/* 响应式样式 */
@media screen and (max-width: 1400px) {
    .container {
        max-width: 1200px;
    }
}

@media screen and (max-width: 1200px) {
    .container {
        max-width: 960px;
        padding: 0 20px;
    }
    
    .hero-wrapper {
        padding: 40px 30px;
        margin: 8px -20px;
    }
    
    .hero-content h2 {
        font-size: 38px;
    }
    
    .benefits-grid {
        gap: 20px;
    }

    .section {
        min-height: calc(100vh - 130px);
    }
    
    .back-button, #back-to-select, #new-paper, #new-paper-unlocked, #cancel-loading {
        left: 25px;
    }

    #create .input-form {
        padding: 45px 50px;
    }
}

@media screen and (max-width: 992px) {
    .container {
        max-width: 720px;
    }
    
    .benefits-grid {
        grid-template-columns: 1fr;
        gap: 18px;
    }
    
    .function-cards {
        flex-direction: column;
        align-items: center;
    }
    
    .hero {
        gap: 25px;
    }
    
    .hero h2 {
        font-size: 34px;
    }
    
    .hero-content p {
        font-size: 16px;
    }
    
    .hero-image {
        max-width: 360px;
    }
    
    .process-steps {
        flex-direction: column;
        gap: 18px;
        max-width: 450px;
    }
    
    .process-connector {
        transform: rotate(90deg);
        margin: 0;
    }
    
    .benefit-item {
        padding: 20px;
    }
    
    .benefit-icon {
        width: 45px;
        height: 45px;
    }

    .section {
        min-height: calc(100vh - 140px);
    }

    .back-button {
        top: 20px;
        left: 20px;
    }

    #create .input-form {
        max-width: 800px;
        padding: 35px 40px;
    }
    
    #back-to-select {
        top: 70px;
    }
    
    #create h2 {
        margin-top: 50px;
    }
}

@media screen and (max-width: 768px) {
    .container {
        max-width: 540px;
        padding: 0 12px;
    }
    
    .hero-wrapper {
        padding: 35px 20px;
        margin: 8px -12px;
    }
    
    header {
        flex-direction: column;
        gap: 12px;
    }
    
    nav ul {
        gap: 12px;
    }
    
    .hero {
        flex-direction: column;
        text-align: center;
    }
    
    .hero-content {
        order: 2;
        max-width: 100%;
    }
    
    .hero-image {
        order: 1;
        margin-bottom: 20px;
    }
    
    .hero-content p {
        max-width: 100%;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .function-card {
        width: 100%;
        max-width: 300px;
        cursor: pointer;
    }
    
    /* 在移动设备上调整卡片动画效果，提高易用性 */
    .function-card .card-inner {
        transition: transform 0.5s;
    }
    
    /* 在小屏幕上，默认显示卡片正面，点击时再翻转 */
    .function-card:hover .card-inner {
        transform: none;
    }
    
    /* 触控友好的卡片设计 */
    .card-front, .card-back {
        padding: 25px 15px;
    }
    
    .btn-select {
        padding: 12px 25px;
        font-size: 15px;
        margin-top: 10px;
    }
    
    .input-form {
        padding: 20px 12px;
    }
    
    .button-group {
        flex-direction: column;
        gap: 10px;
    }
    
    .button-group button {
        width: 100%;
    }
    
    .unlock-panel {
        flex-direction: column;
        gap: 12px;
        align-items: flex-start;
    }
    
    .action-buttons {
        flex-direction: column;
        width: 100%;
    }
    
    .action-buttons button {
        width: 100%;
    }
    
    .download-options {
        flex-wrap: wrap;
    }
    
    .benefits-title, .process-title {
        font-size: 24px;
        margin-bottom: 25px;
    }
    
    .process-section {
        padding: 40px 12px;
    }
    
    .back-button {
        top: 20px;
        left: 15px;
    }
    
    .section {
        min-height: calc(100vh - 160px);
        padding: 35px 0 20px;
    }
    
    #function-select .container h2,
    #create .container h2,
    #result .container h2,
    #unlocked .container h2,
    #loading .container h2 {
        margin-top: 30px;
        padding: 0 10px;
    }
    
    #create .input-form {
        max-width: 100%;
        padding: 30px 25px;
        margin: 20px auto 30px;
    }
    
    #back-to-select {
        top: 70px;
        left: 15px;
    }
    
    #create h2 {
        margin-top: 45px;
        font-size: 26px;
    }
}

@media screen and (max-width: 576px) {
    .container {
        padding: 0 10px;
    }
    
    .hero-wrapper {
        padding: 30px 12px;
        margin: 6px -10px;
    }
    
    nav ul {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .hero-content h2 {
        font-size: 28px;
    }
    
    .hero-content p {
        font-size: 15px;
    }
    
    .benefits-title, .process-title {
        font-size: 22px;
    }
    
    h2 {
        font-size: 24px;
    }
    
    .subtitle {
        font-size: 15px;
    }
    
    .result-meta {
        flex-direction: column;
        gap: 6px;
    }
    
    .benefit-item {
        padding: 16px;
        gap: 10px;
    }
    
    .benefit-icon {
        width: 40px;
        height: 40px;
    }
    
    .benefit-icon i {
        font-size: 20px;
    }
    
    .benefit-content h4 {
        font-size: 16px;
    }
    
    .benefit-content p {
        font-size: 13px;
    }
    
    .back-button {
        top: 15px;
        left: 10px;
    }
    
    .back-button .btn-secondary {
        padding: 6px 12px;
        font-size: 12px;
    }
    
    #function-select .container h2,
    #create .container h2,
    #result .container h2,
    #unlocked .container h2,
    #loading .container h2 {
        margin-top: 40px;
        font-size: 22px;
    }
    
    .section {
        min-height: calc(100vh - 180px);
        padding: 25px 0;
    }
    
    #create .input-form {
        padding: 25px 20px;
        margin: 15px auto 20px;
        border-radius: 12px;
    }
    
    #back-to-select {
        top: 65px;
        padding: 6px 10px;
        border-radius: 18px;
    }
    
    #create h2 {
        margin-top: 40px;
        font-size: 24px;
    }
    
    .form-group {
        margin-bottom: 20px;
    }
    
    #start-creating {
        width: 100%;
        font-size: 15px;
        padding: 10px 20px;
    }
}

@media screen and (max-width: 480px) {
    .back-button, #back-to-select, #new-paper, #new-paper-unlocked, #cancel-loading {
        top: 115px;
    }
    
    #function-select .container h2,
    #create .container h2,
    #result .container h2,
    #unlocked .container h2,
    #loading .container h2 {
        margin-top: 45px;
        line-height: 1.3;
    }
}