:root {
    --primary-color: #5d5cde;
    --secondary-color: #a3a1fc;
    --bg-color: #f0f2f5;
    --card-bg: #ffffff;
    --text-color: #333333;
    --text-sub: #666666;
    --success-color: #2ecc71;
    --warning-color: #e74c3c;
    --border-radius: 16px;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 40px;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
}

.logo-img {
    height: 40px;
}

.site-title {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-color);
}

.main-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
}

/* Hero Section */
.hero-section {
    text-align: center;
    margin-bottom: 30px;
    animation: fadeInDown 0.8s ease;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 10px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.5px;
}

.hero-subtitle {
    font-size: 1.1rem;
    color: var(--text-sub);
    font-weight: 500;
    opacity: 0.8;
}

.upload-container {
    background: var(--card-bg);
    width: 100%;
    max-width: 600px;
    border-radius: var(--border-radius);
    padding: 40px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: transform 0.3s ease;
    animation: fadeInUp 0.8s ease;
}

.upload-container:hover {
    transform: translateY(-5px);
}

.drop-zone {
    border: 2px dashed #dce0e6;
    /* Softer border */
    border-radius: 12px;
    padding: 40px 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #fafafa;
}

.drop-zone:hover,
.drop-zone.dragover {
    border-color: var(--primary-color);
    background: rgba(93, 92, 222, 0.05);
}

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

h2 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: var(--text-color);
}

.sub-text {
    color: var(--text-sub);
    font-size: 0.9rem;
    margin-bottom: 25px;
}

.upload-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 30px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s ease, transform 0.2s;
    box-shadow: 0 4px 15px rgba(93, 92, 222, 0.3);
}

.upload-btn:hover {
    background: #4a49c6;
    transform: translateY(-2px);
}

.upload-btn:active {
    transform: translateY(0);
}

#file-list-container {
    margin-top: 30px;
    width: 100%;
    max-width: 600px;
    display: none;
    /* Hidden by default */
    animation: fadeInUp 1s ease;
}

.file-list {
    list-style: none;
    padding: 0;
}

.file-item {
    background: var(--card-bg);
    margin-bottom: 15px;
    padding: 15px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
    transition: transform 0.2s;
}

.file-item:hover {
    transform: scale(1.01);
}

.file-icon {
    font-size: 1.8rem;
    margin-right: 15px;
    width: 40px;
    text-align: center;
}

.file-icon.pdf {
    color: #e74c3c;
}

.file-icon.ppt {
    color: #e67e22;
}

.file-icon.doc {
    color: #2980b9;
}

.file-icon.hwp {
    color: #3498db;
}

.file-icon.image {
    color: #9b59b6;
}

.file-info {
    flex: 1;
    text-align: left;
}

.file-name {
    font-weight: 600;
    font-size: 0.95rem;
    display: block;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 250px;
}

.progress-track {
    background: #eee;
    height: 6px;
    border-radius: 3px;
    margin-top: 5px;
    width: 100%;
    overflow: hidden;
}

.progress-bar {
    background: var(--primary-color);
    height: 100%;
    width: 0%;
    transition: width 0.3s ease;
    border-radius: 3px;
}

.status-text {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-sub);
    margin: 0 15px;
    min-width: 40px;
    text-align: right;
}

.action-btn {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.1rem;
    color: var(--text-sub);
    transition: color 0.3s;
    padding: 5px;
}

.download-btn {
    color: #bdc3c7;
    pointer-events: none;
}

.download-btn.active {
    color: var(--success-color);
    pointer-events: auto;
    animation: pulse 2s infinite;
}

.download-btn:hover {
    transform: scale(1.1);
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.1);
    }

    100% {
        transform: scale(1);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive adjustments */
@media (max-width: 600px) {
    .hero-title {
        font-size: 1.8rem;
    }

    .hero-subtitle {
        font-size: 0.9rem;
        padding: 0 20px;
    }
}