* {
  box-sizing: border-box;
}

body {
  background: #f5f7fa;
  color: #172033;
  font: 15px/1.45 system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  margin: 0;
}

.shell {
  align-items: center;
  display: grid;
  min-height: 100vh;
  padding: 24px;
}

.panel {
  background: #fff;
  border: 1px solid #dde4ee;
  border-radius: 8px;
  box-shadow: 0 18px 60px rgba(23, 32, 51, 0.08);
  display: grid;
  gap: 22px;
  margin: 0 auto;
  max-width: 480px;
  padding: 28px;
  width: 100%;
}

.back-link {
  color: #526071;
  font-size: 13px;
  font-weight: 750;
  text-decoration: none;
}

.back-link:hover {
  color: #0f766e;
}

.brand {
  display: grid;
  gap: 4px;
}

.brand span {
  color: #0f766e;
  font-size: 13px;
  font-weight: 800;
}

.brand strong {
  font-size: 28px;
  letter-spacing: 0;
}

.login,
.register-panel {
  display: grid;
  gap: 14px;
}

label {
  color: #46556a;
  display: grid;
  font-size: 13px;
  font-weight: 750;
  gap: 6px;
}

input {
  border: 1px solid #bdc8d7;
  border-radius: 6px;
  color: #172033;
  font: inherit;
  padding: 11px 12px;
  width: 100%;
}

button,
.download {
  align-items: center;
  background: #0f766e;
  border: 0;
  border-radius: 6px;
  color: #fff;
  cursor: pointer;
  display: inline-flex;
  font: 800 14px/1 system-ui, sans-serif;
  justify-content: center;
  min-height: 42px;
  padding: 11px 14px;
  text-decoration: none;
}

button:hover,
.download:hover {
  background: #115e59;
}

.outline-button {
  background: #fff;
  border: 1px solid #0f766e;
  color: #0f766e;
}

.outline-button:hover {
  background: #e8f5f3;
}

.muted-button {
  background: #526071;
}

.muted-button:hover {
  background: #3f4b5a;
}

.split-actions {
  display: grid;
  gap: 10px;
  grid-template-columns: 1fr 1fr;
}

.dashboard {
  display: grid;
  gap: 16px;
}

.student-line {
  align-items: center;
  display: flex;
  gap: 12px;
  justify-content: space-between;
}

.student-line span {
  font-size: 20px;
  font-weight: 850;
}

.student-line button {
  background: #526071;
  min-height: 36px;
}

.metrics {
  display: grid;
  gap: 10px;
  grid-template-columns: 1fr 1fr;
}

.metrics div {
  background: #f7fafc;
  border: 1px solid #e0e7ef;
  border-radius: 8px;
  display: grid;
  gap: 4px;
  padding: 16px;
}

.metrics span {
  font-size: 28px;
  font-weight: 900;
}

.metrics small,
.api-box small {
  color: #657386;
  font-size: 12px;
  font-weight: 750;
}

.api-box {
  border: 1px solid #d8e1ec;
  border-radius: 8px;
  display: grid;
  gap: 8px;
  padding: 14px;
}

code {
  background: #f1f5f9;
  border-radius: 5px;
  color: #0f172a;
  display: block;
  overflow-wrap: anywhere;
  padding: 9px;
}

#message {
  color: #526071;
  margin: 0;
  min-height: 20px;
}

#message.error {
  color: #b91c1c;
}

@media (max-width: 520px) {
  .shell {
    padding: 12px;
  }

  .panel {
    padding: 20px;
  }

  .brand strong {
    font-size: 24px;
  }
}