:root {
    --primary-color: #222222;
    --secondary-color: #444444;
    --accent-color: #666666;
    --light-bg: #f5f5f5;
    --border-color: #e0e0e0;
    --text-color: #333;
    --error-color: #ef4444;
    --success-color: #10b981;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--light-bg);
    padding: 0;
    margin: 0;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background-color: var(--primary-color);
    color: white;
    padding: 1rem 0;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
}

main {
    padding: 2rem 0;
}

.converter-card {
    background-color: white;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    padding: 2rem;
    margin-bottom: 2rem;
    border: 1px solid var(--border-color);
}

h1 {
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.file-upload {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border: 2px dashed var(--border-color);
    border-radius: 8px;
    padding: 2rem;
    background-color: var(--light-bg);
    position: relative;
    transition: all 0.3s ease;
    cursor: pointer;
}

.file-upload:hover {
    border-color: var(--secondary-color);
}

.file-upload.drag-over {
    background-color: rgba(68, 68, 68, 0.1);
    border-color: var(--secondary-color);
}

.file-upload input {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    opacity: 0;
    cursor: pointer;
}

.file-upload-icon {
    font-size: 3rem;
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.file-info {
    margin-top: 1rem;
    display: none;
}

.file-info.active {
    display: block;
}

select {
    width: 100%;
    padding: 0.75rem;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    font-size: 1rem;
    background-color: white;
    color: var(--text-color);
}

optgroup {
    font-weight: bold;
}

button {
    background-color: var(--accent-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

button:hover {
    background-color: #333333;
}

button:disabled {
    background-color: #a8a8a8;
    cursor: not-allowed;
}

button svg {
    margin-right: 0.5rem;
}

#result {
    padding: 1rem;
    border-radius: 6px;
    margin-top: 1.5rem;
    display: none;
}

#result.success {
    background-color: rgba(16, 185, 129, 0.1);
    border: 1px solid var(--success-color);
    color: var(--success-color);
    display: block;
}

#result.error {
    background-color: rgba(239, 68, 68, 0.1);
    border: 1px solid var(--error-color);
    color: var(--error-color);
    display: block;
}

#result.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: rgba(34, 34, 34, 0.1);
    border: 1px solid var(--primary-color);
    color: var(--primary-color);
}

.loading-spinner {
    border: 4px solid rgba(0, 0, 0, 0.1);
    width: 24px;
    height: 24px;
    border-radius: 50%;
    border-left-color: var(--primary-color);
    animation: spin 1s linear infinite;
    margin-right: 10px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

footer {
    background-color: var(--primary-color);
    color: white;
    text-align: center;
    padding: 1rem 0;
    margin-top: 2rem;
}

@media (max-width: 768px) {
    .converter-card {
        padding: 1.5rem;
    }
}

/* Çoklu dosya yükleme stilleri */
.multi-file-upload {
    border: 2px dashed var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    background-color: var(--light-bg);
    position: relative;
    cursor: pointer;
    margin-bottom: 1rem;
}

.multi-file-upload:hover {
    border-color: var(--secondary-color);
}

.multi-file-list {
    margin-top: 1rem;
}

.multi-file-item {
    display: flex;
    justify-content: space-between;
    padding: 0.5rem;
    background-color: white;
    border-radius: 4px;
    margin-bottom: 0.5rem;
    border: 1px solid var(--border-color);
}

.remove-file {
    cursor: pointer;
    color: var(--error-color);
    font-weight: bold;
}

.remove-file:hover {
    color: darkred;
}

/* Responsive düzenlemeler */
@media (max-width: 600px) {
    .converter-card {
        padding: 1rem;
    }
    
    .file-upload, .multi-file-upload {
        padding: 1rem;
    }
    
    button {
        width: 100%;
        padding: 1rem;
    }
}