/* Unit Convert - 单位换算闯关 */
* { margin: 0; padding: 0; box-sizing: border-box; }

.uc-fullscreen {
    width: 100vw;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background: linear-gradient(180deg, #EEF2FF, #E0E7FF);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    overflow-x: hidden;
}

/* Header */
.uc-header {
    display: flex;
    align-items: center;
    padding: 12px 16px;
    background: linear-gradient(135deg, #6366F1, #8B5CF6);
    color: #fff;
    position: sticky;
    top: 0;
    z-index: 100;
    min-height: 52px;
}

.back-btn-wrap { position: relative; flex-shrink: 0; }

.back-btn {
    display: flex;
    align-items: center;
    gap: 4px;
    color: #fff;
    text-decoration: none;
    font-size: 14px;
    padding: 4px 0;
}

.back-overlay {
    display: none;
    position: absolute;
    top: -8px; left: -8px; right: -8px; bottom: -8px;
    cursor: pointer;
    z-index: 1;
}

.back-overlay.active { display: block; }

.uc-header .title {
    flex: 1;
    text-align: center;
    font-size: 17px;
    font-weight: 600;
}

.header-actions { flex-shrink: 0; display: flex; align-items: center; gap: 8px; }

.points-badge {
    display: flex;
    align-items: center;
    gap: 4px;
    background: rgba(255,255,255,0.2);
    padding: 4px 10px;
    border-radius: 14px;
    font-size: 13px;
    color: #FFD700;
    font-weight: 600;
    cursor: pointer;
}

.points-badge i { font-size: 12px; }
.points-badge.pulse { animation: badgePulse 0.5s ease; }
.points-badge.pulse-big { animation: badgePulseBig 0.6s ease; }

@keyframes badgePulse {
    0% { transform: scale(1); }
    40% { transform: scale(1.25); background: rgba(255,215,0,0.5); }
    100% { transform: scale(1); }
}

@keyframes badgePulseBig {
    0% { transform: scale(1); }
    30% { transform: scale(1.4); background: rgba(255,100,0,0.6); }
    100% { transform: scale(1); }
}

/* Main */
.uc-main { flex: 1; display: flex; flex-direction: column; }

.screen {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 20px 16px;
    animation: fadeIn 0.3s ease;
}

.screen.hidden { display: none; }

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ===== Menu Screen ===== */
.menu-title {
    text-align: center;
    font-size: 26px;
    font-weight: 800;
    color: #4338CA;
    margin-bottom: 4px;
}

.menu-desc {
    text-align: center;
    font-size: 14px;
    color: #7C3AED;
    margin-bottom: 20px;
}

.opt-group {
    max-width: 380px;
    margin: 0 auto 16px;
    width: 100%;
}

.opt-label {
    font-size: 13px;
    color: #6B7280;
    text-align: center;
    margin-bottom: 8px;
}

.cat-btns {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: center;
}

.cat-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 3px;
    padding: 10px 12px;
    min-width: 64px;
    background: #fff;
    border: 2px solid #E0E7FF;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.2s;
}

.cat-btn:active { transform: scale(0.95); }

.cat-btn i { font-size: 18px; color: #6366F1; }

.cat-btn span {
    font-size: 12px;
    font-weight: 600;
    color: #4338CA;
}

.cat-btn.active {
    border-color: #6366F1;
    background: #EEF2FF;
    box-shadow: 0 2px 12px rgba(99, 102, 241, 0.2);
}

.diff-btns {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.diff-btn {
    padding: 10px 24px;
    background: #fff;
    border: 2px solid #E0E7FF;
    border-radius: 12px;
    font-size: 15px;
    font-weight: 700;
    color: #4338CA;
    cursor: pointer;
    transition: all 0.2s;
}

.diff-btn:active { transform: scale(0.96); }

.diff-btn.active {
    border-color: #6366F1;
    background: #EEF2FF;
    box-shadow: 0 2px 12px rgba(99, 102, 241, 0.2);
}

.start-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin: 20px auto;
    padding: 14px 48px;
    background: linear-gradient(135deg, #6366F1, #8B5CF6);
    border: none;
    border-radius: 16px;
    color: #fff;
    font-size: 18px;
    font-weight: 700;
    cursor: pointer;
    box-shadow: 0 4px 16px rgba(99, 102, 241, 0.3);
}

.start-btn:active { transform: scale(0.96); }

.menu-stats {
    display: flex;
    justify-content: center;
    gap: 24px;
    margin-bottom: 20px;
}

.stat-item { text-align: center; }

.stat-value { font-size: 24px; font-weight: 800; color: #6366F1; }

.stat-label { font-size: 12px; color: #9CA3AF; margin-top: 2px; }

.lottery-entry-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin: 0 auto;
    padding: 12px 28px;
    background: linear-gradient(135deg, #F59E0B, #D97706);
    border: none;
    border-radius: 24px;
    color: #fff;
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    box-shadow: 0 4px 16px rgba(245, 158, 11, 0.3);
}

.lottery-entry-btn:active { transform: scale(0.96); }

/* ===== Game Screen ===== */

/* Progress */
.progress-wrap {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
}

.progress-bar {
    flex: 1;
    height: 6px;
    background: #E0E7FF;
    border-radius: 3px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #6366F1, #8B5CF6);
    border-radius: 3px;
    transition: width 0.4s ease;
    width: 0%;
}

.progress-text {
    font-size: 13px;
    font-weight: 700;
    color: #6366F1;
    white-space: nowrap;
}

/* Streak */
.streak-badge {
    text-align: center;
    margin-bottom: 8px;
}

.streak-badge span {
    display: inline-block;
    background: linear-gradient(135deg, #FF6B35, #F7931E);
    color: #fff;
    padding: 3px 12px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 700;
    animation: streakPop 0.4s ease;
}

.streak-badge.hidden { display: none; }
.streak-badge.fire span { background: linear-gradient(135deg, #FF4136, #FF6B35); }

@keyframes streakPop {
    0% { transform: scale(0.5); opacity: 0; }
    60% { transform: scale(1.15); }
    100% { transform: scale(1); opacity: 1; }
}

/* Question Card */
.question-card {
    background: #fff;
    border-radius: 18px;
    padding: 24px 20px;
    text-align: center;
    box-shadow: 0 4px 16px rgba(99, 102, 241, 0.08);
    max-width: 360px;
    margin: 0 auto 20px;
    width: 100%;
    animation: fadeIn 0.3s ease;
}

.q-cat {
    font-size: 13px;
    color: #8B5CF6;
    margin-bottom: 12px;
    font-weight: 600;
}

.q-cat i { margin-right: 4px; }

.q-text {
    font-size: 26px;
    font-weight: 800;
    color: #1E1B4B;
    line-height: 1.4;
}

.q-text .q-blank {
    display: inline-block;
    min-width: 60px;
    border-bottom: 3px solid #6366F1;
    color: #6366F1;
    margin: 0 4px;
}

/* Option Grid */
.option-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
    max-width: 340px;
    margin: 0 auto 12px;
    width: 100%;
}

.option-btn {
    padding: 18px 12px;
    font-size: 22px;
    font-weight: 700;
    background: #fff;
    border: 3px solid #E0E7FF;
    border-radius: 14px;
    color: #1E1B4B;
    cursor: pointer;
    transition: all 0.15s;
    -webkit-tap-highlight-color: transparent;
    text-align: center;
}

.option-btn:active:not(.correct):not(.wrong):not(.disabled) {
    transform: scale(0.95);
}

.option-btn.correct {
    background: #D1FAE5;
    border-color: #10B981;
    color: #065F46;
    animation: optCorrect 0.4s ease;
}

.option-btn.wrong {
    background: #FEE2E2;
    border-color: #EF4444;
    color: #991B1B;
    animation: optShake 0.4s ease;
}

.option-btn.disabled {
    opacity: 0.4;
    pointer-events: none;
}

.option-btn.dim {
    opacity: 0.5;
    pointer-events: none;
}

@keyframes optCorrect {
    0% { transform: scale(1); }
    40% { transform: scale(1.06); }
    100% { transform: scale(1); }
}

@keyframes optShake {
    0%, 100% { transform: translateX(0); }
    20% { transform: translateX(-4px); }
    40% { transform: translateX(4px); }
    60% { transform: translateX(-3px); }
    80% { transform: translateX(3px); }
}

/* Rule Text */
.rule-text {
    text-align: center;
    font-size: 14px;
    color: #7C3AED;
    font-weight: 600;
    background: #F5F3FF;
    padding: 8px 16px;
    border-radius: 10px;
    max-width: 340px;
    margin: 0 auto;
    animation: fadeIn 0.3s ease;
}

.rule-text.hidden { display: none; }

/* Points Popup */
.points-popup {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 28px;
    font-weight: 800;
    color: #F59E0B;
    text-shadow: 0 2px 8px rgba(0,0,0,0.15);
    pointer-events: none;
    z-index: 200;
}

.points-popup.hidden { display: none; }

.points-popup.show {
    display: block;
    animation: pointsFly 0.8s ease-out forwards;
}

@keyframes pointsFly {
    0% { opacity: 1; transform: translate(-50%, -50%) scale(0.5); }
    30% { opacity: 1; transform: translate(-50%, -70%) scale(1.2); }
    100% { opacity: 0; transform: translate(-50%, -120%) scale(1); }
}

/* Result Flash */
.result-flash {
    position: fixed;
    top: 38%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 36px;
    font-weight: 800;
    pointer-events: none;
    z-index: 200;
    animation: resultFlash 0.8s ease-out forwards;
}

.result-flash.ok { color: #10B981; }
.result-flash.fail { color: #EF4444; }

@keyframes resultFlash {
    0% { opacity: 0; transform: translate(-50%, -50%) scale(0.5); }
    20% { opacity: 1; transform: translate(-50%, -50%) scale(1.1); }
    60% { opacity: 1; transform: translate(-50%, -50%) scale(1); }
    100% { opacity: 0; transform: translate(-50%, -60%) scale(1); }
}

/* ===== Summary ===== */
.complete-card {
    background: #fff;
    border-radius: 20px;
    padding: 32px 24px;
    text-align: center;
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.1);
    max-width: 360px;
    margin: auto;
    width: 100%;
    animation: completeIn 0.5s ease;
}

@keyframes completeIn {
    from { opacity: 0; transform: scale(0.9) translateY(20px); }
    to { opacity: 1; transform: scale(1) translateY(0); }
}

.complete-icon { font-size: 48px; margin-bottom: 12px; }

.complete-title { font-size: 22px; font-weight: 700; color: #1E1B4B; margin-bottom: 12px; }

.complete-stars { font-size: 36px; margin-bottom: 16px; letter-spacing: 8px; color: #F59E0B; }
.complete-stars .star-empty { color: #E5E7EB; }

.complete-stats { font-size: 14px; color: #6B7280; line-height: 1.8; margin-bottom: 20px; }
.complete-stats strong { color: #F59E0B; }

.complete-actions { display: flex; flex-direction: column; gap: 10px; }

.action-btn {
    padding: 14px 24px;
    font-size: 16px;
    font-weight: 600;
    border-radius: 12px;
    border: 2px solid #C7D2FE;
    background: #fff;
    color: #6366F1;
    cursor: pointer;
    transition: all 0.2s;
}

.action-btn:active { transform: scale(0.97); }

.action-btn.primary {
    background: linear-gradient(135deg, #6366F1, #8B5CF6);
    border-color: transparent;
    color: #fff;
}

/* ===== Lottery ===== */
.lottery-card {
    background: #fff;
    border-radius: 20px;
    padding: 32px 24px;
    text-align: center;
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.1);
    max-width: 360px;
    margin: auto;
    width: 100%;
    animation: completeIn 0.5s ease;
}

.lottery-title { font-size: 24px; font-weight: 700; color: #F59E0B; margin-bottom: 8px; }
.lottery-cost { font-size: 14px; color: #9CA3AF; margin-bottom: 4px; }
.lottery-cost strong { color: #F59E0B; }
.lottery-balance { font-size: 14px; color: #9CA3AF; margin-bottom: 20px; }
.lottery-balance strong { color: #F59E0B; font-size: 18px; }

.lottery-box {
    width: 120px; height: 120px;
    margin: 0 auto 16px;
    display: flex; align-items: center; justify-content: center;
}

.lottery-gift { font-size: 72px; line-height: 1; }
.lottery-gift.spinning { animation: giftSpin 1.2s cubic-bezier(0.4, 0, 0.2, 1); }
.lottery-gift.opened { animation: giftOpen 0.5s ease forwards; }

@keyframes giftSpin {
    0% { transform: scale(1) rotate(0deg); }
    20% { transform: scale(1.1) rotate(-10deg); }
    40% { transform: scale(1.15) rotate(10deg); }
    60% { transform: scale(1.2) rotate(-8deg); }
    80% { transform: scale(1.25) rotate(6deg); }
    100% { transform: scale(1.3) rotate(0deg); }
}

@keyframes giftOpen {
    0% { transform: scale(1.3); }
    50% { transform: scale(1.5); }
    100% { transform: scale(1.1); }
}

.lottery-result { min-height: 56px; margin-bottom: 16px; opacity: 0; transition: opacity 0.3s; }
.lottery-result.show { opacity: 1; }
.lottery-result .prize-name { font-size: 22px; font-weight: 700; color: #1E1B4B; margin-bottom: 4px; }
.lottery-result .prize-desc { font-size: 14px; color: #9CA3AF; }
.lottery-draw-btn { margin-bottom: 10px; width: 100%; }
.lottery-draw-btn:disabled { opacity: 0.4; cursor: default; }

/* Responsive */
@media (max-width: 360px) {
    .q-text { font-size: 22px; }
    .option-btn { padding: 14px 8px; font-size: 18px; }
    .option-grid { gap: 8px; }
    .cat-btn { padding: 8px 10px; min-width: 56px; }
}

@media (min-width: 500px) {
    .uc-main { max-width: 480px; margin: 0 auto; width: 100%; }
}