/* Global Styles */
:root {
    --primary-color: #4A90E2;
    --secondary-color: #2C3E50;
    --accent-color: #E74C3C;
    --background-color: #F5F6FA;
    --text-color: #2C3E50;
    --light-gray: #ECF0F1;
    --dark-gray: #7F8C8D;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Noto Sans KR', sans-serif;
    word-break: keep-all;
    word-wrap: break-word;
}

body {
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
}

/* Navigation */
.navbar {
    background-color: white;
    padding: 1rem 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.logo h1 {
    color: var(--primary-color);
    font-size: 1.8rem;
    font-weight: 700;
}

.nav-links a {
    color: var(--text-color);
    text-decoration: none;
    margin-left: 2rem;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: var(--primary-color);
}

/* Hero Section */
.hero-section {
    padding: 8rem 5% 4rem;
    text-align: center;
    background: linear-gradient(135deg, var(--primary-color), #7474BF);
    color: white;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-content h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    font-weight: 700;
    letter-spacing: -0.05em;
}

.hero-content p {
    font-size: 1.3rem;
    margin-bottom: 2rem;
    font-weight: 300;
}

.upload-container {
    max-width: 600px;
    margin: 0 auto;
}

.upload-box {
    background-color: rgba(255, 255, 255, 0.1);
    border: 2px dashed white;
    border-radius: 10px;
    padding: 2rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.upload-box:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

.upload-box i {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.upload-btn {
    background-color: white;
    color: var(--primary-color);
    border: none;
    padding: 0.8rem 2rem;
    border-radius: 5px;
    font-weight: 600;
    margin-top: 1rem;
    cursor: pointer;
    transition: transform 0.3s ease;
}

.upload-btn:hover {
    transform: translateY(-2px);
}

/* Features Section */
.features-section {
    padding: 5rem 5%;
    background-color: white;
}

.features-section h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    font-weight: 700;
    letter-spacing: -0.05em;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.feature-card {
    text-align: center;
    padding: 2rem;
    background-color: var(--background-color);
    border-radius: 10px;
    transition: transform 0.3s ease;
}

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

.feature-card i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin: 1rem 0;
    font-weight: 700;
    letter-spacing: -0.03em;
}

/* Footer */
footer {
    background-color: var(--secondary-color);
    color: white;
    padding: 3rem 5% 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.footer-section h3 {
    margin-bottom: 1rem;
}

.footer-section a {
    color: white;
    text-decoration: none;
    display: block;
    margin-bottom: 0.5rem;
}

.footer-bottom {
    text-align: center;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

/* Responsive Design */
@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        padding: 1rem;
    }

    .nav-links {
        margin-top: 1rem;
    }

    .nav-links a {
        margin: 0 1rem;
        font-size: 0.9rem;
    }

    .hero-content h1 {
        font-size: 2.5rem;
    }

    .hero-content p {
        font-size: 1.1rem;
    }
}

@media (max-width: 480px) {
    .hero-content h1 {
        font-size: 2rem;
    }

    .hero-content p {
        font-size: 1rem;
    }

    .nav-links a {
        margin: 0 0.5rem;
        font-size: 0.8rem;
    }
}

/* Image Preview Styles */
.preview-container {
    margin: 2rem auto;
    max-width: 600px;
}

.image-preview {
    background-color: white;
    padding: 1rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.image-preview img {
    max-width: 100%;
    height: auto;
    border-radius: 5px;
    margin-bottom: 1rem;
}

.image-info {
    background-color: var(--background-color);
    padding: 1rem;
    border-radius: 5px;
    margin: 1rem 0;
}

.file-size {
    display: flex;
    justify-content: space-around;
    font-size: 0.9rem;
    color: var(--secondary-color);
}

.conversion-options {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    padding: 1rem;
    background-color: var(--background-color);
    border-radius: 5px;
}

.format-group, .quality-group {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.format-group label, .quality-group label {
    min-width: 60px;
    font-weight: 500;
}

.quality-slider {
    flex: 1;
    height: 8px;
    -webkit-appearance: none;
    background: #e0e0e0;
    border-radius: 4px;
    outline: none;
}

.quality-slider::-webkit-slider-runnable-track {
    width: 100%;
    height: 8px;
    background: #e0e0e0;
    border-radius: 4px;
    border: 1px solid #ccc;
}

.quality-slider::-moz-range-track {
    width: 100%;
    height: 8px;
    background: #e0e0e0;
    border-radius: 4px;
    border: 1px solid #ccc;
}

.quality-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
    margin-top: -4px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
    transition: all 0.2s ease;
}

.quality-slider::-moz-range-thumb {
    width: 16px;
    height: 16px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
    transition: all 0.2s ease;
}

/* Remove the progress bar */
.quality-slider::-moz-range-progress {
    display: none;
}

.quality-value {
    min-width: 48px;
    text-align: right;
    color: #4A90E2;
    font-weight: 500;
}

.format-select {
    flex: 1;
    padding: 0.5rem;
    border: 1px solid var(--light-gray);
    border-radius: 5px;
    font-size: 1rem;
    outline: none;
}

.convert-btn, .download-btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 0.8rem;
    border-radius: 5px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s ease;
    text-align: center;
    text-decoration: none;
}

.download-btn {
    background-color: var(--accent-color);
}

.convert-btn:hover, .download-btn:hover {
    background-color: #357ABD;
}

.download-btn:hover {
    background-color: #c0392b;
}

.convert-btn:disabled {
    background-color: var(--dark-gray);
    cursor: not-allowed;
}

@media (max-width: 480px) {
    .conversion-options {
        padding: 0.5rem;
    }

    .format-group, .quality-group {
        flex-direction: column;
        align-items: stretch;
        gap: 0.5rem;
    }

    .format-group label, .quality-group label {
        min-width: auto;
    }

    .file-size {
        flex-direction: column;
        gap: 0.5rem;
        text-align: center;
    }
}