:root {
    --bg-color: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.7);
    --text-color: #f8fafc;
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --accent-color: #8b5cf6;
    --border-color: rgba(255, 255, 255, 0.1);
}

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

body {
    font-family: 'Inter', sans-serif;
    background: var(--bg-color);
    background-image: radial-gradient(circle at top right, #1e1b4b, #0f172a);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 600px;
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 40px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    transition: transform 0.3s ease;
}

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

header h1 {
    font-weight: 600;
    font-size: 2.5rem;
    margin-bottom: 10px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

header p {
    color: #94a3b8;
    font-size: 0.95rem;
}

.tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    background: rgba(15, 23, 42, 0.5);
    padding: 5px;
    border-radius: 12px;
}

.tab-btn {
    flex: 1;
    padding: 12px;
    border: none;
    background: transparent;
    color: #94a3b8;
    font-family: inherit;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tab-btn.active {
    background: var(--primary-color);
    color: white;
    box-shadow: 0 4px 6px -1px rgba(59, 130, 246, 0.3);
}

.tab-content {
    display: none;
    animation: fadeIn 0.4s ease;
}

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

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

.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-size: 0.9rem;
    font-weight: 600;
    color: #cbd5e1;
}

input[type="file"] {
    width: 100%;
    padding: 12px;
    background: rgba(15, 23, 42, 0.4);
    border: 1px dashed var(--border-color);
    border-radius: 12px;
    color: var(--text-color);
    cursor: pointer;
    transition: border-color 0.3s;
}

input[type="file"]:hover {
    border-color: var(--primary-color);
}

textarea {
    width: 100%;
    height: 120px;
    padding: 15px;
    background: rgba(15, 23, 42, 0.4);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    color: var(--text-color);
    font-family: inherit;
    resize: vertical;
    transition: border-color 0.3s;
}

textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.action-btn {
    width: 100%;
    padding: 15px;
    border: none;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
    font-family: inherit;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4);
}

.action-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.6);
}

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

.preview-container {
    margin-top: 15px;
    width: 100%;
    max-height: 250px;
    overflow: hidden;
    border-radius: 12px;
    display: none;
    border: 1px solid var(--border-color);
    background: rgba(0,0,0,0.2);
}

.preview-container img {
    width: 100%;
    height: 100%;
    max-height: 250px;
    display: block;
    object-fit: contain;
}

.error-msg {
    color: #ef4444;
    margin-top: 10px;
    font-size: 0.9rem;
    text-align: center;
    min-height: 20px;
}