:root {
  --bg: #07111f;
  --panel: #0f172a;
  --card: rgba(255, 255, 255, 0.06);
  --border: rgba(255, 255, 255, 0.1);
  --text: #f8fafc;
  --muted: #94a3b8;
  --soft: #cbd5e1;
  --accent: #38bdf8;
  --accent-dark: #0284c7;
  --warning: #facc15;
  --danger: #fb7185;
  --radius: 16px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: Arial, sans-serif;
  background: radial-gradient(circle at top, #10213a 0%, var(--bg) 45%, #020617 100%);
  color: var(--text);
  min-height: 100vh;
}

button,
select,
textarea,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

.app-shell {
  display: grid;
  grid-template-columns: 280px 1fr;
  min-height: 100vh;
}

.sidebar {
  background: rgba(15, 23, 42, 0.92);
  border-right: 1px solid var(--border);
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 22px;
}

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

.sidebar__logo {
  font-size: 24px;
  font-weight: 800;
  color: var(--accent);
}

.sidebar__tagline,
.sidebar__usage-title,
.sidebar__history-title {
  font-size: 13px;
  color: var(--muted);
}

.sidebar__new-chat,
.chat-area__send-btn,
.api-panel__save-btn {
  border: none;
  border-radius: 12px;
  background: var(--accent);
  color: #020617;
  font-weight: 700;
  padding: 13px 16px;
}

.sidebar__usage-list,
.sidebar__history-list {
  list-style: none;
  display: grid;
  gap: 10px;
  margin-top: 10px;
}

.sidebar__usage-item,
.sidebar__history-btn,
.sidebar__action-btn {
  width: 100%;
  text-align: left;
  background: var(--card);
  border: 1px solid var(--border);
  color: var(--soft);
  border-radius: 12px;
  padding: 11px 12px;
}

.sidebar__actions {
  margin-top: auto;
  display: grid;
  gap: 10px;
}

.main-content {
  min-width: 0;
  display: flex;
  flex-direction: column;
}

.top-header {
  padding: 20px 28px;
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.top-header__page-title {
  font-size: 21px;
}

.top-header__meta {
  display: flex;
  align-items: center;
  gap: 12px;
}

.top-header__status {
  color: var(--warning);
  background: rgba(250, 204, 21, 0.1);
  border: 1px solid rgba(250, 204, 21, 0.18);
  padding: 8px 12px;
  border-radius: 999px;
  font-size: 13px;
}

select,
input,
textarea {
  background: #020617;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px;
  outline: none;
}

.content-body {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 36px 28px;
  flex: 1;
}

.hero {
  text-align: center;
  margin-bottom: 30px;
}

.hero__headline {
  font-size: 42px;
  line-height: 1.15;
  margin-bottom: 16px;
}

.hero__description {
  color: var(--soft);
  font-size: 17px;
  line-height: 1.7;
  max-width: 850px;
  margin: 0 auto;
}

.hero__feature-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-top: 28px;
}

.feature-card,
.api-panel,
.settings-panel,
.chat-area {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  backdrop-filter: blur(12px);
}

.feature-card__title,
.prompt-presets__heading,
.api-panel__heading,
.settings-panel__heading {
  color: var(--accent);
  margin-bottom: 10px;
}

.feature-card__desc,
.api-panel__description,
.api-panel__warning,
.chat-area__disclaimer {
  color: var(--soft);
  line-height: 1.6;
  font-size: 14px;
}

.prompt-presets {
  margin-bottom: 24px;
}

.prompt-presets__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.prompt-preset-btn {
  text-align: left;
  background: #111827;
  color: var(--soft);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 15px;
}

.chat-area {
  margin-bottom: 24px;
}

.chat-area__messages {
  min-height: 120px;
  margin-bottom: 16px;
}

.chat-message {
  background: rgba(2, 6, 23, 0.7);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 14px;
  color: var(--soft);
  line-height: 1.6;
}

.chat-area__input-row {
  display: grid;
  gap: 12px;
}

.chat-area__textarea {
  width: 100%;
  min-height: 80px;
  resize: vertical;
}

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

.chat-area__file-label,
.chat-area__clear-btn,
.api-panel__test-btn {
  border: 1px solid var(--border);
  border-radius: 12px;
  background: #111827;
  color: var(--soft);
  padding: 12px 15px;
}

.chat-area__disclaimer {
  margin-top: 12px;
  font-size: 12px;
  text-align: center;
  color: var(--muted);
}

.api-panel,
.settings-panel {
  margin-bottom: 24px;
}

.api-panel__form,
.settings-panel__group {
  display: grid;
  gap: 10px;
  margin-top: 14px;
}

.settings-panel__group {
  grid-template-columns: 180px 1fr;
  align-items: center;
}

.settings-panel__label {
  color: var(--muted);
}

.app-footer {
  border-top: 1px solid var(--border);
  padding: 18px 28px;
  color: var(--muted);
  display: flex;
  justify-content: space-between;
  gap: 12px;
}

button:hover,
.prompt-preset-btn:hover,
.sidebar__history-btn:hover,
.sidebar__action-btn:hover {
  border-color: rgba(56, 189, 248, 0.45);
}

@media (max-width: 900px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    display: none;
  }

  .top-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .top-header__meta,
  .app-footer {
    flex-direction: column;
    align-items: flex-start;
  }

  .hero__headline {
    font-size: 31px;
  }

  .hero__feature-cards,
  .prompt-presets__grid {
    grid-template-columns: 1fr;
  }

  .settings-panel__group {
    grid-template-columns: 1fr;
  }

  .content-body {
    padding: 26px 16px;
  }
}
.settings-panel__save-btn {
  width: 100%;
  margin-top: 18px;
  border: none;
  border-radius: 12px;
  background: var(--accent);
  color: #020617;
  font-weight: 700;
  padding: 14px 16px;
}

body.light-theme {
  --bg: #f8fafc;
  --panel: #ffffff;
  --card: rgba(15, 23, 42, 0.06);
  --border: rgba(15, 23, 42, 0.12);
  --text: #0f172a;
  --muted: #475569;
  --soft: #334155;
  background: #f8fafc;
}
body.light-theme select,
body.light-theme input,
body.light-theme textarea {
  background: #ffffff;
  color: #0f172a;
  border-color: rgba(15, 23, 42, 0.18);
}

body.light-theme .chat-message {
  background: #ffffff;
  color: #0f172a;
}

body.light-theme .prompt-preset-btn,
body.light-theme .sidebar__usage-item,
body.light-theme .sidebar__history-btn,
body.light-theme .sidebar__action-btn,
body.light-theme .chat-area__file-label,
body.light-theme .chat-area__clear-btn,
body.light-theme .api-panel__test-btn {
  background: #ffffff;
  color: #0f172a;
  border-color: rgba(15, 23, 42, 0.16);
}

body.light-theme .top-header__status {
  color: #854d0e;
  background: #fef3c7;
  border-color: #fde68a;
}

body.light-theme .feature-card,
body.light-theme .api-panel,
body.light-theme .settings-panel,
body.light-theme .chat-area {
  background: rgba(255, 255, 255, 0.92);
}