* {
  box-sizing: border-box;
}

:root {
  --bg: #f3f5f7;
  --surface: #ffffff;
  --surface-2: #f8fafc;
  --text: #0f172a;
  --muted: #64748b;
  --line: #e2e8f0;
  --line-strong: #cbd5e1;
  --primary: #111827;
  --primary-hover: #1f2937;
  --danger-bg: #fef2f2;
  --danger-border: #fecaca;
  --danger-text: #b91c1c;
  --shadow: 0 24px 70px rgba(15, 23, 42, 0.10);
  --radius-xl: 24px;
  --radius-lg: 18px;
  --radius-md: 14px;
}

html,
body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  font-family: Inter, "Segoe UI", Arial, sans-serif;
  background: linear-gradient(180deg, #f8fafc 0%, #eef2f7 100%);
  color: var(--text);
}

body {
  min-height: 100vh;
}

.login-page {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.login-panel {
  width: 100%;
  max-width: 440px;
}

.login-brand {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 22px;
  padding: 0 4px;
}

.brand-mark {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, #111827, #374151);
  color: #fff;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.5px;
  box-shadow: 0 12px 30px rgba(17, 24, 39, 0.20);
}

.brand-text h1 {
  margin: 0;
  font-size: 22px;
  font-weight: 700;
  line-height: 1.15;
  color: var(--text);
}

.brand-text p {
  margin: 3px 0 0;
  font-size: 13px;
  color: var(--muted);
  letter-spacing: 0.2px;
}

.login-card {
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(226, 232, 240, 0.9);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow);
  padding: 30px;
}

.login-card-head {
  margin-bottom: 22px;
}

.login-card-head h2 {
  margin: 0 0 8px;
  font-size: 28px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.02em;
}

.login-card-head p {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
}

.alert-error {
  margin-bottom: 18px;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid var(--danger-border);
  background: var(--danger-bg);
  color: var(--danger-text);
  font-size: 14px;
  line-height: 1.5;
}

.login-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group label {
  font-size: 14px;
  font-weight: 600;
  color: #334155;
}

.form-group input {
  width: 100%;
  height: 50px;
  padding: 0 15px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--text);
  font-size: 15px;
  outline: none;
  transition: border-color .18s ease, box-shadow .18s ease, background .18s ease;
}

.form-group input::placeholder {
  color: #94a3b8;
}

.form-group input:hover {
  border-color: var(--line-strong);
}

.form-group input:focus {
  border-color: #94a3b8;
  box-shadow: 0 0 0 4px rgba(148, 163, 184, 0.18);
  background: #fff;
}

.btn-primary {
  margin-top: 4px;
  width: 100%;
  height: 52px;
  border: 0;
  border-radius: var(--radius-md);
  background: var(--primary);
  color: #fff;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.2px;
  cursor: pointer;
  transition: transform .12s ease, background .18s ease, box-shadow .18s ease;
  box-shadow: 0 10px 24px rgba(17, 24, 39, 0.18);
}

.btn-primary:hover {
  background: var(--primary-hover);
}

.btn-primary:active {
  transform: translateY(1px);
}

@media (max-width: 640px) {
  .login-page {
    padding: 16px;
  }

  .login-panel {
    max-width: 100%;
  }

  .login-card {
    padding: 22px 18px;
    border-radius: 20px;
  }

  .brand-mark {
    width: 42px;
    height: 42px;
    border-radius: 12px;
    font-size: 18px;
  }

  .brand-text h1 {
    font-size: 20px;
  }

  .login-card-head h2 {
    font-size: 24px;
  }

  .form-group input,
  .btn-primary {
    height: 48px;
  }
}