:root {
    --bg-color: #0f0f13;
    --text-primary: #ffffff;
    --text-secondary: #a0a0b0;
    --card-bg: rgba(255, 255, 255, 0.05);
    --card-border: rgba(255, 255, 255, 0.1);
    --primary-color: #6c5ce7;
    --primary-hover: #5649c0;
    --success-color: #00b894;
    --error-color: #ff6b6b;
    --glass-blur: 20px;
}

[data-theme="pink"] {
    --bg-color: #ffcfce;
    --text-primary: #ffaaaa;
    --text-secondary: #ffaaaa;
    --card-bg: #ffe2e3;
    --card-border: #ffffff;
    --primary-color: #ffaaaa;
    --primary-hover: #ffcfce;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Outfit', sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    transition: background-color 0.5s ease;
}

[data-theme="pink"] body {
    background-image: none;
}

.background-blobs {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: linear-gradient(135deg, var(--bg-color) 0%, #1a1a24 100%);
}

.app-container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 40px;
    padding-top: 20px;
}

.back-btn {
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 1.2rem;
    cursor: pointer;
    padding: 10px;
    border-radius: 50%;
    transition: background 0.3s;
    text-decoration: none;
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-btn:hover {
    background: var(--card-bg);
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    color: var(--primary-color);
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
}

.icon-btn {
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 1.2rem;
    cursor: pointer;
    padding: 10px;
    border-radius: 50%;
    transition: all 0.3s;
}

.icon-btn:hover {
    background: var(--card-bg);
    transform: rotate(15deg);
}

/* Glass Card */
.glass-card {
    background: var(--card-bg);
    backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--card-border);
    border-radius: 20px;
    padding: 30px;
    margin-bottom: 20px;
    transition: all 0.3s ease;
}

.glass-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 40px rgba(108, 92, 231, 0.2);
}

/* Upload Grid */
.upload-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin-bottom: 20px;
}

.upload-card {
    padding: 20px;
}

.upload-zone {
    border: 2px dashed var(--primary-color);
    border-radius: 16px;
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

.upload-zone:hover {
    background: rgba(108, 92, 231, 0.1);
    border-color: var(--primary-hover);
    transform: scale(1.02);
}

.upload-zone.drag-over {
    background: rgba(108, 92, 231, 0.2);
    border-color: var(--success-color);
    transform: scale(1.05);
}

.upload-icon {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.upload-zone h3 {
    font-size: 1.2rem;
    margin-bottom: 8px;
    color: var(--text-primary);
    font-weight: 600;
}

.upload-zone p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 300;
}

/* File Info */
.file-info {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px;
    background: rgba(108, 92, 231, 0.1);
    border-radius: 12px;
    margin-bottom: 15px;
    margin-top: 15px;
}

.file-name {
    flex: 1;
    color: var(--text-primary);
    font-weight: 500;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    font-size: 0.9rem;
}

.remove-btn {
    background: var(--error-color);
    color: white;
    border: none;
    border-radius: 50%;
    width: 32px;
    height: 32px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.remove-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 0 15px var(--error-color);
}

/* Volume Control */
.volume-control {
    margin-top: 15px;
}

.volume-control label {
    display: block;
    margin-bottom: 10px;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

.volume-control label i {
    color: var(--primary-color);
    margin-right: 5px;
}

.volume-value {
    color: var(--primary-color);
    font-weight: 700;
}

.volume-slider {
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: rgba(108, 92, 231, 0.2);
    outline: none;
    -webkit-appearance: none;
    appearance: none;
}

.volume-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    transition: all 0.3s ease;
}

.volume-slider::-webkit-slider-thumb:hover {
    transform: scale(1.3);
    box-shadow: 0 0 15px var(--primary-color);
}

.volume-slider::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    border: none;
}

/* Progress Section */
.progress-section {
    text-align: center;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: rgba(108, 92, 231, 0.2);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 15px;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--success-color));
    border-radius: 4px;
    width: 0%;
    transition: width 0.3s ease;
}

.progress-text {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

/* Primary Button */
.primary-btn {
    width: 100%;
    padding: 18px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
    color: white;
    border: none;
    border-radius: 16px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-bottom: 20px;
}

.primary-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(108, 92, 231, 0.4);
}

.primary-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.primary-btn i {
    font-size: 1.2rem;
}

/* Result Section */
.result-section {
    text-align: center;
}

.result-header {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-bottom: 25px;
}

.success-icon {
    color: var(--success-color);
    font-size: 2rem;
}

.result-header h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--text-primary);
}

.preview-player {
    margin-bottom: 20px;
}

.preview-player audio {
    width: 100%;
    border-radius: 12px;
}

.download-btn {
    width: 100%;
    padding: 16px;
    background: var(--success-color);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(0, 184, 148, 0.4);
}

/* Info Box */
.info-box h4 {
    margin-bottom: 15px;
    color: var(--text-primary);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 8px;
}

.info-box h4 i {
    color: var(--primary-color);
}

.info-box ul {
    list-style: none;
    padding-left: 0;
}

.info-box li {
    padding: 10px 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 25px;
    font-size: 0.9rem;
    font-weight: 300;
}

.info-box li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* Responsive */
@media (max-width: 768px) {
    .app-container {
        padding: 15px;
    }

    header {
        margin-bottom: 30px;
    }

    .logo h1 {
        font-size: 1.2rem;
    }

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

    .glass-card {
        padding: 20px;
    }

    .upload-zone {
        padding: 30px 15px;
    }

    .upload-icon {
        font-size: 2.5rem;
    }
}