:root {
  --bg-color: #f6f8fb;
  --panel-color: #ffffff;
  --border-color: #d9e1ec;
  --text-color: #2f3d4c;
  --accent-color: #2563eb;
  --accent-hover: #1d4ed8;
  --danger-color: #ef4444;
  --shadow: 0 12px 32px rgba(15, 23, 42, 0.08);
  font-family: 'Segoe UI', Roboto, Hiragino Sans, 'Hiragino Kaku Gothic ProN', Meiryo, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: linear-gradient(180deg, #ebf1ff 0%, #f7faff 40%, #fdfdff 100%);
  min-height: 100vh;
  color: var(--text-color);
}

.app-header {
  text-align: center;
  padding: 48px 16px 24px;
}

.app-header h1 {
  margin: 0;
  font-size: 2.4rem;
  font-weight: 700;
}

.app-header p {
  margin: 12px 0 0;
  color: #50627a;
  font-size: 1rem;
}

.app-main {
  display: grid;
  grid-template-columns: minmax(280px, 400px) minmax(340px, 1fr);
  gap: 32px;
  padding: 0 24px 48px;
  max-width: 1200px;
  margin: 0 auto;
}

.search-panel,
.summary-panel {
  padding: 28px;
  background-color: var(--panel-color);
  border-radius: 24px;
  box-shadow: var(--shadow);
  border: 1px solid rgba(255, 255, 255, 0.4);
}

.search-label {
  display: block;
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.search-box {
  display: flex;
  align-items: stretch;
  background-color: #f8fafc;
  border: 2px solid transparent;
  border-radius: 18px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.search-box:focus-within {
  border-color: rgba(37, 99, 235, 0.5);
  box-shadow: 0 8px 24px rgba(37, 99, 235, 0.15);
}

.search-input {
  flex: 1;
  padding: 14px 16px;
  border: none;
  border-radius: 18px 0 0 18px;
  outline: none;
  font-size: 1rem;
  background-color: transparent;
}

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

.search-button {
  width: 56px;
  display: grid;
  place-items: center;
  border: none;
  border-radius: 0 18px 18px 0;
  background: linear-gradient(135deg, var(--accent-color), #60a5fa);
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  color: #fff;
}

.search-button:focus-visible,
.search-button:hover {
  outline: none;
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(37, 99, 235, 0.3);
}

.search-button:disabled {
  cursor: not-allowed;
  opacity: 0.6;
  transform: none;
  box-shadow: none;
}

.search-icon {
  width: 24px;
  height: 24px;
  fill: currentColor;
}

.validation-message {
  min-height: 1.4em;
  margin: 12px 0 0;
  font-size: 0.9rem;
  color: var(--danger-color);
}

.summary-panel {
  display: flex;
  flex-direction: column;
}

.summary-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.summary-header h2 {
  margin: 0;
  font-size: 1.4rem;
}

.reset-button {
  border: none;
  border-radius: 1rem;
  padding: 8px 16px;
  background-color: #e2e8f0;
  color: #475569;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.reset-button:hover,
.reset-button:focus-visible {
  background-color: #cbd5f5;
  color: var(--accent-color);
}

.summary-output {
  flex: 1;
  background-color: #f8fafc;
  border-radius: 16px;
  padding: 18px 20px;
  border: 1px solid rgba(148, 163, 184, 0.25);
  overflow-y: auto;
  min-height: 200px;
  line-height: 1.6;
}

.placeholder {
  color: #94a3b8;
}

.summary-meta {
  margin-bottom: 12px;
  border-left: 3px solid var(--accent-color);
  padding-left: 12px;
}

.summary-title {
  margin: 0;
  font-weight: 700;
}

.summary-url {
  margin: 4px 0 0;
  font-size: 0.9rem;
  color: #64748b;
  word-break: break-all;
}

.summary-text {
  margin: 0;
  white-space: pre-wrap;
}

.loading {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: #64748b;
}

.loading::after {
  content: '';
  width: 14px;
  height: 14px;
  border-radius: 50%;
  border: 2px solid #cbd5f5;
  border-top-color: var(--accent-color);
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@media (max-width: 960px) {
  .app-main {
    grid-template-columns: 1fr;
    padding: 0 16px 32px;
  }

  .search-panel,
  .summary-panel {
    padding: 24px;
  }
}