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

body {
    width: 100vw;
    height: 100vh;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

.invoice-container {
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.invoice-box {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    border: 2px solid rgba(0, 168, 255, 0.3);
    border-radius: 10px;
    padding: 30px;
    min-width: 400px;
    max-width: 500px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
}

.invoice-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 25px;
    padding-bottom: 15px;
    border-bottom: 2px solid rgba(0, 168, 255, 0.3);
}

.invoice-header h2 {
    color: #fff;
    font-size: 24px;
    font-weight: 600;
}

.close-btn {
    background: transparent;
    border: none;
    color: #fff;
    font-size: 32px;
    cursor: pointer;
    padding: 0;
    width: 30px;
    height: 30px;
    line-height: 1;
    transition: color 0.3s;
}

.close-btn:hover {
    color: #ff4444;
}

.invoice-content {
    margin-bottom: 25px;
}

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

.form-group label {
    display: block;
    color: #fff;
    font-size: 14px;
    margin-bottom: 8px;
    font-weight: 500;
}

.form-group input[type="text"],
.form-group input[type="number"] {
    width: 100%;
    padding: 12px;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(0, 168, 255, 0.3);
    border-radius: 5px;
    color: #fff;
    font-size: 14px;
    transition: border-color 0.3s;
}

.form-group input[type="text"]:focus,
.form-group input[type="number"]:focus {
    outline: none;
    border-color: #00a8ff;
    background: rgba(255, 255, 255, 0.15);
}

.form-group input::placeholder {
    color: rgba(255, 255, 255, 0.5);
}

.value-text {
    padding: 12px;
    background: rgba(0, 168, 255, 0.2);
    border: 1px solid rgba(0, 168, 255, 0.3);
    border-radius: 5px;
    color: #00a8ff;
    font-size: 14px;
    font-weight: 600;
}

.invoice-footer {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
}

.btn {
    padding: 12px 30px;
    border: none;
    border-radius: 5px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-primary {
    background: linear-gradient(135deg, #00a8ff 0%, #0097e6 100%);
    color: #fff;
}

.btn-primary:hover {
    background: linear-gradient(135deg, #0097e6 0%, #0088d5 100%);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 168, 255, 0.4);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
}