/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    background: white;
    border-radius: 24px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
    max-width: 750px;
    width: 100%;
    padding: 40px 35px;
    transition: all 0.3s ease;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 30px;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 8px;
}

.logo .icon {
    font-size: 36px;
}

.logo h1 {
    font-size: 32px;
    font-weight: 700;
    background: linear-gradient(135deg, #4A90D9, #357ABD);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: #666;
    font-size: 15px;
}

.subtitle strong {
    color: #4A90D9;
    -webkit-text-fill-color: #4A90D9;
}

/* Tabs */
.tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 25px;
    border-bottom: 2px solid #e0e0e0;
    padding-bottom: 10px;
}

.tab-btn {
    padding: 10px 24px;
    background: none;
    border: none;
    border-radius: 10px;
    font-size: 15px;
    font-weight: 600;
    color: #666;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tab-btn:hover {
    background: #f0f4f8;
    color: #333;
}

.tab-btn.active {
    background: #4A90D9;
    color: white;
    box-shadow: 0 4px 15px rgba(74, 144, 217, 0.3);
}

.tab-content {
    display: none;
    animation: fadeIn 0.3s ease;
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Form */
.form-group {
    margin-bottom: 22px;
}

.form-group label {
    display: block;
    font-weight: 600;
    font-size: 14px;
    color: #333;
    margin-bottom: 6px;
}

.form-group input[type="text"],
.form-group input[type="url"],
.form-group select {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    font-size: 15px;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    background: white;
}

.form-group input[type="text"]:focus,
.form-group input[type="url"]:focus,
.form-group select:focus {
    outline: none;
    border-color: #4A90D9;
    box-shadow: 0 0 0 4px rgba(74, 144, 217, 0.1);
}

.form-group small {
    display: block;
    color: #888;
    font-size: 12px;
    margin-top: 4px;
}

/* File Upload */
.file-upload-wrapper {
    position: relative;
}

.file-upload-wrapper input[type="file"] {
    position: absolute;
    opacity: 0;
    width: 0.1px;
    height: 0.1px;
    z-index: -1;
}

.file-upload-box {
    border: 2px dashed #d0d0d0;
    border-radius: 12px;
    padding: 30px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #fafafa;
}

.file-upload-box:hover {
    border-color: #4A90D9;
    background: #f0f7ff;
}

.file-upload-box.dragover {
    border-color: #4A90D9;
    background: #e3f0ff;
    transform: scale(1.02);
}

.file-upload-box .upload-icon {
    font-size: 40px;
    display: block;
    margin-bottom: 8px;
}

.file-upload-box p {
    color: #555;
    font-size: 14px;
    margin-bottom: 4px;
}

.file-upload-box small {
    color: #999;
    font-size: 12px;
}

/* Icon Preview */
#iconPreview {
    display: none;
    align-items: center;
    gap: 15px;
    margin-top: 12px;
    padding: 12px 16px;
    background: #f5f7fa;
    border-radius: 12px;
    border: 2px solid #4A90D9;
}

#iconPreviewImg {
    width: 64px;
    height: 64px;
    border-radius: 12px;
    object-fit: cover;
    border: 2px solid #e0e0e0;
}

#removeIcon {
    background: #ff4444;
    color: white;
    border: none;
    border-radius: 50%;
    width: 28px;
    height: 28px;
    font-size: 14px;
    cursor: pointer;
    transition: background 0.3s ease;
    margin-left: auto;
}

#removeIcon:hover {
    background: #cc0000;
}

/* Color Picker */
.color-picker-wrapper {
    display: flex;
    gap: 12px;
    align-items: center;
}

.color-picker-wrapper input[type="color"] {
    width: 50px;
    height: 50px;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    padding: 0;
    background: none;
}

.color-picker-wrapper input[type="color"]::-webkit-color-swatch-wrapper {
    padding: 0;
}

.color-picker-wrapper input[type="color"]::-webkit-color-swatch {
    border: 2px solid #e0e0e0;
    border-radius: 12px;
}

.color-picker-wrapper input[type="text"] {
    flex: 1;
    padding: 12px 16px;
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    font-size: 15px;
    font-family: monospace;
    transition: border-color 0.3s ease;
}

.color-picker-wrapper input[type="text"]:focus {
    outline: none;
    border-color: #4A90D9;
}

/* Checkbox Group */
.checkbox-group {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-top: 4px;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    font-size: 14px;
    color: #444;
}

.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: #4A90D9;
    cursor: pointer;
}

/* Submit Button */
#generateBtn {
    width: 100%;
    padding: 16px;
    background: linear-gradient(135deg, #4A90D9, #357ABD);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-top: 8px;
}

#generateBtn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(74, 144, 217, 0.4);
}

#generateBtn:active {
    transform: translateY(0);
}

#generateBtn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

#generateBtn .btn-icon {
    font-size: 20px;
}

/* Instructions */
.instructions-card {
    padding: 10px 0;
}

.instructions-card h3 {
    font-size: 24px;
    color: #333;
    margin-bottom: 20px;
}

.step {
    display: flex;
    gap: 16px;
    margin-bottom: 20px;
    padding: 16px;
    background: #f8f9fa;
    border-radius: 12px;
    transition: background 0.3s ease;
}

.step:hover {
    background: #f0f4f8;
}

.step-number {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 36px;
    height: 36px;
    background: #4A90D9;
    color: white;
    border-radius: 50%;
    font-weight: 700;
    font-size: 16px;
}

.step h4 {
    color: #333;
    font-size: 16px;
    margin-bottom: 4px;
}

.step p {
    color: #666;
    font-size: 14px;
    line-height: 1.5;
}

.step code {
    background: #e8ecf1;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 13px;
    color: #333;
}

.tip-box {
    background: #fff3cd;
    border: 1px solid #ffc107;
    border-radius: 12px;
    padding: 16px;
    margin-top: 16px;
    color: #856404;
}

.tip-box strong {
    color: #856404;
}

/* Footer */
footer {
    margin-top: 30px;
    text-align: center;
    color: #999;
    font-size: 13px;
    border-top: 1px solid #eee;
    padding-top: 20px;
}

/* Responsive */
@media (max-width: 600px) {
    .container {
        padding: 24px 18px;
    }

    .logo h1 {
        font-size: 26px;
    }

    .subtitle {
        font-size: 14px;
    }

    .tabs {
        flex-wrap: wrap;
        gap: 4px;
    }

    .tab-btn {
        font-size: 13px;
        padding: 8px 16px;
        flex: 1;
        text-align: center;
    }

    .step {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }

    .step-number {
        min-width: 32px;
        height: 32px;
        font-size: 14px;
    }

    .checkbox-group {
        gap: 8px;
    }
}