin: 16px 0 18px; max-width: 760px; }
.hero-copy { color: #3f4d6d; font-size: 19px; line-height: 1.65; max-width: 670px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.course-resume-meta { display: inline-flex; align-items: center; color: #33415f; font-weight: 750; min-height: 44px; }
.lab-preview { background: #0f141b; color: #7dff61; border: 1px solid #273142; border-radius: 8px; box-shadow: 0 20px 70px rgba(15, 23, 42, .18); overflow: hidden; }
.lab-preview-top { background: #f8fafc; color: var(--ink); padding: 16px 18px; border-bottom: 1px solid var(--line); display: flex; justify-content: space-between; gap: 14px; }
.lab-preview-top span { color: var(--purple); font-weight: 800; }
.mini-topology { background: white; color: var(--ink); display: flex; align-items: center; justify-content: center; gap: 14px; padding: 24px 16px; }
.mini-topology span { width: 58px; height: 44px; border-radius: 8px; display: grid; place-items: center; background: #3979b5; color: white; font-weight: 850; }
.mini-topology i { width: 72px; height: 2px; background: #7e8aa5; display: block; }
.lab-preview pre { margin: 0; padding: 20px; min-height: 260px; white-space: pre-wrap; font: 14px/1.65 ui-monospace, SFMono-Regular, Menlo, monospace; }
.lab-checks { background: #111827; color: #d1fae5; display: flex; justify-content: space-between; gap: 12px; padding: 14px 18px; border-top: 1px solid #273142; }
.public-section { padding: 58px 44px; }
.section-heading { max-width: 680px; margin-bottom: 24px; }
.section-heading h2, .feature-grid h2 { font-size: 34px; margin: 8px 0 10px; }
.course-card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 18px; }
.public-course-card { background: white; border: 1px solid var(--line); border-radius: 8px; padding: 22px; min-height: 230px; display: flex; flex-direction: column; gap: 12px; }
.public-course-card:hover { border-color: #b8c8e6; box-shadow: 0 12px 32px rgba(15, 23, 42, .08); }
.public-course-card h2, .public-course-card h3 { margin: 0; font-size: 25px; }
.public-course-card p { margin: 0; line-height: 1.55; }
.course-card-top, .course-stats { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.course-stats { margin-top: auto; color: #33415f; font-weight: 750; }
.feature-band { background: white; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.feature-grid { display: grid; grid-template-columns: .85fr 1.15fr; gap: 40px; align-items: start; }
.feature-list { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.feature-item { border: 1px solid var(--line); border-radius: 8px; padding: 18px; background: #fbfcff; }
.feature-item strong { display: block; margin-bottom: 8px; }
.feature-item span { color: var(--muted); line-height: 1.55; }
.course-detail-hero { background: #f8fbff; border-bottom: 1px solid var(--line); padding: 58px 44px; }
.course-detail-hero h1 { font-size: 46px; margin: 14px 0 10px; }
.course-detail-hero p { max-width: 760px; line-height: 1.6; }
.detail-stats { justify-content: flex-start; margin-top: 22px; }
.course-outline { display: grid; gap: 18px; }
.outline-section { border: 1px solid var(--line); border-radius: 8px; background: white; padding: 20px; }
.outline-section h3 { margin: 0 0 14px; }
.outline-topic { border-top: 1px solid var(--line); padding: 14px 0 4px; }
.outline-topic > strong { display: block; margin-bottom: 4px; }
.outline-lesson { border-top: 1px solid var(--line); padding: 14px 0; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.outline-topic .outline-lesson:first-of-type { border-top: 0; }
.outline-lesson strong, .outline-lesson small { display: block; }
.outline-lesson small { color: var(--muted); margin-top: 4px; }
@media (max-width: 1320px) {
  .dashboard-header { grid-template-columns: 1fr; }
  .dashboard-grid { grid-template-columns: 1fr; }
  .dashboard-side { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .dashboard-side .card:last-child { grid-column: 1 / -1; }
}
@media (max-width: 1100px) {
  .course-layout, .pricing, .studio-shell, .form-grid, .hero-grid, .feature-grid, .feature-list, .studio-course-grid { grid-template-columns: 1fr; }
  .course-nav, .lab-panel { border: 0; }
  .lesson-reader-grid { grid-template-columns: 1fr; }
  .lesson-outline { display: none; }
  .lesson-outline-mobile { display: block; }
  .nav { display: none; }
  .public-hero h1 { font-size: 40px; }
  .hero-grid { min-height: auto; padding: 44px 22px; }
  .public-section, .course-detail-hero { padding: 40px 22px; }
  .studio-main { padding: 24px; }
  .studio-lesson-row { grid-template-columns: 1fr; }
  .studio-lesson-actions { display: flex; flex-wrap: wrap; }
  .studio-lesson-actions .btn { width: auto; }
  .studio-badge-row { grid-template-columns: 58px minmax(0, 1fr); }
  .studio-badge-meta, .studio-badge-actions { grid-column: 2; justify-content: flex-start; }
  .studio-badge-edit-grid { grid-template-columns: 1fr; }
  .studio-ticket-filters, .studio-ticket-detail-grid { grid-template-columns: 1fr; }
  .studio-ticket-row { grid-template-columns: 1fr; }
  .studio-ticket-side { justify-items: start; text-align: left; }
}
@media (max-width: 900px) {
  .main { padding: 28px 24px; }
  .app-shell { grid-template-columns: 240px minmax(0, 1fr); }
  .sidebar { padding: 20px 12px; }
  .side-link { padding: 11px 12px; }
  .dashboard-metrics { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
  .metric { gap: 10px; padding: 16px; }
  .metric-icon { font-size: 22px; }
  .metric strong { font-size: 21px; }
  .dashboard-split, .dashboard-side { grid-template-columns: 1fr; }
  .dashboard-side .card:last-child { grid-column: auto; }
}
@media (max-width: 820px) {
  .topbar { height: auto; min-height: 72px; flex-wrap: wrap; gap: 16px; padding: 14px 18px; }
  .brand { width: 100%; }
  .app-shell { grid-template-columns: 1fr; }
  .sidebar { border-right: 0; border-bottom: 1px solid var(--line); display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 6px; }
  .side-link { margin-bottom: 0; }
  .side-heading { grid-column: 1 / -1; margin: 14px 12px 4px; }
  .dashboard-metrics { grid-template-columns: 1fr; }
  .continue-footer { align-items: stretch; flex-direction: column; }
  .continue-footer .btn { width: 100%; }
  .notification-card { grid-template-columns: 48px minmax(0, 1fr); }
  .notification-card > .btn { grid-column: 2; width: fit-content; }
  .notification-card-icon { width: 48px; height: 48px; border-radius: 12px; font-size: 24px; }
  .notification-card-icon img { width: 42px; height: 42px; }
  .reward-toast-root { right: 12px; top: 84px; width: calc(100vw - 24px); }
  .reward-toast { grid-template-columns: 42px minmax(0, 1fr) auto; }
  .reward-toast a { grid-column: 2; justify-self: start; }
  .reward-toast-icon { width: 42px; height: 42px; font-size: 22px; }
  .reward-toast-icon img { width: 38px; height: 38px; }
}
@media (max-width: 520px) {
  .main { padding: 22px 16px; }
  .topbar { gap: 12px; }
  .user-pill { gap: 0; }
  .user-pill span:not(.avatar) { display: none; }
  .card { padding: 16px; }
  .dashboard-card-header { align-items: flex-start; flex-direction: column; gap: 8px; }
  .dashboard-course-title { font-size: 26px; }
  .hero-card { padding: 20px; }
  .activity-item { grid-template-columns: 34px minmax(0, 1fr); }
  .activity-icon { width: 34px; height: 34px; }
  .achievement-item { grid-template-columns: 42px minmax(0, 1fr); padding: 9px; }
  .achievement-item img, .achievement-fallback { width: 42px; height: 42px; }
  .achievement-item img { max-width: 42px; max-height: 42px; }
  .weekly-chart { gap: 6px; }
  .report-issue-root { right: 14px; bottom: 14px; }
  .report-issue-fab { width: 52px; height: 52px; }
  .report-issue-modal { padding: 20px; }
  .report-issue-actions { flex-direction: column-reverse; align-items: stretch; }
  .report-issue-actions .btn { width: 100%; }
}
@media (prefers-reduced-motion: reduce) {
  .reward-toast, .reward-toast.leaving, .confetti-piece { animation: none !important; }
}

html, body { max-width: 100%; overflow-x: hidden; }
img, svg, video, canvas { max-width: 100%; }
.mobile-only { display: none !important; }
.desktop-only { display: initial !important; }
.mobile-menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid #1f3358;
  border-radius: 8px;
  background: transparent;
  color: white;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
}
.mobile-menu-toggle span { display: block; width: 20px; height: 2px; border-radius: 99px; background: currentColor; }
.mobile-menu-backdrop, .mobile-panel-backdrop {
  position: fixed;
  inset: 0;
  z-index: 105;
  background: rgba(2, 11, 31, .45);
}
.mobile-menu-backdrop[hidden], .mobile-panel-backdrop[hidden] { display: none !important; }
.mobile-menu-panel {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  z-index: 110;
  width: min(390px, 92vw);
  background: white;
  color: var(--ink);
  box-shadow: -18px 0 55px rgba(15, 23, 42, .22);
  transform: translateX(105%);
  transition: transform .22s ease;
  overflow-y: auto;
  padding: 18px;
}
.mobile-menu-panel.is-open { transform: translateX(0); }
.mobile-menu-header, .mobile-drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 14px;
}
.mobile-menu-panel .brand { width: auto; color: var(--ink); font-size: 25px; margin: 0; }
.mobile-drawer-close {
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: white;
  color: var(--ink);
  display: inline-grid;
  place-items: center;
  cursor: pointer;
  font-size: 28px;
  line-height: 1;
}
.mobile-menu-user {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 12px;
  align-items: center;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfdff;
  margin-bottom: 14px;
}
.mobile-menu-user small { display: block; color: var(--muted); overflow-wrap: anywhere; margin-top: 2px; }
.mobile-menu-nav { display: grid; gap: 14px; }
.mobile-menu-section { display: grid; gap: 6px; }
.mobile-menu-section > strong {
  color: var(--muted);
  font-size: 12px;
  letter-spacing: .06em;
  text-transform: uppercase;
  margin: 4px 4px;
}
.mobile-menu-section a, .mobile-menu-section form button {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  min-height: 44px;
  padding: 11px 12px;
  border-radius: 8px;
  color: #111936;
  background: white;
  border: 0;
  font-weight: 750;
  text-align: left;
}
.mobile-menu-section a:hover, .mobile-menu-section a:focus { background: #eef5ff; color: var(--blue); outline: none; }
.mobile-menu-submit { width: 100%; justify-content: center !important; color: white !important; }
.mobile-context-bar { margin-bottom: 16px; }
.mobile-context-bar .btn { width: 100%; }
.mobile-drawer-open { overflow: hidden; }

@media (max-width: 768px) {
  .mobile-only { display: flex !important; }
  .desktop-only { display: none !important; }
  .topbar {
    height: 64px;
    min-height: 64px;
    flex-wrap: nowrap;
    gap: 10px;
    padding: 10px 14px;
    z-index: 100;
  }
  .topbar .brand { width: auto; min-width: 0; font-size: clamp(22px, 7vw, 28px); margin-right: auto; overflow: hidden; text-overflow: ellipsis; }
  .nav, .topbar-auth-link, .topbar-user-pill, .topbar-signout-form { display: none !important; }
  .mobile-menu-toggle { display: inline-flex; flex: 0 0 auto; }

  .main, .studio-main, .course-content {
    padding: 20px 14px 92px;
    min-width: 0;
  }
  .app-shell, .studio-shell, .course-layout, .course-layout.lesson-focus {
    display: block;
    min-height: calc(100vh - 64px);
  }
  .sidebar { display: none !important; }

  .dashboard-header {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
    margin-bottom: 18px;
  }
  .dashboard-welcome h1 { font-size: 30px; }
  .dashboard-metrics, .metric-row, .dashboard-grid, .dashboard-split, .dashboard-side {
    grid-template-columns: 1fr !important;
    gap: 14px;
  }
  .metric { min-height: 88px; }
  .dashboard-card-header { flex-direction: column; align-items: stretch; gap: 8px; }
  .dashboard-card-header a { white-space: normal; }
  .hero-card { padding: 20px; }
  .dashboard-course-code { color: white !important; border-color: rgba(255,255,255,.82) !important; background: transparent !important; }
  .dashboard-course-title { font-size: 28px; line-height: 1.12; }
  .continue-footer { flex-direction: column; align-items: stretch; }
  .continue-footer .btn { width: 100%; min-height: 48px; }
  .list-item { grid-template-columns: 44px minmax(0, 1fr) 18px; gap: 12px; }
  .icon-tile { width: 44px; height: 44px; font-size: 21px; }
  .weekly-chart { height: 154px; }

  .course-nav, .studio-sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    z-index: 108;
    width: min(360px, 88vw);
    height: 100dvh;
    overflow-y: auto;
    transform: translateX(-105%);
    transition: transform .22s ease;
    box-shadow: 18px 0 55px rgba(15, 23, 42, .22);
  }
  .course-nav.is-open, .studio-sidebar.is-open { transform: translateX(0); }
  .course-nav {
    padding: 18px 14px 28px;
    border-right: 0;
  }
  .studio-sidebar {
    padding: 18px 14px 28px;
    border-right: 0;
  }
  .desktop-studio-title { display: none; }
  .mobile-drawer-header.mobile-only {
    display: flex !important;
    color: white;
    border-bottom-color: rgba(255,255,255,.18);
  }
  .course-nav .mobile-drawer-close, .studio-sidebar .mobile-drawer-close {
    background: rgba(255,255,255,.08);
    border-color: rgba(255,255,255,.22);
    color: white;
  }
  .course-content.lesson-reader { overflow: visible; }
  .course-content .muted:first-of-type { overflow-wrap: anywhere; }
  .course-content h1 { font-size: clamp(34px, 10vw, 46px); line-height: 1.08; }
  .course-content > div[style*="display:flex"] {
    display: grid !important;
    grid-template-columns: 1fr;
    align-items: start !important;
  }
  #complete-action { justify-self: stretch; }
  #complete-action .btn { width: 100%; }
  .tabs { gap: 18px; overflow-x: auto; padding-bottom: 1px; }
  .lesson-reader-grid { grid-template-columns: 1fr; gap: 18px; }
  .lesson-outline { display: none; }
  .lesson-outline-mobile { display: block; }
  .lesson-body {
    font-size: 16px;
    line-height: 1.68;
    overflow-wrap: anywhere;
  }
  .lesson-body h1 { font-size: 28px; }
  .lesson-body h2 { font-size: 24px; }
  .lesson-body h3 { font-size: 20px; }
  .lesson-body pre, .code-box, .studio-ticket-json { max-width: 100%; overflow-x: auto; }
  .practice-launches form { align-items: stretch; flex-direction: column; }
  .practice-launches .btn { width: 100%; }
  .split-actions {
    position: sticky;
    bottom: 0;
    z-index: 30;
    margin: 24px -14px -92px;
    padding: 12px 14px calc(12px + env(safe-area-inset-bottom));
    background: rgba(255,255,255,.96);
    border-top: 1px solid var(--line);
    box-shadow: 0 -12px 30px rgba(15, 23, 42, .08);
    display: grid;
    grid-template-columns: 1fr;
    gap: 8px;
  }
  .split-actions > .muted { text-align: center; order: -1; }
  .split-actions .btn, .inline-next-form .btn { width: 100%; min-height: 48px; }

  .lab-drawer-backdrop {
    z-index: 115;
    justify-content: stretch;
    background: rgba(2,11,31,.55);
  }
  .lab-drawer {
    width: 100vw;
    max-width: none;
    height: 100dvh;
    border-left: 0;
    padding: 14px;
    border-radius: 0;
  }
  .drawer-toolbar { position: sticky; top: 0; z-index: 2; background: #fbfcff; padding-bottom: 10px; }
  .topology { padding: 12px; overflow-x: auto; }
  .lab-topology-diagram { min-height: 120px; min-width: 420px; }
  .terminal {
    min-height: 360px;
    max-height: 52dvh;
    font-size: 13px;
    padding: 14px;
  }
  .lab-panel { padding: 0; border: 0; overflow: visible; }
  .lab-panel .tabs { white-space: nowrap; }

  .studio-main { padding-top: 18px; }
  .toolbar, .studio-course-header, .studio-section-toolbar, .studio-domain-header {
    flex-direction: column;
    align-items: stretch;
  }
  .studio-header-actions, .studio-toolbar-actions, .studio-filter-actions {
    justify-content: stretch;
    display: grid;
    grid-template-columns: 1fr;
  }
  .studio-header-actions .btn,
  .studio-header-actions form,
  .studio-header-actions button,
  .studio-toolbar-actions .btn,
  .studio-filter-actions .btn {
    width: 100%;
  }
  .studio-course-grid, .studio-ticket-detail-grid, .studio-badge-edit-grid, .form-grid, .pricing, .hero-grid, .feature-grid, .feature-list {
    grid-template-columns: minmax(0, 1fr) !important;
  }
  .card, form.card, .form-grid, .form-grid > *, .form-row,
  input:not([type="checkbox"]):not([type="radio"]):not([type="hidden"]):not([type="submit"]):not([type="button"]),
  textarea,
  select,
  .input,
  .quill-markdown-editor {
    min-width: 0;
    max-width: 100%;
  }
  .studio-side-panel { order: 2; }
  .studio-metadata-grid { grid-template-columns: 1fr 1fr; }
  .studio-topic-header {
    display: grid;
    grid-template-columns: 1fr;
    gap: 10px;
  }
  .studio-topic-header .btn, .studio-domain-header .btn { width: 100%; }
  .studio-lesson-list { border: 0; display: grid; gap: 10px; background: transparent; }
  .studio-lesson-row {
    display: grid;
    grid-template-columns: 1fr;
    gap: 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: white;
  }
  .studio-lesson-actions {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    justify-content: stretch;
  }
  .studio-lesson-actions .btn { min-width: 0; width: 100%; }
  .studio-ticket-filters { grid-template-columns: 1fr; }
  .studio-ticket-row {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  .studio-ticket-side {
    justify-items: stretch;
    text-align: left;
  }
  .studio-ticket-side .btn { width: 100%; }
  .studio-ticket-context { grid-template-columns: 1fr; }
  .studio-badge-row {
    grid-template-columns: 52px minmax(0, 1fr);
  }
  .studio-badge-meta, .studio-badge-actions {
    grid-column: 1 / -1;
  }
  .studio-badge-actions .btn { width: 100%; }
  .quill-lesson-toolbar.ql-toolbar.ql-snow { overflow-x: auto; flex-wrap: nowrap; align-items: center; }
  .quill-markdown-editor .ql-editor { padding: 16px; min-height: 340px; }
  .table {
    display: block;
    border: 0;
    background: transparent;
  }
  .table thead { display: none; }
  .table tbody, .table tr, .table td { display: block; width: 100%; }
  .table tr {
    border: 1px solid var(--line);
    border-radius: 8px;
    background: white;
    margin-bottom: 12px;
    overflow: hidden;
  }
  .table td {
    border-bottom: 1px solid var(--line);
    padding: 12px;
  }
  .table td:last-child { border-bottom: 0; }

  .public-section, .course-detail-hero, .hero-grid { padding: 30px 14px; }
  .public-hero h1, .course-detail-hero h1 { font-size: 36px; }
  .hero-actions, .course-card-top, .course-stats, .detail-stats {
    align-items: stretch;
    flex-direction: column;
  }
  .hero-actions .btn, .course-detail-hero .btn { width: 100%; }
  .outline-lesson {
    align-items: stretch;
    flex-direction: column;
  }

  .notification-page { padding: 0; }
  .notification-card {
    grid-template-columns: 48px minmax(0, 1fr);
    align-items: start;
  }
  .notification-card > .btn {
    grid-column: 1 / -1;
    width: 100%;
  }
  .report-issue-root {
    right: 14px;
    bottom: calc(14px + env(safe-area-inset-bottom));
  }
  .report-issue-fab { width: 52px; height: 52px; }
  .report-issue-tooltip { display: none; }
}

@media (max-width: 520px) {
  .brand small { display: none; }
  .card { padding: 16px; }
  .dashboard-welcome h1 { font-size: 28px; }
  .metric { padding: 15px; }
  .studio-metadata-grid { grid-template-columns: 1fr; }
  .studio-lesson-actions { grid-template-columns: 1fr; }
  .studio-badge-row { grid-template-columns: 46px minmax(0, 1fr); }
  .studio-badge-preview img, .studio-badge-preview .achievement-fallback { width: 44px; height: 44px; }
  .lesson-body table { font-size: 14px; }
  .lab-topology-diagram { min-width: 360px; }
  .terminal { min-height: 320px; font-size: 12px; }
}