/* 背包页面样式 - 活泼而神秘的设计 */
.backpack-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px;
    /* 活泼的深紫蓝渐变 */
    background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    border-radius: 15px;
    min-height: 80vh;
    box-shadow: 0 10px 30px rgba(102, 126, 234, 0.3);
    position: relative;
    overflow: hidden;
}

/* 动态粒子效果 */
.backpack-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 15% 25%, rgba(255, 255, 255, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 85% 75%, rgba(255, 182, 193, 0.2) 0%, transparent 50%),
        radial-gradient(circle at 45% 15%, rgba(173, 216, 230, 0.18) 0%, transparent 50%),
        radial-gradient(circle at 75% 35%, rgba(255, 215, 0, 0.12) 0%, transparent 50%),
        radial-gradient(circle at 25% 85%, rgba(144, 238, 144, 0.15) 0%, transparent 50%);
    animation: sparkle 8s ease-in-out infinite alternate;
    pointer-events: none;
    z-index: 1;
}

@keyframes sparkle {
    0% { opacity: 0.8; transform: scale(1); }
    50% { opacity: 1; transform: scale(1.05); }
    100% { opacity: 0.8; transform: scale(1); }
}

.backpack-container > * {
    position: relative;
    z-index: 2;
}

.backpack-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 15px;
    border-bottom: 2px solid rgba(255,255,255,0.3);
}

.backpack-header h2 {
    font-size: 2rem;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
    background: linear-gradient(45deg, #ffffff, #ffd700, #ff69b4);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: glow 3s ease-in-out infinite alternate;
}

@keyframes glow {
    0% { filter: drop-shadow(0 0 5px rgba(255, 215, 0, 0.5)); }
    100% { filter: drop-shadow(0 0 15px rgba(255, 105, 180, 0.7)); }
}

.backpack-status {
    color: #ffffff;
    font-size: 1.1rem;
    text-shadow: 1px 1px 3px rgba(0,0,0,0.5);
    background: rgba(255,255,255,0.1);
    padding: 5px 15px;
    border-radius: 20px;
    backdrop-filter: blur(10px);
}

.backpack-description {
    text-align: center;
    margin-bottom: 30px;
}

.backpack-description p {
    color: #ffffff !important;
    font-size: 1.1rem;
    margin: 10px 0;
    text-shadow: 1px 1px 3px rgba(0,0,0,0.5);
    background: rgba(255,255,255,0.1);
    padding: 10px 20px;
    border-radius: 15px;
    backdrop-filter: blur(10px);
    display: inline-block;
}

.papers-collection {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.paper-slot {
    background: rgba(255,255,255,0.15);
    border-radius: 15px;
    padding: 20px;
    border: 2px solid rgba(255,255,255,0.3);
    transition: all 0.3s ease;
    text-align: center;
    backdrop-filter: blur(15px);
    position: relative;
    overflow: hidden;
}

.paper-slot::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(45deg, transparent, rgba(255,255,255,0.1), transparent);
    transform: rotate(45deg);
    transition: all 0.5s ease;
    opacity: 0;
}

.paper-slot:hover::before {
    opacity: 1;
    animation: shimmer 1.5s ease-in-out;
}

@keyframes shimmer {
    0% { transform: translateX(-100%) translateY(-100%) rotate(45deg); }
    100% { transform: translateX(100%) translateY(100%) rotate(45deg); }
}

.paper-slot:hover {
    border-color: rgba(255,255,255,0.5);
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4);
}

.paper-slot.collected {
    background: rgba(255,255,255,0.25) !important;
    border-color: rgba(255, 215, 0, 0.6);
    box-shadow: 0 5px 20px rgba(255, 215, 0, 0.3);
    animation: collectGlow 2s ease-in-out infinite alternate;
}

@keyframes collectGlow {
    0% { box-shadow: 0 5px 20px rgba(255, 215, 0, 0.3); }
    100% { box-shadow: 0 8px 30px rgba(255, 215, 0, 0.5); }
}

.paper-slot.empty {
    background: rgba(255,255,255,0.08);
    border-color: rgba(255,255,255,0.15);
}

.paper-label {
    font-size: 1.1rem;
    font-weight: bold;
    margin-bottom: 8px;
    color: #1a202c !important;
}

.paper-slot.collected .paper-label {
    color: #1a202c !important;
}

.paper-slot.empty .paper-label {
    color: rgba(255,255,255,0.8) !important;
}

.paper-source {
    font-size: 0.9rem;
    color: #4a5568 !important;
    margin-bottom: 12px;
    font-style: italic;
}

.paper-slot.collected .paper-source {
    color: #4a5568 !important;
}

.paper-slot.empty .paper-source {
    color: rgba(255,255,255,0.7) !important;
}

.paper-content {
    font-family: 'Courier New', monospace;
    font-size: 1.3rem;
    font-weight: bold;
    color: #1a365d !important;
    background: rgba(255, 255, 255, 0.95);
    padding: 15px;
    border-radius: 10px;
    letter-spacing: 2px;
    margin: 15px 0;
    min-height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    border: 1px solid rgba(255, 215, 0, 0.3);
}

.paper-slot.empty .paper-content {
    color: rgba(255,255,255,0.6) !important;
    background: rgba(255,255,255,0.1);
    font-size: 2rem;
    box-shadow: none;
    border: 1px solid rgba(255,255,255,0.2);
}

.paper-status {
    font-size: 0.9rem;
    color: #4a5568 !important;
    font-weight: 500;
    padding: 5px 12px;
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.9);
}

.paper-slot.empty .paper-status {
    color: rgba(255,255,255,0.8) !important;
    background: rgba(255,255,255,0.15);
}

.paper-slot.collected .paper-status {
    color: #2e7d32 !important;
    background: rgba(76, 175, 80, 0.3);
}

.puzzle-action {
    text-align: center;
    margin-top: 30px;
}

.solve-btn {
    background: linear-gradient(135deg, #ff6b6b, #4ecdc4, #45b7d1);
    color: #ffffff !important;
    border: none;
    padding: 15px 40px;
    border-radius: 30px;
    font-size: 1.2rem;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    text-shadow: 1px 1px 3px rgba(0,0,0,0.3);
    box-shadow: 0 6px 20px rgba(255, 107, 107, 0.4);
    position: relative;
    overflow: hidden;
}

.solve-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    transition: left 0.5s ease;
}

.solve-btn:not(:disabled):hover::before {
    left: 100%;
}

.solve-btn:disabled {
    background: rgba(255,255,255,0.2);
    color: rgba(255,255,255,0.5) !important;
    cursor: not-allowed;
    box-shadow: none;
}

.solve-btn:not(:disabled):hover {
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 10px 30px rgba(255, 107, 107, 0.6);
}

.puzzle-note {
    color: rgba(255,255,255,0.9) !important;
    font-size: 0.9rem;
    margin-top: 15px;
    text-shadow: 1px 1px 3px rgba(0,0,0,0.5);
    background: rgba(255,255,255,0.1);
    padding: 8px 15px;
    border-radius: 15px;
    backdrop-filter: blur(10px);
    display: inline-block;
}

.back-btn {
    background: rgba(255,255,255,0.2) !important;
    color: #ffffff !important;
    border: 2px solid rgba(255,255,255,0.4);
    padding: 12px 25px;
    border-radius: 25px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-shadow: 1px 1px 3px rgba(0,0,0,0.3);
    backdrop-filter: blur(15px);
}

.back-btn:hover {
    background: rgba(255,255,255,0.3) !important;
    border-color: rgba(255,255,255,0.6);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(255,255,255,0.2);
}

/* 移动端适配 */
@media (max-width: 768px) {
    .backpack-container {
        margin: 10px;
        padding: 15px;
    }
    
    .papers-collection {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .backpack-header {
        flex-direction: column;
        text-align: center;
    }
    
    .backpack-header h2 {
        margin-bottom: 10px;
    }
}