* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: Georgia, sans-serif; background: #F9F5F0; color: #1A1A1A; }
.screen { display: none; min-height: 100vh; }
.screen.active { display: block; }
.container { max-width: 800px; margin: 40px auto; text-align: center; padding: 20px; }

/* 1. 开始界面 */
.paper-list { display: flex; gap: 20px; justify-content: center; margin-top: 30px; flex-wrap: wrap; }
.paper-card { background: #fff; padding: 20px; border-radius: 8px; box-shadow: 0 4px 12px rgba(0,0,0,0.08); width: 250px; }
.paper-year { font-size: 14px; color: #888; }
.paper-name { font-size: 20px; font-weight: bold; margin: 5px 0; }
.paper-meta { font-size: 12px; color: #666; margin-bottom: 15px; }
.paper-card button { background: #B83A2E; color: white; border: none; padding: 8px 16px; border-radius: 20px; cursor: pointer; }
.paper-card button:hover { background: #A02B20; }

/* 2. 答题界面 */
.exam-header { display: flex; justify-content: space-between; align-items: center; background: #1A1A1A; color: #fff; padding: 10px 20px; position: sticky; top: 0; z-index: 100; }
.exam-title { font-weight: bold; }
.timer { background: #B83A2E; padding: 4px 12px; border-radius: 4px; font-size: 14px; }
.end-btn { background: transparent; border: 1px solid #fff; color: #fff; padding: 4px 12px; border-radius: 4px; cursor: pointer; }

.exam-body { display: flex; gap: 20px; padding: 20px; max-width: 1200px; margin: 0 auto; }
.question-area { flex: 2; background: #fff; padding: 25px; border-radius: 8px; box-shadow: 0 2px 8px rgba(0,0,0,0.05); }
.question-title { font-size: 16px; font-weight: bold; margin-bottom: 15px; border-bottom: 1px solid #eee; padding-bottom: 10px; }
.question-content { margin-bottom: 20px; line-height: 1.8; }
.options-area { display: flex; flex-direction: column; gap: 10px; }
.option-label { display: flex; align-items: center; gap: 10px; padding: 10px; border: 1px solid #ddd; border-radius: 6px; cursor: pointer; transition: all 0.2s; }
.option-label:hover { background: #F0EBE3; }
.option-label input { width: 18px; height: 18px; accent-color: #B83A2E; }
.nav-buttons { display: flex; justify-content: space-between; margin-top: 30px; }
.nav-buttons button { background: #eee; border: none; padding: 8px 20px; border-radius: 20px; cursor: pointer; }
.nav-buttons #flagBtn.flagged { background: #ffc107; }

/* 右侧导航 */
.navigator-area { flex: 1; background: #fff; padding: 20px; border-radius: 8px; height: fit-content; }
.navigator-title { font-weight: bold; margin-bottom: 15px; text-align: center; }
.navigator-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 10px; }
.nav-dot { width: 36px; height: 36px; display: flex; align-items: center; justify-content: center; border: 1px solid #ccc; border-radius: 50%; cursor: pointer; font-size: 14px; }
.nav-dot.answered { background: #B83A2E; color: #fff; border-color: #B83A2E; }
.nav-dot.flagged { border-color: #ffc107; border-width: 2px; }
.nav-dot.current { box-shadow: 0 0 0 2px #1A1A1A; }

/* 3. 成绩单界面 */
.result-banner { font-size: 24px; font-weight: bold; color: #B83A2E; margin: 20px 0; }
.result-card { background: #fff; padding: 15px; border-radius: 8px; margin-bottom: 10px; text-align: left; }
.result-card.correct { border-left: 4px solid #2E7D32; }
.result-card.wrong { border-left: 4px solid #C62828; }