:root {
  color-scheme: dark;
  
  /* Color Palette */
  --bg: #090a0f;
  --panel: #11131c;
  --panel-strong: #171b26;
  --card: #151822;
  --card-hover: #1e2230;
  --input: #0a0b10;
  --input-focus: #0f1118;
  --text: #f3f4f6;
  --text-strong: #ffffff;
  --muted: #9ca3af;
  --line: rgba(255, 255, 255, 0.06);
  --line-strong: rgba(255, 255, 255, 0.12);
  
  /* Brand and Accent Colors */
  --accent: #10b981;
  --accent-dark: #059669;
  --accent-muted: rgba(16, 185, 129, 0.08);
  --accent-border: rgba(16, 185, 129, 0.3);
  
  /* Status Colors */
  --ok: #10b981;
  --ok-bg: rgba(16, 185, 129, 0.08);
  --ok-border: rgba(16, 185, 129, 0.25);
  
  --warn: #f59e0b;
  --warn-bg: rgba(245, 158, 11, 0.08);
  --warn-border: rgba(245, 158, 11, 0.25);
  
  --error: #ef4444;
  --error-bg: rgba(239, 68, 68, 0.08);
  --error-border: rgba(239, 68, 68, 0.25);
  
  --neutral: #6b7280;
  --neutral-bg: rgba(107, 114, 128, 0.08);
  --neutral-border: rgba(107, 114, 128, 0.25);
  
  --info: #3b82f6;
  
  /* Box Shadow & Glows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
  --shadow: 0 12px 34px rgba(0, 0, 0, 0.5);
  --glow-accent: 0 0 12px rgba(16, 185, 129, 0.15);
  
  /* Borders and Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-full: 9999px;
  --dropdown-chevron: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%239ca3af' stroke-width='2.5'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' d='M19.5 8.25l-7.5 7.5-7.5-7.5'/%3E%3C/svg%3E");
  
  /* Typography */
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.22s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-width: 320px;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  letter-spacing: -0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Custom Scrollbars */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg);
}
::-webkit-scrollbar-thumb {
  background: var(--panel-strong);
  border-radius: var(--radius-full);
}
::-webkit-scrollbar-thumb:hover {
  background: var(--muted);
}

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

/* App Shell Layout */
.app-shell {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  min-height: 100vh;
  padding-bottom: 96px; /* Space for action bar */
}

/* Sidebar Navigation */
.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  border-right: 1px solid var(--line);
  background: var(--bg);
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 32px;
}

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

.brand-mark {
  display: grid;
  width: 40px;
  height: 40px;
  place-items: center;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  color: #ffffff;
  font-weight: 800;
  font-size: 15px;
  box-shadow: var(--glow-accent);
}

.brand h1 {
  font-size: 16px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-strong);
  margin: 0;
}

.brand p {
  color: var(--muted);
  font-size: 12px;
  margin: 0;
}

.section-nav {
  display: grid;
  gap: 6px;
}

.nav-link {
  display: flex;
  align-items: center;
  width: 100%;
  min-height: 40px;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  background: transparent;
  color: var(--muted);
  padding: 10px 14px;
  text-align: left;
  cursor: pointer;
  font-weight: 600;
  font-size: 14px;
  transition: all var(--transition-fast);
}

.nav-link:hover {
  background: var(--panel-strong);
  color: var(--text-strong);
}

.nav-link.active {
  background: var(--accent-muted);
  border-color: var(--accent-border);
  color: var(--accent);
  box-shadow: var(--shadow-sm);
}

/* Accessible focus outlines */
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
.nav-link:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Main Content Area */
.main {
  min-width: 0;
  padding: 40px 48px;
}

.topbar {
  margin-bottom: 32px;
}

.topbar h2 {
  font-size: 30px;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--text-strong);
  margin: 0;
}

/* Provider Strip & Panels */
.provider-strip,
.settings-section {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--panel);
  box-shadow: var(--shadow);
  margin-bottom: 24px;
  transition: border-color var(--transition-normal);
}

.provider-strip {
  padding: 24px;
}

.strip-header,
.section-heading {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 20px;
}

.strip-header h3,
.section-heading h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-strong);
  margin: 0;
}

.section-heading p {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.4;
  margin: 4px 0 0 0;
}

/* Provider Status Cards */
.provider-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 16px;
}

.provider-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 16px;
  min-height: 140px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 16px;
  background: var(--card);
  transition: all var(--transition-normal);
}

.provider-card:hover {
  border-color: var(--line-strong);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
  background: var(--card-hover);
}

.provider-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.provider-title strong {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-strong);
}

/* Modern status pills with color indicators */
.status-pill {
  display: inline-flex;
  align-items: center;
  min-height: 22px;
  border: 1px solid var(--neutral-border);
  border-radius: var(--radius-full);
  padding: 2px 10px;
  background: var(--neutral-bg);
  color: var(--muted);
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  white-space: nowrap;
}

.status-pill.ok {
  color: var(--ok);
  background: var(--ok-bg);
  border-color: var(--ok-border);
}

.status-pill.warn {
  color: var(--warn);
  background: var(--warn-bg);
  border-color: var(--warn-border);
}

.status-pill.error {
  color: var(--error);
  background: var(--error-bg);
  border-color: var(--error-border);
}

.provider-meta {
  color: var(--muted);
  font-size: 12px;
  line-height: 1.4;
  word-break: break-all;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

.provider-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  align-items: center;
}

/* Button & Form Controls styling */
.test-button,
.ghost-button,
.secondary-button,
.primary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 36px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line-strong);
  padding: 6px 14px;
  font-weight: 600;
  font-size: 13px;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.test-button {
  background: var(--panel-strong);
  color: var(--text);
  border-color: var(--line);
  margin-top: auto;
  align-self: flex-start;
}

.test-button:hover:not(:disabled) {
  background: var(--card-hover);
  border-color: var(--accent);
  color: var(--accent);
}

.test-button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.secondary-button {
  background: transparent;
  color: var(--text);
  border-color: var(--line-strong);
}

.secondary-button:hover:not(:disabled) {
  background: var(--panel-strong);
  border-color: var(--text);
}

.primary-button {
  border-color: var(--accent);
  background: var(--accent);
  color: #06100b;
}

.primary-button:hover:not(:disabled) {
  background: var(--accent-dark);
}

.primary-button:disabled {
  cursor: not-allowed;
  border-color: var(--line);
  background: var(--panel-strong);
  color: var(--muted);
}

.ghost-button {
  background: transparent;
  color: var(--muted);
  border-color: transparent;
}

.ghost-button:hover:not(:disabled) {
  color: var(--text-strong);
  background: var(--panel-strong);
}

/* Forms layout */
.form-sections {
  display: grid;
  gap: 24px;
}

.settings-section {
  padding: 24px;
  scroll-margin-top: 24px;
}

.section-heading {
  border-bottom: 1px solid var(--line);
  padding-bottom: 16px;
  margin-bottom: 24px;
}

.field-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

/* Field Grouping */
.field {
  display: flex;
  flex-direction: column;
  gap: 8px;
  align-content: start;
}

.field label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  font-size: 13px;
  font-weight: 700;
  color: var(--text-strong);
}

.field-source {
  color: var(--accent);
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: var(--accent-muted);
  padding: 1px 6px;
  border-radius: var(--radius-sm);
}

/* Form Inputs, Select, Textareas */
.field input[type="text"],
.field input[type="number"],
.field input[type="password"],
.field select,
.field textarea {
  width: 100%;
  min-height: 40px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-md);
  background: var(--input);
  color: var(--text-strong);
  padding: 10px 14px;
  font-size: 14px;
  transition: all var(--transition-fast);
}

/* Custom Dropdown Styling for Select Elements */
.field select {
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  background-image: var(--dropdown-chevron);
  background-repeat: no-repeat;
  background-position: right 14px center;
  background-size: 14px;
  padding-right: 36px;
}

.model-combobox {
  position: relative;
  width: 100%;
}

.model-combobox.open {
  z-index: 110;
}

.field .model-combobox input[type="text"] {
  padding-right: 44px;
}

.model-combobox-toggle {
  position: absolute;
  top: 0;
  right: 0;
  display: grid;
  width: 42px;
  height: 40px;
  place-items: center;
  border: 0;
  background: transparent;
  cursor: pointer;
}

.model-combobox-toggle::before {
  width: 14px;
  height: 14px;
  background-image: var(--dropdown-chevron);
  background-position: center;
  background-repeat: no-repeat;
  background-size: 14px;
  content: "";
  transition: transform var(--transition-fast);
}

.model-combobox-toggle[aria-expanded="true"]::before {
  transform: rotate(180deg);
}

.model-combobox-toggle:disabled {
  cursor: not-allowed;
  opacity: 0.5;
}

.model-combobox-list {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  left: 0;
  z-index: 120;
  max-height: 280px;
  overflow-y: auto;
  overscroll-behavior: contain;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-md);
  background: var(--panel-strong);
  box-shadow: var(--shadow);
  padding: 6px;
}

.model-combobox-list[hidden] {
  display: none;
}

.model-combobox-option {
  border-radius: var(--radius-sm);
  padding: 9px 10px;
  color: var(--text);
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 12px;
  line-height: 1.35;
  overflow-wrap: anywhere;
  cursor: pointer;
}

.model-combobox-option:hover,
.model-combobox-option.active {
  background: var(--accent-muted);
  color: var(--accent);
}

.model-combobox-empty {
  padding: 10px;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.4;
}

.field input:focus,
.field select:focus,
.field textarea:focus {
  border-color: var(--accent);
  background: var(--input-focus);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.15);
  outline: none;
}

/* Checkbox specific layout styling */
.field input[type="checkbox"] {
  align-self: flex-start;
  width: 20px;
  height: 20px;
  accent-color: var(--accent);
  cursor: pointer;
  margin: 4px 0;
}

.field textarea {
  min-height: 100px;
  resize: vertical;
  line-height: 1.5;
}

.field input:disabled,
.field select:disabled,
.field textarea:disabled {
  background: rgba(255, 255, 255, 0.02);
  border-color: var(--line);
  color: var(--muted);
  cursor: not-allowed;
}

.field-description {
  color: var(--muted);
  font-size: 12px;
  line-height: 1.4;
  margin-top: 2px;
}

/* Show/Hide Advanced fields */
.field.advanced-field {
  display: none;
}

.settings-section.show-advanced .advanced-field {
  display: flex;
}

.advanced-toggle {
  margin-top: 20px;
  font-size: 12px;
  border: 1px solid var(--line-strong);
}

/* Fixed Bottom Action Bar */
.action-bar {
  position: fixed;
  right: 0;
  bottom: 0;
  left: 260px;
  z-index: 100;
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(200px, 1fr) auto;
  gap: 20px;
  align-items: center;
  min-height: 80px;
  border-top: 1px solid var(--line);
  background: rgba(9, 10, 15, 0.82);
  padding: 16px 40px;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 -8px 30px rgba(0, 0, 0, 0.3);
}

.action-meta {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.action-meta strong {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-strong);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.action-meta span {
  color: var(--muted);
  font-size: 11px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.message-area {
  min-width: 0;
  color: var(--muted);
  font-size: 13px;
  font-weight: 500;
  line-height: 1.4;
}

.message-area.error {
  color: var(--error);
  font-weight: 600;
}

.message-area.ok {
  color: var(--ok);
  font-weight: 600;
}

.message-area.warn {
  color: var(--warn);
  font-weight: 600;
}

.action-buttons {
  display: flex;
  gap: 12px;
}

.action-buttons button {
  min-width: 100px;
}

/* Tablet Layout Optimization */
@media (max-width: 900px) {
  .app-shell {
    display: flex;
    flex-direction: column;
    padding-bottom: 180px; /* More room for stacked action bar */
  }

  .sidebar {
    position: relative;
    height: auto;
    border-right: 0;
    border-bottom: 1px solid var(--line);
    padding: 20px;
    gap: 20px;
  }

  .section-nav {
    grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  }

  .main {
    padding: 24px 20px;
  }

  .action-bar {
    left: 0;
    grid-template-columns: 1fr;
    gap: 12px;
    padding: 16px 20px;
    min-height: auto;
    background: rgba(9, 10, 15, 0.95);
  }

  .action-meta {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }

  .action-meta span {
    text-align: right;
  }

  .action-buttons {
    width: 100%;
  }

  .action-buttons button {
    flex: 1;
    min-height: 44px; /* Better touch target on mobile */
  }
}

/* Mobile Layout Optimization */
@media (max-width: 600px) {
  .brand {
    justify-content: center;
    text-align: center;
    flex-direction: column;
  }
  
  .brand-mark {
    width: 48px;
    height: 48px;
  }

  .section-nav {
    grid-template-columns: 1fr;
  }
  
  .topbar {
    text-align: center;
  }

  .topbar h2 {
    font-size: 24px;
  }

  .provider-grid {
    grid-template-columns: 1fr;
  }
  
  .field-grid {
    grid-template-columns: 1fr;
  }

  .action-meta {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
  }

  .action-meta span {
    text-align: left;
  }
}