/* 整体页面样式 */
body {
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* 卡片式布局 */
.card {
    background: white;
    width: 90%;
    max-width: 420px;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
    padding: 30px;
    text-align: center;
}

header h1 {
    margin: 0 0 10px 0;
    color: #333;
    font-size: 28px;
}

header p {
    margin: 0 0 30px 0;
    color: #666;
    font-size: 16px;
}

/* 输入区域 */
.input-group {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

#guessInput {
    flex: 1;
    padding: 12px 16px;
    font-size: 18px;
    border: 2px solid #ddd;
    border-radius: 8px;
    outline: none;
    transition: border-color 0.3s;
}

#guessInput:focus {
    border-color: #6a9eff;
}

#submitBtn {
    padding: 12px 24px;
    font-size: 16px;
    background-color: #6a9eff;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.1s;
}

#submitBtn:hover {
    background-color: #5a8ee6;
}

#submitBtn:active {
    transform: scale(0.98);
}

#submitBtn:disabled {
    background-color: #aaa;
    cursor: not-allowed;
}

/* 提示信息 */
.message {
    min-height: 30px;
    margin: 20px 0;
    font-size: 20px;
    font-weight: bold;
    color: #444;
}

.message.success {
    color: #28a745;
}

.message.too-high {
    color: #dc3545;
}

.message.too-low {
    color: #007bff;
}

/* 猜测次数 */
.info {
    margin: 15px 0;
    font-size: 18px;
    color: #555;
}

/* 重新开始按钮 */
.restart-btn {
    padding: 10px 20px;
    font-size: 16px;
    background-color: #28a745;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.restart-btn:hover {
    background-color: #218838;
}

.powered-by {
    position: fixed;
    right: 20px;
    bottom: 13px;
    font-size: 12px;
    color: #999;
    z-index: 10;
    user-select: none;
}