/* ============================================
   MBTI Test — Components
   ============================================ */

/* ---- 按钮 ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: none;
  cursor: pointer;
  font-family: var(--font-sans);
  font-weight: 600;
  transition: all var(--duration-normal) var(--ease-out);
  -webkit-tap-highlight-color: transparent;
}

.btn--primary {
  background: var(--gradient-button);
  background-size: 200% 100%;
  color: #fff;
  font-size: var(--text-lg);
  padding: 16px 48px;
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-button);
  letter-spacing: 0.02em;
}

.btn--primary:active {
  transform: scale(0.96);
  box-shadow: 0 2px 12px rgba(124, 58, 237, 0.3);
}

.btn--secondary {
  background: var(--bg-glass);
  color: var(--text-primary);
  font-size: var(--text-base);
  padding: 12px 32px;
  border-radius: var(--radius-full);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn--secondary:active {
  background: var(--bg-card-hover);
}

.btn--ghost {
  background: none;
  color: var(--text-secondary);
  font-size: var(--text-sm);
  padding: 8px 16px;
  border-radius: var(--radius-md);
}

.btn--ghost:active {
  color: var(--text-primary);
}

/* ---- 进度条 ---- */
.progress-bar {
  width: 100%;
  height: 4px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-bottom: var(--space-sm);
}

.progress-bar__fill {
  height: 100%;
  background: var(--gradient-purple);
  border-radius: var(--radius-full);
  transition: width var(--duration-normal) var(--ease-out);
  will-change: width;
}

.progress-text {
  font-size: var(--text-sm);
  color: var(--text-muted);
  text-align: right;
}

/* ---- 题目卡片 ---- */
.question-card {
  will-change: transform, opacity;
}

.question-text {
  font-size: var(--text-xl);
  font-weight: 600;
  line-height: 1.5;
  margin-bottom: var(--space-xl);
  color: var(--text-primary);
}

.question-number {
  font-size: var(--text-xs);
  color: var(--text-accent);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-sm);
}

/* ---- 选项按钮 ---- */
.option-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.option-btn {
  width: 100%;
  text-align: left;
  background: var(--bg-card);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-lg);
  padding: var(--space-md) var(--space-lg);
  color: var(--text-primary);
  font-size: var(--text-base);
  font-family: var(--font-sans);
  font-weight: 500;
  line-height: 1.5;
  cursor: pointer;
  transition: all var(--duration-fast) var(--ease-out);
  -webkit-tap-highlight-color: transparent;
  position: relative;
  overflow: hidden;
}

.option-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--gradient-purple);
  opacity: 0;
  transition: opacity var(--duration-fast);
}

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

.option-btn:active::before,
.option-btn.selected::before {
  opacity: 0.2;
}

.option-btn.selected {
  border-color: var(--purple-400);
  box-shadow: 0 0 20px rgba(124, 58, 237, 0.2);
}

.option-label {
  position: relative;
  z-index: 1;
}

/* ---- 回退按钮 ---- */
.back-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: var(--text-sm);
  font-family: var(--font-sans);
  cursor: pointer;
  padding: var(--space-sm);
  border-radius: var(--radius-md);
  transition: color var(--duration-fast);
  -webkit-tap-highlight-color: transparent;
}

.back-btn:active {
  color: var(--text-primary);
}

.back-btn svg {
  width: 16px;
  height: 16px;
}

/* ---- 加载动画 ---- */
.loading-spinner {
  width: 80px;
  height: 80px;
  margin-bottom: var(--space-xl);
  position: relative;
}

.loading-spinner::before,
.loading-spinner::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 3px solid transparent;
}

.loading-spinner::before {
  border-top-color: var(--purple-400);
  animation: spin 1s linear infinite;
}

.loading-spinner::after {
  border-bottom-color: var(--purple-600);
  animation: spin 1.5s linear infinite reverse;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.loading-text {
  font-size: var(--text-lg);
  color: var(--text-secondary);
  margin-bottom: var(--space-md);
}

.loading-dimensions {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  align-items: center;
}

.loading-dim {
  font-size: var(--text-sm);
  color: var(--text-muted);
  opacity: 0;
  transform: translateY(10px);
  transition: all var(--duration-normal) var(--ease-out);
}

.loading-dim.visible {
  opacity: 1;
  transform: translateY(0);
}

.loading-dim.active {
  color: var(--text-accent);
}

/* ---- 屏幕切换动画 ---- */
.screen.fade-in {
  animation: fadeIn var(--duration-slow) var(--ease-out);
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* 题目切换动画 */
.question-card.slide-in-right {
  animation: slideInRight var(--duration-normal) var(--ease-out);
}

.question-card.slide-in-left {
  animation: slideInLeft var(--duration-normal) var(--ease-out);
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(40px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-40px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* ---- 装饰粒子 ---- */
.particle {
  position: fixed;
  border-radius: 50%;
  pointer-events: none;
  z-index: 0;
  opacity: 0.3;
}

.particle--1 {
  width: 200px;
  height: 200px;
  background: radial-gradient(circle, rgba(124, 58, 237, 0.15), transparent);
  top: -60px;
  right: -60px;
  animation: float 8s ease-in-out infinite;
}

.particle--2 {
  width: 150px;
  height: 150px;
  background: radial-gradient(circle, rgba(168, 85, 247, 0.1), transparent);
  bottom: 20%;
  left: -40px;
  animation: float 10s ease-in-out infinite reverse;
}

@keyframes float {
  0%, 100% { transform: translate(0, 0); }
  50% { transform: translate(20px, -20px); }
}