:root {
  color-scheme: dark;
  --bg: #090d0b;
  --bg-soft: #0d1310;
  --panel: #111814;
  --panel-2: #151f19;
  --panel-3: #1a251e;
  --line: #243229;
  --line-strong: #314439;
  --text: #eef5f0;
  --muted: #96a79d;
  --brand: #50c98b;
  --brand-strong: #2fa86d;
  --brand-soft: rgba(80, 201, 139, .12);
  --accent: #d9a84a;
  --accent-soft: rgba(217, 168, 74, .12);
  --danger: #ef6d75;
  --danger-soft: rgba(239, 109, 117, .12);
  --warning: #f0bb59;
  --success: #59d896;
  --shadow: 0 24px 80px rgba(0, 0, 0, .28);
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 11px;
  --content: 1240px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 8% -10%, rgba(80, 201, 139, .11), transparent 30rem),
    radial-gradient(circle at 90% 0%, rgba(217, 168, 74, .07), transparent 26rem),
    var(--bg);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: .2;
  background-image: linear-gradient(rgba(255,255,255,.018) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.018) 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: linear-gradient(to bottom, #000, transparent 68%);
}

button,
input,
select,
textarea {
  font: inherit;
}

button,
a,
input,
select,
textarea {
  -webkit-tap-highlight-color: transparent;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  border: 0;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 2px;
}

.hidden {
  display: none !important;
}

.shell {
  width: min(calc(100% - 36px), var(--content));
  margin-inline: auto;
}

.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid rgba(255,255,255,.06);
  background: rgba(9, 13, 11, .82);
  backdrop-filter: blur(18px);
}

.nav-inner {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  letter-spacing: -.02em;
}

.brand-mark {
  width: 38px;
  height: 38px;
  border: 1px solid rgba(80, 201, 139, .34);
  border-radius: 12px;
  display: grid;
  place-items: center;
  color: var(--brand);
  background: linear-gradient(145deg, rgba(80,201,139,.16), rgba(80,201,139,.04));
  box-shadow: inset 0 0 24px rgba(80, 201, 139, .06);
  font-size: .78rem;
}

.brand-text small {
  display: block;
  margin-top: 2px;
  font-size: .68rem;
  font-weight: 650;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--muted);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 26px;
  color: #bbc8c0;
  font-size: .94rem;
}

.nav-links a:hover {
  color: var(--text);
}

.btn {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 0 17px;
  border-radius: 12px;
  font-weight: 760;
  cursor: pointer;
  color: #07100b;
  background: var(--brand);
  transition: transform .18s ease, background .18s ease, border-color .18s ease, color .18s ease, opacity .18s ease;
}

.btn:hover {
  transform: translateY(-1px);
  background: #61d99a;
}

.btn:active {
  transform: translateY(0);
}

.btn:disabled {
  cursor: not-allowed;
  opacity: .5;
  transform: none;
}

.btn-secondary {
  color: var(--text);
  background: var(--panel-3);
  border: 1px solid var(--line);
}

.btn-secondary:hover {
  background: #1e2b23;
  border-color: var(--line-strong);
}

.btn-ghost {
  color: #c8d4cc;
  background: transparent;
  border: 1px solid var(--line);
}

.btn-ghost:hover {
  color: var(--text);
  background: rgba(255,255,255,.035);
}

.btn-danger {
  color: #ffecee;
  background: #8e343a;
}

.btn-danger:hover {
  background: #a63e45;
}

.btn-small {
  min-height: 36px;
  padding-inline: 12px;
  border-radius: 10px;
  font-size: .84rem;
}

.hero {
  padding: 96px 0 74px;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.04fr) minmax(420px, .96fr);
  gap: 64px;
  align-items: center;
}

.eyebrow {
  width: fit-content;
  margin: 0 0 18px;
  padding: 7px 11px;
  border: 1px solid rgba(80,201,139,.2);
  border-radius: 999px;
  background: var(--brand-soft);
  color: #88e0b3;
  font-size: .73rem;
  font-weight: 800;
  letter-spacing: .1em;
  text-transform: uppercase;
}

.hero h1 {
  margin: 0;
  max-width: 790px;
  font-size: clamp(3rem, 6.2vw, 6.15rem);
  line-height: .98;
  letter-spacing: -.062em;
}

.hero h1 span {
  color: var(--brand);
}

.hero-copy {
  max-width: 680px;
  margin: 26px 0 0;
  color: #aebdb4;
  font-size: clamp(1rem, 1.5vw, 1.18rem);
  line-height: 1.8;
}

.hero-points {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 30px;
}

.pill {
  padding: 9px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255,255,255,.022);
  color: #bcc9c1;
  font-size: .82rem;
  font-weight: 700;
}

.auth-card {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 28px;
  background: linear-gradient(165deg, rgba(21,31,25,.96), rgba(13,19,16,.96));
  box-shadow: var(--shadow);
}

.auth-card::before {
  content: "";
  position: absolute;
  width: 280px;
  height: 280px;
  top: -170px;
  right: -100px;
  border-radius: 50%;
  background: rgba(80,201,139,.12);
  filter: blur(10px);
}

.auth-head {
  position: relative;
  padding: 28px 30px 12px;
}

.auth-head h2 {
  margin: 0 0 7px;
  font-size: 1.55rem;
  letter-spacing: -.025em;
}

.auth-head p {
  margin: 0;
  color: var(--muted);
  line-height: 1.6;
  font-size: .92rem;
}

.auth-tabs {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
  margin: 16px 30px 8px;
  padding: 5px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: #0d1310;
}

.auth-tab {
  min-height: 40px;
  border-radius: 9px;
  background: transparent;
  color: var(--muted);
  font-weight: 760;
  cursor: pointer;
}

.auth-tab.active {
  color: var(--text);
  background: var(--panel-3);
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.035);
}

.auth-form {
  position: relative;
  padding: 20px 30px 30px;
}

.field {
  display: grid;
  gap: 8px;
  margin-bottom: 16px;
}

.field-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.field label {
  color: #c8d4cc;
  font-size: .82rem;
  font-weight: 720;
}

.field input,
.field select,
.toolbar select,
.quiz-controls select,
.admin-controls select,
.admin-controls input {
  width: 100%;
  min-height: 47px;
  border: 1px solid var(--line);
  border-radius: 11px;
  padding: 0 13px;
  color: var(--text);
  background: #0d1310;
  transition: border-color .18s ease, box-shadow .18s ease, background .18s ease;
}

.field input:hover,
.field select:hover,
.toolbar select:hover,
.quiz-controls select:hover,
.admin-controls select:hover,
.admin-controls input:hover {
  border-color: var(--line-strong);
}

.field input:focus,
.field select:focus,
.toolbar select:focus,
.quiz-controls select:focus,
.admin-controls select:focus,
.admin-controls input:focus {
  border-color: rgba(80,201,139,.58);
  box-shadow: 0 0 0 4px rgba(80,201,139,.08);
  outline: 0;
}

.field-hint {
  color: #74867b;
  font-size: .73rem;
  line-height: 1.5;
}

.auth-submit {
  width: 100%;
  margin-top: 4px;
}

.form-message {
  margin: 14px 0 0;
  padding: 11px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  color: #bdc9c1;
  background: rgba(255,255,255,.025);
  font-size: .83rem;
  line-height: 1.55;
}

.form-message.error {
  border-color: rgba(239,109,117,.28);
  color: #ffacb2;
  background: var(--danger-soft);
}

.form-message.success {
  border-color: rgba(89,216,150,.28);
  color: #9aebbf;
  background: rgba(89,216,150,.09);
}

.feature-section {
  padding: 54px 0 110px;
}

.section-heading {
  max-width: 720px;
  margin-bottom: 28px;
}

.section-heading h2 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3.3rem);
  letter-spacing: -.045em;
}

.section-heading p {
  margin: 14px 0 0;
  color: var(--muted);
  line-height: 1.75;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.feature-card {
  min-height: 230px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: linear-gradient(160deg, rgba(21,31,25,.82), rgba(13,19,16,.72));
}

.feature-icon {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  color: var(--brand);
  background: var(--brand-soft);
  font-weight: 900;
}

.feature-card h3 {
  margin: 22px 0 9px;
  font-size: 1.16rem;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
  font-size: .92rem;
}

.footer {
  padding: 32px 0 42px;
  border-top: 1px solid rgba(255,255,255,.055);
  color: #76887d;
  font-size: .82rem;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 24px;
}

.app-layout {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  display: flex;
  flex-direction: column;
  padding: 24px 18px;
  border-right: 1px solid var(--line);
  background: rgba(10,15,12,.96);
  backdrop-filter: blur(14px);
}

.sidebar .brand {
  padding: 0 8px 24px;
}

.sidebar-nav {
  display: grid;
  gap: 6px;
}

.side-link {
  min-height: 44px;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 12px;
  border-radius: 11px;
  border: 1px solid transparent;
  color: #91a298;
  background: transparent;
  cursor: pointer;
  text-align: left;
  font-weight: 720;
}

.side-link:hover {
  color: #d6e1da;
  background: rgba(255,255,255,.025);
}

.side-link.active {
  color: #c8f7de;
  border-color: rgba(80,201,139,.18);
  background: rgba(80,201,139,.095);
}

.side-icon {
  width: 22px;
  text-align: center;
  color: inherit;
}

.sidebar-foot {
  margin-top: auto;
  padding: 18px 8px 0;
  border-top: 1px solid var(--line);
}

.sidebar-user {
  margin-bottom: 13px;
}

.sidebar-user strong,
.sidebar-user span {
  display: block;
}

.sidebar-user strong {
  font-size: .9rem;
}

.sidebar-user span {
  margin-top: 3px;
  color: var(--muted);
  font-size: .73rem;
}

.app-main {
  min-width: 0;
}

.app-topbar {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 0 30px;
  border-bottom: 1px solid var(--line);
  background: rgba(9,13,11,.72);
  backdrop-filter: blur(14px);
}

.page-title h1 {
  margin: 0;
  font-size: 1.16rem;
  letter-spacing: -.02em;
}

.page-title p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: .76rem;
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  min-height: 32px;
  padding: 0 10px;
  border: 1px solid rgba(80,201,139,.2);
  border-radius: 999px;
  color: #9de8bd;
  background: var(--brand-soft);
  font-size: .74rem;
  font-weight: 800;
}

.status-badge::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: currentColor;
  box-shadow: 0 0 12px currentColor;
}

.status-badge.warning {
  border-color: rgba(240,187,89,.22);
  color: #f0c877;
  background: rgba(240,187,89,.09);
}

.status-badge.danger {
  border-color: rgba(239,109,117,.22);
  color: #ff9ea4;
  background: var(--danger-soft);
}

.mobile-menu {
  display: none;
}

.view {
  display: none;
  padding: 28px 30px 48px;
}

.view.active {
  display: block;
}

.dashboard-hero {
  display: flex;
  justify-content: space-between;
  gap: 30px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background:
    radial-gradient(circle at 90% 0%, rgba(80,201,139,.12), transparent 24rem),
    linear-gradient(160deg, #151f19, #0f1612);
}

.dashboard-hero h2 {
  margin: 0 0 9px;
  font-size: clamp(1.65rem, 3vw, 2.45rem);
  letter-spacing: -.04em;
}

.dashboard-hero p {
  max-width: 720px;
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
}

.dashboard-hero .btn {
  align-self: center;
  flex: 0 0 auto;
}

.metrics-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-top: 16px;
}

.metric-card,
.panel {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: rgba(17,24,20,.88);
  box-shadow: 0 16px 45px rgba(0,0,0,.13);
}

.metric-card {
  padding: 20px;
}

.metric-label {
  color: var(--muted);
  font-size: .76rem;
  font-weight: 700;
}

.metric-value {
  margin-top: 9px;
  font-size: 1.65rem;
  font-weight: 850;
  letter-spacing: -.04em;
}

.metric-meta {
  margin-top: 5px;
  color: #6f8276;
  font-size: .72rem;
}

.progress-track {
  height: 8px;
  margin-top: 13px;
  overflow: hidden;
  border-radius: 999px;
  background: #0b100d;
}

.progress-fill {
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--brand-strong), var(--brand));
  transition: width .3s ease;
}

.content-grid {
  display: grid;
  grid-template-columns: 1.45fr .55fr;
  gap: 16px;
  margin-top: 16px;
}

.panel-head {
  min-height: 58px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 0 18px;
  border-bottom: 1px solid var(--line);
}

.panel-head h3 {
  margin: 0;
  font-size: .95rem;
}

.panel-head span {
  color: var(--muted);
  font-size: .72rem;
}

.panel-body {
  padding: 18px;
}

.activity-list {
  display: grid;
}

.activity-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 13px 0;
  border-bottom: 1px solid rgba(255,255,255,.055);
}

.activity-item:last-child {
  border-bottom: 0;
}

.activity-main strong,
.activity-main span {
  display: block;
}

.activity-main strong {
  font-size: .86rem;
}

.activity-main span {
  margin-top: 4px;
  color: var(--muted);
  font-size: .73rem;
}

.activity-score {
  color: #a9e9c4;
  font-size: .82rem;
  font-weight: 800;
}

.toolbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px;
  margin-bottom: 14px;
}

.toolbar-label {
  flex: 0 0 auto;
  color: var(--muted);
  font-size: .78rem;
  font-weight: 750;
}

.toolbar select {
  min-width: 260px;
  flex: 1;
}

.toolbar-actions {
  display: flex;
  gap: 8px;
}

.challenge-info {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding: 20px;
  margin-bottom: 14px;
}

.challenge-info h2 {
  margin: 6px 0 7px;
  font-size: 1.4rem;
  letter-spacing: -.03em;
}

.challenge-info p {
  max-width: 780px;
  margin: 0;
  color: var(--muted);
  line-height: 1.62;
  font-size: .9rem;
}

.chapter-tag {
  display: inline-flex;
  min-height: 25px;
  align-items: center;
  padding: 0 9px;
  border-radius: 999px;
  color: #a5e9c1;
  background: var(--brand-soft);
  font-size: .68rem;
  font-weight: 850;
  letter-spacing: .04em;
  text-transform: uppercase;
}

.challenge-actions {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  flex-wrap: wrap;
}

.hint-box {
  margin-bottom: 14px;
  padding: 14px 16px;
  border: 1px solid rgba(217,168,74,.18);
  border-radius: 13px;
  color: #ddc48d;
  background: var(--accent-soft);
  font-size: .86rem;
  line-height: 1.65;
}

.lab-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.target-panel {
  grid-column: 1 / -1;
}

.frame-shell {
  padding: 10px;
  background: #0a0f0c;
}

.lab-frame {
  display: block;
  width: 100%;
  min-height: 320px;
  border: 1px solid #26342b;
  border-radius: 12px;
  background: #0d1310;
}

.preview-panel .lab-frame {
  min-height: 490px;
}

.editor-panel {
  overflow: hidden;
}

.editor-tabs {
  display: flex;
  gap: 4px;
  padding: 10px 12px 0;
  border-bottom: 1px solid var(--line);
  background: #0d1310;
}

.editor-tab {
  min-height: 36px;
  padding: 0 13px;
  border-radius: 9px 9px 0 0;
  color: #788b80;
  background: transparent;
  cursor: pointer;
  font-size: .76rem;
  font-weight: 850;
  letter-spacing: .04em;
}

.editor-tab.active {
  color: #d8e6dd;
  background: var(--panel-2);
}

.code-editor {
  width: 100%;
  height: 410px;
  display: none;
  resize: vertical;
  border: 0;
  outline: 0;
  padding: 18px;
  color: #d9e7df;
  background: #0c120f;
  font: 13px/1.65 "Cascadia Code", "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  tab-size: 2;
}

.code-editor.active {
  display: block;
}

.editor-footer {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  padding: 11px 12px;
  border-top: 1px solid var(--line);
  background: #0d1310;
}

.editor-status {
  align-self: center;
  color: #6f8276;
  font-size: .7rem;
}

.requirements-panel {
  margin-top: 14px;
}

.requirements-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
  margin: 0;
  padding: 14px;
}

.requirement {
  display: flex;
  align-items: flex-start;
  gap: 9px;
  min-height: 44px;
  padding: 10px 11px;
  border: 1px solid var(--line);
  border-radius: 10px;
  color: #9bac9f;
  background: #0d1310;
  font-size: .78rem;
  line-height: 1.5;
}

.requirement::before {
  content: "○";
  color: #65776b;
}

.requirement.pass {
  border-color: rgba(89,216,150,.18);
  color: #a9e9c4;
  background: rgba(89,216,150,.065);
}

.requirement.pass::before {
  content: "✓";
  color: var(--success);
}

.requirement.fail {
  border-color: rgba(239,109,117,.15);
  color: #d99599;
  background: rgba(239,109,117,.055);
}

.requirement.fail::before {
  content: "×";
  color: var(--danger);
}

.quiz-panel {
  max-width: 900px;
  margin: 0 auto;
}

.quiz-start {
  padding: 26px;
}

.quiz-start h2 {
  margin: 0 0 8px;
  font-size: 1.55rem;
}

.quiz-start > p {
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
}

.quiz-controls {
  display: grid;
  grid-template-columns: 1fr 170px auto;
  gap: 12px;
  margin-top: 24px;
  align-items: end;
}

.quiz-controls label {
  display: grid;
  gap: 7px;
  color: #b7c4bc;
  font-size: .76rem;
  font-weight: 750;
}

.quiz-card {
  padding: 24px;
}

.quiz-meta {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  color: var(--muted);
  font-size: .77rem;
  font-weight: 720;
}

.quiz-card h3 {
  margin: 26px 0 20px;
  font-size: clamp(1.25rem, 2.4vw, 1.7rem);
  line-height: 1.42;
  letter-spacing: -.025em;
}

.answers {
  display: grid;
  gap: 10px;
}

.answer-btn {
  min-height: 54px;
  padding: 13px 15px;
  border: 1px solid var(--line);
  border-radius: 12px;
  color: #c4d0c8;
  background: #0d1310;
  cursor: pointer;
  text-align: left;
  line-height: 1.5;
  transition: border-color .16s ease, background .16s ease, color .16s ease;
}

.answer-btn:hover:not(:disabled) {
  border-color: #3c5244;
  background: #121a15;
}

.answer-btn.correct {
  border-color: rgba(89,216,150,.35);
  color: #b8f2d0;
  background: rgba(89,216,150,.1);
}

.answer-btn.wrong {
  border-color: rgba(239,109,117,.3);
  color: #ffadb2;
  background: var(--danger-soft);
}

.answer-btn:disabled {
  cursor: default;
}

.explanation {
  margin-top: 15px;
  padding: 14px 15px;
  border: 1px solid rgba(217,168,74,.18);
  border-radius: 12px;
  color: #d6c18f;
  background: var(--accent-soft);
  line-height: 1.65;
  font-size: .84rem;
}

.quiz-footer {
  display: flex;
  justify-content: flex-end;
  margin-top: 16px;
}

.progress-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.progress-list {
  padding: 8px 16px;
}

.progress-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 13px 0;
  border-bottom: 1px solid rgba(255,255,255,.055);
}

.progress-row:last-child {
  border-bottom: 0;
}

.progress-row strong {
  display: block;
  font-size: .83rem;
}

.progress-row span {
  display: block;
  margin-top: 4px;
  color: var(--muted);
  font-size: .7rem;
}

.score-chip {
  min-width: 54px;
  padding: 6px 8px;
  border-radius: 9px;
  color: #9fe8bd;
  background: rgba(80,201,139,.09);
  text-align: center;
  font-size: .76rem;
  font-weight: 850;
}

.account-card {
  max-width: 720px;
}

.account-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  padding: 18px;
}

.account-item {
  padding: 15px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #0d1310;
}

.account-item span,
.account-item strong {
  display: block;
}

.account-item span {
  color: var(--muted);
  font-size: .7rem;
  text-transform: uppercase;
  letter-spacing: .05em;
}

.account-item strong {
  margin-top: 7px;
  font-size: .9rem;
}

.admin-summary {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-bottom: 16px;
}

.admin-controls {
  display: grid;
  grid-template-columns: minmax(220px, 1fr) 170px 170px;
  gap: 10px;
  padding: 14px;
}

.table-wrap {
  width: 100%;
  overflow: auto;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 920px;
}

.data-table th,
.data-table td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: middle;
}

.data-table th {
  color: #829489;
  background: #0d1310;
  font-size: .69rem;
  letter-spacing: .06em;
  text-transform: uppercase;
}

.data-table td {
  color: #becbc3;
  font-size: .8rem;
}

.data-table tr:last-child td {
  border-bottom: 0;
}

.user-cell strong,
.user-cell span {
  display: block;
}

.user-cell strong {
  color: #e5eee8;
  font-size: .84rem;
}

.user-cell span {
  margin-top: 3px;
  color: var(--muted);
  font-size: .7rem;
}

.table-actions {
  display: flex;
  gap: 7px;
  flex-wrap: wrap;
}

.mini-select {
  min-height: 36px !important;
  width: 112px !important;
  padding-inline: 9px !important;
  border-radius: 9px !important;
  font-size: .75rem;
}

.empty-state {
  padding: 38px 20px;
  color: var(--muted);
  text-align: center;
  font-size: .86rem;
}

.modal-backdrop {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: grid;
  place-items: center;
  padding: 20px;
  background: rgba(0,0,0,.68);
  backdrop-filter: blur(6px);
}

.modal-card {
  width: min(520px, 100%);
  border: 1px solid var(--line-strong);
  border-radius: 20px;
  background: #111814;
  box-shadow: var(--shadow);
}

.modal-head {
  padding: 20px 22px 12px;
}

.modal-head h3 {
  margin: 0;
  font-size: 1.2rem;
}

.modal-head p {
  margin: 7px 0 0;
  color: var(--muted);
  line-height: 1.6;
  font-size: .83rem;
}

.modal-body {
  padding: 12px 22px 22px;
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  margin-top: 18px;
}

.toast-stack {
  position: fixed;
  z-index: 200;
  right: 18px;
  bottom: 18px;
  display: grid;
  gap: 9px;
  width: min(390px, calc(100vw - 36px));
}

.toast {
  padding: 13px 14px;
  border: 1px solid var(--line-strong);
  border-radius: 12px;
  color: #d8e3dc;
  background: #151f19;
  box-shadow: 0 16px 50px rgba(0,0,0,.3);
  font-size: .8rem;
  line-height: 1.5;
  animation: toast-in .2s ease-out;
}

.toast.success {
  border-color: rgba(89,216,150,.26);
}

.toast.error {
  border-color: rgba(239,109,117,.28);
}

@keyframes toast-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.setup-screen {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 30px;
}

.setup-card {
  width: min(760px, 100%);
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.setup-card h1 {
  margin-top: 0;
}

.setup-card p,
.setup-card li {
  color: var(--muted);
  line-height: 1.7;
}

.setup-card code {
  color: #9be7bc;
}

@media (max-width: 1100px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 44px;
  }

  .auth-card {
    max-width: 680px;
  }

  .metrics-grid,
  .admin-summary {
    grid-template-columns: repeat(2, 1fr);
  }

  .content-grid {
    grid-template-columns: 1fr;
  }

  .lab-grid {
    grid-template-columns: 1fr;
  }

  .target-panel {
    grid-column: auto;
  }

  .progress-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 820px) {
  .nav-links {
    display: none;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .app-layout {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: fixed;
    z-index: 80;
    left: 0;
    top: 0;
    width: 270px;
    transform: translateX(-102%);
    transition: transform .2s ease;
    box-shadow: var(--shadow);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .mobile-menu {
    display: inline-flex;
  }

  .view {
    padding: 20px 16px 42px;
  }

  .app-topbar {
    padding: 0 16px;
  }

  .toolbar,
  .challenge-info,
  .dashboard-hero {
    align-items: stretch;
    flex-direction: column;
  }

  .toolbar {
    display: grid;
  }

  .toolbar select {
    min-width: 0;
  }

  .toolbar-actions,
  .challenge-actions {
    width: 100%;
  }

  .toolbar-actions .btn,
  .challenge-actions .btn {
    flex: 1;
  }

  .requirements-list {
    grid-template-columns: 1fr;
  }

  .quiz-controls {
    grid-template-columns: 1fr;
  }

  .account-grid,
  .field-row {
    grid-template-columns: 1fr;
  }

  .admin-controls {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  .shell {
    width: min(calc(100% - 24px), var(--content));
  }

  .hero {
    padding-top: 66px;
  }

  .hero h1 {
    font-size: clamp(2.65rem, 14vw, 4.2rem);
  }

  .auth-head,
  .auth-form {
    padding-left: 20px;
    padding-right: 20px;
  }

  .auth-tabs {
    margin-left: 20px;
    margin-right: 20px;
  }

  .metrics-grid,
  .admin-summary {
    grid-template-columns: 1fr;
  }

  .app-topbar .status-badge {
    display: none;
  }

  .footer-inner {
    flex-direction: column;
  }
}

/* =========================================================
   V4 LANDING PAGE
   Editorial dark theme — scoped so the student/admin app keeps
   its existing layout while the public landing page is redesigned.
   ========================================================= */

.landing-page {
  --landing-bg: #080912;
  --landing-bg-deep: #06070d;
  --landing-surface: rgba(14, 16, 29, .82);
  --landing-surface-strong: #101321;
  --landing-line: rgba(172, 182, 218, .15);
  --landing-line-strong: rgba(172, 182, 218, .26);
  --landing-text: #f5f3ef;
  --landing-muted: #9ca5b9;
  --landing-violet: #8f82ff;
  --landing-cyan: #63dce2;
  --landing-amber: #e9ad68;
  --landing-gradient: linear-gradient(112deg, #9c8fff 0%, #74aefa 46%, #61ddd7 100%);
  margin: 0;
  color: var(--landing-text);
  background:
    radial-gradient(circle at 11% 14%, rgba(143, 130, 255, .13), transparent 29rem),
    radial-gradient(circle at 89% 22%, rgba(99, 220, 226, .08), transparent 25rem),
    radial-gradient(circle at 72% 94%, rgba(233, 173, 104, .055), transparent 26rem),
    linear-gradient(180deg, #080912 0%, #070810 54%, #06070d 100%);
  font-family: "Manrope", ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  overflow-x: hidden;
}

.landing-page::before {
  opacity: .13;
  background-image:
    linear-gradient(rgba(255,255,255,.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.025) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: linear-gradient(to bottom, #000 0%, rgba(0,0,0,.75) 55%, transparent 100%);
}

.landing-page .shell {
  width: min(calc(100% - 56px), 1360px);
}

.landing-page .landing-nav {
  position: relative;
  top: auto;
  z-index: 20;
  border-bottom: 1px solid rgba(255,255,255,.055);
  background: rgba(8, 9, 18, .62);
  backdrop-filter: blur(20px);
}

.landing-page .nav-inner {
  min-height: 82px;
}

.landing-page .landing-brand {
  gap: 14px;
  font-family: "Bricolage Grotesque", ui-sans-serif, sans-serif;
  font-weight: 650;
}

.landing-page .brand-mark {
  width: 42px;
  height: 42px;
  border: 1px solid rgba(143,130,255,.34);
  border-radius: 12px 5px 12px 5px;
  color: #ded9ff;
  background:
    linear-gradient(145deg, rgba(143,130,255,.20), rgba(99,220,226,.06));
  box-shadow: inset 0 0 30px rgba(143,130,255,.08);
  font-family: "Manrope", sans-serif;
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .03em;
}

.landing-page .brand-text {
  color: #f6f3ef;
  letter-spacing: -.02em;
}

.landing-page .brand-text small {
  color: #7e879b;
  font-family: "Manrope", sans-serif;
  font-size: .61rem;
  font-weight: 650;
  letter-spacing: .13em;
}

.landing-nav-meta {
  display: flex;
  align-items: center;
  gap: 28px;
  color: #7f899d;
  font-size: .76rem;
  font-weight: 650;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.landing-nav-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: #dcdde5;
  letter-spacing: .02em;
  text-transform: none;
  transition: color .18s ease;
}

.landing-nav-link span {
  color: var(--landing-cyan);
  font-size: .92rem;
}

.landing-nav-link:hover {
  color: #fff;
}

.landing-main {
  position: relative;
}

.landing-hero {
  position: relative;
  min-height: calc(100vh - 82px - 54px);
  display: grid;
  align-items: center;
  padding: 68px 0 58px;
  isolation: isolate;
}

.landing-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.16fr) minmax(430px, .84fr);
  gap: clamp(56px, 7vw, 112px);
  align-items: center;
}

.landing-copy {
  position: relative;
  z-index: 2;
  padding: 26px 0 20px;
}

.course-line {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 28px;
  color: #aeb5c5;
  font-size: .72rem;
  font-weight: 650;
  letter-spacing: .12em;
  text-transform: uppercase;
}

.course-line-mark {
  width: 30px;
  height: 2px;
  background: linear-gradient(90deg, var(--landing-amber), var(--landing-violet));
  box-shadow: 0 0 20px rgba(233,173,104,.18);
}

.landing-copy h1 {
  max-width: 860px;
  margin: 0;
  color: var(--landing-text);
  font-family: "Bricolage Grotesque", ui-sans-serif, sans-serif;
  font-size: clamp(4rem, 6.5vw, 7.7rem);
  font-weight: 600;
  line-height: .91;
  letter-spacing: -.07em;
  text-wrap: balance;
}

.landing-copy h1 span {
  display: inline-block;
  margin-top: .1em;
  color: transparent;
  background: var(--landing-gradient);
  -webkit-background-clip: text;
  background-clip: text;
}

.landing-lead {
  max-width: 710px;
  margin: 30px 0 0;
  color: #aeb5c4;
  font-size: clamp(1rem, 1.3vw, 1.13rem);
  line-height: 1.85;
}

.practice-sequence {
  max-width: 760px;
  display: grid;
  grid-template-columns: auto 1fr auto 1fr auto;
  align-items: center;
  gap: 18px;
  margin-top: 42px;
  padding: 22px 0 0;
  border-top: 1px solid rgba(255,255,255,.09);
}

.sequence-item {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.sequence-no {
  color: var(--landing-amber);
  font-family: "Bricolage Grotesque", sans-serif;
  font-size: .72rem;
  font-weight: 650;
  letter-spacing: .08em;
}

.sequence-item div {
  display: grid;
  gap: 4px;
}

.sequence-item strong {
  color: #ececf2;
  font-size: .86rem;
  font-weight: 650;
}

.sequence-item small {
  color: #6f788c;
  white-space: nowrap;
  font-size: .67rem;
  font-weight: 550;
}

.sequence-rule {
  height: 1px;
  min-width: 22px;
  background: linear-gradient(90deg, rgba(143,130,255,.45), rgba(99,220,226,.18));
}

.landing-caption {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 32px;
  color: #687185;
  font-size: .72rem;
}

.caption-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--landing-cyan);
  box-shadow: 0 0 14px rgba(99,220,226,.55);
}

.landing-page .landing-auth {
  position: relative;
  z-index: 3;
  overflow: hidden;
  border: 1px solid var(--landing-line);
  border-radius: 4px 24px 4px 24px;
  background:
    linear-gradient(160deg, rgba(20,22,39,.90), rgba(10,12,23,.94));
  box-shadow:
    0 42px 110px rgba(0,0,0,.40),
    inset 0 1px 0 rgba(255,255,255,.04);
  backdrop-filter: blur(24px);
}

.landing-page .landing-auth::before {
  content: "";
  position: absolute;
  width: 230px;
  height: 230px;
  top: -155px;
  right: -95px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(99,220,226,.17), rgba(143,130,255,.08) 45%, transparent 72%);
  filter: blur(2px);
  pointer-events: none;
}

.landing-page .landing-auth::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: .38;
  background: linear-gradient(125deg, transparent 22%, rgba(255,255,255,.018) 50%, transparent 74%);
}

.auth-topline {
  position: relative;
  z-index: 1;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 17px 26px;
  border-bottom: 1px solid rgba(255,255,255,.065);
  color: #777f92;
  font-size: .64rem;
  font-weight: 700;
  letter-spacing: .15em;
}

.access-code {
  color: #9e97d4;
}

.landing-page .auth-head {
  z-index: 1;
  padding: 28px 28px 11px;
}

.landing-page .auth-head h2 {
  margin: 0 0 9px;
  color: #f5f2ed;
  font-family: "Bricolage Grotesque", ui-sans-serif, sans-serif;
  font-size: clamp(1.75rem, 2.3vw, 2.25rem);
  font-weight: 600;
  letter-spacing: -.045em;
}

.landing-page .auth-head p {
  max-width: 520px;
  margin: 0;
  color: #8f98ab;
  font-size: .82rem;
  line-height: 1.7;
}

.landing-page .auth-tabs {
  z-index: 1;
  gap: 0;
  margin: 17px 28px 5px;
  padding: 0;
  border: 0;
  border-bottom: 1px solid var(--landing-line);
  border-radius: 0;
  background: transparent;
}

.landing-page .auth-tab {
  position: relative;
  min-height: 46px;
  border-radius: 0;
  color: #747d90;
  background: transparent;
  font-family: "Manrope", sans-serif;
  font-size: .79rem;
  font-weight: 650;
}

.landing-page .auth-tab::after {
  content: "";
  position: absolute;
  left: 15%;
  right: 15%;
  bottom: -1px;
  height: 2px;
  opacity: 0;
  background: var(--landing-gradient);
  transform: scaleX(.45);
  transition: opacity .18s ease, transform .18s ease;
}

.landing-page .auth-tab.active {
  color: #f0eef4;
  background: transparent;
  box-shadow: none;
}

.landing-page .auth-tab.active::after {
  opacity: 1;
  transform: scaleX(1);
}

.landing-page .auth-form {
  z-index: 1;
  padding: 22px 28px 22px;
}

.landing-page .field {
  gap: 8px;
  margin-bottom: 15px;
}

.landing-page .field-row {
  gap: 12px;
}

.landing-page .field label {
  color: #afb6c5;
  font-size: .71rem;
  font-weight: 650;
  letter-spacing: .015em;
}

.landing-page .field input {
  min-height: 48px;
  border: 1px solid rgba(166,176,207,.16);
  border-radius: 10px;
  padding: 0 14px;
  color: #f2f0ec;
  caret-color: var(--landing-cyan);
  background: rgba(5, 7, 15, .55);
  box-shadow: inset 0 1px 0 rgba(255,255,255,.015);
}

.landing-page .field input::placeholder {
  color: #4e576b;
}

.landing-page .field input:hover {
  border-color: rgba(166,176,207,.26);
}

.landing-page .field input:focus {
  border-color: rgba(116,174,250,.58);
  box-shadow: 0 0 0 4px rgba(116,174,250,.075);
}

.landing-page .field-hint {
  color: #626c80;
  font-size: .64rem;
  line-height: 1.55;
}

.landing-page .auth-submit {
  width: 100%;
  min-height: 50px;
  margin-top: 4px;
  border-radius: 10px;
  color: #090a12;
  background: var(--landing-gradient);
  box-shadow: 0 14px 35px rgba(106,145,238,.13);
  font-size: .79rem;
  font-weight: 750;
  letter-spacing: .01em;
}

.landing-page .auth-submit span {
  font-size: 1rem;
  transition: transform .18s ease;
}

.landing-page .auth-submit:hover {
  background: linear-gradient(112deg, #aa9eff 0%, #83b8fa 46%, #6ee9e2 100%);
  box-shadow: 0 18px 42px rgba(106,145,238,.18);
}

.landing-page .auth-submit:hover span {
  transform: translateX(3px);
}

.landing-page .form-message {
  margin-top: 14px;
  border-radius: 8px;
  font-size: .7rem;
}

.auth-foot {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px 17px;
  border-top: 1px solid rgba(255,255,255,.055);
  color: #626b7e;
  font-size: .63rem;
}

.auth-foot-dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--landing-amber);
  box-shadow: 0 0 12px rgba(233,173,104,.42);
}

.landing-orb {
  position: absolute;
  z-index: -1;
  border-radius: 50%;
  pointer-events: none;
  filter: blur(2px);
}

.landing-orb-a {
  width: 420px;
  height: 420px;
  left: -230px;
  top: 8%;
  border: 1px solid rgba(143,130,255,.07);
  background: radial-gradient(circle at 65% 50%, rgba(143,130,255,.08), transparent 68%);
}

.landing-orb-b {
  width: 360px;
  height: 360px;
  right: -190px;
  bottom: 2%;
  border: 1px solid rgba(99,220,226,.055);
  background: radial-gradient(circle at 35% 35%, rgba(99,220,226,.06), transparent 68%);
}

.landing-footer {
  position: relative;
  z-index: 3;
  min-height: 54px;
  border-top: 1px solid rgba(255,255,255,.045);
  color: #50586b;
  background: rgba(6,7,13,.35);
}

.landing-footer-inner {
  min-height: 54px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  font-size: .63rem;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
}

@media (max-width: 1120px) {
  .landing-page .landing-grid {
    grid-template-columns: 1fr;
    gap: 46px;
  }

  .landing-page .landing-copy {
    max-width: 880px;
  }

  .landing-page .landing-auth {
    width: min(690px, 100%);
  }

  .landing-page .landing-hero {
    min-height: auto;
    padding-top: 74px;
  }
}

@media (max-width: 720px) {
  .landing-page .shell {
    width: min(calc(100% - 28px), 1360px);
  }

  .landing-page .nav-inner {
    min-height: 70px;
  }

  .landing-nav-meta .nav-course {
    display: none;
  }

  .landing-page .landing-hero {
    padding: 54px 0 34px;
  }

  .landing-copy h1 {
    font-size: clamp(3.15rem, 14.5vw, 5.1rem);
    line-height: .94;
  }

  .course-line {
    margin-bottom: 22px;
    font-size: .62rem;
    letter-spacing: .085em;
  }

  .practice-sequence {
    grid-template-columns: 1fr;
    gap: 14px;
    margin-top: 32px;
  }

  .sequence-rule {
    display: none;
  }

  .sequence-item {
    padding-bottom: 12px;
    border-bottom: 1px solid rgba(255,255,255,.055);
  }

  .sequence-item:last-child {
    border-bottom: 0;
  }

  .sequence-item small {
    white-space: normal;
  }

  .landing-page .landing-auth {
    border-radius: 3px 18px 3px 18px;
  }

  .landing-page .auth-head,
  .landing-page .auth-form {
    padding-left: 20px;
    padding-right: 20px;
  }

  .landing-page .auth-tabs {
    margin-left: 20px;
    margin-right: 20px;
  }

  .auth-topline,
  .auth-foot {
    padding-left: 20px;
    padding-right: 20px;
  }

  .landing-page .field-row {
    grid-template-columns: 1fr;
  }

  .landing-footer-inner {
    flex-direction: column;
    justify-content: center;
    padding: 12px 0;
    text-align: center;
  }
}

@media (max-width: 460px) {
  .landing-page .brand-text small {
    display: none;
  }

  .landing-nav-link {
    font-size: .68rem;
  }

  .landing-copy h1 {
    letter-spacing: -.06em;
  }

  .landing-lead {
    margin-top: 24px;
  }
}


/* =========================================================
   V4.1 LANDING QUALITY PASS
   Fix typography clipping, form alignment and public-facing copy spacing.
   ========================================================= */

.landing-page .landing-copy h1 {
  line-height: .98;
  overflow: visible;
}

.landing-page .landing-copy h1 span {
  padding-bottom: .10em;
  margin-bottom: -.10em;
  overflow: visible;
}

.landing-page .field-row {
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  align-items: start;
}

.landing-page .field-row > .field {
  min-width: 0;
  align-content: start;
}

.landing-page .field {
  align-content: start;
}

.landing-page .field input {
  width: 100%;
  height: 48px;
  min-height: 48px;
  max-height: 48px;
}

.landing-page .auth-form {
  padding-bottom: 28px;
}

.landing-page .auth-submit {
  margin-top: 2px;
}

@media (max-width: 720px) {
  .landing-page .field-row {
    grid-template-columns: 1fr;
  }
}