:root {
  --edubal-navy: #1f3a5f;
  --edubal-blue: #3f6fa8;
  --edubal-blue-soft: #eaf1f8;
  --text-main: #2c3338;
  --text-sub: #6b7480;
  --border-soft: #e2e6ea;
  --bg: #ffffff;
  --bg-page: #fafbfc;
  --warn-bg: #fff4e5;
  --warn-text: #8a5a00;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Hiragino Kaku Gothic ProN", "Yu Gothic", "Noto Sans JP", sans-serif;
  background: var(--bg-page);
  color: var(--text-main);
  -webkit-font-smoothing: antialiased;
}

.app-header {
  background: var(--bg);
  border-bottom: 1px solid var(--border-soft);
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  position: sticky;
  top: 0;
  z-index: 10;
}

.logo {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--edubal-navy);
  letter-spacing: 0.02em;
}

.settings-toggle {
  background: none;
  border: 1px solid var(--border-soft);
  color: var(--text-sub);
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 0.78rem;
  cursor: pointer;
}

.settings-toggle:hover {
  border-color: var(--edubal-blue);
  color: var(--edubal-blue);
}

/* 設定パネル */
.settings-panel {
  background: var(--bg);
  border-bottom: 1px solid var(--border-soft);
}

.settings-panel.hidden {
  display: none;
}

.settings-inner {
  max-width: 640px;
  margin: 0 auto;
  padding: 16px 20px 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.settings-desc {
  font-size: 0.8rem;
  color: var(--text-sub);
  line-height: 1.6;
  margin: 0 0 6px;
}

.settings-label {
  font-size: 0.78rem;
  color: var(--text-sub);
  font-weight: 600;
}

.settings-input {
  border: 1px solid var(--border-soft);
  border-radius: 8px;
  padding: 9px 12px;
  font-size: 0.88rem;
  font-family: inherit;
  color: var(--text-main);
  background: var(--bg-page);
}

.settings-input:focus {
  outline: none;
  border-color: var(--edubal-blue);
}

.settings-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 6px;
}

.settings-saved-msg {
  font-size: 0.8rem;
  color: var(--edubal-blue);
  font-weight: 600;
}

.settings-saved-msg.hidden {
  display: none;
}

.primary-btn {
  background: var(--edubal-blue);
  color: #fff;
  border: none;
  border-radius: 999px;
  padding: 10px 24px;
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
}

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

/* メイン */
.app-main {
  max-width: 640px;
  margin: 0 auto;
  min-height: calc(100vh - 60px);
  display: flex;
  flex-direction: column;
}

.intro-card {
  padding: 20px 16px 8px;
}

.intro-text {
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--text-main);
  margin: 0 0 14px;
}

.example-questions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.example-btn {
  background: var(--bg);
  border: 1px solid var(--edubal-blue);
  color: var(--edubal-blue);
  border-radius: 999px;
  padding: 8px 14px;
  font-size: 0.82rem;
  cursor: pointer;
  transition: background 0.12s ease, color 0.12s ease;
}

.example-btn:hover {
  background: var(--edubal-blue-soft);
}

/* チャット */
.chat-screen {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.chat-log {
  flex: 1;
  padding: 16px 16px 12px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  overflow-y: auto;
}

.msg-row {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.msg-row.row-user {
  align-items: flex-end;
}

.msg-row.row-bot {
  align-items: flex-start;
}

.msg {
  max-width: 82%;
  padding: 12px 16px;
  border-radius: 16px;
  line-height: 1.7;
  font-size: 0.93rem;
  white-space: pre-wrap;
  word-break: break-word;
}

.msg-bot {
  background: var(--bg);
  border: 1px solid var(--border-soft);
  color: var(--text-main);
  border-bottom-left-radius: 4px;
}

.msg-user {
  background: var(--edubal-blue);
  color: #fff;
  border-bottom-right-radius: 4px;
}

.msg-error {
  background: var(--warn-bg);
  color: var(--warn-text);
  border: 1px solid #f0d9a8;
  border-bottom-left-radius: 4px;
}

.msg-loading {
  background: var(--bg);
  border: 1px solid var(--border-soft);
  color: var(--text-sub);
  border-bottom-left-radius: 4px;
}

.related-toggle {
  align-self: flex-start;
  background: none;
  border: 1px solid var(--edubal-blue);
  color: var(--edubal-blue);
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 0.78rem;
  cursor: pointer;
}

.related-toggle:hover {
  background: var(--edubal-blue-soft);
}

.related-excerpts {
  align-self: flex-start;
  max-width: 82%;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.related-excerpts.hidden {
  display: none;
}

.excerpt-card {
  background: var(--bg-page);
  border: 1px solid var(--border-soft);
  border-left: 3px solid var(--edubal-blue);
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 0.82rem;
  line-height: 1.6;
  white-space: pre-wrap;
}

.excerpt-title {
  font-weight: 700;
  color: var(--edubal-navy);
  margin-bottom: 4px;
  font-size: 0.8rem;
}

.chat-input-area {
  padding: 12px 16px 20px;
  background: var(--bg-page);
  border-top: 1px solid var(--border-soft);
  display: flex;
  gap: 8px;
}

.text-input {
  flex: 1;
  border: 1px solid var(--border-soft);
  border-radius: 999px;
  padding: 11px 16px;
  font-size: 0.92rem;
  font-family: inherit;
  color: var(--text-main);
  background: var(--bg);
}

.text-input:focus {
  outline: none;
  border-color: var(--edubal-blue);
}

.send-btn {
  background: var(--edubal-blue);
  color: #fff;
  border: none;
  border-radius: 999px;
  padding: 0 22px;
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
}

.send-btn:hover {
  background: var(--edubal-navy);
}

.send-btn:disabled {
  background: #b7c3d1;
  cursor: default;
}

/* スマートフォン対応 */
@media (max-width: 480px) {
  .app-main {
    max-width: 100%;
  }
  .msg,
  .related-excerpts {
    max-width: 90%;
  }
}