:root {
  --bg: #0d1117;
  --bg-panel: #161b22;
  --bg-panel-2: #1c2330;
  --border: #30363d;
  --text: #e6edf3;
  --text-muted: #8b949e;
  --accent: #58a6ff;
  --accent-hover: #79b8ff;
  --radius: 12px;
}

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

body {
  font-family: "Pretendard", -apple-system, BlinkMacSystemFont, "Segoe UI",
    "Noto Sans KR", "Apple SD Gothic Neo", sans-serif;
  background: radial-gradient(1200px 600px at 50% -10%, #1b2a4a 0%, var(--bg) 60%);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ---------- 헤더 ---------- */
.app-header {
  padding: 2.5rem 1.5rem 1.5rem;
  text-align: center;
}

.app-header h1 {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.subtitle {
  margin-top: 0.5rem;
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* ---------- 메인 ---------- */
.app-main {
  flex: 1;
  width: 100%;
  max-width: 960px;
  margin: 0 auto;
  padding: 0 1.25rem 3rem;
}

.panel {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
}

.hidden {
  display: none;
}

/* ---------- 드롭존 ---------- */
.drop-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 3rem 1.5rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s, transform 0.15s;
}

.drop-zone:hover,
.drop-zone.dragover {
  border-color: var(--accent);
  background: rgba(88, 166, 255, 0.06);
}

.drop-zone.dragover {
  transform: scale(1.01);
}

.drop-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.drop-title {
  font-size: 1.1rem;
  font-weight: 600;
}

.drop-hint {
  margin-top: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.upload-actions {
  margin-top: 1rem;
  display: flex;
  justify-content: center;
  gap: 0.75rem;
}

/* ---------- 버튼 ---------- */
.btn {
  border: none;
  border-radius: 8px;
  padding: 0.65rem 1.25rem;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
  font-family: inherit;
}

.btn:active {
  transform: scale(0.98);
}

.btn-secondary {
  background: var(--bg-panel-2);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: #242e3f;
  border-color: var(--accent);
}

/* ---------- 탭 ---------- */
.tabs {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
}

.tab {
  flex: 1;
  padding: 0.7rem 0.5rem;
  background: var(--bg-panel-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}

.tab:hover {
  color: var(--text);
  border-color: var(--accent);
}

.tab.active {
  background: rgba(88, 166, 255, 0.15);
  border-color: var(--accent);
  color: var(--accent-hover);
}

.tab-panel {
  display: none;
  text-align: center;
}

.tab-panel.active {
  display: block;
}

.tab-panel canvas {
  max-width: 100%;
  max-height: 60vh;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: #000;
}

.panel-note {
  margin-top: 0.75rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ---------- 3D 컨테이너 ---------- */
.three-container {
  width: 100%;
  height: 55vh;
  min-height: 320px;
  border-radius: 8px;
  border: 1px solid var(--border);
  overflow: hidden;
  background: #05070c;
  cursor: grab;
}

.three-container:active {
  cursor: grabbing;
}

/* ---------- 컨트롤 ---------- */
.controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  margin-top: 1rem;
  padding: 1rem;
  background: var(--bg-panel-2);
  border: 1px solid var(--border);
  border-radius: 8px;
}

.control {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.9rem;
  color: var(--text);
}

.control.checkbox {
  cursor: pointer;
  user-select: none;
}

.control input[type="range"] {
  width: 160px;
  accent-color: var(--accent);
  cursor: pointer;
}

.control input[type="checkbox"] {
  width: 1.1rem;
  height: 1.1rem;
  accent-color: var(--accent);
  cursor: pointer;
}

.control b {
  color: var(--accent-hover);
}

/* ---------- 푸터 ---------- */
.app-footer {
  text-align: center;
  padding: 1.5rem;
  color: var(--text-muted);
  font-size: 0.8rem;
  border-top: 1px solid var(--border);
}

/* ---------- 업로드 에러 ---------- */
.upload-error {
  margin-top: 1rem;
  padding: 0.8rem 1rem;
  background: rgba(248, 81, 73, 0.12);
  border: 1px solid rgba(248, 81, 73, 0.4);
  border-radius: 8px;
  color: #ffa198;
  font-size: 0.9rem;
  text-align: center;
}

/* ---------- 반응형 ---------- */@media (max-width: 600px) {
  .app-header h1 {
    font-size: 1.5rem;
  }

  .controls {
    gap: 0.75rem;
  }

  .control input[type="range"] {
    width: 120px;
  }
}