:root {
  --bg: #07111f;
  --surface: #0d1b2a;
  --surface-2: #102338;
  --border: rgba(53, 217, 255, 0.16);
  --cyan: #35d9ff;
  --violet: #8b7cff;
  --text: #eef7ff;
  --muted: #a9bbcc;
  --success: #55e6a5;
  --max-width: 920px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at top left, rgba(53, 217, 255, 0.08), transparent 32rem),
    radial-gradient(circle at top right, rgba(139, 124, 255, 0.08), transparent 28rem),
    var(--bg);
  color: var(--text);
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.75;
}

header {
  padding: 4rem 1.25rem 3rem;
  text-align: center;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(135deg, rgba(53, 217, 255, 0.08), rgba(139, 124, 255, 0.08));
}

header h1 {
  max-width: 900px;
  margin: 0 auto 1rem;
  font-size: clamp(2rem, 5vw, 3.4rem);
  line-height: 1.12;
  letter-spacing: -0.03em;
}

header p {
  max-width: 720px;
  margin: 0 auto;
  color: var(--muted);
  font-size: 1.05rem;
}

main,
.container {
  width: min(calc(100% - 2rem), var(--max-width));
  margin: 0 auto;
  padding: 2rem 0 4rem;
}

section {
  margin: 0 0 1.25rem;
  padding: 1.5rem;
  background: linear-gradient(145deg, rgba(13, 27, 42, 0.96), rgba(16, 35, 56, 0.88));
  border: 1px solid var(--border);
  border-radius: 18px;
  box-shadow: 0 12px 35px rgba(0, 0, 0, 0.18);
}

section:last-child {
  margin-bottom: 0;
}

h2 {
  margin: 0 0 0.85rem;
  color: var(--text);
  font-size: clamp(1.35rem, 3vw, 1.8rem);
  line-height: 1.25;
}

h3 {
  color: var(--cyan);
}

p {
  margin: 0 0 1rem;
  color: var(--muted);
}

p:last-child {
  margin-bottom: 0;
}

ul,
ol {
  margin: 0.75rem 0 0;
  padding-left: 1.4rem;
  color: var(--muted);
}

li {
  margin: 0.45rem 0;
}

li::marker {
  color: var(--cyan);
}

a {
  color: var(--cyan);
  font-weight: 700;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

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

a:focus-visible {
  outline: 3px solid var(--cyan);
  outline-offset: 4px;
  border-radius: 4px;
}

footer {
  padding: 2rem 1.25rem;
  text-align: center;
  border-top: 1px solid var(--border);
  background: #050d18;
}

footer p {
  margin: 0.25rem 0;
  color: var(--muted);
  font-size: 0.9rem;
}

@media (max-width: 680px) {
  header {
    padding: 3rem 1rem 2.25rem;
  }

  main,
  .container {
    width: min(calc(100% - 1rem), var(--max-width));
    padding-top: 1rem;
  }

  section {
    padding: 1.15rem;
    border-radius: 14px;
  }

  header h1 {
    font-size: 2rem;
  }

  header p {
    font-size: 0.98rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

/* Phishing Detective Lab */
.lab-header {
  margin-bottom: 30px;
}

.lab-badge {
  display: inline-block;
  margin-bottom: 12px;
  padding: 6px 10px;
  border: 1px solid var(--cyan);
  border-radius: 999px;
  color: var(--cyan);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
}

.email-card {
  max-width: 820px;
  margin: 30px auto;
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
}

.email-meta {
  padding-bottom: 18px;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--border);
}

.email-meta p {
  margin: 7px 0;
}

.email-body {
  line-height: 1.8;
}

.clue-grid {
  display: grid;
  gap: 12px;
  margin-top: 24px;
}

.clue {
  width: 100%;
  padding: 15px 16px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: transparent;
  color: var(--text);
  text-align: left;
  cursor: pointer;
  font: inherit;
}

.clue:hover,
.clue:focus-visible {
  border-color: var(--cyan);
  outline: none;
}

.clue.selected {
  border-color: var(--cyan);
  background: rgba(53, 217, 255, 0.08);
}

.clue.correct {
  border-color: var(--success);
}

.clue.incorrect {
  border-color: #ff6b6b;
}

.feedback {
  display: none;
  margin-top: 24px;
  padding: 20px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--surface);
}

.feedback.visible {
  display: block;
}

.feedback li {
  margin-bottom: 12px;
}

.lab-actions {
  margin-top: 24px;
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.lab-actions button {
  padding: 12px 18px;
  border-radius: 8px;
  cursor: pointer;
  font: inherit;
  font-weight: 700;
}

.lab-actions button[type="submit"] {
  border: 0;
  background: var(--cyan);
  color: #06111f;
}

.lab-actions .reset-button {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.score {
  font-size: 20px;
  font-weight: 700;
}

/* Safe URL Challenge Lab */
.url-card {
  max-width: 820px;
  margin: 30px auto;
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
}

.url-options {
  display: grid;
  gap: 12px;
  margin-top: 24px;
}

.url-option {
  width: 100%;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: transparent;
  color: var(--text);
  text-align: left;
  cursor: pointer;
  font: inherit;
}

.url-option strong {
  display: block;
  margin-bottom: 8px;
  color: var(--cyan);
}

.url-option code {
  display: block;
  overflow-wrap: anywhere;
  color: var(--text);
  line-height: 1.6;
}

.url-option:hover,
.url-option:focus-visible {
  border-color: var(--cyan);
  outline: none;
}

.url-option.selected {
  border-color: var(--cyan);
  background: rgba(53, 217, 255, 0.08);
}

.url-option.correct {
  border-color: var(--success);
}

.url-option.incorrect {
  border-color: #ff6b6b;
}

/* Security Checkup Lab */
.checkup-card {
  max-width: 820px;
  margin: 30px auto;
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
}

.checklist {
  display: grid;
  gap: 12px;
  margin-top: 24px;
}

.check-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: transparent;
  cursor: pointer;
}

.check-item:hover,
.check-item:focus-within {
  border-color: var(--cyan);
}

.check-item input {
  width: 18px;
  height: 18px;
  margin-top: 3px;
  flex: 0 0 auto;
  accent-color: var(--cyan);
}

.check-item strong {
  display: block;
  margin-bottom: 6px;
}

.check-item small {
  display: block;
  color: var(--muted);
  line-height: 1.6;
}

/* Password Security Demonstration */
.demo-card {
  margin: 32px 0;
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
}

.demo-question {
  margin-top: 28px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}

.demo-question h3 {
  margin-bottom: 16px;
}

.demo-options {
  display: grid;
  gap: 10px;
}

.demo-options button {
  width: 100%;
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: transparent;
  color: var(--text);
  text-align: left;
  cursor: pointer;
  font: inherit;
  line-height: 1.5;
}

.demo-options button:hover,
.demo-options button:focus-visible {
  border-color: var(--cyan);
  outline: none;
}

.demo-options button.selected {
  border-color: var(--cyan);
  background: rgba(53, 217, 255, 0.08);
}

.demo-options button.correct {
  border-color: var(--success);
}

.demo-options button.incorrect {
  border-color: #ff6b6b;
}

.demo-feedback {
  min-height: 24px;
  margin-top: 14px;
  line-height: 1.6;
}