:root {
    --primary-color: #4361ee;
    --primary-light: #4895ef;
    --success-color: #4CAF50;
    --share-color: #9c27b0;
    --error-color: #f44336;
    --warning-color: #ff9800;
    --text-color: #333;
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    --border-radius: 16px;
    --transition: all 0.3s ease;
}

.dark-theme {
    --text-color: #f8f9fa;
    --bg-color: #121212;
    --card-bg: #1e1e1e;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: var(--transition);
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
}

.background-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    opacity: 0.7;
}

.circle {
    position: absolute;
    border-radius: 50%;
    background: radial-gradient(circle, var(--primary-light) 0%, transparent 70%);
    opacity: 0.1;
    animation: float 15s infinite ease-in-out;
}

.circle:nth-child(1) {
    width: 80px;
    height: 80px;
    top: 10%;
    left: 10%;
    animation-delay: 0s;
}

.circle:nth-child(2) {
    width: 120px;
    height: 120px;
    top: 60%;
    left: 80%;
    animation-delay: 2s;
}

.circle:nth-child(3) {
    width: 60px;
    height: 60px;
    top: 80%;
    left: 20%;
    animation-delay: 4s;
}

.circle:nth-child(4) {
    width: 100px;
    height: 100px;
    top: 30%;
    left: 70%;
    animation-delay: 6s;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0) translateX(0);
    }
    25% {
        transform: translateY(-20px) translateX(10px);
    }
    50% {
        transform: translateY(10px) translateX(-10px);
    }
    75% {
        transform: translateY(-10px) translateX(-20px);
    }
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.2rem;
    color: var(--text-color);
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    border-radius: 8px;
    transition: var(--transition);
}

.theme-toggle:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

.dark-theme .theme-toggle:hover {
    background-color: rgba(255, 255, 255, 0.05);
}

main {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 80vh;
    padding: 40px 0;
}

.paste-box {
    width: 100%;
    max-width: 600px;
    height: 400px;
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 20px;
    cursor: pointer;
    transition: var(--transition);
    border: 2px dashed #ccc;
    position: relative;
    overflow: hidden;
}

.paste-box:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.12);
    border-color: var(--primary-color);
}

.paste-box.active {
    border-color: var(--primary-color);
    background-color: rgba(67, 97, 238, 0.05);
}

.paste-box.has-image {
    border-style: solid;
    padding: 0;
}

.dark-theme .paste-box {
    border-color: #444;
}

.dark-theme .paste-box.active {
    background-color: rgba(67, 97, 238, 0.1);
}

.paste-box-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
}

.paste-box-content i {
    font-size: 4rem;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.paste-box-content h2 {
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 10px;
}

.paste-box-content p {
    color: #666;
    font-size: 1rem;
}

.dark-theme .paste-box-content p {
    color: #aaa;
}

.image-preview {
    width: 100%;
    height: 100%;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

#previewImage {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    border-radius: 8px;
}

.preview-overlay {
    position: absolute;
    bottom: 20px;
    left: 0;
    right: 0;
    display: flex;
    justify-content: center;
    gap: 10px;
    padding: 0 20px;
}

.share-btn, .clear-btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.95rem;
}

.share-btn {
    background-color: var(--share-color);
    color: white;
}

.share-btn:hover {
    background-color: #8e24aa;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(156, 39, 176, 0.3);
}

.clear-btn {
    background-color: rgba(0, 0, 0, 0.7);
    color: white;
}

.clear-btn:hover {
    background-color: rgba(0, 0, 0, 0.9);
    transform: translateY(-2px);
}

.dark-theme .clear-btn {
    background-color: rgba(255, 255, 255, 0.2);
}

.dark-theme .clear-btn:hover {
    background-color: rgba(255, 255, 255, 0.3);
}

.instructions {
    margin-top: 15px;
    text-align: center;
    font-size: 0.9rem;
    color: #666;
}

.dark-theme .instructions {
    color: #aaa;
}

.browser-support {
    margin-top: 15px;
    text-align: center;
    max-width: 500px;
}

.browser-support h4 {
    font-size: 1rem;
    margin-bottom: 5px;
    color: var(--primary-color);
}

.browser-support p {
    font-size: 0.85rem;
    color: #666;
    line-height: 1.4;
}

.dark-theme .browser-support p {
    color: #aaa;
}

.features-section {
    margin-top: 80px;
    width: 100%;
    max-width: 1000px;
}

.features-section h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 30px;
    text-align: center;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
}

.feature-card {
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 25px;
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-card i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.feature-card h4 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 10px;
}

.feature-card p {
    font-size: 0.95rem;
    color: #666;
}

.dark-theme .feature-card p {
    color: #aaa;
}

.usage-guide {
    margin-top: 80px;
    width: 100%;
    max-width: 800px;
}

.usage-guide h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 30px;
    text-align: center;
}

.steps-container {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.step {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 25px;
    transition: var(--transition);
}

.step:hover {
    transform: translateX(5px);
}

.step-number {
    background-color: var(--primary-color);
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.2rem;
    flex-shrink: 0;
}

.step-content h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.step-content p {
    color: #666;
    font-size: 0.95rem;
}

.dark-theme .step-content p {
    color: #aaa;
}

.download-feedback {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: var(--card-bg);
    padding: 20px 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 10px;
    opacity: 0;
    pointer-events: none;
    transition: var(--transition);
    z-index: 100;
    border-left: 4px solid var(--success-color);
}

.download-feedback i {
    color: var(--success-color);
}

.download-feedback.show {
    opacity: 1;
    animation: fadeOut 2s forwards;
}

.share-feedback {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: var(--card-bg);
    padding: 20px 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 10px;
    opacity: 0;
    pointer-events: none;
    transition: var(--transition);
    z-index: 100;
    border-left: 4px solid var(--share-color);
}

.share-feedback i {
    color: var(--share-color);
}

.share-feedback.show {
    opacity: 1;
    animation: fadeOut 2s forwards;
}

.error-notification {
    position: fixed;
    top: 20px;
    right: 20px;
    background-color: var(--card-bg);
    padding: 15px 20px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 10px;
    opacity: 0;
    pointer-events: none;
    transition: var(--transition);
    z-index: 100;
    border-left: 4px solid var(--error-color);
    max-width: 400px;
}

.error-notification i {
    color: var(--error-color);
}

.error-notification.show {
    opacity: 1;
    animation: slideInRight 0.3s ease, fadeOut 4s 0.3s forwards;
}

@keyframes fadeOut {
    0% {
        opacity: 1;
    }
    70% {
        opacity: 1;
    }
    100% {
        opacity: 0;
    }
}

@keyframes slideInRight {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@media (max-width: 768px) {
    .paste-box {
        height: 350px;
        padding: 15px;
    }

    .paste-box-content h2 {
        font-size: 1.5rem;
    }

    .paste-box-content i {
        font-size: 3rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .step {
        flex-direction: column;
        text-align: center;
        gap: 15px;
    }

    .error-notification {
        top: 10px;
        right: 10px;
        left: 10px;
        max-width: none;
    }

    .preview-overlay {
        flex-direction: column;
        align-items: center;
    }

    .share-btn, .clear-btn {
        width: 200px;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .paste-box {
        height: 300px;
        padding: 10px;
    }

    .paste-box-content h2 {
        font-size: 1.3rem;
    }

    .paste-box-content i {
        font-size: 2.5rem;
    }

    .theme-toggle span {
        display: none;
    }

    .browser-support {
        margin-top: 10px;
    }

    .browser-support h4 {
        font-size: 0.9rem;
    }

    .browser-support p {
        font-size: 0.8rem;
    }

    .share-btn, .clear-btn {
        padding: 10px 20px;
        font-size: 0.9rem;
    }
}