/* === Codex WebUI — AtomCode-inspired design system === */
:root {
  --app-brand:#10a37f; --app-brand-button:#0d8c6d; --app-brand-ivory:#f5f5f0; --app-brand-slate:#141413;
  --app-primary-foreground:#e8e6df; --app-primary-background:#212121; --app-brand-text:#f5f4ee;
  --app-secondary-foreground:#b0ada4; --app-secondary-background:#1a1a1a;
  --app-input-foreground:#e8e6df; --app-input-background:#2a2a2a; --app-input-border:#3d3d3d;
  --app-input-active-border:#10a37f; --app-input-placeholder-foreground:#8f8c83; --app-input-secondary-background:#242424;
  --app-button-foreground:#ffffff; --app-button-background:#0d8c6d; --app-button-hover-background:#10a37f; --app-ghost-button-hover-background:#ffffff14;
  --app-tool-background:#1a1a1a; --app-header-background:#212121; --app-primary-border-color:#333333; --app-accent-color:#10a37f;
  --app-list-hover-background:#2a2a2a; --app-list-active-background:#333333; --app-list-active-foreground:#ffffff;
  --app-menu-background:#2a2a2a; --app-menu-border:#3d3d3d; --app-menu-foreground:#e8e6df; --app-menu-selection-background:#1a3a2e;
  --app-command-menu-hover-background:color-mix(in srgb,var(--app-brand) 10%,var(--app-menu-background)); --app-command-menu-active-background:color-mix(in srgb,var(--app-brand) 22%,var(--app-menu-background)); --app-command-menu-active-accent:var(--app-brand);
  --app-success-foreground:#74c991; --app-error-foreground:#f14c4c; --app-warning-accent:#e5a54b;
  --app-spinner-foreground:var(--app-brand); --app-disabled-foreground:#777777;
  --app-link-color:#4daafc; --app-modal-background:#00000073; --app-transparent-inner-border:#ffffff1a;
  --app-spacing-small:4px; --app-spacing-medium:8px; --app-spacing-large:12px; --app-spacing-xlarge:16px;
  --corner-radius-small:6px; --corner-radius-medium:10px; --corner-radius-large:14px;
  --app-sans-font-family:ui-sans-serif,-apple-system,BlinkMacSystemFont,'Segoe UI','PingFang SC','Hiragino Sans GB','Microsoft YaHei',sans-serif;
  --app-serif-font-family:'Tiempos Text','Source Serif 4','Songti SC',ui-serif,Georgia,Cambria,'Times New Roman',serif;
  --app-monospace-font-family:ui-monospace,'SFMono-Regular','Menlo','Monaco','Courier New',monospace;
  --app-monospace-font-size:13px; --app-monospace-font-size-small:12px;
}
:root[data-theme='light'] {
  --app-primary-foreground:#1f1e1d; --app-primary-background:#faf9f5; --app-brand-text:#29261f;
  --app-secondary-foreground:#6b6a63; --app-secondary-background:#f0eee6;
  --app-input-foreground:#1f1e1d; --app-input-background:#ffffff; --app-input-border:#e6e2d6;
  --app-input-placeholder-foreground:#9b988e; --app-input-secondary-background:#f0eee6;
  --app-ghost-button-hover-background:#0000000d; --app-tool-background:#f0eee6; --app-header-background:#faf9f5;
  --app-primary-border-color:#eae6db; --app-list-hover-background:#efece3; --app-list-active-background:#e6e1d4;
  --app-menu-background:#ffffff; --app-menu-border:#e6e2d6; --app-menu-foreground:#1f1e1d; --app-menu-selection-background:#e8f5f0;
  --app-command-menu-hover-background:color-mix(in srgb,var(--app-brand) 10%,var(--app-menu-background)); --app-command-menu-active-background:color-mix(in srgb,var(--app-brand) 22%,var(--app-menu-background)); --app-command-menu-active-accent:var(--app-brand);
  --app-link-color:#0969da; --app-transparent-inner-border:#00000012;
  --app-spinner-foreground:var(--app-brand-button);
}
@media (prefers-color-scheme: light) {
  :root:not([data-theme='dark']):not([data-theme='light']) {
    --app-primary-foreground:#1f1e1d; --app-primary-background:#faf9f5; --app-brand-text:#29261f;
    --app-secondary-foreground:#6b6a63; --app-secondary-background:#f0eee6;
    --app-input-foreground:#1f1e1d; --app-input-background:#ffffff; --app-input-border:#e6e2d6;
    --app-input-placeholder-foreground:#9b988e; --app-input-secondary-background:#f0eee6;
    --app-ghost-button-hover-background:#0000000d; --app-tool-background:#f0eee6; --app-header-background:#faf9f5;
    --app-primary-border-color:#eae6db; --app-list-hover-background:#efece3; --app-list-active-background:#e6e1d4;
    --app-menu-background:#ffffff; --app-menu-border:#e6e2d6; --app-menu-foreground:#1f1e1d; --app-menu-selection-background:#e8f5f0;
    --app-command-menu-hover-background:color-mix(in srgb,var(--app-brand) 10%,var(--app-menu-background)); --app-command-menu-active-background:color-mix(in srgb,var(--app-brand) 22%,var(--app-menu-background)); --app-command-menu-active-accent:var(--app-brand);
    --app-link-color:#0969da; --app-transparent-inner-border:#00000012;
    --app-spinner-foreground:var(--app-brand-button);
  }
}
html, body { height: 100%; overflow: hidden; overscroll-behavior: none; margin: 0; }
body {
  font-family: var(--app-sans-font-family); font-size: 14px;
  color: var(--app-primary-foreground); background: var(--app-primary-background);
  -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale;
}
#app { display: flex; height: 100dvh; width: 100%; overflow: hidden; }
a { color: var(--app-link-color); text-decoration: none; }
a:hover { text-decoration: underline; }

/* === Sidebar === */
.sidebar {
  width: clamp(240px, 18vw, 300px);
  background: var(--app-secondary-background);
  border-right: 1px solid var(--app-primary-border-color);
  display: flex; flex-direction: column; overflow: hidden; flex-shrink: 0;
  transition: width 0.2s ease, min-width 0.2s ease;
}
.sidebar.collapsed { width: 52px; min-width: 52px; }
.sidebar.collapsed .sidebar-brand-name,
.sidebar.collapsed .sidebar-actions,
.sidebar.collapsed .sidebar-search-row,
.sidebar.collapsed .sidebar-body,
.sidebar.collapsed .sidebar-account .login-name { display: none; }
.sidebar.collapsed .sidebar-brand-row { justify-content: center; padding: 14px 8px; }
.sidebar.collapsed .sidebar-brand-btns { display: none; }

.sidebar-brand-row { display: flex; align-items: center; justify-content: space-between; gap: 8px; padding: 14px 14px 10px; flex-shrink: 0; }
.sidebar-brand { display: flex; align-items: center; gap: 7px; min-width: 0; }
.sidebar-brand-logo { color: var(--app-brand); flex-shrink: 0; }
.sidebar-brand-name { font-family: var(--app-serif-font-family); font-weight: 600; font-size: 16px; letter-spacing: -0.01em; white-space: nowrap; color: var(--app-brand-text); }
.sidebar-brand-btns { display: flex; align-items: center; gap: 2px; flex-shrink: 0; }
.sidebar-icon-btn {
  width: 28px; height: 28px; flex-shrink: 0; display: flex; align-items: center; justify-content: center;
  border: none; border-radius: var(--corner-radius-small); background: transparent;
  color: var(--app-secondary-foreground); cursor: pointer; font-size: 13px;
}
.sidebar-icon-btn:hover { background: var(--app-ghost-button-hover-background); color: var(--app-primary-foreground); }

.sidebar-actions { display: flex; flex-direction: column; gap: 4px; padding: 4px 12px 10px; flex-shrink: 0; }
.sidebar-action {
  display: flex; align-items: center; gap: 8px; width: 100%; padding: 8px 10px;
  border: none; border-radius: var(--corner-radius-medium); background: transparent;
  color: var(--app-primary-foreground); cursor: pointer; font-size: 13.5px; font-family: inherit; text-align: left;
}
.sidebar-action:hover { background: var(--app-list-active-background); }
.sidebar-action-icon { display: flex; align-items: center; color: var(--app-brand); flex-shrink: 0; }
.sidebar-action-label { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.sidebar-search-row { padding: 0 12px 8px; flex-shrink: 0; }
.sidebar-search {
  width: 100%; height: 32px; padding: 0 10px; box-sizing: border-box;
  background: var(--app-input-background); border: 1px solid var(--app-input-border);
  border-radius: var(--corner-radius-small); color: var(--app-input-foreground);
  font-family: inherit; font-size: 12px; outline: none;
}
.sidebar-search:focus { border-color: var(--app-input-active-border); }
.sidebar-search::placeholder { color: var(--app-input-placeholder-foreground); }

.sidebar-body { flex: 1; overflow-y: auto; overflow-x: hidden; padding: 4px 8px 8px; }
.session-group-label { padding: 10px 8px 4px; font-size: 11px; font-weight: 600; letter-spacing: 0.5px; color: var(--app-secondary-foreground); }
.session-empty { padding: 20px; text-align: center; color: var(--app-secondary-foreground); font-size: 12px; }

.session-item { display: flex; align-items: center; gap: 2px; width: 100%; border-radius: var(--corner-radius-medium); color: var(--app-primary-foreground); cursor: pointer; }
.session-item:hover { background: var(--app-list-hover-background); }
.session-item.active { background: var(--app-list-active-background); }
.session-item-main { flex: 1; min-width: 0; padding: 8px 4px 8px 8px; display: flex; flex-direction: column; gap: 2px; }
.session-item-name { width: 100%; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: 14px; }
.session-item.active .session-item-name { font-weight: 600; }
.session-item-meta { font-size: 11px; color: var(--app-secondary-foreground); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.sidebar-bottom {
  display: flex; align-items: center; gap: 8px; padding: 10px 12px;
  border-top: 1px solid var(--app-primary-border-color); flex-shrink: 0;
}
.sidebar-bottom-spacer { flex: 1; min-width: 0; }
.sidebar-account { display: flex; align-items: center; gap: 6px; min-width: 0; max-width: 150px; height: 32px; padding: 0 8px; border-radius: var(--corner-radius-small); color: var(--app-secondary-foreground); font-size: 13px; }
.login-avatar { width: 20px; height: 20px; border-radius: 50%; display: flex; align-items: center; justify-content: center; background: var(--app-brand-button); color: var(--app-brand-ivory); font-size: 11px; font-weight: 600; flex-shrink: 0; }
.login-name { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* === Main Column === */
.main-column { display: flex; flex-direction: column; flex: 1; min-width: 0; overflow: hidden; position: relative; background: var(--app-primary-background); }
.session-header {
  display: flex; align-items: center; gap: 6px; padding: 10px 24px; flex-shrink: 0;
  background: color-mix(in srgb, var(--app-primary-background), transparent 12%);
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); z-index: 5;
}
.session-title-btn { display: flex; align-items: center; gap: 6px; max-width: min(460px, 60%); height: 28px; padding: 5px 10px; border: none; border-radius: var(--corner-radius-small); background: transparent; color: var(--app-primary-foreground); cursor: pointer; font-weight: 600; font-size: 13.5px; }
.session-title-btn:hover { background: var(--app-ghost-button-hover-background); }
.session-title-text { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; min-width: 0; }
.session-title-chevron { color: var(--app-secondary-foreground); flex-shrink: 0; }
.header-spacer { flex: 1; }
.mobile-menu-btn { display: none; position: absolute; top: 10px; left: 10px; z-index: 30; width: 36px; height: 36px; align-items: center; justify-content: center; border: 1px solid var(--app-primary-border-color); border-radius: var(--corner-radius-small); background: var(--app-primary-background); color: var(--app-primary-foreground); cursor: pointer; font-size: 16px; }

/* === Model Selector === */
.model-selector { position: relative; min-width: 0; }
.model-selector-trigger { display: flex; align-items: center; gap: 4px; background: transparent; border: 1px solid var(--app-input-border); border-radius: var(--corner-radius-small); padding: 2px 8px; cursor: pointer; color: var(--app-primary-foreground); font-size: 12px; max-width: 220px; min-width: 0; height: 24px; }
.model-selector-trigger:hover { background: var(--app-ghost-button-hover-background); }
.model-selector-label { min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.model-selector-chevron { font-size: 8px; opacity: 0.6; flex-shrink: 0; }
.model-dropdown {
  position: absolute; top: 100%; right: 0; margin-top: 4px; min-width: 180px; max-width: min(300px, calc(100vw - 32px));
  max-height: 280px; overflow-y: auto; background: var(--app-menu-background); border: 1px solid var(--app-menu-border);
  border-radius: var(--corner-radius-medium); box-shadow: 0 4px 12px #0000004d; z-index: 100; padding: 4px; display: flex; flex-direction: column; gap: 2px;
}
.model-item { display: flex; align-items: center; gap: 5px; padding: 7px 10px; border: none; border-radius: var(--corner-radius-small); background: transparent; color: var(--app-menu-foreground); cursor: pointer; font-size: 12px; text-align: left; width: 100%; min-height: 32px; font-family: inherit; }
.model-item:hover { background: var(--app-list-hover-background); }

/* === Chat Body === */
.chat-body { display: flex; flex-direction: column; flex: 1; min-width: 0; min-height: 0; overflow: hidden; position: relative; }

/* === Landing === */
.chat-landing { flex: 1; display: flex; align-items: center; justify-content: center; overflow-y: auto; padding: 24px; }
.landing-inner { width: 100%; max-width: 760px; display: flex; flex-direction: column; align-items: center; gap: 22px; margin-bottom: min(8vh, 96px); }
.landing-brand { display: flex; align-items: center; gap: 12px; }
.landing-brand-name { font-family: var(--app-serif-font-family); font-size: clamp(32px, 2.4vw, 40px); font-weight: 600; letter-spacing: -0.01em; color: var(--app-brand-text); }
.landing-tagline { font-family: var(--app-serif-font-family); font-size: 18px; color: var(--app-secondary-foreground); margin-top: -8px; }
.landing-input { width: 100%; display: flex; flex-direction: column; gap: 6px; }
.landing-chips { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; max-width: 100%; }
.landing-chip {
  display: inline-flex; align-items: center; gap: 6px; padding: 8px 14px; border-radius: 999px;
  border: 1px solid var(--app-primary-border-color); background: var(--app-secondary-background);
  color: var(--app-primary-foreground); font-family: inherit; font-size: 13px;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis; cursor: pointer;
}
.landing-chip:hover { border-color: var(--app-brand); color: var(--app-brand); }

/* === Messages === */
.messages-container { display: flex; flex-direction: column; flex: 1; min-height: 0; overflow-y: auto; overflow-x: hidden; padding: 20px 24px 8px; gap: 0; min-width: 0; background: var(--app-primary-background); position: relative; }
.timeline-inner { width: 100%; max-width: 760px; margin: 0 auto; display: flex; flex-direction: column; }
.messages-empty { flex: 1; display: flex; align-items: center; justify-content: center; text-align: center; color: var(--app-secondary-foreground); font-size: 13px; }

.timeline-message { position: relative; padding-top: 8px; padding-bottom: 8px; display: flex; flex-direction: column; align-items: flex-start; color: var(--app-primary-foreground); }
.timeline-message:first-child { padding-top: 0; }

.user-message-wrapper { position: relative; z-index: 2; padding: 10px 0 12px; width: 100%; display: flex; flex-direction: column; align-items: flex-end; }
.user-message-bubble {
  display: block; position: relative; white-space: pre-wrap; word-break: break-word;
  border: 1px solid var(--app-input-border); border-radius: var(--corner-radius-large);
  background: var(--app-input-secondary-background); color: var(--app-primary-foreground);
  padding: 9px 13px; max-width: 85%; width: auto; user-select: text;
  font-size: 15px; line-height: 1.5; font-weight: 400;
}

.assistant-message-content { font-size: 15px; line-height: 1.6; width: 100%; min-width: 0; white-space: pre-wrap; word-break: break-word; color: var(--app-primary-foreground); }
.msg-time { margin-top: 4px; font-size: 11px; line-height: 1.4; color: var(--app-secondary-foreground); opacity: 0.7; user-select: none; }
.msg-time-user { align-self: flex-end; margin-right: 2px; }

/* === Input === */
.input-container { flex-shrink: 0; display: flex; flex-direction: column; padding: 12px 24px 18px; background: var(--app-primary-background); }
.input-wrap { width: 100%; max-width: 760px; margin: 0 auto; display: flex; flex-direction: column; gap: 6px; }
.input-box {
  background: var(--app-input-background); border: 1px solid var(--app-input-border);
  border-radius: var(--corner-radius-large); box-shadow: 0 2px 12px #0000001f, 0 1px 3px #00000008;
  display: flex; flex-direction: column; gap: 8px; padding: 10px 12px; position: relative; color: var(--app-input-foreground);
}
.input-box:focus-within { border-color: var(--app-brand); box-shadow: 0 0 0 3px color-mix(in srgb, var(--app-brand) 12%, transparent); }
.landing-inner .input-box { width: 100%; }
.landing-inner .message-input { min-height: 6em; }

.message-input {
  background: transparent; border: none; outline: none; resize: none; color: var(--app-input-foreground);
  font-family: inherit; font-size: 15px; line-height: 1.5; min-height: 3em; max-height: 200px;
  overflow-y: auto; padding: 4px 2px 0; width: 100%;
}
.message-input::placeholder { color: var(--app-input-placeholder-foreground); }
.message-input:disabled { opacity: 0.5; }

.input-footer { display: flex; align-items: center; gap: 6px; min-width: 0; padding: 0; color: var(--app-secondary-foreground); font-size: 11px; }
.footer-hint { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.footer-spacer { flex: 1; }

.btn-send {
  width: 34px; height: 34px; border-radius: 50%; border: none;
  background: var(--app-brand-button); color: var(--app-brand-ivory);
  cursor: pointer; display: flex; align-items: center; justify-content: center;
  flex-shrink: 0; font-size: 17px; line-height: 1;
}
.btn-send:disabled { opacity: 0.4; cursor: default; }
.btn-send:not(:disabled):hover { filter: brightness(1.1); }

/* === Modal === */
.modal-overlay { position: fixed; inset: 0; z-index: 60; background: var(--app-modal-background); display: flex; align-items: center; justify-content: center; padding: 16px; }
.modal-card { width: min(480px, 100%); max-height: 85dvh; display: flex; flex-direction: column; background: var(--app-menu-background); color: var(--app-menu-foreground); border: 1px solid var(--app-menu-border); border-radius: var(--corner-radius-large); box-shadow: 0 8px 32px rgba(0,0,0,0.4); overflow: hidden; }
.modal-header { display: flex; align-items: center; gap: 8px; padding: 14px 16px; border-bottom: 1px solid var(--app-menu-border); flex-shrink: 0; }
.modal-header h3 { font-size: 14px; font-weight: 700; color: var(--app-primary-foreground); margin: 0; }
.modal-close { margin-left: auto; width: 28px; height: 28px; display: flex; align-items: center; justify-content: center; border: none; border-radius: var(--corner-radius-small); background: transparent; color: var(--app-secondary-foreground); cursor: pointer; font-size: 16px; }
.modal-close:hover { background: var(--app-ghost-button-hover-background); }
.modal-body { padding: 16px; overflow-y: auto; display: flex; flex-direction: column; gap: 16px; }
.modal-label { font-size: 11px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.04em; color: var(--app-secondary-foreground); }
.field-group { display: flex; flex-direction: column; gap: 6px; }
.field-hint { font-size: 12px; color: var(--app-secondary-foreground); line-height: 1.5; }

/* === Segmented Control === */
.segmented { display: inline-flex; gap: 2px; padding: 2px; background: var(--app-input-secondary-background); border: 1px solid var(--app-input-border); border-radius: var(--corner-radius-medium); align-self: flex-start; }
.segmented-btn { flex: 1; min-width: 64px; height: 30px; padding: 0 14px; border: none; border-radius: var(--corner-radius-small); background: transparent; color: var(--app-secondary-foreground); cursor: pointer; font-size: 12px; font-family: inherit; white-space: nowrap; }
.segmented-btn:hover { color: var(--app-primary-foreground); }
.segmented-btn.active { background: var(--app-brand-button); color: var(--app-button-foreground); font-weight: 500; }

/* === Code Block === */
.code-block-wrapper { position: relative; margin: 10px 0; }
.code-block-wrapper pre {
  overflow-x: auto; white-space: pre; border-radius: 6px; padding: 14px 16px; max-width: 100%; margin: 0;
  font-family: var(--app-monospace-font-family); font-size: var(--app-monospace-font-size); line-height: 1.65;
  background: color-mix(in srgb, var(--app-tool-background), var(--app-primary-background) 30%);
  border: 1px solid var(--app-input-border); color: var(--app-primary-foreground);
}
.code-block-wrapper .copy-button { position: absolute; top: 6px; right: 6px; opacity: 0.55; transition: opacity 0.15s; background: var(--app-secondary-background); border: 1px solid var(--app-input-border); border-radius: var(--corner-radius-small); padding: 4px 8px; cursor: pointer; color: var(--app-secondary-foreground); display: inline-flex; align-items: center; font-size: 11px; }
.code-block-wrapper:hover .copy-button { opacity: 1; }
.code-block-wrapper .copy-button:hover { opacity: 1; background: var(--app-ghost-button-hover-background); color: var(--app-primary-foreground); }

/* === Markdown === */
.markdown-root { text-wrap: auto; overflow-x: clip; width: 100%; white-space: normal; }
.markdown-root > :first-child { margin-top: 0; }
.markdown-root > :last-child { margin-bottom: 0; }
.markdown-root p { white-space: pre-wrap; margin: 0.1em 0 0.4em; }
.markdown-root ul { list-style: disc; padding-inline-start: 1.5em; margin: 0.3em 0 0.5em; }
.markdown-root ol { list-style: decimal; padding-inline-start: 1.5em; margin: 0.3em 0 0.5em; }
.markdown-root li { margin-bottom: 3px; }
.markdown-root h1, .markdown-root h2, .markdown-root h3, .markdown-root h4 { margin: 0.8em 0 0.3em; font-weight: 600; }
.markdown-root h1 { font-size: 1.3em; } .markdown-root h2 { font-size: 1.15em; } .markdown-root h3 { font-size: 1.05em; }
.markdown-root blockquote { border-left: 3px solid var(--app-primary-border-color); padding-left: 12px; margin: 0.3em 0; color: var(--app-secondary-foreground); }
.markdown-root code { font-family: var(--app-monospace-font-family); border-radius: 3px; padding: 1px 5px; font-size: 0.9em; background: color-mix(in srgb, var(--app-secondary-background), transparent 40%); color: var(--app-primary-foreground); }
.markdown-root pre code { padding: 0; background: none; }
.markdown-root table { border-collapse: collapse; margin: 0.5em 0; font-size: 0.95em; display: block; width: max-content; max-width: 100%; overflow-x: auto; }
.markdown-root th, .markdown-root td { border: 1px solid var(--app-primary-border-color); padding: 5px 10px; text-align: left; }
.markdown-root th { background: color-mix(in srgb, var(--app-tool-background), var(--app-primary-background) 30%); font-weight: 600; }

/* === Tool Call === */
.tool-list { display: flex; flex-direction: column; gap: 6px; margin: 0 0 10px; width: 100%; }
.tool-header { display: flex; align-items: center; padding: 5px 6px; gap: 8px; border-radius: var(--corner-radius-small); cursor: pointer; user-select: none; min-width: 0; }
.tool-header:hover { background: var(--app-list-hover-background); }
.tool-name { font-weight: 600; font-size: 13px; color: var(--app-primary-foreground); flex-shrink: 0; }
.tool-status { margin-left: auto; font-size: 11px; flex-shrink: 0; }
.tool-status.success { color: var(--app-success-foreground); }
.tool-status.error { color: var(--app-error-foreground); }

/* === Mobile === */
@media (max-width: 768px) {
  .mobile-menu-btn { display: flex; }
  .sidebar { position: fixed; top: 0; left: 0; bottom: 0; z-index: 50; width: 80vw; max-width: 300px; transform: translateX(-100%); transition: transform 0.2s ease; box-shadow: 2px 0 16px rgba(0,0,0,0.35); }
  .sidebar.open { transform: translateX(0); }
  .sidebar-backdrop { position: fixed; inset: 0; z-index: 45; background: var(--app-modal-background); display: none; }
  .sidebar-backdrop.show { display: block; }
  .session-header { padding: 10px 12px 10px 54px; }
  .messages-container { padding: 12px 12px 6px; }
  .input-container { padding: 6px 8px 8px; }
  .modal-overlay { align-items: flex-end; padding: 0; }
  .modal-card { width: 100%; max-width: 100%; max-height: 85dvh; border-radius: var(--corner-radius-large) var(--corner-radius-large) 0 0; }
}