/* =============================================================================
 * ui_template_elements.ts
 * 공통 컴포넌트 및 그룹 템플릿 정의
 *
 * 원칙:
 *   - 모든 컴포넌트는 임의 스타일링 금지, 여기 규격을 최우선 상속/참조 (frontend.md §2).
 *   - 색상/간격은 CSS 클래스 + theme.css 변수로만 처리, JS 내 인라인 색상 금지.
 *   - 팩토리 함수는 HTMLElement를 반환하는 vanilla TS 패턴.
 *   - 스타일 규칙은 injectBaseStyles()로 1회 주입 (design.md 컴포넌트 명세 기반).
 * ========================================================================== */

/* -----------------------------------------------------------------------------
 * 0. 내부 유틸
 * -------------------------------------------------------------------------- */

/** 요소 생성 + 속성/클래스/자식 일괄 설정 헬퍼 */
function el<K extends keyof HTMLElementTagNameMap>(
  tag: K,
  options: {
    className?: string;
    text?: string;
    attrs?: Record<string, string>;
    children?: (HTMLElement | string)[];
  } = {},
): HTMLElementTagNameMap[K] {
  const node = document.createElement(tag);
  if (options.className) node.className = options.className;
  if (options.text !== undefined) node.textContent = options.text;
  if (options.attrs) {
    for (const [k, v] of Object.entries(options.attrs)) {
      node.setAttribute(k, v);
    }
  }
  if (options.children) {
    for (const child of options.children) {
      node.append(child);
    }
  }
  return node;
}

/* -----------------------------------------------------------------------------
 * 1. 버튼 (Button) — design.md: Filled Brand / Ghost Outlined / Pill Nav
 * -------------------------------------------------------------------------- */

export type ButtonVariant = "filled" | "ghost" | "pill" | "danger";

export interface ButtonOptions {
  /** 표시 텍스트 (i18n 결과 문자열을 전달) */
  label: string;
  variant?: ButtonVariant;
  /** 이벤트 핸들러 (frontend.md §4: on[페이지]_[기능]_[액션] 명명) */
  onClick?: (ev: MouseEvent) => void;
  disabled?: boolean;
  type?: "button" | "submit" | "reset";
  /** 앞쪽 아이콘 요소 (선택) */
  iconStart?: HTMLElement;
}

export function createButton(opts: ButtonOptions): HTMLButtonElement {
  const variant = opts.variant ?? "filled";
  const btn = el("button", {
    className: `ui-btn ui-btn--${variant}`,
    attrs: { type: opts.type ?? "button" },
  });
  if (opts.iconStart) {
    opts.iconStart.classList.add("ui-btn__icon");
    btn.append(opts.iconStart);
  }
  btn.append(el("span", { className: "ui-btn__label", text: opts.label }));
  if (opts.disabled) btn.disabled = true;
  if (opts.onClick) btn.addEventListener("click", opts.onClick);
  return btn;
}

/* -----------------------------------------------------------------------------
 * 2. 입력 필드 (Input Field) — design.md: 1px mist border, 8px radius, focus ring
 * -------------------------------------------------------------------------- */

export interface InputFieldOptions {
  /** 라벨 텍스트 (i18n 결과) */
  label?: string;
  /** placeholder (i18n 결과) */
  placeholder?: string;
  type?: "text" | "password" | "email" | "number" | "search" | "tel";
  value?: string;
  required?: boolean;
  /** number 타입 범위 (1차 유효성 검사용, frontend.md §4) */
  min?: number;
  max?: number;
  onInput?: (value: string) => void;
}

export interface InputFieldHandle {
  /** 필드 컨테이너 (라벨 + 입력 + 에러 슬롯) */
  root: HTMLDivElement;
  input: HTMLInputElement;
  /** 에러 메시지 표시/해제. msg가 없으면 에러 해제. */
  setError: (msg?: string) => void;
}

export function createInputField(opts: InputFieldOptions): InputFieldHandle {
  const root = el("div", { className: "ui-field" });

  if (opts.label) {
    root.append(el("label", { className: "ui-field__label", text: opts.label }));
  }

  const input = el("input", {
    className: "ui-input",
    attrs: {
      type: opts.type ?? "text",
      ...(opts.placeholder ? { placeholder: opts.placeholder } : {}),
      ...(opts.required ? { required: "true" } : {}),
      ...(opts.min !== undefined ? { min: String(opts.min) } : {}),
      ...(opts.max !== undefined ? { max: String(opts.max) } : {}),
    },
  });
  if (opts.value !== undefined) input.value = opts.value;
  if (opts.onInput) {
    input.addEventListener("input", () => opts.onInput!(input.value));
  }

  // 에러 메시지 슬롯 (입력창 하단 표기, frontend.md §4)
  const errorSlot = el("span", { className: "ui-field__error", attrs: { role: "alert" } });

  root.append(input, errorSlot);

  const setError = (msg?: string): void => {
    if (msg) {
      input.classList.add("ui-input--error");
      errorSlot.textContent = msg;
      errorSlot.classList.add("is-visible");
    } else {
      input.classList.remove("ui-input--error");
      errorSlot.textContent = "";
      errorSlot.classList.remove("is-visible");
    }
  };

  return { root, input, setError };
}

/* -----------------------------------------------------------------------------
 * 2-1. 드롭다운 필드 (Select Field) — design.md: input과 조화되는 8px radius, focus
 * -------------------------------------------------------------------------- */

export interface SelectFieldOptions {
  /** 라벨 텍스트 */
  label?: string;
  /** 옵션 항목 목록 */
  options: { value: string; text: string }[];
  /** 초기 선택값 */
  value?: string;
  onChange?: (value: string) => void;
  disabled?: boolean;
}

export interface SelectFieldHandle {
  root: HTMLDivElement;
  select: HTMLSelectElement;
}

export function createSelectField(opts: SelectFieldOptions): SelectFieldHandle {
  const root = el("div", { className: "ui-field" });

  if (opts.label) {
    root.append(el("label", { className: "ui-field__label", text: opts.label }));
  }

  const select = el("select", {
    className: "ui-select",
  });

  for (const opt of opts.options) {
    const optEl = el("option", {
      attrs: { value: opt.value },
      text: opt.text,
    });
    if (opts.value !== undefined && opt.value === opts.value) {
      optEl.selected = true;
    }
    select.append(optEl);
  }

  if (opts.disabled) select.disabled = true;

  if (opts.onChange) {
    select.addEventListener("change", () => opts.onChange!(select.value));
  }

  root.append(select);

  return { root, select };
}

/* -----------------------------------------------------------------------------
 * 3. 카드 / 패널 (Card) — design.md: white surface, 8px radius, shadow
 * -------------------------------------------------------------------------- */

export interface CardOptions {
  title?: string;
  /** 본문 자식 요소들 */
  body?: (HTMLElement | string)[];
  /** 그림자 강조 여부 (shadow-lg 사용) */
  raised?: boolean;
}

export function createCard(opts: CardOptions): HTMLDivElement {
  const card = el("div", {
    className: `ui-card${opts.raised ? " ui-card--raised" : ""}`,
  });
  if (opts.title) {
    card.append(el("h3", { className: "ui-card__title", text: opts.title }));
  }
  if (opts.body) {
    card.append(el("div", { className: "ui-card__body", children: opts.body }));
  }
  return card;
}

/* -----------------------------------------------------------------------------
 * 4. 태그 / 배지 (Tag / Pill) — design.md: 1440px radius pill
 * -------------------------------------------------------------------------- */

export type TagVariant = "accent" | "neutral" | "success" | "warning" | "danger";

export function createTag(label: string, variant: TagVariant = "neutral"): HTMLSpanElement {
  return el("span", { className: `ui-tag ui-tag--${variant}`, text: label });
}

/* -----------------------------------------------------------------------------
 * 5. 로딩 오버레이 (Loading Overlay) — frontend.md §4: API 호출 시 필수
 *    싱글턴 오버레이. show/hide로 참조 카운트 관리.
 * -------------------------------------------------------------------------- */

let overlayEl: HTMLDivElement | null = null;
let overlayCount = 0;

function ensureOverlay(): HTMLDivElement {
  if (overlayEl) return overlayEl;
  const spinner = el("div", { className: "ui-spinner", attrs: { "aria-hidden": "true" } });
  overlayEl = el("div", {
    className: "ui-overlay",
    attrs: { role: "status", "aria-live": "polite" },
    children: [spinner],
  });
  document.body.append(overlayEl);
  return overlayEl;
}

/** 로딩 스피너 오버레이 표시 (중첩 호출 안전) */
export function showLoadingOverlay(): void {
  overlayCount += 1;
  ensureOverlay().classList.add("is-active");
}

/** 로딩 스피너 오버레이 해제 (모든 참조 종료 시 실제 숨김) */
export function hideLoadingOverlay(): void {
  overlayCount = Math.max(0, overlayCount - 1);
  if (overlayCount === 0 && overlayEl) {
    overlayEl.classList.remove("is-active");
  }
}

/* -----------------------------------------------------------------------------
 * 6. 토스트 알림 (Toast) — 성공/에러 배너
 * -------------------------------------------------------------------------- */

export type ToastKind = "success" | "error" | "info" | "warning";

let toastContainer: HTMLDivElement | null = null;

function ensureToastContainer(): HTMLDivElement {
  if (toastContainer) return toastContainer;
  toastContainer = el("div", { className: "ui-toast-container" });
  document.body.append(toastContainer);
  return toastContainer;
}

/** 토스트 표시. durationMs 후 자동 소멸. */
export function showToast(message: string, kind: ToastKind = "info", durationMs = 3000): void {
  const toast = el("div", { className: `ui-toast ui-toast--${kind}`, text: message });
  ensureToastContainer().append(toast);
  // 진입 애니메이션 트리거
  requestAnimationFrame(() => toast.classList.add("is-visible"));
  window.setTimeout(() => {
    toast.classList.remove("is-visible");
    window.setTimeout(() => toast.remove(), 200);
  }, durationMs);
}

/* -----------------------------------------------------------------------------
 * 7. 워크플로우 3단 레이아웃 셸 (frontend.md §2)
 *    상단 헤더 + 좌측 고정 패널 + 우측 뷰어 영역.
 * -------------------------------------------------------------------------- */

export interface WorkflowShellOptions {
  /** 상단 페이지 타이틀 (i18n 결과) */
  title: string;
  /** 상단 진행 단계 라벨 배열 (i18n 결과) */
  steps?: string[];
  /** 현재 활성 단계 인덱스 */
  activeStep?: number;
}

export interface WorkflowShellHandle {
  root: HTMLDivElement;
  /** 좌측 입력 폼/설정 영역 (너비 고정) */
  leftPanel: HTMLDivElement;
  /** 우측 WebCAD 뷰어 / 결과 그리드 영역 */
  rightArea: HTMLDivElement;
}

export function createWorkflowShell(opts: WorkflowShellOptions): WorkflowShellHandle {
  // 상단 헤더
  const titleEl = el("h2", { className: "ui-wf__title", text: opts.title });
  const headerChildren: HTMLElement[] = [titleEl];

  if (opts.steps && opts.steps.length > 0) {
    const stepsEl = el("div", { className: "ui-wf__steps" });
    opts.steps.forEach((label, idx) => {
      const isActive = idx === (opts.activeStep ?? 0);
      stepsEl.append(
        el("span", {
          className: `ui-wf__step${isActive ? " is-active" : ""}`,
          text: label,
        }),
      );
    });
    headerChildren.push(stepsEl);
  }

  const header = el("header", { className: "ui-wf__header", children: headerChildren });
  const leftPanel = el("div", { className: "ui-wf__left" });
  const rightArea = el("div", { className: "ui-wf__right" });
  const bodyRow = el("div", { className: "ui-wf__body", children: [leftPanel, rightArea] });

  const root = el("div", { className: "ui-wf", children: [header, bodyRow] });
  return { root, leftPanel, rightArea };
}

/* -----------------------------------------------------------------------------
 * 7-1. 라인 차트 (Line Chart) — 시계열 데이터 SVG 렌더링
 *    외부 라이브러리 없이 인라인 SVG. 색상은 CSS 클래스 + theme.css 변수 참조.
 * -------------------------------------------------------------------------- */

export interface LineChartSeries {
  /** 범례에 표시할 이름 (i18n 결과 문자열) */
  name: string;
  /** y 값 배열 (x는 인덱스 순서, null은 결측으로 선 끊김) */
  values: (number | null)[];
  /** 선 색상 클래스 접미사: 0~3 (theme.css의 --color-chart-N 참조) */
  colorIndex?: 0 | 1 | 2 | 3;
}

export interface LineChartOptions {
  series: LineChartSeries[];
  /** x축 라벨 (values와 같은 길이 권장, 일부만 자동 선택 표기) */
  xLabels?: string[];
  /** y축 최대값 (기본: 100 = 퍼센트) */
  yMax?: number;
  /** y축 단위 접미사 (기본: "%") */
  yUnit?: string;
  /** 접근성 설명 */
  ariaLabel?: string;
  /** 커스텀 가상 가로폭 (기본: CHART_W = 640) */
  width?: number;
  /** 커스텀 가상 세로폭 (기본: CHART_H = 200) */
  height?: number;
}

const CHART_W = 640;
const CHART_H = 200;
const CHART_PAD = { top: 12, right: 12, bottom: 26, left: 36 };
const X_TICK_STEP = 3; // x축 라벨 표기 간격 (3개마다 1개 표시)

/** 유효 점들을 Catmull-Rom → 3차 베지어로 변환한 스플라인 path 데이터를 만든다. */
function splinePath(points: { x: number; y: number }[]): string {
  if (points.length === 0) return "";
  if (points.length === 1) return `M${points[0].x},${points[0].y}`;
  let d = `M${points[0].x.toFixed(1)},${points[0].y.toFixed(1)}`;
  for (let i = 0; i < points.length - 1; i += 1) {
    const p0 = points[i - 1] ?? points[i];
    const p1 = points[i];
    const p2 = points[i + 1];
    const p3 = points[i + 2] ?? p2;
    // Catmull-Rom (tension 1/6) → cubic Bézier 제어점
    const c1x = p1.x + (p2.x - p0.x) / 6;
    const c1y = p1.y + (p2.y - p0.y) / 6;
    const c2x = p2.x - (p3.x - p1.x) / 6;
    const c2y = p2.y - (p3.y - p1.y) / 6;
    d +=
      ` C${c1x.toFixed(1)},${c1y.toFixed(1)} ` +
      `${c2x.toFixed(1)},${c2y.toFixed(1)} ` +
      `${p2.x.toFixed(1)},${p2.y.toFixed(1)}`;
  }
  return d;
}

/** 시계열 스플라인 차트를 반환. 데이터가 없으면 안내 문구를 담은 빈 상태를 반환. */
export function createLineChart(opts: LineChartOptions): HTMLDivElement {
  const w = opts.width ?? CHART_W;
  const h = opts.height ?? CHART_H;
  const yMax = opts.yMax ?? 100;
  const yUnit = opts.yUnit ?? "%";
  const wrap = el("div", { className: "ui-chart" });

  const pointCount = Math.max(0, ...opts.series.map((s) => s.values.length));
  if (pointCount < 2) {
    wrap.append(el("div", { className: "ui-chart__empty", text: "—" }));
    wrap.setAttribute("data-empty", "true");
    return wrap;
  }

  const plotW = w - CHART_PAD.left - CHART_PAD.right;
  const plotH = h - CHART_PAD.top - CHART_PAD.bottom;
  const xAt = (i: number) => CHART_PAD.left + (plotW * i) / (pointCount - 1);
  const yAt = (v: number) => CHART_PAD.top + plotH * (1 - Math.min(v, yMax) / yMax);

  const svgNs = "http://www.w3.org/2000/svg";
  const svg = document.createElementNS(svgNs, "svg");
  svg.setAttribute("class", "ui-chart__svg");
  svg.setAttribute("viewBox", `0 0 ${w} ${h}`);
  svg.setAttribute("role", "img");
  svg.setAttribute("width", "100%");
  svg.setAttribute("height", "100%");
  svg.setAttribute("preserveAspectRatio", "none");
  if (opts.ariaLabel) svg.setAttribute("aria-label", opts.ariaLabel);

  // y축 그리드 + 라벨 (0, 25, 50, 75, 100%)
  for (let g = 0; g <= 4; g += 1) {
    const v = (yMax / 4) * g;
    const y = yAt(v);
    const line = document.createElementNS(svgNs, "line");
    line.setAttribute("class", "ui-chart__grid");
    line.setAttribute("x1", String(CHART_PAD.left));
    line.setAttribute("x2", String(w - CHART_PAD.right));
    line.setAttribute("y1", String(y));
    line.setAttribute("y2", String(y));
    svg.append(line);
    const tick = document.createElementNS(svgNs, "text");
    tick.setAttribute("class", "ui-chart__tick");
    tick.setAttribute("x", String(CHART_PAD.left - 6));
    tick.setAttribute("y", String(y + 4));
    tick.setAttribute("text-anchor", "end");
    tick.textContent = `${Math.round(v)}${yUnit}`;
    svg.append(tick);
  }

  // x축 라벨 (데이터 포인트 개수만큼, X_TICK_STEP 간격으로 표기) + 수직 점선 그리드
  if (opts.xLabels && opts.xLabels.length > 0) {
    const labels = opts.xLabels;
    const baseY = CHART_PAD.top + plotH;
    for (let idx = 0; idx < pointCount; idx += X_TICK_STEP) {
      const label = labels[idx];
      const x = xAt(idx);
      if (label !== undefined && label !== "") {
        // 수직 점선 그리드
        const vline = document.createElementNS(svgNs, "line");
        vline.setAttribute("class", "ui-chart__grid ui-chart__grid--vertical");
        vline.setAttribute("x1", String(x));
        vline.setAttribute("x2", String(x));
        vline.setAttribute("y1", String(CHART_PAD.top));
        vline.setAttribute("y2", String(baseY));
        svg.append(vline);
        // x축 라벨
        const tick = document.createElementNS(svgNs, "text");
        tick.setAttribute("class", "ui-chart__tick ui-chart__tick--x");
        tick.setAttribute("x", String(x));
        tick.setAttribute("y", String(baseY + 16));
        tick.setAttribute("text-anchor", "middle");
        tick.textContent = label;
        svg.append(tick);
      }
    }
  }

  // 시리즈별 스플라인 (null 구간은 연속 세그먼트로 나눠 각각 곡선 처리)
  for (const s of opts.series) {
    let segment: { x: number; y: number }[] = [];
    let d = "";
    const flush = () => {
      if (segment.length > 0) d += `${splinePath(segment)} `;
      segment = [];
    };
    s.values.forEach((v, i) => {
      if (v === null || v === undefined) {
        flush();
        return;
      }
      segment.push({ x: xAt(i), y: yAt(v) });
    });
    flush();
    const path = document.createElementNS(svgNs, "path");
    path.setAttribute("class", `ui-chart__line ui-chart__line--c${s.colorIndex ?? 0}`);
    path.setAttribute("d", d.trim());
    svg.append(path);
  }

  // 범례 (그래프 영역 우상단 오버레이)
  const legend = el("div", { className: "ui-chart__legend" });
  opts.series.forEach((s) => {
    legend.append(
      el("span", {
        className: `ui-chart__legend-item ui-chart__legend-item--c${s.colorIndex ?? 0}`,
        text: s.name,
      }),
    );
  });

  const plot = el("div", { className: "ui-chart__plot" });
  plot.append(svg, legend);
  wrap.append(plot);
  return wrap;
}

/* =============================================================================
 * 8. 기본 컴포넌트 스타일 주입 (injectBaseStyles)
 *    theme.css 변수만 참조. 앱 진입 시 1회 호출.
 * ========================================================================== */

const BASE_STYLE_ID = "ui-template-elements-style";

const BASE_CSS = `
/* --- Button --- */
.ui-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-8);
  font-family: var(--font-body);
  font-size: var(--text-body-sm);
  font-weight: var(--font-weight-medium);
  line-height: 1;
  border: 1px solid transparent;
  border-radius: var(--radius-buttons);
  padding: var(--spacing-8) var(--spacing-16);
  cursor: pointer;
  transition: background-color var(--transition-fast),
    border-color var(--transition-fast), color var(--transition-fast);
}
.ui-btn:disabled { opacity: 0.5; cursor: not-allowed; }
.ui-btn__icon { display: inline-flex; width: 16px; height: 16px; }

.ui-btn--filled {
  background-color: var(--color-primary);
  color: var(--color-primary-text);
  box-shadow: var(--shadow-sm);
}
.ui-btn--filled:hover:not(:disabled) { background-color: var(--color-royal-amethyst); }

.ui-btn--ghost {
  background-color: transparent;
  border-color: var(--color-primary);
  color: var(--color-primary);
}
.ui-btn--ghost:hover:not(:disabled) { background-color: var(--color-mist-violet); }

.ui-btn--pill {
  background-color: transparent;
  color: var(--color-plum-velvet);
  border-radius: var(--radius-pills);
}
.ui-btn--pill:hover:not(:disabled),
.ui-btn--pill.is-active { background-color: var(--color-mist-violet); }

.ui-btn--danger {
  background-color: var(--color-danger);
  color: var(--color-canvas);
}

/* --- Input Field --- */
.ui-field { display: flex; flex-direction: column; gap: var(--spacing-4); }
.ui-field__label {
  font-size: var(--text-caption);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
}
.ui-input {
  font-family: var(--font-body);
  font-size: var(--text-body-sm);
  color: var(--color-text-body);
  background-color: var(--color-canvas);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-inputs);
  padding: 10px 14px;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.ui-input::placeholder { color: var(--color-text-muted); }
.ui-input:focus {
  outline: none;
  border-color: var(--color-focus-ring);
  box-shadow: 0 0 0 1px var(--color-focus-ring);
}
.ui-input--error { border-color: var(--color-danger); }
.ui-field__error {
  font-size: var(--text-caption);
  color: var(--color-danger);
  min-height: 0;
  visibility: hidden;
}
.ui-field__error.is-visible { visibility: visible; }

.ui-select {
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  font-family: var(--font-body);
  font-size: var(--text-body-sm);
  color: var(--color-text-body);
  background-color: var(--color-canvas);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-inputs);
  padding: 10px 36px 10px 14px;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%233e0079'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M19 9l-7 7-7-7'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 16px;
  cursor: pointer;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.ui-select:focus {
  outline: none;
  border-color: var(--color-focus-ring);
  box-shadow: 0 0 0 1px var(--color-focus-ring);
}
.ui-select:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* --- Card --- */
.ui-card {
  background-color: var(--color-surface-raised);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-cards);
  padding: var(--card-padding);
  box-shadow: var(--shadow-sm);
}
.ui-card--raised { box-shadow: var(--shadow-lg); border-color: transparent; }
.ui-card__title {
  font-family: var(--font-display);
  color: var(--color-plum-velvet);
  margin-bottom: var(--spacing-16);
}
.ui-card__body { display: flex; flex-direction: column; gap: var(--spacing-16); }

/* --- Tag / Pill --- */
.ui-tag {
  display: inline-flex;
  align-items: center;
  border-radius: var(--radius-pills);
  padding: var(--spacing-4) var(--spacing-16);
  font-size: var(--text-caption);
  font-weight: var(--font-weight-medium);
  line-height: 1.3;
}
.ui-tag--accent { background-color: var(--color-mist-violet); color: var(--color-royal-amethyst); }
.ui-tag--neutral { background-color: var(--color-paper); color: var(--color-slate); }
.ui-tag--success { background-color: var(--color-mist-violet); color: var(--color-success); }
.ui-tag--warning { background-color: var(--color-paper); color: var(--color-warning); }
.ui-tag--danger { background-color: var(--color-paper); color: var(--color-danger); }

/* --- Loading Overlay + Spinner --- */
.ui-overlay {
  position: fixed;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
  background-color: rgba(38, 17, 74, 0.24);
  z-index: var(--z-overlay);
}
.ui-overlay.is-active { display: flex; }
.ui-spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--color-mist-violet);
  border-top-color: var(--color-royal-amethyst);
  border-radius: var(--radius-pills);
  animation: ui-spin 0.8s linear infinite;
}
@keyframes ui-spin { to { transform: rotate(360deg); } }

/* --- Toast --- */
.ui-toast-container {
  position: fixed;
  top: var(--spacing-24);
  right: var(--spacing-24);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-8);
  z-index: var(--z-toast);
}
.ui-toast {
  padding: var(--spacing-16) var(--spacing-24);
  border-radius: var(--radius-cards);
  font-size: var(--text-body-sm);
  color: var(--color-canvas);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  transform: translateX(16px);
  transition: opacity var(--transition-base), transform var(--transition-base);
}
.ui-toast.is-visible { opacity: 1; transform: translateX(0); }
.ui-toast--success { background-color: var(--color-success); }
.ui-toast--error { background-color: var(--color-danger); }
.ui-toast--warning { background-color: var(--color-warning); }
.ui-toast--info { background-color: var(--color-royal-amethyst); }

/* --- Workflow Shell (3단 레이아웃) --- */
.ui-wf { display: flex; flex-direction: column; height: 100%; }
.ui-wf__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--wf-header-height);
  padding: 0 var(--spacing-24);
  border-bottom: 1px solid var(--color-border);
  background-color: var(--color-surface-raised);
}
.ui-wf__title { font-size: var(--text-subheading); }
.ui-wf__steps { display: flex; gap: var(--spacing-8); }
.ui-wf__step {
  padding: var(--spacing-4) var(--spacing-16);
  border-radius: var(--radius-pills);
  font-size: var(--text-caption);
  font-weight: var(--font-weight-medium);
  color: var(--color-slate);
  background-color: var(--color-paper);
}
.ui-wf__step.is-active {
  color: var(--color-royal-amethyst);
  background-color: var(--color-mist-violet);
}
.ui-wf__body { display: flex; flex: 1; min-height: 0; }
.ui-wf__left {
  width: var(--wf-left-panel-width);
  flex-shrink: 0;
  padding: var(--spacing-24);
  border-right: 1px solid var(--color-border);
  overflow-y: auto;
  background-color: var(--color-surface);
}
.ui-wf__right {
  flex: 1;
  min-width: 0;
  overflow: auto;
  background-color: var(--color-bg);
}

/* --- Line Chart --- */
.ui-chart {
  width: 100%;
}
.ui-chart__plot {
  position: relative;
  width: 100%;
}
.ui-chart__svg {
  width: 100%;
  height: auto;
  display: block;
}
.ui-chart__empty {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 120px;
  color: var(--color-text-muted);
  font-size: var(--text-body);
}
.ui-chart__grid {
  stroke: var(--color-border);
  stroke-width: 1;
  opacity: 0.5;
}
.ui-chart__grid--vertical {
  stroke-dasharray: 4, 4;
}
.ui-chart__tick {
  fill: var(--color-text-muted);
  font-size: 12px;
  font-family: var(--font-body);
}
.ui-chart__tick--x {
  font-size: 11px;
}
.ui-chart__line {
  fill: none;
  stroke-width: 2;
  stroke-linejoin: round;
  stroke-linecap: round;
}
.ui-chart__line--c0 { stroke: var(--color-chart-0); }
.ui-chart__line--c1 { stroke: var(--color-chart-1); }
.ui-chart__line--c2 { stroke: var(--color-chart-2); }
.ui-chart__line--c3 { stroke: var(--color-chart-3); }
.ui-chart__point {
  stroke-width: 1.5;
  stroke: var(--color-surface);
}
.ui-chart__point--c0 { fill: var(--color-chart-0); }
.ui-chart__point--c1 { fill: var(--color-chart-1); }
.ui-chart__point--c2 { fill: var(--color-chart-2); }
.ui-chart__point--c3 { fill: var(--color-chart-3); }

.ui-chart__legend {
  position: absolute;
  top: var(--spacing-4);
  right: var(--spacing-8);
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: var(--spacing-8) var(--spacing-16);
  padding: var(--spacing-4) var(--spacing-8);
  border-radius: var(--radius-cards);
  background-color: color-mix(in srgb, var(--color-surface) 78%, transparent);
  pointer-events: none;
}
.ui-chart__legend-item {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-8);
  font-size: var(--text-caption);
  color: var(--color-text);
}
.ui-chart__legend-item::before {
  content: "";
  width: 12px;
  height: 3px;
  border-radius: 2px;
  background-color: currentColor;
}
.ui-chart__legend-item--c0 { color: var(--color-chart-0); }
.ui-chart__legend-item--c1 { color: var(--color-chart-1); }
.ui-chart__legend-item--c2 { color: var(--color-chart-2); }
.ui-chart__legend-item--c3 { color: var(--color-chart-3); }
`;

/** 공통 컴포넌트 기본 스타일을 <head>에 1회 주입. 앱 진입 시 호출. */
export function injectBaseStyles(): void {
  if (document.getElementById(BASE_STYLE_ID)) return;
  const style = el("style", { attrs: { id: BASE_STYLE_ID } });
  style.textContent = BASE_CSS;
  document.head.append(style);
}