:root {
  color-scheme: dark;
  --bg: #0f1226;
  --surface: #171b3d;
  --surface-2: #1e2356;
  --text: #f1f3ff;
  --muted: #abb0d5;
  --accent: #6c8cff;
  --success: #3bd29d;
  --warn: #ffb545;
  --danger: #ff6f6f;
}

* {
  box-sizing: border-box;
}

.hidden {
  display: none !important;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: radial-gradient(circle at top, #24315c 0%, #0f1226 55%);
  color: var(--text);
}

.app-shell {
  width: min(1200px, calc(100% - 24px));
  margin: 0 auto;
  padding: 24px 0 60px;
}

header {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: center;
  margin-bottom: 24px;
}

h1,
h2,
p,
label {
  margin: 0;
}

h1 {
  font-size: clamp(2rem, 3vw, 3rem);
}

h2 {
  font-size: 1.2rem;
  margin-bottom: 12px;
}

header p {
  color: var(--muted);
  margin-top: 6px;
}

.status-pill {
  padding: 10px 16px;
  border-radius: 999px;
  background: rgba(109, 127, 255, 0.16);
  color: #dbe0ff;
  font-size: 0.95rem;
}

main {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

.card {
  border-radius: 22px;
  background: rgba(20, 24, 52, 0.92);
  border: 1px solid rgba(255, 255, 255, 0.08);
  padding: 24px;
  box-shadow: 0 18px 55px rgba(0, 0, 0, 0.24);
}

.auth-card,
.input-card,
.file-card {
  max-width: 100%;
}

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

.form-row label {
  color: var(--muted);
  font-size: 0.95rem;
}

input[type="text"],
input[type="email"],
input[type="password"],
textarea,
button,
input[type="file"] {
  width: 100%;
}

input[type="text"],
input[type="email"],
input[type="password"],
textarea {
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 16px;
  background: rgba(16, 19, 45, 0.95);
  color: var(--text);
  padding: 14px 16px;
  font-size: 1rem;
}

textarea {
  resize: vertical;
  min-height: 160px;
}

input[type="file"] {
  padding: 12px 10px;
  background: rgba(255, 255, 255, 0.04);
  border-radius: 16px;
  cursor: pointer;
}

.button-row {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

button {
  border: none;
  border-radius: 999px;
  padding: 14px 24px;
  background: linear-gradient(135deg, #647bff 0%, #4fd1ff 100%);
  color: #0f1226;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.2s ease, filter 0.2s ease;
}

button:hover {
  transform: translateY(-1px);
}

button:disabled {
  opacity: 0.35;
  cursor: not-allowed;
  transform: none;
}

.output-card {
  min-height: 200px;
}

.output-block {
  margin-top: 14px;
  display: grid;
  gap: 12px;
  color: var(--text);
}

.message {
  min-height: 1.2em;
  margin-top: 12px;
  color: var(--muted);
}

.message.error {
  color: var(--danger);
}

.message.success {
  color: var(--success);
}

.quiz-item,
.wiki-card,
.video-card {
  padding: 16px;
  background: rgba(10, 13, 30, 0.9);
  border-radius: 18px;
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.quiz-item label {
  display: block;
  margin-bottom: 10px;
  font-weight: 600;
}

.quiz-item input {
  width: 100%;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 14px;
  padding: 12px 14px;
  background: rgba(18, 22, 44, 0.95);
  color: var(--text);
}

.quiz-item .feedback {
  margin-top: 10px;
  font-size: 0.95rem;
}

.video-grid {
  display: grid;
  gap: 16px;
}

.video-card {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 14px;
  align-items: center;
}

.video-card img {
  width: 120px;
  border-radius: 14px;
  object-fit: cover;
}

@media (min-width: 900px) {
  main {
    grid-template-columns: 1fr 1fr;
  }

  .auth-card,
  .input-card,
  .file-card {
    grid-column: span 2;
  }
}

@media (max-width: 720px) {
  .video-card {
    grid-template-columns: 1fr;
  }
}