body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  color: #222;
  background: #f7f7f4;
}

.site-header {
  background: #111;
}

.hero-img {
  display: block;
  width: 100%;
  height: auto;
}

.container {
  width: min(1050px, calc(100% - 32px));
  margin: 0 auto;
}

.home-card, .content-card, .problem-card, .admin-card {
  background: white;
  border-radius: 18px;
  box-shadow: 0 8px 28px rgba(0,0,0,0.08);
  padding: 28px;
  margin: 26px 0;
}

h1, h2, h3 {
  color: #16343a;
}

.tagline {
  text-align: center;
  font-size: clamp(1.7rem, 3vw, 2.8rem);
  line-height: 1.1;
  margin: 28px 0 18px;
}

.lead-link {
  display: block;
  text-align: center;
  color: #078c99;
  font-size: 1.2rem;
  font-weight: 700;
  margin: 12px 0 30px;
  text-decoration: none;
}

.form-row {
  margin: 14px 0;
}

label {
  display: block;
  font-weight: 700;
  margin-bottom: 6px;
}

input, select, textarea {
  width: 100%;
  box-sizing: border-box;
  padding: 13px 14px;
  border: 1px solid #ccc;
  border-radius: 12px;
  font-size: 1rem;
}

textarea {
  min-height: 150px;
}

button, .button {
  display: inline-block;
  background: #078c99;
  color: white;
  border: none;
  border-radius: 999px;
  padding: 12px 22px;
  text-decoration: none;
  font-weight: 700;
  cursor: pointer;
}

.button.secondary {
  background: #333;
}

.button.danger {
  background: #b00020;
}

.button.light {
  background: #e8f6f7;
  color: #075c65;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.problem-meta {
  font-weight: 700;
  color: #111;
  margin-bottom: 8px;
}

.problem-text {
  color: #666;
  line-height: 1.55;
  white-space: pre-wrap;
}

.notice {
  background: #e8f6f7;
  border-left: 5px solid #078c99;
  padding: 14px 16px;
  border-radius: 10px;
  margin: 18px 0;
}

.error {
  background: #ffecec;
  border-left: 5px solid #b00020;
  padding: 14px 16px;
  border-radius: 10px;
  margin: 18px 0;
}

.captcha-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 220px));
  gap: 18px;
}

.captcha-img {
  width: 150px;
  height: 150px;
  object-fit: contain;
  display: block;
  border: 1px solid #ddd;
  border-radius: 14px;
  background: #fafafa;
  padding: 10px;
  margin-bottom: 8px;
}

.table-wrap {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  background: white;
}

th, td {
  border-bottom: 1px solid #ddd;
  padding: 10px;
  text-align: left;
  vertical-align: top;
}

th {
  background: #f0f6f7;
}

.admin-nav {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin: 18px 0;
}

.pdf-frame {
  width: 100%;
  height: 90vh;
  border: 0;
  background: white;
}

@media (max-width: 700px) {
  .home-card, .content-card, .problem-card, .admin-card {
    padding: 18px;
  }

  .captcha-grid {
    grid-template-columns: 1fr;
  }
}