:root {
  --bg-sky: #F3F9FD;
  --card-bg: #FFFFFF;
  --accent-primary: #0B6FA4;
  --accent-secondary: #4BA8DD;
  --accent-dark: #08557E;
  --accent-light: #E3F2FB;
  --border-light: #D6E9F5;
  --border-medium: #C5E0F1;
  --text-primary: #12324A;
  --text-secondary: #4A6478;
  --danger-bg: #FEF2F2;
  --danger-border: #FECACA;
  --danger-text: #991B1B;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Malgun Gothic", "Noto Sans KR", -apple-system, BlinkMacSystemFont, sans-serif;
  background: linear-gradient(160deg, var(--bg-sky) 0%, var(--accent-light) 100%);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.login-wrapper {
  width: 100%;
  max-width: 420px;
}

.login-card {
  background: var(--card-bg);
  border: 1px solid var(--border-light);
  border-radius: 12px;
  padding: 32px 28px;
  box-shadow: 0 8px 24px rgba(11, 111, 164, 0.08);
}

.brand-header {
  text-align: center;
  margin-bottom: 18px;
}

.brand-pill {
  display: inline-block;
  background: var(--accent-primary);
  color: #fff;
  font-weight: 700;
  font-size: 0.78rem;
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 8px;
}

.brand-header h1 {
  margin: 0;
  font-size: 1.65rem;
  color: var(--text-primary);
}

.brand-tagline {
  margin: 4px 0 0;
  font-size: 0.92rem;
  color: var(--accent-primary);
  font-weight: 600;
}

.login-guide,
.change-guide {
  text-align: center;
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin: 0 0 18px;
}

.sub-heading {
  margin: 0 0 8px;
  font-size: 1.1rem;
  text-align: center;
  color: var(--text-primary);
}

.alert-box {
  background: var(--danger-bg);
  border: 1px solid var(--danger-border);
  color: var(--danger-text);
  padding: 10px 12px;
  border-radius: 6px;
  font-size: 0.86rem;
  margin-bottom: 16px;
}

.hidden {
  display: none !important;
}

.form-field {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 14px;
}

.form-field label {
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--text-primary);
}

.form-field input {
  padding: 10px 12px;
  border: 1px solid var(--border-medium);
  border-radius: 6px;
  font-size: 0.95rem;
  color: var(--text-primary);
}

.form-field input:focus {
  outline: 2px solid var(--accent-secondary);
  border-color: var(--accent-primary);
}

.btn-submit {
  width: 100%;
  padding: 11px 16px;
  background: var(--accent-primary);
  color: #fff;
  border: none;
  border-radius: 6px;
  font-size: 0.96rem;
  font-weight: 700;
  cursor: pointer;
  margin-top: 6px;
}

.btn-submit:hover:not(:disabled) {
  background: var(--accent-dark);
}

.btn-submit:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.login-footer {
  margin-top: 22px;
  padding-top: 14px;
  border-top: 1px solid var(--border-light);
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.login-footer p {
  margin: 0;
}