/* iPhone 15 外观样式 */
.phone-container {
    width: 393px;
    height: 852px;
    background: #000;
    border-radius: 47px;
    padding: 8px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    position: relative;
}

.phone-content {
    width: 100%;
    height: calc(100% - 120px);
    background: #fff;
    border-radius: 39px;
    overflow: hidden;
    margin-top: 44px;
}

.status-bar {
    position: absolute;
    top: 8px;
    left: 8px;
    right: 8px;
    height: 44px;
    background: linear-gradient(180deg, #000 0%, rgba(0,0,0,0.8) 100%);
    border-radius: 39px 39px 0 0;
    z-index: 10;
}

.dynamic-island {
    position: absolute;
    top: 12px;
    left: 50%;
    transform: translateX(-50%);
    width: 126px;
    height: 37px;
    background: #000;
    border-radius: 19px;
    z-index: 20;
    box-shadow: 0 0 20px rgba(0,0,0,0.5);
}

.battery {
    width: 24px;
    height: 12px;
    border: 1px solid #fff;
    border-radius: 2px;
    position: relative;
}

.battery::after {
    content: '';
    position: absolute;
    right: -3px;
    top: 3px;
    width: 2px;
    height: 6px;
    background: #fff;
    border-radius: 0 1px 1px 0;
}

.battery::before {
    content: '';
    position: absolute;
    left: 2px;
    top: 2px;
    width: 16px;
    height: 8px;
    background: #fff;
    border-radius: 1px;
}

.bottom-nav {
    position: absolute;
    bottom: 8px;
    left: 8px;
    right: 8px;
    height: 84px;
    background: #fff;
    border-radius: 0 0 39px 39px;
    display: flex;
    justify-content: space-around;
    align-items: center;
    padding: 8px 0 20px;
    box-shadow: 0 -2px 10px rgba(0,0,0,0.05);
    z-index: 10;
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    color: #999;
    font-size: 10px;
    background: none;
    border: none;
    cursor: pointer;
    transition: all 0.3s;
}

.nav-item i {
    font-size: 22px;
}

.nav-item.active {
    color: #4F46E5;
}

.nav-item.active i {
    transform: scale(1.1);
}

/* 通用页面样式 */
.page-container {
    width: 100%;
    height: 100%;
    overflow-y: auto;
    background: linear-gradient(180deg, #667EEA 0%, #764BA2 100%);
}

.content-wrapper {
    padding: 20px;
    padding-bottom: 100px;
}

/* 卡片样式 */
.card {
    background: #fff;
    border-radius: 20px;
    padding: 20px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    margin-bottom: 16px;
}

/* 按钮样式 */
.btn-primary {
    background: linear-gradient(135deg, #667EEA 0%, #764BA2 100%);
    color: white;
    border-radius: 16px;
    padding: 14px 24px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: transform 0.2s;
}

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

.btn-secondary {
    background: #F3F4F6;
    color: #4F46E5;
    border-radius: 16px;
    padding: 14px 24px;
    font-weight: 600;
    border: none;
    cursor: pointer;
}

/* 单词卡片翻转效果 */
.word-card {
    width: 100%;
    height: 300px;
    perspective: 1000px;
    margin: 20px 0;
}

.word-card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.6s;
    transform-style: preserve-3d;
}

.word-card.flipped .word-card-inner {
    transform: rotateY(180deg);
}

.word-card-front,
.word-card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 24px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 30px;
    box-shadow: 0 8px 30px rgba(0,0,0,0.15);
}

.word-card-back {
    transform: rotateY(180deg);
    background: linear-gradient(135deg, #667EEA 0%, #764BA2 100%);
    color: white;
}

/* 游戏卡片 */
.game-card {
    background: white;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    transition: transform 0.2s;
    cursor: pointer;
}

.game-card:active {
    transform: scale(0.98);
}

/* 进度条 */
.progress-bar {
    width: 100%;
    height: 8px;
    background: #E5E7EB;
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #667EEA 0%, #764BA2 100%);
    border-radius: 4px;
    transition: width 0.3s;
}

/* 徽章样式 */
.badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: linear-gradient(135deg, #FBBF24 0%, #F59E0B 100%);
    color: white;
    font-size: 24px;
    box-shadow: 0 4px 15px rgba(251, 191, 36, 0.4);
}