:root {
  --header-h: 48px;
  --status-h: 36px;
  --panel-w: 320px;
  --accent: #2f6fdb;
  --accent-dark: #234e9c;
  --bg: #f4f6fb;
  --panel-bg: #ffffff;
  --border: #d6dce8;
  --text: #1f2733;
  --muted: #6b7787;
  --warn-bg: #fff6e5;
  --warn-border: #e0a93a;
  --error-bg: #fdecec;
  --error-border: #d9534f;
  --viewer-bg: #f9fbff;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  font-family: "Segoe UI", "Hiragino Kaku Gothic ProN", "Yu Gothic UI", Meiryo, sans-serif;
  color: var(--text);
  background: var(--bg);
}

body {
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

/* ===== ヘッダー ===== */
.app-header {
  height: var(--header-h);
  flex: 0 0 var(--header-h);
  background: linear-gradient(90deg, var(--accent), var(--accent-dark));
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
}
.app-title { font-size: 16px; font-weight: 600; margin: 0; }
.header-right { display: flex; align-items: center; gap: 10px; font-size: 13px; }
.header-preset { display: flex; align-items: center; gap: 6px; }
.header-preset select { padding: 3px 6px; border-radius: 4px; border: none; }
.header-btn {
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: 4px;
  padding: 4px 10px;
  cursor: pointer;
  font-size: 13px;
}
.header-btn:disabled { opacity: 0.5; cursor: not-allowed; }
.header-btn:not(:disabled):hover { background: rgba(255, 255, 255, 0.28); }

/* ===== 本体 ===== */
.app-body {
  flex: 1 1 auto;
  display: flex;
  min-height: 0;
}

/* ===== 左サイドパネル ===== */
.side-panel {
  width: var(--panel-w);
  flex: 0 0 var(--panel-w);
  background: var(--panel-bg);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  padding: 10px 12px 24px;
}
/* 曲線タイプ切替タブ */
.curve-tabs {
  display: flex;
  gap: 4px;
  margin-bottom: 14px;
  background: #eef1f7;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 3px;
}
.curve-tabs button {
  flex: 1;
  padding: 7px 4px;
  border: none;
  border-radius: 4px;
  background: transparent;
  color: var(--muted);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}
.curve-tabs button:hover { background: #e1e7f2; }
.curve-tabs button.active {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 1px 3px rgba(35, 78, 156, 0.3);
}

.panel-section { margin-bottom: 16px; }
.panel-section h2 {
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-dark);
  margin: 0 0 8px;
  padding-bottom: 4px;
  border-bottom: 1px solid var(--border);
}

.mode-toggle { display: flex; gap: 14px; margin-bottom: 10px; font-size: 13px; }
.mode-toggle label { display: flex; align-items: center; gap: 4px; cursor: pointer; }

.param-row {
  display: grid;
  grid-template-columns: 52px 1fr 64px;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}
.param-label { font-size: 13px; color: var(--muted); }
.param-slider { width: 100%; }
.param-number {
  width: 100%;
  padding: 3px 6px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 13px;
  text-align: right;
}
.param-row.disabled { opacity: 0.45; }
.param-row.disabled input { pointer-events: none; }

.reset-btn, .action-btn {
  width: 100%;
  padding: 7px;
  margin-top: 6px;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: #f0f3fa;
  color: var(--text);
  font-size: 13px;
  cursor: pointer;
}
.reset-btn:hover, .action-btn:hover { background: #e4eaf6; }
.action-btn.primary {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent-dark);
}
.action-btn.primary:hover { background: var(--accent-dark); }

.range-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  font-size: 12px;
  color: var(--muted);
}
.range-grid label { display: flex; flex-direction: column; gap: 3px; }
.range-grid input {
  padding: 3px 6px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 12px;
}
.range-note { font-size: 11px; color: var(--muted); margin: 8px 0 0; }

.formula-box {
  background: #f7f9fc;
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 8px 10px;
  font-size: 12px;
  line-height: 1.5;
  white-space: pre-wrap;
  word-break: break-word;
  margin: 0;
  font-family: "Consolas", "Courier New", monospace;
}

.info-list { margin: 0; font-size: 12.5px; }
.info-list > div {
  display: flex;
  justify-content: space-between;
  padding: 2px 0;
  border-bottom: 1px dotted #e7ebf2;
}
.info-list dt { color: var(--muted); margin: 0; }
.info-list dd { margin: 0; font-variant-numeric: tabular-nums; }

.messages { font-size: 12px; }
.messages .msg-empty { color: var(--muted); margin: 0; }
.messages .msg {
  padding: 6px 8px;
  border-radius: 4px;
  margin: 0 0 6px;
  border-left: 3px solid;
}
.messages .msg.warn { background: var(--warn-bg); border-color: var(--warn-border); }
.messages .msg.error { background: var(--error-bg); border-color: var(--error-border); color: #a3302c; }

/* ===== 3Dビューア ===== */
.viewer-area {
  flex: 1 1 auto;
  position: relative;
  display: flex;
  flex-direction: column;
  background: var(--viewer-bg);
  min-width: 0;
}
.viewer-toolbar {
  flex: 0 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 8px 10px;
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(2px);
  z-index: 2;
}
.viewer-toolbar button {
  padding: 5px 11px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: #fff;
  font-size: 12.5px;
  cursor: pointer;
  color: var(--text);
}
.viewer-toolbar button:hover { background: #eef3fb; }
.viewer-toolbar button.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent-dark);
}
.toolbar-sep { width: 1px; background: var(--border); margin: 0 2px; }

.viewer-canvas { flex: 1 1 auto; position: relative; min-height: 0; }
.viewer-canvas canvas { display: block; }

.viewer-overlay {
  position: absolute;
  left: 12px;
  bottom: 12px;
  font-size: 12px;
  color: var(--muted);
  background: rgba(255, 255, 255, 0.7);
  border-radius: 4px;
  padding: 4px 8px;
  pointer-events: none;
  white-space: pre-line;
}

/* ===== ステータスバー ===== */
.status-bar {
  height: var(--status-h);
  flex: 0 0 var(--status-h);
  display: flex;
  align-items: center;
  gap: 22px;
  padding: 0 16px;
  border-top: 1px solid var(--border);
  background: var(--panel-bg);
  font-size: 12.5px;
  color: var(--muted);
}
.status-bar b { color: var(--text); font-variant-numeric: tabular-nums; }
.status-state { margin-left: auto; }
.state-idle { color: var(--muted); }
.state-calculating { color: var(--warn-border); }
.state-ready { color: #2c9c4f; }
.state-error { color: var(--error-border); }