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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
    overflow: hidden;
}

/* Header */
header {
    background: linear-gradient(to right, #3498db, #2c3e50);
    color: white;
    padding: 30px;
    text-align: center;
}

header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
}

header h1 i {
    margin-right: 15px;
}

header p {
    opacity: 0.9;
    font-size: 1.1em;
}

/* Upload Area */
.upload-container {
    padding: 40px;
}

.upload-area {
    border: 3px dashed #3498db;
    border-radius: 10px;
    padding: 60px 20px;
    text-align: center;
    margin-bottom: 30px;
    transition: all 0.3s;
    cursor: pointer;
}

.upload-area:hover {
    background: #f8f9fa;
    border-color: #2980b9;
}

.upload-area.highlight {
    background: #e3f2fd;
    border-color: #1a73e8;
}

.upload-area i {
    font-size: 64px;
    color: #3498db;
    margin-bottom: 20px;
}

.upload-area h3 {
    color: #2c3e50;
    margin-bottom: 10px;
}

.upload-area p {
    color: #7f8c8d;
    margin: 10px 0;
}

.file-info {
    margin-top: 15px;
    padding: 10px;
    background: #e8f4fc;
    border-radius: 5px;
    border-left: 4px solid #3498db;
}

/* Form Elements */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #2c3e50;
    font-weight: 600;
}

select {
    width: 100%;
    padding: 12px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s;
}

select:focus {
    outline: none;
    border-color: #3498db;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 30px;
    background: #3498db;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
}

.btn:hover {
    background: #2980b9;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.btn:disabled {
    background: #bdc3c7;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.upload-btn {
    width: 100%;
    padding: 15px;
    font-size: 18px;
}

.download-btn {
    background: #2ecc71;
    padding: 15px 40px;
    font-size: 18px;
}

.download-btn:hover {
    background: #27ae60;
}

.copy-btn {
    background: #9b59b6;
}

.copy-btn:hover {
    background: #8e44ad;
}

/* File Info Page */
.file-info-container {
    padding: 40px;
}

.file-header {
    display: flex;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 2px solid #f0f0f0;
}

.file-icon {
    width: 80px;
    height: 80px;
    margin-right: 20px;
}

.file-details h2 {
    color: #2c3e50;
    margin-bottom: 10px;
    word-break: break-all;
}

.file-size {
    color: #7f8c8d;
    font-size: 1.2em;
}

/* File Stats */
.file-stats {
    display: flex;
    gap: 30px;
    margin-bottom: 30px;
}

.stat {
    display: flex;
    align-items: center;
    gap: 10px;
    color: #2c3e50;
}

.stat i {
    color: #3498db;
    font-size: 24px;
}

/* Timer */
.timer-container {
    background: #f8f9fa;
    padding: 25px;
    border-radius: 10px;
    margin-bottom: 30px;
    text-align: center;
}

.timer-container h3 {
    color: #2c3e50;
    margin-bottom: 15px;
}

.timer {
    font-size: 3em;
    font-family: monospace;
    font-weight: bold;
    color: #e74c3c;
}

.timer span {
    background: #2c3e50;
    color: white;
    padding: 5px 10px;
    border-radius: 5px;
    margin: 0 5px;
}

/* Share Section */
.share-section {
    text-align: center;
    padding: 30px;
    background: #e8f4fc;
    border-radius: 10px;
}

.share-link {
    display: flex;
    gap: 10px;
    margin: 20px 0;
}

.share-link input {
    flex: 1;
    padding: 12px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
}

/* Features */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.feature {
    text-align: center;
    padding: 20px;
}

.feature i {
    font-size: 48px;
    color: #3498db;
    margin-bottom: 20px;
}

.feature h4 {
    color: #2c3e50;
    margin-bottom: 10px;
}

/* Footer */
footer {
    text-align: center;
    padding: 20px;
    background: #f8f9fa;
    color: #7f8c8d;
    border-top: 1px solid #eee;
}

footer a {
    color: #3498db;
    text-decoration: none;
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        border-radius: 0;
    }

    header h1 {
        font-size: 2em;
    }

    .upload-area {
        padding: 40px 15px;
    }

    .file-stats {
        flex-direction: column;
        gap: 15px;
    }

    .timer {
        font-size: 2em;
    }

    .share-link {
        flex-direction: column;
    }
}

/* Admin Header */
.admin-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid rgba(255,255,255,0.2);
}

.logout-btn {
    background: #e74c3c;
}

.logout-btn:hover {
    background: #c0392b;
}

/* Alerts */
.alert {
    padding: 15px;
    border-radius: 5px;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.alert.success {
    background: #d4edda;
    color: #155724;
    border-left: 4px solid #28a745;
}

.back-link {
    display: inline-block;
    margin-top: 10px;
    color: #ecf0f1;
    text-decoration: none;
}

.back-link:hover {
    color: white;
    text-decoration: underline;
}

input[type="file"] {
    display: none;
}